Thursday, February 14, 2013

Severe Solar Storm Safety Issues

The Davistown Museum has just released: A press release on the current state of readiness concerning severe solar storms and nuclear safety An open letter to the editor regarding severe solar storms and potential nuclear safety issues A request for a public information update and action regarding the impact of a severe solar storm on nuclear power plants

Thursday, January 26, 2012

FrontLine's Nuclear Aftershocks program

The following comments were sent to FrontLine's editors.

I would like to compliment FrontLine on the generally excellent show Nuclear Aftershocks on the Fukushima Daiichi accident and nuclear power generation in general. But, I would also like to point out a glaring error in your report and comment on several important pieces of information that should have been included. I would also be interested in a phone chat with a FrontLine editor once you receive and review my publication Fukushima Daiichi: Nuclear Information Handbook.

• The incorrect information: The source term (total radiation release) from the accident was much greater than 10% of the Chernobyl release. Even TEPCO acknowledges a release of 50% or higher. In the Nuclear Information Handbook the model of release estimates is too high given the rapid and successful cooling of the seven multiple interlocking meltdown events (MIME) since the publication of the book in June. Given that ±4,400 fuel assemblies were involved in these 7 accidents and the huge quantity of radioactive water released by the successful cooling efforts, the source term will at least equal and probably exceed that of the Chernobyl accident.
• Several important facts not included in the report:
o Luckily, prevailing winds brought ±90% of airborne emissions over the Pacific Ocean. Why were no graphics, which are readily available online, included to illustrate the “luck of the Irish”, i.e. that most fallout went in the direction of the Great Pacific Garbage Patch?
o While interviewing David Lockbaum, why were his observations, reported in detail in the New York Times, on the design flaws of these ancient General Electric (GE) design boiling water reactors not reported? In particular, there was no mention of the important design flaw of the location of the spent fuel pool adjacent to and slightly above the reactor vessel. You showed graphic images of the destruction of the spent fuel pools without mentioning the location or pointing out that the largest radiation release occurred when the spent fuel pool of unit 4 (which had no fuel in its reactor vessel) exploded.
o Why no mention of the Plymouth, MA and VT Yankee reactors and 33 other US reactors with similar extraordinary design flaws, both of which put residents of the Boston area at a greater risk of a similar accident, which might occur from causes other than a tsunami?
Thank you for an otherwise excellent report. The time limitations of your program obviously are a problem. Is there any chance you might do another FrontLine special on the design flaws of GE sponsored boiling water reactors, not to mention the safety issues of over 100 aging nuclear reactors operating for another 20 years?

Thursday, November 10, 2011


Hiroko Tabuchi reports in The New York Times November 3, 2011 that “…the plant’s owner admitted for the first time that fuel deep inside three stricken reactors was probably continuing to experience bursts of fission. … The disclosures raise startling questions about how much remains uncertain at the plant… The presence of xenon 135 in particular, which has a half-life of just nine hours, seemed to indicate that fission took place very recently. … The jumble of material and conditions in the damaged reactors seem very unlikely to be able to produce sustained fission, but some experts have long suspected intermittent criticalities. In other accidents, nuclear material has burst into fission, but the released energy then re-arranges the damaged fuel into a configuration that no longer support (sic) fission. Gradually, the material re-forms in a way to support another burst. …Junichi Matsumoto, a Tokyo Electric spokesman, acknowledged episodes of fission, saying… ‘There is a possibility that certain conditions came together temporarily that were conducive to re-criticality,’ and that the measurements indicated a burst that occurred at a slightly higher rate than prior cases. ‘It’s not that we’ve had zero fission until now,’ Mr. Matsumoto said. ‘But at this point, we do not think there is a large-scale and self-sustained re-criticality.’ … Hiroaki Koide, assistant professor at Kyoto University’s Research Reactor Institute… [said] if episodes of fission at Fukushima were confirmed… ‘our entire understanding of nuclear safety would be turned on its head.’”

The IAEA issued a follow-up status report the day after the Times article appeared, indicating a re-criticality event was highly unlikely ( The IAEA update notes the following:
“Based on further analysis, Japanese authorities have concluded that the xenon concentrations are not due to a criticality event but rather from the spontaneous fission of curium-242 and 244. (Spontaneous fission is a form of radioactive decay that does not involve chain reactions and is characteristic of very heavy isotopes. Spontaneous fission occurs in low levels in all nuclear reactors.)
This conclusion is based on three key factors outlined and discussed in the report:
• The inventory of Cm-242 and Cm-244 was calculated as was the concentration of Xe-135, resulting from the spontaneous fission of Cm-242 and Cm-244. If nuclear fission of the reactor's uranium fuel were occurring, at the lowest possible level, the levels of xenon detected would be several orders of magnitude higher than those measured. Current levels of xenon are consistent with those that would be generated by spontaneous fission of Cm-242 and Cm-244;
• If the core had been experiencing a criticality event, the injection of boron water should have stopped the criticality and terminated the generation of xenon. However, the xenon levels were not influenced by injection of boron water into the core; and
• If the core was undergoing a criticality event the temperature and pressure readings would be expected to rise as the event would increase heat production within the core. However, the temperature and pressure levels have not undergone any significant increases either before or after xenon were detected, indicating that no criticality event is occurring.”
The issue of intermittent criticalities could certainly be clarified if TEPCO and NISA would install real time monitors at each of the four reactors that would provide minute by minute, and thus hourly data on airborne emissions. Any re-criticality incidents would create enough heat to cause increased steam emissions, which would be much more obvious and easy to monitor than the micro-emissions in the spontaneous emission of curium-242 and -244. The IAEA status report is probably correct in that no re-criticality has occurred, but it’s certainly interesting that there remains a potential for re-criticality until such time as the molten fuel actually is removed from the reactor vessels.

Further information on the re-criticality issue can be accessed at:

Also in the news is the new estimate of the time period needed to decommission the four reactors at Fukushima Daiichi. A CNN report by Junko Ogura (Tuesday November 1, 2011) quotes the Japanese Atomic Energy Commission as stating “Decommissioning… will likely take more than 30 years to complete [following cold shutdown, which is expected by the end of the year.]… Removal of debris – or nuclear fuel – should begin by the end of 2021.”

Also of note is a recent headline in Yahoo! News (October 24, 2011; “Up to 20 million tons of debris from Japan’s tsunami moving toward Hawaii”. While the Yahoo! News article provides a graphic illustration of when the debris is expected to reach the west coast, within three years or sooner, there was no mention that this debris field is likely to be highly contaminated with fallout resulting from the prevailing winds depositing Fukushima-derived radioactive contamination on the tsunami debris. Also of continuing interest is that significant hot particle fallout would accompany any contamination of the tsunami debris. For information on the nature of hot particle nuclear accident-derived contamination and its presence in the Chernobyl plumes please refer to our publication Fukushima Daiichi: Nuclear Information Handbook. See page 77 for the definition as well as the bibliographic citations of the literature pertaining to hot particle fallout from the Chernobyl accident on pages 229-232.

Thursday, October 27, 2011

Lessons learned and questions to be asked pertaining to American boiling water reactor (and pressurized water reactor) accidents

The accidents at Fukushima Daiichi represent a new paradigm in nuclear power plant accidents, where in contrast to the meltdown at Three Mile Island, emissions from melted fuel assemblies were not contained within a pressurized vessel. Given the large numbers of boiling water reactors still operating in the United States as well as in other nations, and the high risk of operating these reactors without a tertiary power backup system, failure of the primary electrical system (as happened during the recent earthquake in the Maryland area) followed by failure of the backup diesel generators is now a much more likely possible scenario than was previously recognized before the accident in Japan. Considering the key role that first responders utilizing traditional fire equipment played in mitigating the impact of the accident in Japan, all community first responders in the area of any nuclear power plant should now be training in the methodologies necessary to provide large quantities of water to cool melted fuel assemblies in an emergency situation where primary and secondary containment structures and electrical cooling capacities have been damaged or destroyed.

Question 1: are the Plymouth, Kingston, and Duxbury fire departments aware that in the event of a similar accident at the Plymouth, MA, boiling water reactor they may be called to provide services similar to those executed by the fire companies in Japan, who may have saved the day in the several weeks following the Fukushima Daiichi disaster? Are there any fire departments anywhere in the US that are preparing for this kind of emergency situation?

Question 2: With respect to the large quantities of water pumped onto the melted fuel assemblies in Japan, wouldn’t it be practical to surround each American water reactor with a series of dikes that would prevent runoff of highly contaminated accident-derived cooling water? What are the contingency plans of the US NRC, which was very proactive in proposing emergency responses to the Japan accident, for US reactors to recover highly radioactive water used to cool melted fuel assemblies during an accident?

Question 3: A lingering question pertaining to liability for damages resulting from the accident in Japan remains unresolved. General Electric’s blatantly incompetent boiling water design, discussed in the first chapter of the Fukushima Daiichi: Nuclear Information Handbook, provides an obvious legal basis for significant compensation by GE to the many communities impacted by the accident in Japan (+/- 20 billion US dollars)? Why has GE been exempt from any damage claims with respect to the vulnerability of their boiling water reactors to meltdown accidents? Given the large number of GE designed boiling water reactors in the US and the likely possibility of future fuel meltdown accidents, why should GE not set aside +/- 100 billion dollars in an escrow account to compensate future victims of a design flaw-related nuclear accident in the US?

Reduced airborne emissions

In the Wall Street Journal of October 18, 2011, Mitsuru Obe reported that TEPCO estimates airborne radiation releases are now down to 100 million Bq/hr and that steam leakage has essentially ended because all damaged reactor temperatures have recently fallen below 100 degrees Celsius. TEPCO, the Japanese government, and local first responders can be congratulated on the successful mitigation of what could have been a much larger release of accident-derived emissions considering that three reactor cores and four spent fuel pools containing 4,368 fuel assemblies suffered simultaneous meltdowns. Given the approximately 43 million curies of radiocesium in these assemblies at risk of being released in this series of accidents, the successful cooling of the fuel assemblies that melted during this series of accidents is a major step in preventing further airborne releases. Three important issues remain to be documented and resolved.
• What is the ongoing rate of emissions of water-borne discharges from the continuing efforts to cool the melted fuel assemblies and maintain temperature below the boiling point of water?
• What proportion of these water-borne discharges have been recovered, and what is the amount of radiocesium and other isotopes that the radioactive waste water filters have successfully captured?
• What is the current estimate of the total source term of the Fukushima Daiichi MIME (multiple interlocking meltdown event), including both airborne and water-borne emissions?
Since there are seven accident point sources at Fukushima Daiichi, will TEPCO and NISA be more forthcoming and issue more detailed reports on airborne emissions from all seven accident sites as well as further information about the water-borne contaminants generated at each of the four reactor sites, which will need continual cooling indefinitely?

Thursday, October 6, 2011

NRC letter from Edward Markey

I urge you to read this interesting letter sent to the NRC by Edward Markey about the challenges of hurricanes and other extreme weather to nuclear power plants.

Thursday, September 1, 2011

Catastrophe Pie Charts

The July 26 – August 12 accident emission rate estimate of 200 million Bq/hr of gross radiocesium can be contrasted with the radiocesium soil contamination survey, also released on August 29th. Gross radiocesium levels approaching 30 million Bq/meter squared in the town of Okuma provide a startling juxtaposition with the current accident emissions rate estimate. No similar levels of Chernobyl-derived radiocesium contamination were noted in 2001 when Chernobyl Fallout Data 1986 – 2001 was published. Much of this data is reproduced in Section 8 of the Davistown Museum’s Nuclear Information Handbook ( It should be noted that the Fukushima Daiichi accident source term (release inventory), probably significantly larger than the Chernobyl source term, is only one among thousands of slices of the Anthropogenic Radioactivity Pie Chart. This pie chart includes thousands of point sources ranging from weapons testing cumulative fallout (+/- 3500 Bq/square meter Cs-137) to Savannah River, the Russian Arctic, etc. The Anthropogenic Radioactivity Pie Chart is, in turn, only one slice of the Biocatastrophe Pie Chart. ( For a survey of the ongoing impact of the human ecology soap opera, blog readers are invited to visit and buy a Kindle version of the three volume Phenomenology of Biocatastrophe series and take it to the beach. Both our Fukushima Daiichi Nuclear Information Handbook and our 5 volume survey of Hand Tools in History are also available on