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

Recent photo of the ruins of Fukushima Daiichi Unit 4. Note workers, wearing white protective suits, near the pool's surface (just beneath the topmost girders).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.