Jan 6, 2012 Comments Off on NRC: Exelon reactors designed to leak?
Responding to a petition by watchdog groups, the Nuclear Regulatory Commission has agreed to review a range of safety issues for GE Mark 1 reactors — the type that melted down at Fukushima last year, four of which are operated by Exelon in Illinois.
It’s a rare event, said Dave Kraft of the Nuclear Energy Information Service. He said such petitions, the only avenue for the public to raise nuclear safety concerns, are “routinely disregarded” by NRC.
The NRC rejected the groups’ request that all Fukushima-style reactors in the U.S. be shut down immediately, as well as a request for public safety hearings in the emergency planning zones for each reactor.
But the agency will review design flaws of the Mark 1, agreeing that it “dramatically failed” to prevent radiation releases at Fukushima.
The agency will consider revoking preapproval for ventilation systems installed at many Mark 1’s after it became apparent that the containment structure could fail under high pressure. The ventilation systems “deliberately defeat the purpose of a leak-tight container in order to save it from failure,” the petitioners maintained.
“Their first line of defense is to protect the reactor by irradiating the countryside,” Kraft said, citing an expert who compares it to “a screendoor on a submarine.”
The NRC will consider ordering installation of backup emergency power systems to cool nuclear waste pools, which in the Mark 1 are suspended above the reactor and outside the containment structure. The agency agreed to consider ordering expedited removal of waste from pools to dry casks.
Illinois flood plains
Exelon reactors in Illinois including at Dresden and Quad Cities are among those with the largest accumulations of highly-irradiated spent fuel pools in the nation, according to a recent report (covered here), which notes that as cooling systems are “overtaxed,” heavy accumulation of waste increases risks from mechanical or human failure as well as natural disaster.
The NRC also specifically agreed to review concerns over Illinois reactors that are sited in flood plains.