[Reader-list] Japan’s Reactor Risk Foretold 20 Years Ago in U.S. Agency Report

[Jeebesh]

Japan’s Reactor Risk Foretold 20 Years Ago in U.S. Agency Report

By Makiko Kitamura and Maki Shiraki - Mar 16, 2011 7:56 AM GMT+0530
http://www.bloomberg.com/news/2011-03-16/japan-s-reactor-risk-foretold-20-years-ago-in-u-s-nuclear-agency-s-report.html

The earthquake disaster at the Fukushima nuclear power plant north of  
Tokyo was foretold in a report published two decades ago by a U.S.  
regulatory agency.

In a 1990 report, the U.S. Nuclear Regulatory Commission, an  
independent agency responsible for ensuring the safety of the  
country’s power plants, identified earthquake-induced diesel generator  
failure and power outage leading to failure of cooling systems as one  
of the “most likely causes” of nuclear accidents from an external event.

While the report was cited in a 2004 statement by Japan’s Nuclear and  
Industrial Safety Agency, adequate measures to address the risk were  
not taken by Tokyo Electric Power Co., which operates the plant in  
Fukushima prefecture, said Jun Tateno, a former researcher at the  
Japan Atomic Energy Agency and professor at Chuo University.

“It’s questionable whether Tokyo Electric really studied the risks  
outlined in the report,” Tateno said in an interview. “That they  
weren’t prepared for a once in a thousand year occurrence will not go  
over as an acceptable excuse.”

Hajime Motojuku, a spokesman for Tokyo Electric, said today he  
couldn’t immediately confirm whether or not the company was aware of  
the report.

The 40-year-old Fukushima plant was hit by Japan’s strongest  
earthquake on record March 11 only to have its power and cooling  
systems knocked out by the 7-meter (23-foot) tsunami that followed.

Radioactive Steam

Lacking power to cool reactors, engineers vented radioactive steam to  
release pressure, leading to as many as four explosions that blew out  
containment walls at the plant 135 miles (220 kilometers) north of the  
capital.

While the appropriate measures that should have been implemented are  
still to be evaluated, more extensive waterproofing of the underground  
portion of the reactor could have helped prevent the cooling systems’  
failure, said Tateno, who questions the use of nuclear power in Japan  
because of its seismic activity.

Engineering of the Fukushima Dai-Ichi nuclear plant or its age are  
unlikely causes of the problem, said Tateno, author of a book titled  
“The Coming Age of Scrapping Nuclear Plants.”

While nuclear power has been supported as a way of producing vast  
quantities of energy compared with other sources, “it will be  
difficult to get any more nuclear plants built going forward” in  
Japan, Tateno said.