Dear Akio –
This photo is quite sobering. As you know the pool at Unit No. 4 contains 1,538 fuel assemblies, including a full core that was freshly discharged prior to the accident.
As I might have mentioned, based on data from the U.S. Department of Energy, a spent fuel assembly from a typical boiling water reactor contains about 30,181 curies ( ~1.1E+15 becquerels) of long-lived radioactivity. So the Unit No. 4 pool contains roughly 49 million curies (~1.8E+18 Bq), of which about 40 percent if Cs-137. (Source: U.S. Department of Energy, Final Environmental Impact Statement, for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada, 2002, Appendix A, Tables A-7, A-8, A-9, A-10, BWR/ Burn up = 36,600 MWd/MTHM, enrichment = 3.03 percent, decay time = 23 years.)
As you know, the risk of yet another highly destructive earthquake occurring even closer to the Fukushima reactors has increased, according to the European Geosciences Union. This is particularly worrisome for Daiichi’s structurally damaged spent fuel pool at Reactor No. 4 sitting 100 feet above ground, exposed to the elements. Drainage of water from this pool, resulting from another quake could trigger a catastrophic radiological fire involving about eight times more radioactive cesium than released at Chernobyl.
I thank you very much for your comments on the photo of the Fukushima reactor unit 4.
You and Dr. Gordon Edwards of Canada used the same word, “sobering,” when you saw the photo.
My great concern is what Dr. Hans-Peter Durr, former Director of Astrophysics at the Max Planck Institute in Germany told me ten months ago. Japan had not yet admitted the core had melted down, but Hans-Peter knew that Fukushima was close to bringing us beyond the limits of our scientific knowledge and strongly suggested that Japan’s government should create an independent assessment team to bring the best minds of the nuclear scientists and structural engineers to seek the best solution. In such circumstances, Dr. Edwards accurately said, “It is important to seek the advice of experts who are genuinely independent having no conflict of interest and no need to save face. National pride makes it understandably difficult to seek help from outside, but sometimes it is the best thing to do.”
I have to admit that my country’s strong national pride makes it unrealistic to see an independent assessment team form soon enough, and so I now turn to rely on U.S. leadership to act out of the need for common, global security before a strong earthquake comes in the near future. If the reactor unit 4 building collapses, we will face a global environmental and human catastrophe larger than ever before.
I ask you and your colleagues to help bring this to the attention of U.S. senators and representatives so we may overcome the political hurdles and find a constructive solution.