Major seismic aftershock at Fukushima Daiichi Unit 4 could unleash 8 times Chernobyl's Cs-137

Robert Alvarez of the Institute for Policy Studies released the following message today:

"Here is a recent photo [left] of the Unit No. 4 at the Fukushima-Daichi nuclear ruins provided by Akio Matsumura. It is quite sobering.

The pool at Unit No. 4 contains 1,538 fuel assemblies, including a full core that was freshly discharged prior to the accident. 

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+12 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 is 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.)

The risk of yet another highly destructive earthquake occurring even closer to the Fukushima reactors has increased, according to the European Geosciences Union.http://blogs.wsj.com/japanrealtime/2012/02/15/could-fukushima-daiichi-be-ground-zero-for-the-next-big-one/ 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."

In 2011, Alvarez published a report on the risks of high-level radioactive waste pool storage in the U.S., in light of the Fukushima Daiichi Nuclear Catastrophe.

In 2003, Alvarez et al. published a report on the risks of a high-level radioactive waste pool fire, in light of the 9/11 attacks. This study was largely to entirely backed up by a 2005 National Academies of Science study.

Beyond Nuclear has also published a backgrounder on the risks of General Electric Mark I Boiling Water Reactor high-level radioactive waste pool storage (see entry below), as part of its Freeze Our Fukushimas campaign. The U.S. has 23 operating GE BWR Mark Is, each with pools more packed with waste than Fukushima Daiichi Unit 4's; in addition, the pool at a permanently shut Mark I, Millstone Unit 1 in Connecticut, is still in use.