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.