Court ruling emphasises importance of safety

May 21, 2014

Ruling says plant operator too optimistic

http://www3.nhk.or.jp/nhkworld/english/news/20140521_42.html

The Fukui District Court took issue with the operator's evaluation of maximum ground motion at the Ohi plant in the event of an earthquake .

Utilities nationwide project maximum seismic motion at each nuclear plant. Facilities must be designed to withstand that shock.

Kansai Electric Power Company based designs at the Ohi plant on seismic motion of up to 700 gals.

The court ruling points out that in a period of under 10 years, there have been 5 cases of facilities nationwide hit by tremors exceeding projections.

It says Kansai Electric is optimistic in ruling out the prospect for a mega quake exceeding projected levels in an earthquake-prone country.

The ruling says ground motion lower than 700 gals could lead to a simultaneous loss of power and water used to cool reactors, leading to a serious accident.

The ruling finds fault with some of the plant's structures. It says storage pools for spent nuclear fuel lack strength to prevent leaks of radioactive substances. It says if power and cooling water supplies were lost, a damaged pool could leak.

The ruling criticizes Kansai Electric for relying on an optimistic view that accidents could rarely occur, rather than putting priority on human safety.

May 21, 2014 - Updated 12:03 UTC