Study: Fukushima storage pool was vulnerable to aftershocks

[kristopher]

Study: Fukushima storage pool was vulnerable to aftershocks
BY TATSUYUKI KOBORI STAFF WRITER
2011/10/16

Aftershocks of the March 11 Great East Japan Earthquake could have significantly worsened the crisis at the Fukushima No. 1 nuclear plant in the weeks after the disaster, according to a government simulation.
The storage pool in the No. 4 reactor, which had its building's roof blown off after a hydrogen explosion on March 15, was vulnerable to an aftershock and might have started leaking radioactivity within three hours of a hypothetical aftershock, the study found.
Tokyo Electric Power Co., operator of the plant, initially said the pool was sturdy enough to withstand aftershocks, but Japan Nuclear Energy Safety Organization analysis completed at the end of June but only released on Oct. 14 says radioactive substances could have been discharged 2.3 hours after a temblor knocked out the pool's cooling system.
The simulation, part of a 300-page report commissioned by Japan's Nuclear and Industrial Safety Agency, was based on the assumption that the pool would lose cooling water if it was cracked by an aftershock. After the uncooled fuel rods reached 900 degrees and damaged their casings, radioactive leaks would have begun, according to the study.

It said the fuel rods would have begun melting...

http://www.asahi.com/english/TKY201110150305.html