For up-to-date discussion and information on global events also please visit us at www.MeltingWorld.org
Melting World Forum Page
Global warming is a reality we are facing today, which will have grave consequences to civilization.
As the nature of this effect becomes clearer to the general population it could pit environmental organizations against commercial and societal concerns.
This is a battle neither side can win.
The Global Concern offers an alternative future through education and by engaging the energy companies and environmentalist community in a common struggle; To develop and replace the current carbon dioxide (CO2) producing energy sources with other sources.
Our mission is to ensure that mankind flourishes
in the current era.
A Scientific Challenge From TGC
As our efforts increase to prevent our planet's indirect warming
through CO2 production will we risk accidentally heating our
Planet directly by lowering the Earth's Albedo?
Before we engage in widespread use of Solar Power we need
our scientists to do the math first:
Realistically, to fuel a city by solar power we need solar panels to cover an area even larger. Perhaps we could place these in a desert or unused land but, beware the science...
Every place on the Earth’s surface has an Albedo Factor. The snow and ice at the poles have high albedo and thus reflect much of the Sun’s heat and energy back into space.
After all, when we look up into the night sky and view the planets this albedo effect is exactly what we are seeing; the light and heat reflected and radiated back towards us, from the planets.
If we replace, even, the desert with solar panels we are replacing large areas with a very much lower albedo. A lower albedo will absorb more heat from the sun and scatter and reflect back less heat into space.
In our desire to prevent Global Warming indirectly we may contribute to it directly… it depends on the science and we need this answer now.
NASA's longest running experiment has just been completed and successfully shown Einstein to be right in the subtitles of space-time distortion.
The presence of the Earth in space distorts space-time, something easily measured today. The larger the gravitational field the slower time passes. Satellites in orbit effected by less gravity have to compensate
for the time difference with the surface of our planet and, believe it or not, you are living life slightly faster at the top of a New York sky scraper than on the ground floor.
To make matters even more interesting our planet is also moving through space and so Einstein described how this would create drift, twist and swirl into the 4 dimensional fabric.
Only now do we have the technology to measure such a small change in the effect of gravity itself experimentally. New technologies have been invented to exclude magnetic fields, measure movement without touching, create perfectly spherical quartz balls...
So TGC's challenge is this:
If we can measure such incomprehensibly small differences there must be a way to experimentally determine the change of density and composition of Earth's atmosphere at sea level.
For example. CO2 is heavier than air. As we add more CO2 to our delicately balanced atmosphere carbon dioxide will tend to sink to sea level.
The heavier and denser the atmosphere the more heat it can absorb. This is why when you climb a mountain the air becomes cold. The thin air can hold less energy.
Showing a fractional increase in density would introduce a new mechanism and explanation, together with the Green House Effect, for the increased temperatures we are seeing.
PHILOSOPHY FOR THE YEAR 2016
The Earthquakes in New Zealand and Japan, followed by the horrendous Tsunami, should underscore at least one thing to us;
We, and our civilization, are fragile. These are only the mild forces of the Earth, our little blue dot in Space.
Why should we feel confident that exacerbating the force of the Sun and its effect on us will somehow turn out better?
NEWS AND IMPORTANT EVENTS:
Simply put: "Climate Change is a Fact":
President Barack Obama, 2014
Climate Change news, a discussion:
The recent Washington Post article reads, with headline;
“An unintended consequence of reduced pollution: More storms”
“The Clean Air Act, which has benefited breathing in many American cities over the past few decades, may have worsened the weather in some places.”
“May” used to be as rare a word to find as “suggest” or “seems” in scientific journals, articles or even discussions because of the basic principle of logic: there are almost countless possibilities and events that may happen or may be linked. Scientists are more interested in facts.
The uses of “may” and “suggest” and even “seems” are now commonplace.
“New climate simulations suggest that reducing the level of atmospheric aerosol particles produced by human activity might have been the main cause of a recent increase in tropical storm frequency in the North Atlantic.”
“Tropical Storm Andrea hit Virginia Beach and drenched the East Coast with rain last month. Might aerosol levels help explain such weather?”
It is always a concern when the article asks the reader the question.
“Aerosol levels have increased since the Industrial Revolution began, but there have been periods when emissions stalled or fell, such as the Great Depression, World War II and after clean air legislation was enacted in Europe and the United States in the 1970s and 1980s.
“The climate simulations suggest that these periods of lower emissions eventually increased tropical storm frequency. “It seems the Clean Air Act in particular has led to an increased number of hurricanes over the last decade or so,” says Doug Smith of Met Office Hadley Centre in England, a co-author of the research published last week in the journal Nature Geoscience.”
Aerosol particles come from fuels burned in power plants and cars, as well as from natural sources such as volcanoes, sea spray and dust. Aerosols can cool the Earth’s surface because they scatter the sun’s energy back into space and they seed brighter and more long-lived clouds. The authors suggest that high levels of aerosols in the past cooled the surface of the North Atlantic. This cool patch of the ocean shifted the position of a major air current, suppressing the formation of hurricanes.”
There is a dichotomy between this scientific definition of aerosol and the colloquial understanding of “aerosol”. Certainly the public is familiar with deodorant and other man-made aerosols but, upon close inspection, aerosol here also includes volcanic ash.
It is certainly universally understandable that an eruption can darken the skies and cool the Earth’s surface. Questions unanswered would be:
How accurate are local, historic readings of aerosols during the Great Depression and WWII?
WWII was a time of fire, destruction, explosion and ordnance. It was also a time of dramatically increased industrial war manufacturing. Would we not expect man- made levels to rise, and not fall, during that time period?
How easily can we separate man-made aerosol from natural and the determinant effects of each?
How much has ocean temperature and other factors effected hurricanes independently of aerosol dimming?
Does the report claim new evidence that warming temperatures actually increase frequency of hurricanes and not just their strength?
The scientific principle is that extraordinary claims require extraordinary evidence.
Would not claiming the Clean Air Act has caused increasing numbers of hurricanes require more than “it seems to have…:”?
In effect the Earth’s troubles are the reverse concern. Usually when cataclysmic events cause climate change there is both increased CO2 and an umbrella aerosol effect. Our industrial cleaner burning civilization is quite capable of producing vast amounts of CO2 without Global Dimming.
Other interesting articles:
Volcanic aerosols, not pollutants, tamped down recent Earth warming, says CU study –
Recent anthropogenic increases in SO2 from Asia have minimal impact on stratospheric aerosol
Should this be the case the anthropogenic increases CO2 warming would not be offset by stratospheric aerosol.
Unveiling Climate Change Proposals from the Executive Branch :
At a speech at Georgetown University President Obama said
“The question is not whether we need to act, the question is whether we will have the courage to act before it's too late."
The content of the President's speech was broad.
A summary of the President’s strategy in his current term
· Reducing US carbon pollution
· Preparing the U.S. for the impacts of climate change
· Leading international efforts to cut global emissions
· Imposing the first carbon limits on existing power plants
· Requiring all federal projects to be able to withstand the heightened storms and sea level rise associated with climate change.
Obama also made a point of dismissing those who do not acknowledge the science behind man-made global warming,
"We don't have time for a meeting of the Flat Earth Society," he said.
United States Presidential Inauguration 2013
"We will respond to the threat of climate change, knowing that the failure to do so would betray our children and future generations.
Some may still deny the overwhelming judgment of science, but none can avoid the devastating impact of raging fires, and crippling drought, and more powerful storms.
The path towards sustainable energy sources will be long and sometimes difficult. But America cannot resist this transition; we must lead it.
We cannot cede to other nations the technology that will power new jobs and new industries – we must claim its promise. That is how we will maintain our economic vitality and our national treasure – our forests and waterways; our croplands and snow capped peaks.
That is how we will preserve our planet, commanded to our care by God. That’s what will lend meaning to the creed our fathers
once declared. "
President Barack H. Obama
As Arctic sea ice melted to the lowest level ever recorded, researchers said they were unprepared for the speed of this facet of climate change. As Arctic ice melts, scientists worry it will add heat and moisture to the globe's climate system.
The culprit? Global warming, apparently. The same global warming which trees have helped to limit, but which, with their deaths, will be further accentuated.
New Zealand Government reponse to TGC
Dear Mr Schofield,
New Zealand remains committed to addressing these issues, both domestically and internationally, and participates in a range of fora and regional and international agreements which address sustainable forest management and the increasingly important links between forests and climate change.
The Cancún Agreements under the United Nations Framework Convention on Climate Change (UNFCCC) constitute an important new driver for forest conservation and afforestation/reforestation in both developed and developing countries. New Zealand continues to advocate for effective forestry rules under the UNFCCC.
Both New Zealand and the US are parties to, and participate in, the United Nations Forum on Forests (UNFF) and both countries are active members of the FAO Forestry regional Asia-Pacific Forestry Commission (APFC). These fora deal comprehensively with forests and forestry issues.
Both countries are also members of the voluntary 12-member Montreal Process Working Group that was set up in 1994 and meets regularly to establish and agree and report on criteria and indicators for sustainable forest management.
New Zealand strongly values the dialogue with the US in all these fora on forestry matters, including our respective forest management and conservation objectives.
We believe that these multilateral and plurilateral channels constitute the best opportunity for New Zealand to work alongside the US on forest conservation and reforestation. New Zealand will continue bilateral cooperation with the US on climate change issues more broadly, as was reinforced by the Wellington Declaration in November 2010.
THE DEBATE ABOUT ETHANOL CONTINUES
A few years ago a Stanford University professor calculated that the production of ethanol used more oil than it replaced.
This happened, in part, because the chemical energy in ethanol is only about 90% that in gasoline, and hence cars need to burn more ethanol to compensate. The rest of the costs are in production and distribution.
The methodology which produced those figures has been challenged, but the point remains. Even at best, ethanol seems little better than a wash with regard to oil.
Meanwhile, the President has just announced a new automobile fuel efficiency goal of 54.5 miles per gallon (presumably on oil or gas - ethanol would be more difficult). Sport utility vehicles, such as the Cadillac and Lexus and Porsche SUV's, are excluded from that goal as they are classed as light trucks .
STATEMENT TO THE COMMITTEE ON SCIENCE, SPACE AND TECHNOLOGY OF THE UNITED STATES HOUSE OF REPRESENTATIVES
Richard A. Muller Professor of Physics University of California, Berkeley Chair, Berkeley Earth Surface Temperature Project
Executive Summary The Berkeley Earth Surface Temperature project was created to make the best possible estimate of global temperature change using as complete a record of measurements as possible and by applying novel methods for the estimation and elimination of systematic biases. It was organized under the auspices of Novim, a non-profit public interest group. Our approach builds on the prior work of the groups at NOAA, NASA, and in the UK (Hadley Center – Climate Research Unit, or HadCRU).
Berkeley Earth has assembled 1.6 billion temperature measurements, and will soon make these publicly available in a relatively easy to use format
The difficult issues for understanding global warming are the potential biases. These can arise from many technical issues, including data selection, substandard temperature station quality, urban vs. rural effects, station moves, and changes in the methods and times of measurement
We have done an initial study of the station selection issue. Rather than pick stations with long records (as done by the prior groups) we picked stations randomly from the complete set. This approach eliminates station selection bias. Our results are shown in the Figure; we see a global warming trend that is very similar to that previously reported by the other groups
We have also studied station quality. Many US stations have low quality rankings according to a study led by Anthony Watts. However, we find that the warming seen in the "poor" stations is virtually indistinguishable from that seen in the "good" stations
We are developing statistical methods to address the other potential biases
I suggest that Congress consider the creation of a Climate-ARPA to facilitate the study of climate issues
Based on the preliminary work we have done, I believe that the systematic biases that are the cause for most concern can be adequately handled by data analysis techniques. The world temperature data has sufficient integrity to be used to determine global temperature trends
Testimony of Richard A. Muller Thank you Chairman Hall and Ranking Member Johnson for this opportunity to testify before the Committee
I am a Professor of Physics at UC Berkeley and Faculty Senior Scientist at the Lawrence Berkeley Laboratory. I founded the Berkeley Earth Surface Temperature project under the auspices of Novim, a non-profit public interest group. My testimony represents my personal views and not those of the above organizations
[[Italic part for written statement only, not to be read aloud]] I've published papers on climate change in Science, Nature, and other refereed journals; I am the author of a technical book on the subject. My papers on climate change have appeared in Nature, Science, Paleoceanography, and the Journal of Geophysical Research. I wrote a technical book on the Earth's past temperature changes: "Ice Ages and Astronomical Causes", Springer 2000. I am the author of "Physics for Future Presidents", a popular book which describes many misuses of data in climate. I was a cited referee on the report of the NRC on the hockey stick controversy. For two years I wrote an online column for MIT's Technology Review. My major awards for scientific achievement include the Alan T. Waterman Award of the National Science Foundation, the Texas Instruments Founders Prize, a MacArthur Prize Fellowship, and election to the American Academy of Arts and Sciences and to the California Academy of Sciences.
The Berkeley Earth Surface Temperature study has received a total of $623,087 in financial support from: The Lee and Juliet Folger Fund ($20,000) Lawrence Berkeley National Laboratory ($188,587) William K. Bowes, Jr. Foundation ($100,000) Fund for Innovative Climate and Energy Research (created by Bill Gates) ($100,000) Charles G. Koch Charitable Foundation ($150,000) The Ann & Gordon Getty Foundation ($50,000) We have also received funding from a number of private individuals, totaling $14,500.
For more information on Berkeley Earth, see www.BerkeleyEarth.org For more information on Novim, see www.Novim.org
I begin by talking about Global Warming
Prior groups at NOAA, NASA, and in the UK (HadCRU) estimate about a 1.2 degree C land temperature rise from the early 1900s to the present. This 1.2 degree rise is what we call global warming. Their work is excellent, and the Berkeley Earth project strives to build on it.
Human caused global warming is somewhat smaller. According to the most recent IPCC report (2007), the human component became apparent only after 1957, and it amounts to "most" of the 0.7 degree rise since then. Let's assume the human-caused warming is 0.6 degrees.
The magnitude of this temperature rise is a key scientific and public policy concern. A 0.2 degree uncertainty puts the human component between 0.4 and 0.8 degrees – a factor of two uncertainty. Policy depends on this number. It needs to be improved.
Berkeley Earth is working to improve on the accuracy of this key number by using a more complete set of data, and by looking at biases in a new way.
The project has already merged 1.6 billion land surface temperature measurements from 16 sources, most of them publicly available, and is putting them in a simple format to allow easy use by scientists around the world. By using all the data and new statistical approaches that can handle short records, and by using novel approaches to estimation and avoidance of systematic biases, we expect to improve on the accuracy of the estimate of the Earth's temperature change.
I'll now talk about potential Bias in Data Selection
Prior groups (NOAA, NASA, HadCRU) selected for their analysis 12% to 22% of the roughly 39,000 available stations. (The number of stations they used varied from 4,500 to a maximum of 8,500.)
They believe their station selection was unbiased. Outside groups have questioned that, and claimed that the selection picked records with large temperature increases. Such bias could be inadvertent, for example, a result of choosing long continuous records. (A long record might mean a station that was once on the outskirts and is now within a city.)
To avoid such station selection bias, Berkeley Earth has developed techniques to work with all the available stations. This requires a technique that can include short and discontinuous records
In an initial test, Berkeley Earth chose stations randomly from the complete set of 39,028 stations. Such a selection is free of station selection bias. In our preliminary analysis of these stations, we found a warming trend that is shown in the figure. It is very similar to that reported by the prior groups: a rise of about 0.7 degrees C since 1957. (Please keep in mind that the Berkeley Earth curve, in black, does not include adjustments designed to eliminate systematic bias.) Figure: Land average temperatures from the three major programs, compared with an initial test of the Berkeley Earth dataset and analysis process. Approximately 2 percent of the available sites were chosen randomly from the complete set of 39,028 sites. The Berkeley data are marked as preliminary because they do not include treatments for the reduction of systematic bias.
The Berkeley Earth agreement with the prior analysis surprised us, since our preliminary results don't yet address many of the known biases. When they do, it is possible that the corrections could bring our current agreement into disagreement
Why such close agreement between our uncorrected data and their adjusted data? One possibility is that the systematic corrections applied by the other groups are small. We don't yet know
The main value of our preliminary result is that it demonstrates the Berkeley Earth ability to use all records, including those that are short or fragmented. When we apply our approach to the complete data collection, we will largely eliminate the station selection bias, and significantly reduce statistical uncertainties.
Let me now address the problem of Poor Temperature Station Quality
Many temperature stations in the U.S. are located near buildings, in parking lots, or close to heat sources. Anthony Watts and his team has shown that most of the current stations in the US Historical Climatology Network would be ranked "poor" by NOAA's own standards, with error uncertainties up to 5 degrees C.
Did such poor station quality exaggerate the estimates of global warming? We've studied this issue, and our preliminary answer is no.
The Berkeley Earth analysis shows that over the past 50 years the poor stations in the U.S. network do not show greater warming than do the good stations.
Thus, although poor station quality might affect absolute temperature, it does not appear to affect trends, and for global warming estimates, the trend is what is important
Our key caveat is that our results are preliminary and have not yet been published in a peer reviewed journal. We have begun that process of submitting a paper to the Bulletin of the American Meteorological Society, and we are preparing several additional papers for publication elsewhere.
NOAA has already published a similar conclusion – that station quality bias did not affect estimates of global warming – -- based on a smaller set of stations, and Anthony Anthony Watts and his team have a paper submitted, which is in late stage peer review, using over 1000 stations, but it has not yet been accepted for publication and I am not at liberty to discuss their conclusions and how they might differ. We have looked only at average temperature changes, and additional data needs to be studied, to look at (for example) changes in maximum and minimum temperatures.
In fact, in our preliminary analysis the good stations report more warming in the U.S. than the poor stations by 0.009 ± 0.009 degrees per decade, opposite to what might be expected, but also consistent with zero. We are currently checking these results and performing the calculation in several different ways. But we are consistently finding that there is no enhancement of global warming trends due to the inclusion of the poorly ranked US stations.
Berkeley Earth hopes to complete its analysis including systematic bias avoidance in the next few weeks. We are now studying new approaches to reducing biases from:
1. Urban heat island effects. Some stations in cities show more rapid warming than do stations in rural areas.
2. Time of observation bias. When the time of recording temperature is changed, stations will typically show different mean temperatures than they did previously. This is sometimes corrected in the processes used by existing groups. But this cannot be done easily for remote stations or those that do not report times of observations.
3. Station moves. If a station is relocated, this can cause a "jump" in its temperatures. This is typically corrected in the adjustment process used by other groups. Is the correction introducing another bias? The corrections are sometimes done by hand, making replication difficult.
4. Change of instrumentation. When thermometer type is changed, there is often an offset introduced, which must be corrected.
I was asked what legislation could advance our knowledge of climate change. After some consideration, I felt that the creation of a Climate Advanced Research Project Agency, or Climate-ARPA, could help.
Without the efforts of Anthony Watts and his team, we would have only a series of anecdotal images of poor temperature stations, and we would not be able to evaluate the integrity of the data
This is a case in which scientists receiving no government funding did work crucial to understanding climate change. Similarly for the work done by Steve McIntyre. Their "amateur" science is not amateur in quality; it is true science, conducted with integrity and high standards.
Government policy needs to encourage such work. Climate-ARPA could be an organization that provides quick funding to worthwhile projects without regard to whether they support or challenge current understanding
Despite potential biases in the data, methods of analysis can be used to reduce bias effects well enough to enable us to measure long-term Earth temperature changes. Data integrity is adequate. Based on our initial work at Berkeley Earth, I believe that some of the most worrisome biases are less of a problem than I had previously thought.
Tornado and tornado and tornado
With hundreds dead and devastation through several southern states the US suffers the deadly effects of a record breaking tornado season.
Quite uncharacteristically New Zealand also suffers a deadly tornado in Auckland.
What is remarkable is often the resistance to the costs incurred dealing preventably with climate change.
Just a cursory look will tell you of costs, including irreplaceable life, we are already incurring before a 1 or 2 degree temperature increase.
Ice loss from Antarctica and Greenland has accelerated over the last 20 years, research shows, and will soon become the biggest driver of sea level rise.
Germany is accelerating plans to close its nuclear power plants and Italy is following suit.
This is after the severe nuclear situation
in Japan which Angela Merkel has declared
"a catastrophe of apocalyptic dimensions."
Please read our ongoing update and commentary
Amid the catastrophe and tragedy in Japan extremely brave management and workers are risking their lives in a battle with nuclear forces that may well determine our future:
Despite the safety and ubiquity of nuclear plants, these colossal forces required to compromise them, the age of these plants even the dissimilarity with Chernobyl, public opinion may well shy us away from nuclear power in the near future just when we do not have a high energy alternative to coal and oil.
In fact Germany and Italy's recent decision has underscored this exact concern.
Fukushima Nuclear Power Plants I and II
By Lars P. Hanson, Director, The Global Concern
CRISIS UPDATE JUNE 2011
The situation at the Fukushima I (Dai-ichi) Nuclear Power Plant remains serious. However, to put that situation in perspective, it is useful to remember that so far over 18,000 Japanese citizens are known to have died as a direct result of the 11 March 2011 Tohoku earthquake and ensuing tsunami. That death toll may still rise. So far not a single death has been directly attributed to the problems at the Fukushima I (Dai-Ichi) nuclear power plant. (One contract worker at Fukushima reportedly has died, but that person's death does not/not appear to have resulted from the nuclear accident. There are no indications of radiation overexposure and the corpse reportedly is not at all radioactive.)
There are three closely related developments at Fukushima:
• First, the Tokyo Electric Power Company (TEPCO) recently revised its estimates of the extent of core damage to Reactors One, Two, and Three. All three cores are estimated to have suffered partial or complete meltdowns.
• Second, TEPCO has reported that the water level in Reactor One at Fukushima Dai-Ichi may be below the level of the reactor core, leaving what remains of that core exposed.
• Third, TEPCO has adjusted its estimates of the total amount of radioactivity released upward, almost doubling their estimate, from 370,000 Becquerels to 770,000 Becquerels. (One Becquerel is the amount of radioactivity which results in one decay per second. Think of one click per second on a Geiger counter.) This is still well below the radioactivity release during the accident at Chernobyl, which involved only one reactor, not three.
In addition, several people have asked about the possibility of using a “sarcophagus” approach at Fukushima, like that used by the Soviets at Chernobyl.
Let's look at these events more closely.
Revised Estimates of Reactor Core Damage:
Core Damage Estimates: The Tokyo Electric Power Company (TEPCO) has revised its estimates of core damage significantly, based on at least the following:
· Errors in water level readings were found in Reactor One, leading TEPCO to conclude that Reactor One suffered a complete core meltdown shortly after the earthquake.
· The failure of pumping operations to raise the measured water level in the reactor pressure vessel for Reactor One.
The TEPCO presentation on the condition of Reactor One can be viewed at:
A similar presentation on the status of Reactors Two and Three can be found at:
The presentations are interesting and have good graphics of the core status immediately following the earthquake and tsunami. In the briefings, the cross-section of each core is presented on a 10 x 10 cell matrix, and each core is shown as the core meltdown progresses.
Compare these with the rather optimistic damage revisions cited in Update 13 (15 May 2011).
Reactor One: The complete core meltdown assessed as having occurred at Reactor One would explain the inability to raise the measured water level in that reactor. The corrected water levels remain 5 meters below the top of where the active fuel should have been (TAF), which is 1.24 meters below the bottom of the 3.76-meter-high core. The means the entire core was uncovered. The core would have overheated and melted, and then flowed taffy-like into a molten puddle at the bottom of the reactor pressure vessel. (Molten core materials are sometimes referred to as “corium.”) In that mixture would be control rods, Zircalloy cladding, fuel materials, and fission products.
The molten corium likely has solidified, and even the lowest corrected water level numbers indicate the corium should be under water, albeit at the bottom of the reactor pressure vessel.
However, it is very likely the molten core materials may have damaged control rod drive mechanism seals at the base of the reactor pressure vessel (RPV), and may even have caused some cracking or even melt-through of the RPV. The exact extent of this damage is unlikely to be known for some time.
Reactors Two and Three: Less has been released about the exact status the reactor cores in these plants, but it seems safe to assume from what has been released that at least partial meltdowns and likely nearly complete meltdowns occurred in Units Two and Three as well, with at least some of the molten core materials flowing beneath the core support plate at the bottom of the core to the bottom of the pressure vessel. However, the reported water levels in these plants seem to indicate that water is at least to the half height of where an intact core should be. Given the analyses in the referenced presentations, that would place the core materials in each reactor under water, and thus cooled.
At least one newspaper (The Guardian, UK) reported today that there is a possibility of melt-through of the reactor pressure vessels in on, two, or all three reactors. (See:
However, the exact status of these reactors remains to be seen.
One caveat: The time lines in these analyses are based on certain assumptions which cannot be determined at this point. In other words, when the meltdowns occurred is extremely difficult to pinpoint, even after the fact, because of the loss of instrumentation. As a result, the analyses apparently were performed based on worst-case conditions on a worst-case time line. That having been said, the likelihood that core meltdowns, whether partial or complete, have occurred in all three reactors is very high, as was discussed in Update 10, on 26 March 2011.
Given the course of events at Fukushima Dai-Ichi, it does not appear the operators could have prevented the severe damage to the three reactors there. Such prevention would have had to occur in advance, as was noted in an earlier update. (See the 15 April 2011 discussion of Shock Criteria, and specifically the discussion of the December 1990 U.S. Nuclear Regulatory Commission study report.)
The exact time line probably is less important, except to the engineers and to the companies involved. As noted in Update 13 (15 May 2011), it is to TEPCO’s great financial advantage to place blame, and thus financial liability, on General Electric and Hitachi. Demonstrating that the reactor designs were insufficient to withstand the earthquake would enable just such a shift of responsibility to be asserted. So far, though, even TEPCO’s presentations appear to show the damage occurring as a result of the effects of the tsunami. Last month the World Bank estimated the cost of the nuclear accidents at Fukushima as $235 billion.
There is a more complete discussion of core damage and core meltdown in Update Ten on 26 March 2011. Update 13 on 15 May 2011 provided an initial reaction to the core damage analysis.
For an indication of the time frames involved, roughly half the nuclear fuel in Reactor Two at Three Mile Island had melted. (See the Wikipedia article at:
http://en.wikipedia.org/wiki/Three_Mile_Island_accident.) It should be noted that the true extent of the core damage at Three Mile Island could not be measured until about five years after the accident, when the reactor defueling finally could commence. The defueling was not completed until about ten years after the accident. The same time frames likely will hold for Fukushima -- the actual amount and nature of core damage will not be known until the radioactivity of the nuclear fuel has decreased enough to allow defueling. That likely will be years from now.
So far, however, the nuclear fuel in each reactor appears to be contained within the reactor pressure vessel and its containment structures. What remains a risk is the leakage of water contaminated with nuclear fuel or decay products from the reactors into the environment.
With regard to the feasibility of the possibility of using a “sarcophagus” approach at Fukushima, like that used by the Soviets at Chernobyl, it seems undesirable. To do this is, in effect, giving up. Since 13 May, TEPCO has been preparing to install a heavy plastic cover on a steel framework around Reactor Unit One building. This should not be confused with a concrete sarcophagus. The purpose of this heavy plastic cover is to contain radioactive dust and water while work on the crippled reactor continues. Further discussion in Update 13 (15 May 2011).
Radiation and Radioactivity Issues as of 08 June 2011:
CNN has reported (http://news.blogs.cnn.com/2011/06/07/japan-pushes-estimates-of-initial-nuclear-leak-upward/?iref=allsearch) that the estimates of the amount of radioactivity released at Fukushima have doubled, from 370,000 to 770,000 Becquerels. Curiously, CNN blames Japan’s Nuclear Safety and Industrial Agency (NISA). The fact is that all of the information regarding the nuclear accidents at Fukushima Dai-Ichi has come from TEPCO. That includes all estimates of radioactivity released. NISA, IAEA, the news media, and everyone else has been and remains dependent on TEPCO for plant monitoring and for the release of measurements, estimates, etc.
The revised estimates of the total radioactivity released are of little real consequence – at least so far. What does matter are the radioactivity readings in the areas around the stricken nuclear power plant, and the specific radioisotopes involved. As has been noted in past updates,
Measurements of airborne and dust-borne radioactivity around Fukushima Dai-Ichi plant are about one-thousandth of the allowable limits for nuclear workers.
Foodstuffs: The Japanese government continues to address radioactive contamination of land and food stuffs aggressively. The primary prefecture affected has been Fukushima Prefecture. Restrictions on spinach from Ibaraki Prefecture also remain in effect.
Marine Monitoring: Levels of all radioisotopes in sea water have dropped relatively steadily, with occasional “bumps” along the way. Radioactivity in sea floor sediments are above normal, but decrease with distance from the plant. These isotopes reached the sediments from the water column, and thus no longer are in the sea water.
Evacuation: The evacuation of the population from exclusion zones around Fukushima Dai-Ichi commenced on 15 May 2011. Completion of the evacuation has not yet been announced.
The International Atomic Energy (IAEA) Investigatory Commission has completed the first segment of its fact-finding mission, and the preliminary summary of the initial (preliminary) report can be seen at:
The report notes that:
· All reactors survived the earthquake.
· All plants shut down automatically, as designed.
· Emergency systems functioned properly – the reactors were shut down and the emergency diesel generators started, and so on.
· The ensuing tsunami, with waves higher than 14 meters (46 feet), swamped Fukushima Dai-Ichi, and caused the loss of all but one (DG 6B) of the twelve diesel-generators. This caused a loss of all electric power to the reactors (“dark plant” conditions).
· Loss of all electric power resulted in loss of all instrumentation and control systems at Reactors One through Four. Power to Reactors Five and Six was provided by emergency diesel-generator 6B.
· The IAEA report states the resulting conditions presented the plant operators with a “catastrophic, unprecedented emergency scenario with no power, reactor control or instrumentation,” and severely affected communications systems both on- and off-site.
In addition, the report notes “the tsunami hazard for several sites was underestimated.” The Los Angeles Times stressed this rather obvious – but only with 20-20 hindsight – observation. See: http://articles.latimes.com/2011/jun/02/world/la-fg-japan-fukushima-report-20110602. It is far from clear just how one might have better estimated tsunami wave height.
However, it seems more likely the IAEA report was not referring to specific wave height predictions, but (one hopes!) more likely to the overall engineering approach to preparing for tsunami effects. It seems the approach at the Fukushima Dai-Ichi plant was to rely solely on a sea wall. The placement of the diesel-generators and the switchboards in low, floodable areas seems, in retrospect, ill advised. Nuclear safety engineers likely will be looking at these problems with an eye to necessary changes.
Affects on Nuclear Power Industry:
Germany has pledged to shut down all of its nuclear power plants by 2022. (See article at:
http://www.guardian.co.uk/environment/2011/may/29/nuclear-power-loses-appeal-japan?INTCMP=ILCNETTXT3487.) According to other articles, Europe remains divided on the issue of nuclear power, with the United Kingdom and France continuing their pursuit of nuclear power and the Swiss cabinet calling for the shutdown of Swiss nuclear power plants.
The public reactions to the nuclear catastrophe are quite understandable. However, at some point the reality of a country’s electrical power demands needs to be considered. Whether or not a nation can afford to forego nuclear power really depends upon its sources of electricity, both currently and for the near future. Nuclear power is not a long-term solution, but it is needed in the near and medium term.
The key issue is the demand for power. How that demand is to be met, whether by increased generating capacities or by demand reduction or by some combination of the two, is for each nation to decide. Further, the problem is not just one of meeting today’s demands, but one of how to meet those demands over time into the future.
Each generation of nuclear power plant designs is significantly safer than preceding generation designs (see the George Washington University panel discussions referenced in Update 13 of 15 May 2011). In addition, newer designs offer the promise of better use of fuel stocks, including the re-use of what was once considered nuclear waste. If successful, this would extend greatly the effective life of existing nuclear fuel stocks. Other reactors, such as the thorium-based designs, offer the promise of a cleaner fuel cycle. And so on.
All power sources seem to come with drawbacks and limitations of one sort or another. Resolving the conflicting demands for power and for safety is far from a trivial task. It is easy to “just say no.” What are the consequences of the choices made regarding the use of nuclear power?
In the end, meeting the needs of modern technological societies have to be balanced with the risks associated with meeting those needs. The solutions are neither simple nor easy.
CRISIS UPDATE EARLY JUNE 2011
Many have seen reports that Dai-ichi Reactor 5 lost cooling function on the 28th of May. This was reported with some alarm by outside news agencies, but needlessly so.
Reactor 5 at Dai-ichi has been in cold shutdown since 2:30 p.m. (local time) on 20 March 2011, about 40 days ago. By now, there is little residual heat to be removed in the reactor, and only a nominal amount to be removed from the spent fuel pool. The reactor temperature rose from about 68 degrees C (154 degrees F) to about 87 degrees C (188 degrees F), or 19 degrees C (34 degrees F) during the 27.6 hours the pumps were stopped. Not a very fast temperature rise at all.
The reactor itself was last reported at around 49 degrees C (about 120 degrees F). As the name implies, the Residual Heat Removal System (RHRS) pumps water through the shutdown reactor and also through the spent fuel pool to remove the slight (residual) heat being generated by nuclear decay in the reactor and in the spent fuel.
The following is an extraction of TEPCO reporting which appears credible.
Unit 5 (Outage due to regular inspection)
- Sufficient level of reactor coolant to ensure safety is maintained.
- At 5:00 am on March 19, we started the Residual Heat Removal System Pump
(C) in order to cool the spent fuel pool
- At 2:30 pm on March 20, the reactor achieved cold shutdown.
- At 9:14 pm on May 28, we confirmed temporary RHRS pumps were out of
service, we started replacement of these pumps with spares at 8:12 am on
May 29th and at 12:49 pm we restarted cooling reactor by RHRS system.
- At this moment, we do not consider any reactor coolant leakage inside
the primary containment vessel happened.
While this incident might seem alarming to the uninitiated, it really poseds no threat whatsoever. Furthermore, it appears TEPCO has taken prompt corrective action.
Just to keep things in perspective
CRISIS UPDATE MAY 2011
The challenges at the Fukushima I (Dai-ichi) Nuclear Power Plant are likely to continue for a while. Aggregating accurate data from the reporting remains a challenge, but there is enough at this point to offer some perspectives.
The situation at the Fukushima I (Dai-ichi) Nuclear Power Plant remains serious. However, to put that situation in perspective, so far some 18,000 Japanese citizens are known to have died as a direct result of the 11 March 2011 Tohoku earthquake and ensuing tsunami, and that death toll may rise. So far not a single death has been directly attributed to the problems at the Fukushima I (Dai-Ichi) nuclear power plant. (One contract worker at Fukushima reportedly has died, but that person's death does not appear to have resulted from the nuclear accident. There are no indications of radiation overexposure and the corpse reportedly is not at all radioactive.)
There are two closely related developments at Fukushima:
· First, the Tokyo Electric Power Company (TEPCO) recently revised its estimates of the extent of core damage to Reactors One, Two, and Three.
· Second, TEPCO has reported that the water level in Reactor One at Fukushima Dai-Ichi may be below the level of the reactor core, leaving what remains of that core exposed.
In addition, several people have asked about the possibility of using a “sarcophagus” approach at Fukushima, like that used by the Soviets at Chernobyl.
Let's look at these two events more closely.
Revised Estimates of Reactor Core Damage:
Core Damage Estimates: These really are just estimates inferred from gamma radiation measurements taken on 15 March 2011 in the dry well (primary containment vessel) and wet well (secondary containment vessel, or torus, or suppression pool). The estimates are inferences of core damage based upon gamma radiation readings in the primary and secondary containment vessels of each reactor.
It has been noted in earlier updates that readings from the instrumentation in these plants should be suspect until the detectors or sensors have been checked to ensure there is no damage resulting from the earthquake and tsunami. In the case of Reactor One, it appears that the corrections are to initially erroneous readings.
Reactor One: The amount of core damage originally was estimated at approximately 70%. Based on later measurements and corrections to some erroneous wet well readings, the amount of core damage is now estimated to be 55%.
Reactor Two: The damage estimate has been revised downward slightly, from 35% originally to 30% after the corrections (based on graph readings).
Reactor Three: The damage estimate has been revised downward slightly, from 30% originally to 25% after the corrections (based on graph readings).
For comparison, roughly half the nuclear fuel in Reactor Two at Three Mile Island had melted. (See the Wikipedia article at: http://en.wikipedia.org/wiki/Three_Mile_Island_accident.) It should be noted that the true extent of the core damage could not be measured until about five years after the accident, when the reactor defueling finally could commence. The defueling was not completed until about ten years after the accident. The same time frames likely will hold for Fukushima -- the actual amount of core damage will not be known until the radioactivity of the nuclear fuel has decreased enough to allow defueling. That will be years from now.
So far, however, the nuclear fuel in each reactor appears to be safely contained within the reactor pressure vessel and its containment structures. What remains a risk is the leakage of water contaminated with nuclear fuel or decay products from the reactors.
Water Level in Reactor One:
The reporting on this issue has been conflicting, and determining the actual situation is proving difficult so far.
The announcement of a possible water leak from Reactor One was based at least in part on the fact that, despite having pumped considerable volumes of water into the reactor plant, the level does not seem to have risen. As has been noted in earlier updates, until the instrument calibrations have been verified much of the installed plant instrumentation readings should be considered suspect, as the sensors have been subjected to various abnormal conditions. The current water levels at Reactor One are in doubt.
Perhaps a quick review of Reactor One construction will help. The reactor core sits in a reactor pressure vessel (RPV) which is about 65 feet (19.8 meters) tall and 15 or 16 feet (4.6 to 4.9 meters) in diameter. The reactor fuel rods, sealed (welded) Zircalloy 4 tubes containing uranium oxide fuel pellets, are about 14 feet (4.3 meters) long. The pellets occupy the bottom 12.5 feet (3.8 meters) or so of each tube. The bottom of the reactor core is about 15 or 16 feet above the bottom of the reactor pressure vessel. The space below the reactor core is where the control rods are when they are withdrawn from the core. The bottom of the Reactor pressure vessel has penetrations for the control rod drive mechanisms and for instrumentation.
For some time, the reactor water level in Reactor One has been reported as about 1.7 meters (5.6 feet) below the top of the active fuel (TAF). (TAF is the water level at which the water in the RPV would be just even with the top of the nuclear fuel in the core.) This would indicate about half of the reactor core is not under water, but is exposed, and thus presumably could have undergone some melting. (Steam provides some cooling.)
Just recently, following recalibration of the level indicators, the Japanese have indicated the actual water level in Reactor One is more than 5 meters (16.4 feet) below TAF. This would leave any intact portions of the core above the water level in the reactor pressure vessel.
Given the fact that the core of Reactor One is not intact, but likely has suffered at least a partial meltdown (as have Reactors Two and Three, though apparently not as seriously as reactor One), the nuclear reactor core is not intact.
What happens during a core meltdown, whether a partial or complete meltdown, is that some or all of the nuclear fuel rods melt, forming a substance called "corium." (“Corium” is a word coined from “core” plus the nuclear suffix “-ium” To describe the molten mix of nuclear fuel, Zircalloy, and other core structural materials. This material also has been called fuel-containing material, FCM, or even lava-like fuel-containing material, LFCM.) Since corium is molten at one point, it can flow downward through the core structure. Unless it is cooled before it reaches the bottom of the core structure, at least some of the corium will flow to the bottom of the reactor pressure vessel. Solidified (cooled) corium formed the famous "Elephant Foot" structure at Chernobyl and also was found in Reactor Two at Three Mile Island.
As corium moved toward the bottom of the reactor pressure vessel (RPV) at Fukushima Reactor One, it would have come under water again and been cooled. This cooling may or may not have stopped the corium from reaching the bottom of the RPV. The exact status of the nuclear fuel inside the RPV is impossible to determine until the RPV can be opened for defueling, several years from now.
It does not appear the reactor pressure vessel at Reactor One has ruptured. Any leaks from the reactor pressure vessel most likely would be from damaged instrumentation and control rod drive mechanism penetrations in the lower head of the RPV or from cracks in the RPV, both resulting from contact with molten corium before it solidified. There also is the possibility of leakage from piping associated with the reactor plant.
With that in mind, however, it appears there is water leakage from Reactor One. The Tokyo Electric Power Company (TEPCO) has reported that the water level in the basement of the Reactor One building is 4.2 meters (almost 14 feet) deep and rising. The current plans are to recycle this water through decontamination filters and heat exchangers and pump it back into the reactor pressure vessel for Reactor One to provide cooling. Two of the ten temporary cooling towers have arrived, and the other eight are due on 17 May 2011.
In Update 12 (15 April 2011), the differences between Chernobyl and Fukushima were reviewed in detail. The lack of containment structures at Chernobyl mandated the construction of a containment structure following the accident at Reactor Four there.
The conditions at Fukushima are different, as has been noted. Building massive containment structures around the reactors at Fukushima would, in effect be giving up altogether and burying the reactors above ground. Given that the reactors already have containment structures around them, this would seem to be an unnecessary step at Fukushima, even given the fact that the containment structure of Reactor Two, and also possibly that of Reactor One, may have been damaged during the accident.
What is being proposed by TEPCO is a lightweight structure to surround the Reactor One building in order to contain any releases of loose radioactive materials and debris. The cover being proposed would be a 47 x 42 x 55 meter high (154 x 138 x 180 feet high) steel framework with a coated polyester fiber covering to contain loose radioactive dust and to keep rain water out. The structure would be typhoon-proof, ventilated to prevent overheating, and equipped with spray for the spent fuel pool. Clearing debris within the Reactor One building would continue.
Radiation and Radioactivity Issues as of 15 May 2011:
Shortly after the last report (15 April 2011), maps of radiation levels or of radioactive material deposits around the power plants themselves and the surrounding countryside began to become available.
Overall there seems to be no real risk posed by gamma radiation from the stricken Fukushima I (Dai-Ichi) Nuclear Power Plant (NPP) or from materials released by that plant. The reported gamma radiation (like X-rays) dose rates continue to decline. In only one prefecture (Fukushima) are the dose rates above background, i.e., normal background radiation from rocks, water, and cosmic rays. On 10 May 2011 the remaining dose rates were all below 0.1 microSieverts per hour (mSv/hr), and most were half that or lower. (For those used to dealing in millirem, mrem, 0.1 mSv/hr = 0.01 mrem/hr.)
A single chest X-ray will expose one to 50 mSv (5 mrem), and a round-trip flight from Tokyo to New York will expose someone to 200 mSv (20 mrem).
The current risk remains the contamination of foodstuffs, particularly leafy green vegetables. There no longer is any restriction on drinking water as the iodine concentrations have decayed away.
As noted in earlier updates and above, enormous quantities of water have been poured onto the reactor plants in efforts to control the casualty. Normal wind and wave action should quickly dilute any radioactive contamination to well below safe levels.
As of 11 May, the only food restrictions remaining are in Fukushima prefecture and for the cities of Kitaibaraki and Takahagi in Ibaraki prefecture.
In Fukushima prefecture there are restrictions on the distribution and consumption of some fish. In specified areas of Fukushima prefecture there are also restrictions on the distribution of raw unprocessed milk, and some root vegetables, leafy green vegetables, and mushrooms.
Distribution of spinach produced in the cities of Kitaibaraki and Takahagi in Ibaraki prefecture also remains restricted.
Bottom line: There are no problems with radioactivity from Fukushima outside of Japan. There are few serious problems with radioactivity inside Japan, either.
As noted in previous updates, several pools of water contaminated with highly radioactive materials are located in the basements of the turbine buildings. That radioactive water is being transferred to radioactive waste treatment facilities, condensers, and temporary storage tanks.
Fukushima I (Dai-Ichi) Nuclear Power Plant Status as of 12 April 2011:
Reactor One: Reactor pressure is still high, and about 45% of the core remains uncovered, if level indications are correct. This has been the case since at least 17 March. Partial core meltdown is certain under these conditions. Nitrogen is being injected into the containment vessel to reduce the chances of another hydrogen explosion. Fresh water continues being injected through the normal feedwater line.
Reactor Two: Reactor pressure is low, and about 40% of the core remains uncovered, if level indications are correct. This has been the case since at least 17 March. Partial core meltdown is certain under these conditions. Fresh water continues being injected through fire extinguisher lines.
Reactor Three: Reactor pressure is low, and about 55% of the core remains uncovered, if level indications are correct. This has been the case since at least 17 March. Partial core meltdown is certain under these conditions. Fresh water continues being injected through fire extinguisher lines.
Damage Surveys: Video and photographic surveys of the crippled reactors at Fukushima are being carried out by robotic vehicles, such as PackBot (http://www.irobot.com/gi/ground/510_PackBot). These modern vehicles are a far cry from the toy tank with the video camera strapped on top that the Soviets used to survey Chernobyl. They are far more mobile, better controlled, and are providing very useful images of the plants. (For example, see: http://www.digtriad.com/news/national/article/174141/175/New-Video-From-Inside-Fukushima-Reactor-One. It should be noted the images at this website suffer somewhat by being videos of the video, and thus are not as clear as the actual PackBot images are.)
Debris removal: The Tokyo Electric Power Company (TEPCO) continues using remote-controlled heavy equipment to remove debris from Reactor Plants One, Two, Three, and Four to a common storage site.
Spent Fuel Storage Pools: All spent fuel storage pools are being supplied with fresh water as necessary.
Summary: The nuclear accidents in Japan are indeed serious, but so far the threats are entirely localized to Japan and none seem major so far. TEPCO now has embarked on following its “roadmap for recovery,” a plan for immediate recovery actions over the next six to nine months. The progress made in these actions bears watching.
Some Articles Worth Reading:
1. George Washington University School of Engineering and Applied Sciences Briefings on "The Fukushima Daiichi Incident":
These are excellent presentations which I attended on 03 May 2011. They are too large (4 MB) to send out in this e-mail, but the PowerPoint presentations (in PDF form) can be found at:
The site lists the panelists, and clicking on each panelist’s presentation title brings up that panelist’s slide show. The information is presented at a very basic level,. And thus should be of interest to most here.
An article about the panel discussions can be found at:
2. “Quake Hurt Reactors before Tsunami” – Japan Times
Japan Times is reporting the possibility that the earthquake had already damaged Reactor One at Fukushima Dai-ichi before the tsunami struck. While this is a possibility, it remains to be seen whether or not this is actually true. The article is at:
More on this after the next item.
3. “Core of reactor 1 melted 16 hours after quake: New analysis shows damage to fuel rods was surprisingly quick” –Japan Times
In a second article, the Japan Times reports that the core meltdown at Fukushima Dai-ichi Reactor One occurred quite quickly after the earthquake. The article is at:
These two Japan Times articles should be regarded skeptically, it seems to me.
First of all, it seems far too early to assess the causes of damage to the reactors. Until full access has been restored to the reactor plants, such assessments must remain speculative.
Secondly, and more significantly, from a financial liability standpoint it would seem to be very much in TEPCO’s interest to have the reactor damage be deemed the result of reactor construction being insufficient to withstand the effects of the earthquake rather than being due to any other causes. This would allow for spreading the financial liability to General Electric, Hitachi, and possibly even to the Japanese Government. At this point, TEPCO has much to gain financially and very little to lose in placing blame elsewhere for the events at Fukushima.
While these articles may well prove to be correct, it seems far too soon to tell at this point. For that reason alone, the conclusions therein would be suspect. The financial liability aspects and TEPCO’s past record in nuclear reporting matters simply are additional causes for skepticism at this point.
As always, speculative articles need to be read carefully, and with an eye to distinguishing actual supportable facts from speculation. Speculation may well turn out to be correct, and also can serve to ensure adequate attention is being paid to potential hazards. However, speculation should not substitute for facts when it comes to concern about existing conditions in a situation such as this.
Currently there is an understandable, if at times ill-informed, anti-nuclear reaction to news of the events at Fukushima. It seems important to keep the effects of the accident at Fukushima in perspective, and thus to avoid an unnecessary reflexive negative reaction to them.
Director Lars P. Hanson
As a former nuclear engineer with the United States Navy, I am very concerned that the recent reporting regarding the Fukushima reactors has been unnecessarily alarmist and often inaccurate. Yes, there is cause for alarm, but not of the sort being bandied about – at least not yet. As an attempt to counter the current spate of circular, uninformed, and sensationalist journalism, I offer the following. Because this treatise is based entirely on publicly available information, it is acknowledged that there may be some technical inaccuracies due to misinformation or lack of information. However, I hope to provide a good overview of events to date from the perspective of one trained to operate nuclear reactors under a variety of conditions and in various situations. More importantly, I hope to provide a better understanding of the events at Fukushima, as we know them so far.
Since the recent, violent 6.8 and 7.4 magnitude earthquakes in Japan, two of a plethora of aftershocks from the 9.0 magnitude Tohoku eathquake, no new faults have thus far been reported at the Fukishima Daiichii nuclear power plant.
Two Recent Meetings:
Electricity consumption, 2009..................................1
Coal..................................44.9%Natural gas.........................23.8%Nuclear power.....................19.6%Hydroelectric conventional.....6.2%Other renewables..................4.5%Petroleum.............................0.9%N.B. Numbers total 99.9% due to rounding of individual figures.About 38.7% of the electrical power is consumed by residential customers. The rest is used by commercial (35.4%), industrial (25.7%), and transportation (0.2%) customers.
The costs to customers of providing this electrical power from various sources is as follows (note that the cost per kilowatt-hour is one-thousandth of that per Megawatt-hour -- just move the decimal point three places to the left):
Plant Type ($ / Megawatt-hour)
Advanced Coal with Carbon Sequestration....................$136.2
Conventional Combined Cycle (CC)......................$66.1
Advanced CC with carbon sequestration...............$89.3
Wind - Offshore..........................................................$243.2
Why is all this important? This indicates the need for nuclear power in the current energy mix.
This article details the significant differences between events at Fukushima I (Dai-Ichi) and those at Chernobyl. It is in the form of an interview with
This article has some excellent images, particularly overhead shots of of Reactors Three and Four. Also, the graph of TEPCO stock prices is telling. At least some of the ground level damage and debris is from the tsunami, which overtopped the sea wall, and not just from the events at the various reactors. The debris in the immediate vicinity of the buildings, however, appears to be from the building roof and upper side panels.
This is the article from The Guardian (UK). The IEEE article above is the better reference.
Not at all a bad summary of events. Compare with the timelines which can be found elsewhere, notable at The New York Times web site at:
This comes as no surprise at all. Some good information on status here as well.
Yes, the situation at the Fukushima I (Dai-ichi) Nuclear Power Plant is serious.
No, it is not like Chernobyl, despite the temptation to draw comparisons on the 25th anniversary of the Chernobyl accident.
- First, as many of you know, the 26th of April will be the 25th anniversary of the Chernobyl disaster. Comparisons between the two events by the news media would seem to be irresistible, if not obligatory.
- Second, the Japanese have just upgraded their estimation of the Fukushima disaster to the maximum value of seven (7) on the International Nuclear and Radiological Event Scale (INES).
Let's look at these two events more closely.
Comparison with Chernobyl:
In Update 11's (31 March 2011) section on Some Articles Worth Reading, the following was listed:
"Why Fukushima is not Like Chernobyl" - The Diplomat (UK), 29 March 2011:
This article details the significant differences between events at Fukushima I (Dai-Ichi) and those at Chernobyl. It is in the form of an interview with Alexander Sich, who is an associate professor of physics at Franciscan University of Steubenville in Ohio. Sich was the first American researcher to investigate the Chernobyl reactor meltdown on site. Those who have been following the commentaries should be familiar with the terminology and concepts, as well as the conclusions. (Of course, since I am inclined to agree with Professor Sich, I may be biased in that evaluation.)
At the end of this update, the complete text of the article has been included, with explanatory comments interspersed.
Further comments on Chernobyl in the next section.
Increase in INES Level:
With regard to INES, based on the wording of the NISA report, the Japanese have upgraded the events at Fukushima to a level 7 based not on current events but on past events. Specifically:
- All three reactors are treated as a single event. While some nuclear advocates might object and prefer to treat reactor incident separately, treating the events at Fukushima I (Dai-ichi) as a single event seems to make more sense.
- The upgrade is based solely on the amount of radioactivity already released into the environment.
- The specific criterion cited by the Japanese Nuclear and Industrial Safety Agency (NISA) is "the . . . radiation impact."
- The NISA press release on the change in INES level can be found at:
This press release contains the specific radioactivity levels and calculations upon which the change in INES levels was based.
In terms of the amount of radioactivity released, Chernobyl was ten times worse than Fukushima. Moreover, in terms of the types of radioactive materials released, Chernobyl was far worse, having released such radioactive elements as strontium 90 (Sr 90, with a half-life of 28.9 years). The problem with strontium 90 is that it replaces calcium and accumulates in bones, where it remains until it decays away over a person's lifetime. This means long-term exposure to the affected people.
The primary radioactive contaminant released at Fukushima is cesium 137 (Cs 137), which replaces potassium in muscle tissue. Cs 137 has a biological half-life in the human body of only 70 days or so. This means that the body gets rid of half of the cesium 137 every 70 days, and thus the radiation exposure to those ingesting or inhaling cesium 137 is far less than for equivalent amounts of strontium 90, which was released at Chernobyl, but not at Fukushima. After one year, the amount of cesium is only one-thousandth of the original amount. Thus, even though Cs 137 has a radioactive half-life of 30.17 years, its biological effect is reduced.
It also should be noted that at Chernobyl roughly half of the 190 tons of nuclear fuel and fission products were ejected to the surrounding countryside by the explosion, with 1% - 2% (2 to 4 tons) of the 190 tons thrown as high as 7 to 9 kilometers into the atmosphere. No such explosive core material ejections have occurred at Fukushima, and the amount of material released is far smaller. The accident at Chernobyl was followed by a graphite moderator fire which lasted for seven or eight days, burning nuclear fuel with it and thus resulting in further atmospheric contamination. According to the TORCH report, while the bulk of the contamination occurred inthe Ukraine, Belarus, and Russia, significant amounts of radioactive materials were deposited in each of the following countries: Austria, Bulgaria, Finland, Germany, Norway, Poland, Romania, Sweden, and Yugoslavia. About 3,900,000 square kilometers, or roughly 40% of the surface area of Europe was significantly contaminated, and about 218,000 square kilometers (2.3% of Europe) received the highest levels of contamination.
The accident involving the four nuclear power plants at Fukushima Dai-ichi is not the same as the one involving the single reactor at Chernobyl.
For reference, the following are the International Atomic Energy Agency (IAEA) criteria for various International Nuclear and Radiological Event Scale (INES) levels:
- Major release of radioactive material with widespread health and environmental effects requiring implementation of planned and extended countermeasures.
- Significant release of radioactive material likely to require implementation of planned countermeasures.
- People and Environment:
- Limited release of radioactive material likely to require implementation of some planned countermeasures.
- Several deaths from radiation.
- Radiological Barriers and Control:
- Severe damage to reactor core.
- Release of large quantities of radioactive material within an installation with a high probability of significant public exposure. This could arise from a major criticality accident or fire.
Some examples of incidents rated at each level:
Chernobyl Reactor Four (26 April 1986) – About 80 to 100 tons of highly radioactive nuclear core material ejected by a steam explosion and subsequent graphite moderator fire. Immediate death toll 56, with an estimated 8,000 additional cancer deaths. This number is likely to increase over time. A 30-kilometer (18.75-mile) exclusion zone remains in effect. Details at:
Kyshtym (at Mayak, Soviet Union) Waste Reprocessing Plant (29 September 1969) – 70 – 80 tons of highly radioactive material ejected into environment by a steam explosion. An estimated 8,000 people have died in the after-effects of this disaster. Details at:
Windscale (UK) fire (10 October 1957) – Graphite and uranium fuel fire at an air-cooled graphite pile reactor. An estimated 240 additional deaths resulted from this incident. TThe presence of chimney "scrubbers" (filters) prevented greater damage. Details at:
Three-Mile Island Reactor Two (28 March 1969) – Combination of design and significant operator errors caused loss of coolant accident and partial core meltdown. Radioactive gases released into atmosphere. No health impact on local population.
Goiania accident (Brazil) (13 September 1987) – An unsecured cesium chloride radiation source in an abandoned hospital was stolen and sold at a junkyard. 249 people contaminated and 4 deaths due to exposure. Details at:
The Tokyo Electric Power Company has announced that it now plans to scrap four of the reactors (Reactors One through Four) because of the damage. That really has been almost a foregone conclusion since about Day Three of this crisis. Japan's Nuclear and Industrial Safety Agency (NISA) estimates a decommissioning period of as long as ten years, which seems reasonable, given events to date and reported radioactivity levels in the plants.
The nuclear accidents in Japan are indeed serious, but that so far the major threats are entirely localized to Japan. It is possible that some countries immediately neighboring Japan (the Russian Kurile Islands, for instance) may see some radioactive fallout from this accident.
Radiation and Radioactivity Issues:
As noted in past reports, it appears there still is no good published map of radiation levels or of radioactive material deposits around the power plants themselves or the surrounding countryside.
Published reports of radioactivity and of radiation levels from the area have been spotty, scattered, and from inconsistent locations and distances. This perception may well be the result of incomplete press reporting, but it is also results from the lack of such information coming from either the Tokyo Electric Power Company (TEPCO) or from the Japanese government. This is of concern for all those in Japan.
While the published information so far is spotty, it seems overall there is no real risk posed by gamma radiation from the stricken Fukushima I (Dai-Ichi) Nuclear Power Plant (NPP). The current risk appears to be from contamination of foodstuffs, particularly leafy green vegetables. As has been noted, the iodine-131 concentrations will die off quickly, but the Cesium-137 concentrations will last longer. The Japanese government appears to be addressing this problem aggressively as hazards are identified, although they still may be "behind the power curve" in that it apperars they continue to be in a reactive mode vice starting to get ahead of the problems.
According to the Kyodo News Agency, soil samples taken at Iitatae, a village about 40 km (25 miles) from Fukushima I NPP, were above the IAEA’s limits for evacuation. The Japanese government denied there was any immediate threat to human health. Kyodo News also noted increased iodine-131 levels at a point 330 meters (361 feet) from the drain discharges from the Fukushima I NPP. Tuesday the readings had been 3355 times the “normal,” and Wednesday they were 4385 times the “normal.”
As noted in earlier updates, enormous quantities of water have been poured onto the reactor plants in efforts to control the casualty. This water had to run off. That water became contaminated with fission products, most likely from the damaged fuel in the spent fuel storage pools, and then ran off into the ocean. Normal wind and wave action should quickly dilute the radioactive contamination to well below safe levels.
Reportedly TEPCO is considering spraying the stricken plants with a resin in an effort to prevent contaminated dust (particulate contamination) from being blown about.
As noted in Update 10, several pools of water contaminated with highly radioactive materials are located in the basements of the turbine buildings, as follows:
Reactor One Turbine building: On Friday, 25 March, a pool up to 40 cm (1.3 feet) deep was discovered. Concentrations of radioactivity 10,00 times “normal” were reported.
Reactor Two Turbine building: On Friday, 25 March, a pool up to 1 meter (3.3 feet) deep was discovered. The concentration of radioactivity has not yet been reported.
Reactor Three Turbine building: On Thursday, 24 March, three workers were exposed to excessive radiation when they waded into a pools of highly radioactive water. Two required hospitalization to treat “beta burns,” radiation burns resulting from exposure to beta radiation. The pool reportedly was up to 1.5 meters (4.9 feet) deep. Concentrations of radioactivity 10,00 times “normal” were reported.
Reactor Four Turbine building: On Friday, 25 March, a pool up to 80 cm (2.6 feet) deep was discovered. The concentration of radioactivity has not yet been reported.
To dispose of the highly contaminated water in the turbine halls, TEPCO has elected to pump the water into the condensers which normally would condense the exhaust steam from the turbines. In essence, they will be using the condensers as large tanks. The condenser for turbine hall One is full. Preparations are being made to pump the pools from turbine halls two and three. No word on turbine hall four.
Fukushima I (Dai-Ichi) Nuclear Power Plant Status:
The following is based on International Atomic Energy Agency (IAEA) and other reporting.
Reactors One, Two, and Three: All three reactors sustained significant core damage as a result of the accident, with partial core meltdowns almost certain to have occurred in all three reactors. However, the estimation that a melt-through of the reactor pressure vessel of Reactor Two has occurred may be premature. Even if true, the primary containment building appears to be holding.
Tokyo Electric Power Company (TEPCO) has restored lighting in all three main Control Rooms, and has restored AC electrical power to the instrumentation for Reactors One, Two, and Four. This means that some information is now available on the status of each of these plants. However, some of the readings appear to be of questionable validity.
Fresh water injection along with boric acid (boron is a reactor “poison,” an element which strongly absorbs neutrons, and thus prevents fission, keeping the reactors shut down). Injection is being done by temporary electric pumps with diesel backup.
As noted in Update 10, fresh water continues to be injected into all three reactors. This is good. The use of sea water when no other sources were available was entirely justified. However, now that fresh water can be injected into the plants, it is important to do so, for several reasons:
The chlorine in the sea water is harmful to the stainless steel plant and components.
Caked salt where the sea water boiled off during the efforts to cool the plants can interfere with attempts to remove heat from the core, because of poor heat transfer characteristics and because the presence of salt crystals can interfere with flow and even clog some cooling channels.
Caked salt is abrasive, and can damage rotating plant components and valves if such crystals are pumped around the system.
The fresh water being injected into Reactors One, Two, and Three will reduce the salt water concentration by diluting the sea water. In addition, it is expected that over time any crystallized salt will re-dissolve in the fresh water, and thus be removed.
- Are not linear in nature-- doubling a given radiation exposure does not necessarily mean doubling the biological damage caused.
- Are dependent upon the type of radiation involved. different radiation types have different effects.
- Are dependent upon the specific radionuclides involved- different radioisotopes are accumulated in different areas of the body, and thus the biological effects of radiation can differ greatly from one radioactive element to another. In addition, the types and energy of the radioactive decay particles released varies from one radioactive isotope to the next.
- Are dependent upon the time over which the exposure occurred. Generally, but not always, high exposure over a short time period is more damaging than low exposure over a longer time period. (In part this may be due to the body's ability to repair itself.)
- Are cumulative in nature-- in the nuclear power industries, instantaneous exposures, annual cumulative exposures, and lifetime cumulative exposures are tracked with allowable limits set.
- Are not as well understood as might be wished
Radioactive Water:From a practical standpoint, there is no good way to capture and treat all the water that has been pumped onto the reactor buildings at the Fukushima I (Dai-Ichi) nuclear power plant. The water that runs off into the ocean, as noted yesterday, is the likeliest cause of the elevated levels of iodine 131 noted off shore near the discharges for reactor plant drains. Radioactive materials reaching the ocean will be dispersed and rapidly diluted by the actions of wind, waves, and ocean currents. The radioactive waste water which seeps into the ground will create long-term problems for the site. Some surface decontamination should be possible, and should be conducted, if only to reduce the chances of the radioactive materials drying out and being blown about by winds. The exact level and nature of the problems ground contamination will cause remain to be seen.
- Possibility of Reactor “Breach”:
Since yesterday the news media have been replete with reports about the possibility of a reactor “breach,” the breaking of all boundaries between the reactor core and the environment, at Reactor Three. These fears have been stoked by Thursday’s incident in which three workers stringing cables were exposed to excessively high radiation levels after stepping into a pool of water. (For a more detailed discussion of what the nuclear boundaries are, and of the meaning of such terms as “core damage” and “meltdown,” please see the longer explanatory notes at the end of this update.)
As noted yesterday, the exceedingly high radioactivity levels in the water at Reactor Three turbine hall might indicate a serious problem with the integrity of the reactor plant itself. This fear is heightened by the atmospheric pressure readings reported for Reactor Three. If the reactor plant can hold pressure, then a breach would be unlikely. On the other hand, the mere fact that pressure is near atmospheric by itself does not necessarily indicate a breach of the primary system. Remember that the nuclear core in a boiling water reactor is located within a hermetically sealed system. It is this boundary which may have been breached. So far, the exact status remains unknown and available reporting remains confused and confusing.
If the radioactivity levels in the pool of water in the turbine hall for Reactor Three are due to fission products from the Reactor Three core, then it would seem the primary plant at Reactor Three has been breached. However, that breach either would have to be outside the primary and secondary containment structures (see the reactor construction review at the end of this update) such as in piping in the turbine hall. If outside the containment structures, this would indicate the massive valves at the reactor pressure vessel were not shut or were leaking, as well as steam or feedwater piping in the turbine hall.
Alternatively, if there is a breach of the reactor vessel for Reactor Three, then for the liquids containing the fission products to collect in the basement of the Reactor Three turbine hall would require that they run out of both the primary and secondary containment structures and then across the open space from the Reactor Three building to the Reactor Three turbine hall. The path by which the water might do so is not at all clear.
Based on the information currently available, and given the lack of reports on radiation levels, neither possibility really seems likely. However, neither possibility can be ruled out at this point.
With the discovery of similarly high contamination pools turbine hall basements for all four reactors, the possibility exists that the reactor cores may not be the source of the radioactive contamination. With all the water sprayed on the buildings for Reactors Three and Four in an effort to cool and refill the spent fuel storage pools there, it is quite possible the water pools in the turbine halls actually are water run-off from those spraying operations. The water contamination by radioactive fission products could be from the spent fuel in the pools at Reactors Three and Four.
This option makes more sense, as the spent fuel is not within any containment building, but is out in the open in pools at the tops of the secondary containment structures for each reactor.
The high radioactive iodine 131 concentrations (some 1250 times the legal limit) reported yesterday in the ocean about 330 meters south of the Fukushima I plant, near the drainage outlets from the four stricken reactors, also would seem most likely to be the results of run-off of the 2200 or so metric tons (about 605,000 gallons) of water sprayed onto the buildings for Reactors Three and Four.
A day earlier, the concentrations at the same point were only about 104 times the legal limit. The concentrations of cesium 134 and cesium 137 at the same point also were high, about 117 and 80 times the legal limits respectively. All three radioisotopes are water-soluble.
The half-lives for the radioisotopes being reported are:
Iodine 131 8.0 days
Cesium 134 2.07 years
Cesium 137 30.2 years
The sea water is expected to dilute the concentrations of radioactive materials quite rapidly, but sea life will have to be checked for a while before being sent to market.
In summary, the question of whether or not there has been a core breach at Reactor Three has not been answered. It is known that the secondary containment structure at Reactor Two was damaged by a hydrogen explosion in the torus (the suppression pool) and that the secondary containments for Reactors One and Three may have been damaged during the hydrogen explosions at those plants.
Reactor Accident Terminology
This is another look at some of the information presented in the first report’s primer on nuclear reactors.
Reactor Core Construction:
The nuclear fuel in the core of a boiling water reactor (BWR) is in the form of uranium oxide (UOX) contained in long zirconium alloy (Zircaloy 4) tubes or fuel rods. The uranium in these pellets typically is low-enriched uranium (LEU), naturally occurring uranium 238, enriched to around five percent (5%) with uranium 235.
In Reactor Three up to one third of the fuel tubes contain mixed oxide fuel (MOX) which contains around 7% plutonium oxide mixed with natural, reprocessed, or depleted uranium oxide fuel. MOX behaves similarly to UOX, and thus allows more complete use the nuclear fuel. The “down” side is that plutonium is highly toxic material.
Fuel assemblies are composed of square 8x8 or 9x9 or even 10x10 bundles of these rods, (with some rods omitted for nuclear physics reasons). In the middle of every four square bundles there is a cross-shaped space to allow the passage of cruciform (cross-shaped) control rod blades. When the control rods are inserted into the core, they occupy these spaces. When the control rods are withdrawn, water fills these spaces.
What all this means is that the nuclear fuel within a nuclear reactor is not contained all in one lump, but in fact is located in separate fuel rods. In the case of a reactor core with 9x9 fuel rod bundles, the nuclear fuel is contained in around 70,000 fuel rods.
Nuclear fuel (UOX) which has not been in a reactor is not very radioactive. However, the mixture of fission products in fuel assemblies which have been in an operating reactor is highly radioactive, mainly because of the fission products they contain.
Nuclear Fuel Boundaries:
Reactor Cores: Consider the nuclear power plant description provided in the first summary, but look at it from another point of view.
What boundaries are there to prevent the release of nuclear materials? What boundaries exist between the nuclear fuel and the environment?
The first boundary is the sealed (welded closed) Zircaloy tube which forms the outer boundary of the fuel rod.
The next boundary outward is the reactor pressure vessel and coolant piping. Typically made of stainless steel, this strong metal boundary is designed to contain the reactor primary coolant and the steam produced by the boiling water reactor (BWR).
Outside of that boundary is the primary containment structure, a strong concrete-and-steel structure which is designed to contain a worst-case loss of coolant accident (LOCA) and to suppress the resulting steam released.
The final boundary is the secondary containment structure, the strong concrete-and-steel structure which surrounds the lower portion of the primary containment structure, and which forms the lower sixty percent (60%) or so of the reactor plant building. The upper forty percent (40%) or so of the building is not part of the containment structure, but is a framed building with relatively light outer panels providing shelter from the elements for the spent fuel pool, the refueling machinery, bridge crane, etc, and other equipment.
The containment structure boundaries are not entirely separate, as various connections pass between them and also to the turbine hall so that the electrical generating machinery can be supplied with steam.
In addition, there are penetrations for the feedwater piping which returns the coolant from the condensers back into the BWR.
In an emergency, the steam and feedwater piping penetrating the primary containment structure should be sealed off with valves, which themselves then form part of the primary containment boundary.
In the case of a worst-case reactor coolant leak, the passages between the primary and secondary containment structures guide steam to a suppression pool or torus. (The suppression pool is doughnut-shaped, hence the name torus.)
There are other penetrations as well, but these are the major ones.
Spent Fuel: In the case of spent fuel, the boundaries are far fewer. The spent fuel assemblies – 8x8, 9x9, or 10x10 bundles fuel rods – are removed from the reactor core during refueling and are stored in large pools of water. These fuel assemblies contain some unused nuclear fuel mixed with a highly radioactive mix of fission products.
The primary boundary for the fission products in the spent fuel assemblies is the same as that in the reactor core – the Zircaloy 4 tubes surrounding the nuclear fuel and fission products.
The secondary boundary is the water in the spent fuel pool. This water serves to cool the spent fuel assemblies (in which the radioactive decay of the fission products is producing heat) and to provide some shielding against radiation.
Core Damage: A reactor plant is said to have experienced core damage when the first boundary, the Zircaloy surrounding the fuel, has been breached, allowing fission products and fuel to leak into the reactor coolant. The presence of fission products, such as iodine 131 and cesium 137 in the reactor coolant is prima facie evidence of core damage.
“Meltdown”: Although in common use, this term is not officially recognized by any nuclear agency. The term meltdown refers to the results of a nuclear accident in which reactor core is damaged by overheating. This sort of core damage is severe. The analogous technical terms are things like “core melt accident” and “partial core melt.”
Typically, melting in the core begins at the top of the core, where the fuel is hottest. This also is the region of the core which first becomes uncovered as water level is lost, and thus adding to the likelihood that will be the first region to overheat.
Perhaps it is best to stick with “meltdown,” as it is in common use, but it seems prudent to consider some gradations in terminology to allow distinguishing between degrees of severity. As a proposal, one might consider the following:
Fuel melting: This refers to the melting of the nuclear fuel within the Zircaloy-clad fuel rods. While the melting is contained within the tubes, the tubes themselves may distort and cause local overheating problems due to restricted coolant flow and nuclear effects. Also, control rod motion may be impaired or prevented by the distortion of the fuel rods.
Although the melted fuel is contained within the Zircaloy tubes, cracking of tube welds or of the tubing itself might result, which in turn could allow the release of fission products or fuel into the primary coolant. Such fuel release is not a necessary outcome in this instance.
In many, if not most, cases, the reactor core can be repaired by replacement of the affected fuel rod assemblies.
Partial meltdown: This refers to the partial or complete melting of one or more fuel rods, melting involving both the nuclear fuel pellets and the Zircaloy tubes. This melting destroys the Zircaloy boundary and allows nuclear fuel and fission products to enter the primary coolant.
Partial meltdown invariably results in distortion of the fuel rods, and likely of the fuel assemblies as well, and thus can interfere with coolant flow around the fuel rods and control rod motion. These effects in turn can further aggravate the overheating problem which caused the original partial meltdown.
The reactor core generally cannot be recovered after a partial meltdown.
There are varying degrees of severity involved in partial meltdowns. In the mildest cases, the melting can be quite localized, and perhaps only a portion of some fuel bundles or assemblies are affected.
In more severe cases, such as at Three Mile Island and Chernobyl, major portions of the reactor core melt and form slag puddles which eventually solidify. (Note that Three Mile Island 2, the accident reactor, was a pressurized water reactor (PWR), and that Chernobyl 4 was a Russian RBMK graphite pile reactor, neither of which is a form of boiling water reactor (BWR).)
The meltdown may even be sufficiently severe that the puddles of melted reactor core leave the core and accumulate in the bottom of the reactor pressure vessel.
Because of the heat generated by the nuclear decay of the reactor fission products in the melted core material, it usually is years before the material cools enough to solidify and to allow inspection to ascertain the precise damage.
Complete meltdown: This refers to the complete melting of the reactor core material, which then runs down into the bottom of the reactor pressure vessel. If the reactor pressure vessel in turn softens or melts enough to allow the fuel to burn its way through, the resulting nuclear slag would then run out into the floor of the primary containment structure.
“China Syndrome”: Adding this to the list as the final and ultimate catastrophe is irresistible. The theory behind the China Syndrome is that a complete core meltdown occurs and the molten core materials form a liquid mass in which continuous fission can occur, thus generating heat and more fission products. In this scenario, the core simply melts its way through the bottom of the reactor pressure vessel, then melts its way through the bottom of the containment structures, and nuclear fission continues, resulting in the molten mass melting its way down toward the center of the Earth, and then going “all the way to China.” Don’t hold your breath on this one!
Of course, it could never reach China in any event, as the gravitational pull at the center of the Earth is zero. Furthermore, this scenario requires that the mixture of molten fuel, reactor core structural materials, and other materials somehow retains a mixture and consistency which supports continuous nuclear fission all the while.
On the whole, this seems quite unlikely, but it did form the basis for a successful Hollywood movie!
- Gregory (a Scotland Yard detective): "Is there any other point to which you would wish to draw my attention?"
- Holmes: "To the curious incident of the dog in the night-time."
- Gregory: "The dog did nothing in the night-time."
- Holmes: "That was the curious incident."
- Radiation levels at several points around and at several distances from the reactor plants should be taken and the field should be mapped, both over locations and over time. Such a mapping provides much necessary information, including:
- The overall strength and "shape" of the radiation field
- The presence of any "beaming and streaming" radiation paths, areas of higher exposure (areas to be avoided or areas where localized shielding needs to be erected to protect workers)
- The presence of localized shielded areas (safer areas for workers)
- The changes of the field over time (which can provide vital clues to the status of the individual reactors)
- The distribution, amounts, and types of radioactive materials need to be mapped. This is important for several reasons:
- Distribution and amounts of radioactive materials provides information on the contamination levels of the surrounding areas.
- The types of radioactive materials, the specific radioisotopes involved, provides much-needed information on things such as expected radiation exposure levels, local contamination levels, half-life times, susceptibility of the soil to contamination, possible decontamination strategies, actual nuclear power plant damages, probability of spreading based on local weather reporting, etc., etc.
- Such measurements are essential if one is to make informed public health decisions.
- These measurements would enable decision-makers to make informed assessments of the severity of the situation, and thus to make informed decisions regarding evacuations, relocations, quarantines, etc.
- Basically, these measurements are a rich source of information.
- Radiation and contamination "trip" levels need to be established. Such levels would be used to trigger certain disaster responses based on these levels.
- Radioactive contamination and radiation boundaries need to be established and entry and exit procedures established and maintained.
- Plant damage assessments based on radiological information such as the above. For instance, the presence or absence of fission products provides information on the conditions of the spent fuel pools and on reactor plant integrity.
- Plant status mapping should be used to establish and monitor plant conditions over time as the containment efforts continue.
- And so on.
Distance Exposure Fraction
1 m 100 mSv/hr 1
2 m 25 mSv/hr 1/4
3 m 11 mSv/hr 1/9
4 m 6.3 mSv/hr 1/16
5 m 4.0 mSv/hr 1/25
6 m 2.8 mSv/hr 1/36
7 m 2.0 mSv/hr 1/49
8 m 1.6 mSv/hr 1/64
9 m 1.2 mSv/hr 1/81
10 m 1.0 mSv/hr 1/100
N.B.: The strength of the radiation diminishes as a function of one over the square of the distance from the source.
- Acting as a barrier to the release of radioactive products.
- Restoration of reactor plant and spent fuel cooling pumps;
- Restoration of reactor plant sensors and control systems;
- Containment of radioactive products;
- Reduction of radiation levels; and
- Radioactivity clean-up.
- Minimize the time you are exposed to the radiation,
- Maximize your distance from the radiation source, and
- Place whatever shielding is available between you and the source.
PREVIOUS UPDATE This essay not intended to minimize the hazards of nuclear power, only to keep the concerns grounded in fact rather than fiction.
The overall situation appears to be relatively stable, although the fight to re-establish solid control of the nuclear facility goes on. Progress is being made on that front. Herewith the details.
- Reactors One and Two: No problems reported.
- Reactors Three and Four: These two spent fuel pools (try saying that rapidly ten times!) remain a major concern. The water levels and temperatures in these pools remain unknown. Fire trucks sprayed water on the Reactor Three containment structure, apparently in the hopes of wetting down the spent fuel pool. Water spraying may possibly provide a little water for cooling the spent fuel pools, but it will not cool the reactor cores at any reactor at Dai-ichi.
- Reactors Five and Six: No problems reported. Fuel remains covered by water.
- Common Spent Fuel Pool: No problems reported. Fuel remains covered by water.
- Reactors One, Two, and Three: INES 5, based on core damage caused by loss of all cooling.
- Reactor Four: INES 4, based on problems with the spent fuel pool.
- Reactors One, Two and Four: INES 3, based on loss of cooling functions.
UPDATE This essay not intended to minimize the hazards of nuclear power, only to keep the concerns grounded in fact rather than fiction.
- Reactor One: Core damage (partial or complete core meltdown), sea water and boric acid injected, reactor permanently damaged and not recoverable. So far containment building appears intact (primary, or inner, and secondary, or outer, structures), even though the upper panels have been blown off during the first hydrogen explosion.
- Reactor Two: Core damage (partial or complete core meltdown), sea water and boric acid injected, reactor permanently damaged and not recoverable. Reports that the the dry well (the torus or suppression pool - see last night's update) has been cracked, either in the earthquake or as the result of a hydrogen explosion.
- Reactor Three: Core damage (partial or complete core meltdown), sea water and boric acid injected, reactor permanently damaged and not recoverable. So far containment building appears largely intact (primary, or inner, and secondary, or outer, structures), even though the upper panels have been blown clear and there appears there may be some heat damage to the structure. Spent fuel storage pool (SF on the diagrams from last night) may be partially or completely drained. There are varying reports of the status here. The possibility is that the pool (or tank) might have been cracked during the earthquake or during one or more of the hydrogen explosions. It may also be that the spent fuel simply evaporated the water in the tank. Information is unclear.
- Reactor Four: Spent fuel storage pool (SF on the diagrams from last night) partially or completely drained. There are varying reports of the status here. The possibility is that the pool (or tank) might have been cracked during the earthquake or during one or more of the hydrogen explosions. It may also be that the spent fuel simply evaporated the water in the tank. Information is unclear. In addition, there have been fires probably in or near the spent fuel storage pool, and the roof of the lighter upper structure of the secondary or outer containment structure clearly has been damaged by fire. This is shown clearly in all photos of Reactor Four.
- Reactor Five: Initial reports of water levels lowering and temperatures rising. This is still in the early stages, and the reactor was cooled down for maintenance well before the earthquake struck. This should be controllable, but time will tell.
Electrical power needs to be restored to the Fukushima I site in order to restore the coolant pumps and water injection pumps, to restore the remote controls, and to allow instrumentation to be used to ascertain the actual plant conditions. The degree of damage to these systems is as yet unknown. The Tokyo Electric Power Company (TEPCO) is reported to be stringing in new power lines. It remains to be seen what systems can be restored.
Chinook helicopters have been shown on NHK television dropping water in the Reactor Three housing. The purpose of such drops is unclear, but most likely was aimed at getting water on the spent fuel stored in Reactor Three. Such water drops are not like the drops following the Chernobyl accident. These drops cannot get water onto the reactor cores as these are still covered within the primary (inner) containment structure and the reactor pressure vessels. Such drops cannot be effective, because of the spread of water when dropped. NHK is reporting that water cannons may be tried next.
The next issue, and perhaps the primary issue right now, is that of radioactivity releases and radiation exposures. (Radioactivity and radiation were discussed in yesterday's update.) Venting of steam from an operating nuclear power plant releases short-lived low-level radioactivity. Under normal conditions, steam vented in this manner would be condensed in the wet well and the release to the environment would be nil. Even under a "worst-case" (design worts-case) reactor plant leak, release should be nil. The current conditions are now outside of the design worst-case conditions, and there is reason for localized concern.
Given that there has been core damage at Reactors One, Two, and Three (as evidenced by the detection of radioactive cesium and iodine - see earlier articles), one can assume that fission products have made their way from inside the fuel rods into the water around the core, and thence into the radioactive steam being vented. Given that the wet wells (tori, or suppression pools) at each plant appear to be dry, steam being vented is being released to the atmosphere, carrying with it the fission products. These fission products are highly radioactive, and many are long-lived. The radioactive products from the plant can be expected to be deposited around the plants, with the greatest concentrations nearest the plant, tapering off with distance. radioactive gases will be airborne, but will disperse and be diluted to harmless concentrations as the winds carry them off.
With the radioactive materials concentrated around the plants, the radiation exposures will be highest at the plants, and then will taper off as one moves away from the plants. (This is the basis for establishing exclusion zones by radii, as discussed in yesterday's update.) The amount of radiation and the effects of that radiation is dependent upon the exact nature of the radioactive materials, as discussed yesterday. The Japanese Defense Minister reported readings of 1.3 mSv (130 mrem - see yesterday's updates for information on terms) at 1000 feet, and 87.7 mSv (8.77 rem) lower down (100 meters?) over Reactors Three and Four. These fairly high readings may indicate either radiation from fission products from the reactors, or from the spent fuel stored in the storage pools.
The Japanese government has stood by its recommendations of a 20-kilometer (12.5-mile) exclusion zone and a 30-kilometer (18.8-mile) stay indoors zone. The U.S. Nuclear Regulatory Commission (NRC) has concluded that the spent fuel storage pools at Reactor Four, and possible at Reactor Three, is dry. Based on that, the NRC has recommended a wider evacuation zone of 80 kilometers (50 miles). The differences in estimations of the situation have not yet been resolved. Based on the NRC's remarks, the NRC estimate may be conservative and based on a worst-case analysis for the spent fuel uncovered in the pools at Reactors Three and Four. (The status of the spent fuel pools at other reactors is unknown.)
The local winds currently are blowing off-shore in a loop which circles back over Sakhalin Island and the Kuriles. Radioactive material blown offshore should disperse to harmless levels as a result. There currently appears to be no threat whatsoever to Hawaii or the U.S. mainland from the radioactivity being released at Fukushima. The offshore winds also will help minimize radioactive contamination in Japan as well. Unlike Chernobyl, there as been no large explosion which would launch radioactive material into the stratosphere, but even if there had been, the dispersion of any material in the jet stream over that distance should dilute it to harmless levels before it reached land. Not unexpectedly, criticism of the Tokyo Electric Power Company (TEPCO) and nuclear oversight in Japan has begun. TEPCO has not had a very good history of being forthright with problems. An article in today's (16 March 2011) Christian Science Monitor addresses the problems TEPCO has had.
Most likely the situation at the Fukushima nuclear power plants is as follows:
• The reactors at the Fukushima I and II nuclear power plants are all shut down. I.e., there is no nuclear fission (except for naturally occurring spontaneous fission) occurring in the reactors there. There is no nuclear chain reaction in any of those reactors.
• Plant operators have been unable to restore cooling flow to Reactors One and Three at the Fukushima, causing overheating of the reactor cores.
• There was a hydrogen explosion in the containment building for Reactor One, causing the building's upper panels to be blown off. This is not the same as an explosion in the reactor itself.
• The reactor is not going to explode like the reactor at Chernobyl did.
• Some core damage has occurred to Reactor One at Fukushima I nuclear power plant, as evidenced by the release of a small amount of fission products (I-131 and Ce-137).
• A partial core meltdown may well have occurred at two of the three operating reactors at Fukushima I may have occurred.
• The current threat to personnel in the area is limited, but that may change in the future as more products are released.
• The situation is still evolving.
Nuclear reactors are not constructed in such a way as to allow them to undergo a nuclear explosion. Worrying about this is much like worrying that the engine in one's car will suddenly become a fuel-air explosive (FAE) bomb.
Atomic (fission) bombs work by bringing fissile material together in sufficient quantity and with sufficient rapidity that the material will go "prompt critical," a special case of super-criticality in which the number of fissions occurring, and thus the amount of energy being released, increases exponentially, in an uncontrollable fashion. In other words, a bomb.
Nuclear reactors are constructed quite differently. A nuclear reactor is constructed so a self-sustaining controllable nuclear chain reaction occurs. This chain reaction can be controlled by limiting the amount of material exposed to other material at any moment. The physical construction of a nuclear reactor generally makes prompt criticality physically impossible, even during a meltdown. Nuclear reactors are heat sources, not bombs.
A nuclear reactor uses fuel, typically U-238 (uranium with an atomic weight of 238) enriched with U-235 (with an atomic weight of 235), contained in individual reactor components called fuel elements. The physical arrangement of fuel elements can take many forms, but one common form is uranium oxide (UOX) pellets contained within a cylinder to form fuel rods. The fuel elements are then held in place by the reactor structure to allow coolant to flow around the fuel elements, and thus to remove heat from them. There also are channels for the control rods, which are long rods of materials which absorb neutrons, and thus can remove the neutrons which cause the chain reaction. Inserting the control rods controls or, when fully inserted, stops the nuclear fission process and thus shuts down the reactor.
The reactor core (fuel elements plus control rods, plus various other structural elements) is contained within a reactor pressure vessel, a strong steel vessel capable of containing the high pressures at which the power plant operates. The reactor vessel is connected to similarly strong piping which contains the steam and the coolant. The entire coolant system is a sealed, high-pressure system. All connections to the reactor pressure vessel are high up on the pressure vessel, thus leaving the reactor core in a well in the pressure vessel. This provides a last-ditch means of keeping the core covered with water.
The coolant in a boiling water reactor (BWR) is boiled by the heat from the reactor core, passes through piping to the turbogenerators, then to a condenser, a cooling device which uses water to cool the steam, causing it to condense back to water. High-pressure pumps then force the coolant back into the pressure vessel and the cycle begins anew.
The reactor system itself is housed in a containment building, a steel and reinforced concrete structure which is designed to contain radioactive materials in case of a nuclear accident releasing coolant. Typically, for BWRs, the containment facility looks like a square building rather than the domed structures surrounding a pressurized water reactor (PWR). The Fukushima plants have such square containment buildings.
Criticality: This term refers to the ability of a mass of fissile material to sustain a nuclear chain reaction. If the mass is:
Ø Subcritical, the nuclear chain reaction cannot be sustained and will die off.
Ø Critical, the nuclear chain reaction is sustained, with power neither increasing nor decreasing.
Ø Supercritical, the nuclear chain reaction is increasing, with power increasing.
Ø Prompt critical, the nuclear chain reaction is increasing out of control.
The critical mass of U-235 is about 52 kilograms, or a sphere about 17 centimeters (6.7 inches in diameter. For reactor fuel at 20% enrichment (20% U-235 and 80% U-238), the critical mass is closer to 400 kg.
Fukushima I & II Nuclear Power Plants:
The reactors at Fukushima Dai-ichi (福島第一原子力発電所 – Fukushima I Nuclear Power Plant) plant consist of six (6) GE boiling water reactors (BWRs) with two (2) GE advanced boiling water reactors (ABWRs) under construction (scheduled to be on line around 2016 and 2017). The former are conventional BWRs, and require pumps to force cooling water through the reactor cores in a closed, pressurized system. The heat from the reactor core causes the light-water (deuterium-free) coolant to boil, which produces steam to drive the steam turbogenerators and thus to produce electric power. The ABWRs (which are still being constructed) will use natural circulation to circulate coolant. Natural circulation uses thermal differences to force coolant flow, and thus no electric power is needed to circulate the coolant. Natural circulation provides distinct advantages in this sort of situation.
Reactors one through six have a pressurized system which acts as the primary boundary for the reactor coolant, plus a secondary containment building, which is designed to act as an emergency boundary in case of what is called the design leakage accident, involving failure of the primary pressure boundary. As currently planned, the two (2) ABWRs will have three boundaries, and not just two.
In addition to the normal method for transferring heat from the reactor core, there are a number of possible emergency systems. It is not yet clear exactly which emergency systems are incorporated in the Fukushima I and II nuclear power plants.
The Fukushima II, or Dai-ni (福島第二原子力発電所 – Fukushima II Nuclear Power Plant), nuclear power plant uses four (4) BWR-5 reactors with Mark II containment buildings. Fukushima II is located 11.5 kilometers (7.1 miles) south of the Fukushima I power plant
The Earthquake and the Reactors:
Fukushima I (Dai-ichi): It was reported that Reactors 1, 2, and 3 were shut down automatically during and following the earthquake. Reactors 4, 5, and 6 were undergoing maintenance, and thus were already shut down and thus should need no or at most minimal forced cooling (depending of course, on how recently the reactors had been shut down for maintenance). This means that the control rods were inserted, and the nuclear fission process stopped. The reactors stopped producing heat from nuclear fission at that point.
Fukushima II (Dai-ni): it was reported the four BWR-5 reactors at the Fukushima II nuclear power plant had been operating but were shut down automatically during the earthquake.
However, the nuclear fission products continue to generate heat, even though the reactor has been shut down. The heat is generated by nuclear decay, and can amount to as much as one percent of the reactor's average power output over the last several days. The amount of decay heat being released decreases over time, but still is significant. Typically, when a reactor is scrammed (shut down) after a long and steady power history, the decay heat released might be:
Immediately after shutdown: 6 or 7% of reactor power at which the plant was operating
One hour after shutdown: About 1.5% of average reactor power when operating
One day after shutdown: About 0.4% of average reactor power when operating
One week after shutdown: About 0.2% of average reactor power when operating
It is this decay heat which must be removed.
Loss of Coolant / Loss of Coolant Circulation:
Fukushima I: Reactor Number One (460 MW) lost coolant circulation (cause not yet published), and it appears that Reactor Number 3 (784 MW) also has lost coolant circulation. With no coolant being circulated, the decay heat cannot be removed from these reactors. Initially, the decay heat will cause the water to boil, which provides some cooling, but water must be added to keep the core covered, and thus limit core temperatures. If coolant circulation can be restored, then the reactors can be cooled. The primary coolant would pass through the core, be boiled off, and then pass through the turbines and to condensers, where the coolant steam would condense back to water and be cooled further before being circulated back through the core.
Fukushima II: Reactors One, Two, and Four are reported to have compromised cooling systems, with rising temperatures (above 100 degrees C, 212 degrees F) noted.
Until coolant circulation can be restored, there are a number of other possible solutions. One of these, venting, allows more water to boil off, thus removing more heat energy. (It requires significant amounts of energy just to boil water. It takes about 535 times as much energy to convert a mass of water to steam as it takes simply to raise the temperature of that same mass of water one degree Centigrade.) It appears system venting has been used at Fukushima I Reactors 1 and 3. There is a disadvantage with venting in that it allows primary coolant to escape. Lost coolant must be replaced in order to keep the reactor core covered. Typically the coolant is replaced by pumping water back into the plant, which requires electric power to run the pumps. Electrical power is provided by emergency diesel generators if other sources of electrical power are unavailable.
Replacing coolant requires forcing coolant back into the reactor pressure vessel against the pressure in the vessel. If the pumps being used cannot provide sufficient pressure, then the pressure in the system must be reduced, usually by venting, to a pressure low enough that the pumps can move water into the pressure vessel.
The possibility of having to vent the reactors at Fukushima II also has been announced, but so far that has not occurred.
As noted earlier, the reactor is constructed so that the reactor core is situated low in the pressure vessel, and all openings in the pressure vessel are placed near the top, thus making a well in which the reactor core sits and reducing the chances that the core will become uncovered. Uncovering of the core is highly undesirable, as air is not a very good coolant. (The specific heat, a measure of the amount of heat energy a substance can carry, of water is roughly 4000 times that of air.)
If coolant cannot be circulated, the water in the reactor pressure vessel will boil off. Boiling water consumes considerably more energy than simply heating water, and thus provides a greater cooling effect. It appears that the Fukushima I nuclear power plant has run out of distilled and purified light water normally used for cooling. In that event, any available water can be used to keep the core covered.
Sea water reportedly is being pumped into the overheating Reactors One and Three at Fukushima I. If so, this represents a last-ditch attempt to keep the reactors cool. It is by no means unheard of, but it does mean the power company operating the plants has given up any hope of recovering those plants and restoring them to service.
It appears from the reporting that coolant venting has been used for Fukushima I reactors 1 and 3. Venting releases coolant (as steam, upon depressurization) into the containment building. Whether this venting was deliberate or resulted from the lifting of pressure relief (safety) valves, or both, is unclear. Safety valves release the pressure in a closed system before the pressure reaches the point at which the sealed system might rupture. When the reactor coolant is vented to the containment building, any radioactive material in the coolant is released as well. If this material gets to the atmosphere, then it can be detected, and people in the area can be exposed to radiation. This is what happened at the Three Mile Island nuclear power plant in the United States on 28 March 1979.
In addition, venting releases gases in the coolant into the atmosphere as the pressure is released. (Think of uncapping a soda here - the carbon dioxide in the soda is released as bubbles, or more energetically if the soda has been shaken first.) These gases may be radioactive, and may include hydrogen (on which more below).
Nuclear fission has been stopped by the insertion of the reactor control rods in the plants under discussion. The effectiveness of this method of controlling the chain reaction requires the reactor structure to remain intact. In a partial or complete meltdown, the exact structure of the reactor core cannot be predicted. In order to ensure the nuclear chain reaction remains shut down, boron is introduced into the reactor core. Reportedly this is being done at Fukushima I by injecting boric acid into the primary coolant system. Boron is a strong neutron absorber, and thus acts to shut down the nuclear fission process the same way that a control rod does. Boron is considered a nuclear poison, as it poisons the nuclear fission process. The term nuclear poison does not refer to effects on humans.
Evacuation is a good precaution when venting is occurring. The area to be evacuated generally can be based on current winds, as well as on the amount of radioactivity being released.
Why is this a good approach? Basically, for a given amount of radioactivity being released, the concentration of that material is reduced as the material spreads (roughly spherical spreading). Thus, by clearing people from the immediate vicinity of the reactor venting the exposure to the population as a whole is reduced to acceptable levels.
It has been reported that iodine tablets have been issued to people in the vicinity of the Fukushima I nuclear power plant. The purpose of taking iodine tablets is to saturate the body with iodine, and thus (one hopes) reducing or eliminating the uptake of radioactive iodine (particularly long-lived radioactive I-129) from the environment. The human body concentrates iodine in the thyroid gland, which is a key organ for controlling metabolic functions.
So far, it appears the iodine tablets have been issued as a precaution.
The next time the explosion at the Fukushima I reactor number one building is shown, look closely at the video. You will see a shock wave traveling upward just before the rest of the smoke and clouds appear. Based on this, it appears that what happened was that hydrogen gas released by the venting process had gathered at the top of the containment building. Since there is air in the containment building, there also is oxygen present. With both hydrogen and oxygen present, one has an explosive mixture which needs only a spark to set it off, and that is what appears to have happened. It looks as though it was a hydrogen explosion. This does normally not happen inside the coolant system because that is a sealed system with no air present, but once that gas is vented to the containment building, it will tend to collect in the upper part of the building, and an explosion can result. (Look at the later pictures of the reactor one containment building and you will see panels from the upper half of the building have been blown off.)
Now there has also been an explosion at Fukushima I Reactor Three, and it appears this, too, was due to hydrogen accumulating in the containment building.
There will likely be subsequent similar explosions as steam and hydrogen continue to be vented from the damaged reactors.
Why this is not Chernobyl: Too many have cited the Chernobyl Reactor Four explosion and have compared the conditions there with those at the Fukushima nuclear power plants. Bad comparison.
First of all, the two reactors are considerably different construction and operation. The Chernobyl plant used four Soviet RBMK-1000 reactors, which are graphite pile reactors rather than the sealed boiling water reactors as used at the Fukushima plants. The Chernobyl reactors had a badly flawed design, which allowed the reactors to reach prompt criticality (uncontrollable criticality) when the control rods were inserted during a scram. Prompt criticality is akin to what happens in a nuclear weapon. Modern Western reactor design, such as used at Fukushima I and II, should not allow prompt criticality.
Secondly, the Chernobyl reactor was in operation at the time of the accident (I am sparing you some very pertinent technical details here), whereas the Fukushima reactors had been shut down automatically. This means that fission was continuing at Chernobyl, whereas the controlled fission reaction had stopped at Fukushima.
Thirdly, when the Chernobyl reactor was scrammed (control rods inserted rapidly), the flawed reactor design caused prompt criticality, with an estimated power surge of at least 1700 percent power (17 times rated power) in the reactor core. This means that in the center of the reactor core at Chernobyl nuclear power had reached levels well exceeding design power levels. No power surge at all has been reported in the Fukushima reactors.
Finally, the initial explosion at Chernobyl was a steam explosion, caused by the power surge. This was like a boiler explosion. It is likely the subsequent explosion at Chernobyl may have been from a hydrogen buildup. In any event, it was not a nuclear explosion. The explosions expelled about half the core material into the surrounding countryside. No such explosion, or sequence of events leading to an explosion, is being contemplated at the Fukushima I and II plants.
This sometimes is called the China Syndrome, from the fear that if the core melts, nuclear fission will continue unchecked and the core will melt its was down into the Earth with catastrophic results. Of course, the core could never actually reach China simply because the gravitational pull from the Earth at the center of the Earth is zero. In addition, as soon as the core reached the molten mantle it would no longer be in one place. And it is not even going to reach the mantle. Great science fiction, though! ;-)
First, what is all this about "core meltdown?"
If the decay heat cannot be removed from the reactor core, the core can overheat, causing damage to the fuel elements in the core. The nuclear fuel in a reactor is contained in fuel elements, which can take any of several forms. If the form is cylindrical, these are often called fuel rods. Basically, the uranium fuel is contained in a metal casing. The purpose of the casing (in some cases called fuel cladding) is to contain the radioactive fission products and decay products and keep them from being released into the coolant.
When the reactor core overheats, the fuel elements can be damaged. The first way this can occur is by warping of the elements, and thus possible opening of the seams in the fuel elements. If the heating continues, localized melting of the fuel elements may occur, along with release of fuel and fission products from the fuel element. Finally, in the final stages complete melting is possible, but not as likely.
So, what is going on at Fukushima? Most likely the fuel elements have been compromised. Such core damage cannot be corrected, only contained. The evidence for this is the detection of small amounts of Iodine (I-129 and I-131) and Cesium 137 (Ce-137). These are fission products, and their detection outside the plant would seem to indicate that fuel element damage has occurred. The amount of damage is unknown yet, but clearly some fission products have been released.
Does this indicate a complete "core meltdown?"
No, it does not. It does indicate that there has been some core damage however. Furthermore, it seems as though, given the low levels being reported, the fission products most likely were released during venting (see section above on venting).
Furthermore, the levels being reported do not yet indicate the primary coolant system has been breached.
It is not possible yet to foresee how the nuclear accidents at Fukushima I and II will progress. It seems certain that Reactors One and Three will not be placed back in service very quickly, if at all. At the very least it seems likely the current cores will have to be replaced in Reactor One, and possibly in Reactor Three as well. That will take time. Furthermore, the Reactor One containment building will have to be rebuilt. It is quite possible that the reactor may have been damaged beyond repair.
The status, and thus the future, of Reactor Three is less clear.
In addition, it seems quite likely the existing safety systems will be reviewed extensively. In particular, the reasons for the failure of back-up safety systems need to be determined, the systems need to be redesigned, and possibly upgraded or added to, in order to preclude a recurrence and to enhance reliability.
Clearly natural circulation reactors, plants in which the reactor coolant is circulated as the result of being heated, with no circulation pumps required, offer a good solution to the problem of coolant circulation under emergency conditions.
Finally, a thorough review of nuclear safety studies and accident analyses likely will be undertaken. Do the current analyses adequately and accurately reflect possible accidents, whether man-made or nature-caused? If not, what must be done to make them adequate?
My thanks to Steve B. for the following thoughtful comments and suggestions.
1. As you clearly stated the events causing the failures at Fukushima are a worst-case scenario. This is as bad as it gets from an engineering design perspective. Based on the limited information it is almost certain the cooling loops suffered major failure (brittle fracture of the coolant loop welds), not just a loss of electrical power. The important thing to share is that these plants and the backup systems including the containment structure were DESIGNED for even these extremely unlikely failures. The venting, the reports of pumping sea water into the containment structure, even the hydrogen explosion, are all part of the design based accident scenarios and procedures were already in place to respond to this type of an accident.
Reply: I thoroughly agree with the strong likelihood of brittle fracture of materials and/or stress fracturing of welds in the primary coolant system, given the events reported so far. I have tried not to speculate, though, and so have tried to use only what information has been reported to date. I also have tried to avoid getting too technical in my descriptions.
2. This is a bit speculative but the reports of Cesium-137 and Iodine should confirm the fuel assemblies are compromised. These fission products would not be present in the amounts reported unless the core was significantly damaged. The amount of hydrogen is also indicative of fuel element failure. But again, this is expected in this type of accident. The media likes the term “Meltdown” but the reality is that the fuel assemblies are severely damaged but they are still standing in the core.
Reply: Agree that the reports of detection of Ce-137 and I-131 or I-129 are indicative of core damage leading to the release of fission products. This was mentioned in the section on meltdown, but perhaps not strongly enough.
3. I only see 2 complications in all of this. First, the hydrogen should have been vented from the containment building before it reached explosive levels. This is part of the emergency procedure and unless they missed it or the instrumentation failed, a senior manager would be required to override the automatic release. My guess (and it’s a guess) is that the instrumentation failed in the extreme environment of the accident. The Japanese don’t have a culture where they would miss this or override the automatic venting. Never the less, this should have been anticipated and for the explosion to occur not only once by twice, is unfortunate. Second, there are some reports that the containment structure may be compromised but nothing confirmed. If this is the case it would be surprising to me but not impossible. This would be the only point of concern I have with the entire series of events. Whatever the case, the industry will receive very valuable information from this event.
Reply: After writing the essay and publishing it, I learned that the electrical switchboards are in basement areas beneath the power plants (New York Times reporting). These areas were flooded during the tsunami, and may well have affected instrumentation and control circuitry as well. These areas may still be flooded, as discussed in the attached update. Reactor meltdown was discussed in the original article, and has been mentioned again in the attached update.
Concur on the need to vent hydrogen from the containment building, but in the scramble that may have been missed. Tokyo Electric Power Company (TEPCO) has a spotty record with regard to nuclear plant operation, unfortunately. What does seem clear, however, is that the containment building has functioned as designed during the hydrogen explosion, with the upper half of the building's panels blowing away cleanly, leaving the lower half panels in place, as the photographs in the attached document show.
4. The 2 damaged units will likely never run again because of their age and the cost to cure. I repeatedly hear exaggerated reports about the dire situation with these plants and how this disaster is just another example of the dangers of nuclear power. What the critics fail to report is that not one person suffered any ill affects from Three Mile Island or from these 2 severely damaged plants. How many men died in 2010 from coal mining accidents? Where will they get their power if these 3 options are removed. There isn’t enough acreage on planet earth to provide the power needs from solar and wind.
Reply: As discussed in the attached update, it seems quite likely that Reactors One, Two, and Three now have all suffered core damage and sea water injection which will preclude their ever returning to service. In addition, it seems the fire at Reactor Four (which reportedly was in cold shutdown for maintenance) started in the spent fuel assemblies. That reporting is somewhat confused and jumbled. With regard to personnel hazards, right now it seems you are correct. The iodine released has been reported as I-131, which is relatively short-lived. Some have ranted on about the radiation levels being reported, much as they did after TMI. Most people are unaware of the naturally occurring background radiation to which we are all exposed (and which may contribute to evolution), and that, too has been addressed in the attached update.
This is an effort to keep up with a rapidly evolving situation. The attached represents my best estimate of the situation as of this evening, but this casualty is still in progress. Just what happens, just how all this will play out, remains to be seen.
Global Food Prices at All Time Highs
Prices could even rise further according to the UN
Consider : this is a reminder of how fragile our ecosystem and financial systems really are. We would do well to consider the effects
from even minor changes;
The widespread unrest in the Middle East, for example, is indeed fueled in part by these and other genuine grievances.
In drought years, the Amazon region changes from being a net absorber of carbon dioxide into a net emitter.
The 2005 drought had been termed a "one in a century" event. Researchers report in the journal Science that the 2010 drought was more widespread than in 2005 - the last big one - with more trees probably lost.
Last year's drought in the Amazon raises concerns about the region's capacity to continue absorbing carbon dioxide, scientists say.
NASA scientists discover Antimatter created in Thunderstorms
Even though the juggernaught of our oil/coal based civilization continues down the current myopic path there are a plethora of possibilities in our yet underappreciated Universe. Does the choice have to be between pouring trillions of tons of CO2 into the atmosphere or waiting for a puff of wind or a sunny day?
Humanity has always managed to survive by its wits. Why should today be any different?
R&D is the key.
The Gulf of Mexico oil spill continues to be an issue well into 2011
Please read the following considerations:
While the investigations of the blowout and final capping of the Macondo Well in the Gulf of Mexico continue, it seems there are some immediate questions which should be addressed. Among these are:
Earlier, under the section on combating the oil leak, we asked what seemed a rather obvious question: Why was the far more difficult seal against the riser pipe chosen as opposed to using the upper blowout preventer valve (BOP) flange for both sealing surface and clamping surface?
After almost three months (86 days), the leak finally was stopped by doing just that – connecting a pipe section (“Dutchman”) to the upper end of the blowout preventer (BOP) stack, and then connecting another BOP to the Dutchman.
• The equipment used was commercially available, and had been all along. Why was this solution not pursued at the outset?
• Prior to issuing permits for future wells, why not require the following equipment be available both prior to commencing and during drilling:
A fully operational blowout preventer (BOP) valve stack (of three valves) be used on the well. This BOP should have current maintenance and be properly tested prior to use.
A clear bolting flange above the blowout preventer (BOP) valve stack (of three valves) for attaching a Dutchman in case of emergency;
A Dutchman available and held in reserve until the well has been completed and hooked up; and
A fully tested and properly maintained spare BOP valve stack (of three valves) available and held in reserve until the well has been completed and hooked up.
Elseswhere in the world it is a requirement for a relief well to be drilled in parallel with the main drilling operation.
The connection flange characteristics (dimensions, materials, bolting ring, fasteners, etc.) could be standardized within the industry. Such an arrangement would allow faster reaction to future blowouts, enabling the following sequence of actions in the event of a failure of the BOP to shut off a blowout:
• Cutting the drilling pipe just above the flange,
• Installing the standby Dutchman and BOP valve
stack above the blowout point,
• Thus shutting off the oil flow until
• The relief well finally can be completed to seal the well.
Lars P. Hanson, Director, The Global Concern
"As Arctic melts, U.S. ill-positioned to tap resources" Washington Post, January, 2011
Listen to the president of Global Concern address the China Policy debate with regards to climate change
US Assistant Secretary of Defense Wallace Gregson; Keynote speaker, US Senator The Honorable Chris Coons; Introduction Panalists addressing this question are:
James Fellows; The Atlantic Monthly
Dr. Joseph Nye; Harvard University
Michael Chase; strategy and policy Naval War College
Watch the event in its entirety LINK
Read also press coverage from the Wall Street Journal, Reuters, VoA, Washington Times, and several Chinese outlets
Be mindful that the Crisis in the Gulf of Mexico also overshadows June 2010 being globally the hottest month in recorded history and the soaring temperatures in Russia in July never before recorded
Goals Of The Global Concern, Inc.
The Global Concern will:
1. Bring together those elements of the power industry and environmental community interested in finding a common practical long-term replacement of carbon-based energy systems.
2. Explore the best and most practical solutions to serious reduction of CO2, including wind, solar and nuclear, with the focus being on nuclear.
3. Address all the issues related to further development of nuclear power, including waste, proliferation, security, and public hazards.
4. Provide an education and communication program to help bring together those elements in the power industry and environmental movement who are interested in moving forward with a jointly agreed upon approach.
5. Provide a general education program for the public to help the transition away from carbon-based energy systems.
6. Help the search for technological answers that will address the concerns of the power industry and environmentalists.
Past Concerns and Suggestions :
Reforestation Reforestation Reforestation
Be sure to read our paper on Reforestation and Global Warming as a National Security Issue
Environmental Crisis in the Gulf of Mexico
The ongoing crisis in the Gulf of Mexico continues to raise questions. What follows is a list of just some of the more immediate questions.
Earlier, under the section on combating the oil leak, we asked what seemed to us a rather obvious question:
Why was the more difficult seal against the riser pipe chosen as opposed to using the upper blowout preventer valve (BOP) flange for both sealing surface and clamping surface?
After 86 days, the leak finally was stopped by doing just that – connecting a pipe section (“Dutchman”) to the upper end of the blowout preventer (BOP) stack, and then connecting another BOP to the Dutchman.
· The equipment used was, and has been, commercially available.
Why was this solution not pursued at the outset?
· For permits for future wells, why not require the following prior to commencing drilling:
Ø A fully operational blowout preventer (BOP) valve stack (of three valves) be used on the well;
Ø A clear bolting flange above the blowout preventer (BOP) valve stack (of three valves) for attaching a Dutchman in case of emergency;
Ø A Dutchman available and held in reserve until the well has been completed and hooked up; and
Ø A spare BOP valve stack (of three valves) available and held in reserve until the well has been completed and hooked up.
Ø A relief well be drilled in parallel with the main drilling operation.
The connection flange characteristics (dimensions, materials, etc.) should be standardized within the industry. Such an arrangement would allow faster reaction to future blowouts, enabling the following sequence of actions in the event of a failure of the BOP to shut off a blowout:
· Cutting the drilling pipe just above the flange,
· Installing the standby Dutchman and BOP valve stack above the blowout point,
· Thus shutting off the oil flow until
· The relief well finally can be completed to seal the well.
Also visit us at www.meltingworld.org
'Melting World', at last a site that cares with flair!
Environmental Crisis in the Gulf of Mexico
As do most observers, Global Concern, Inc. has questions of immediate import. (2010)
Many of these questions stem from the paucity of credible and coherent information being released in press reports, public relations efforts, advertising, etc.
Why is information regarding the crisis in the gulf not being presented clearly, coherently, and more completely?
Why are there not regular news conferences with regular updates on:
o Specific leak source or sources
o Leak rate (including methodology for determining the rate)
N.B.: The current practice of the various parties ascribing leak rate estimates to other parties simply is not an acceptable “solution” to the problem of estimating leak rate, and needs to be halted.
o Spill extent to date
o N.B.: A “spill” has finite extent (such as the contents of an oil tanker) whereas a leak has no finite extent as it is a continuing stream. Currently there is a significant and continuing leak of oil (what used to be called a “gusher” on land) into the Gulf of Mexico.
o Affected areas with countermeasures
o Affected areas without countermeasures
o Plans for countermeasures in potentially affected areas (timing, methods, availability, etc.)
o Effectiveness of countermeasures in affected areas
o Resources available, and from where
o Resources required, and possible sources
· Damage claims
o Claims to date
o Payments to date
o Average backlog (delay in payments)
What is required to make such information regularly available?
What is the delay in making such information regularly available?
Combating the oil leak
It would seem the problems fall into two main categories:
· Stopping the flow of oil from the damaged well, and
· Neutralizing the environmental impact of the oil already released into the Gulf of Mexico
Who is in charge of:
· Overall response the oil leak,
· Technological and engineering efforts directed at stopping the leak,
· Technological and engineering efforts to mitigate the environmental impact, and
· Marshaling resources (including expertise) in this effort?
How is (or should) the available information (see previous section on information) be used to examine the problems being caused and to propose solutions?
What group or groups have been empaneled to work on this problem? What are their qualifications, who is funding them, etc.?
What alternative solutions are possible?
Are the possible solutions being considered being unduly limited by concerns for saving the well rather than just stopping the leak at all costs?
For instance, the time lost (months) waiting for a relief well to be drilled may stem directly from the premise that any acceptable solution preferably should leave the well usable in the future.
What is the basis for the estimate that cutting the riser pipe would only increase the flow by 20%? Who made this calculation, and on what was it based?
What arguments were made for and against cutting the riser pipe? What level of assurance was there that doing so would enable a sound technical solution?
Who reviewed and commented on the proposed technical solution to be tried once the riser pipe had been cut? Why was the more difficult seal against the riser pipe chosen as opposed to using the upper blowout preventer valve (BOP) flange for both sealing surface and clamping surface? Who, outside of BP, reviewed and commented on the proposed technical solution?
Consider recent responses to the question even from our government federal representative in this matter National Incident Commander Admiral Allen.
Certainly all parties share an interest in stopping the flow, though perhaps for quite different reasons. Are claims of convergent or even identical goals really credible?
Is it not possible that divergent interests, differing primary concerns may well be impeding progress in finding a solution to stopping the spill?
Why were safety requirements employed by other nations not required prior to granting approval for this (or any other undersea) well in United States (U.S.) coastal waters? Such practices include:
· Requiring the simultaneous drilling of a relief well along with the main well (which eliminates the delay in drilling a relief well),
· Requiring the use of a BOP which can be remotely activated (generally acoustically), and
· Requiring thorough safety testing and monitoring.
Why were environmental protection plans not properly reviewed prior to granting approval for the well?
What other permits have been issued without adequate review? Should not all current drilling permits be suspended until the safety plans and environmental impact statements for each and every permit request have been reviewed and approved?
With the danger of such a disaster could not a relief well already have been dug and been in place?
How were the results of Project “Deep Spill” (http://www.mms.gov/tarprojects/377.htm) used in formulating the safety plan and safety measures for undersea drilling permits issued since 2005?
Why has there been such a disproportionate investment in undersea oil well drilling techniques as opposed to undersea oil well safety technology in the three decades since the Ixtoc oil leak in the Gulf of Mexico in 1979? Why apparently have no new safety techniques been developed in the three decades since the 1979 Ixtoc oil leak?
Why are all parties “behind the power curve” in combating this disaster?
Had this oil leak disaster been described accurately from the outset and had the sole aim been to end the gusher, regardless of the cost, regardless of the destruction of equipment and any potential for the well ever to siphon oil again, could the industry's finest engineers have devised a practical alternative plan?
It seems what is needed are three key people:
· Someone charged solely with stopping the current massive gush of oil and nothing more,
· Someone charged only with mitigating and remediating the environmental impact of the undersea oil gusher, and
· Someone charged with coordinating and marshaling resources required by the first two people.
The last question:
Can we please have an alternative plan now?
The time to act is now. (In fact, we already are late.)
It is hurricane season.
We need a plan for the worst-case scenario.
Please let us not also lose sight of the big picture as well. As Christopher Lawrence President of the Dupuy Institute said. "Oil is a finite resource why are we burning it for so many redundant reasons, even in the production of electricity?"
I firmly believe the U.S. Government should now run the operation (paid for from using the assets of those companies responsible for creating this undersea gusher) and should collect and coordinate the efforts of those professionals in the U.S. and international community with the experience and expertise necessary to immediately stop the gusher at all costs.
Gary S. Schofield
Lars P. Hanson
The Global Concern, Inc.
Even though the juggernaught of our oil/coal based civilization continues down the current myopic path there are a plethora of possibilities in our yet underappreciated Universe. Does the choice have to be between pouring trillions of tons of CO2 into the atmosphere or waiting for a puff of wind or a sunny day?
Humanity has always managed to survive by its wits. Why should today be any different?
R&D is the key.
Gary S. Schofield