Restart Takahama reactors? No way.

August 15, 2013

Revised tsunami projection dashes hopes of early Takahama reactor restarts

http://ajw.asahi.com/article/0311disaster/fukushima/AJ201308150054

By RYUTA KOIKE/ Staff Writer

A revised estimate of maximum tsunami heights means additional measures are needed at the Takahama nuclear power plant in Fukui Prefecture before the go-ahead can be given to restart the plant's idled reactors.

Kansai Electric Power Co., the plant's operator, had projected the maximum tsunami height at 2.6 meters when it applied on July 8 to restart the Takahama plant's No. 3 and No. 4 reactors. The Nuclear Regulation Authority, however, ordered Kansai Electric to make plans based on the Fukui prefectural government's projection that a 3.7-meter wave could inundate the facility.

Kansai Electric later presented new simulation results to an NRA meeting that monitors compliance to industry safety standards. The utility said its simulations showed a tsunami could reach as high as 50 centimeters above the height of the plant site, which lies at an elevation of 3.5 meters.

Some facilities, including a pump chamber adjacent to the No. 3 and No. 4 reactor buildings, could be swamped, Kansai Electric said Aug. 14.

The NRA's new standards do not allow key nuclear plant facilities to be inundated. Kansai Electric's previous worst-case scenario predicted no flooding, and the utility volunteered to build a 6-meter-high seawall and a levee along a water intake channel for completion by March 2015 and March 2016, respectively.

The current NRA safety standards, which were upgraded to incorporate lessons learned from the 2011 Fukushima nuclear disaster, took effect on July 8.

In response to the latest review of projected worst-case tsunami scenarios, Kansai Electric said it will build an additional levee to surround key facilities that are under threat of flooding.

The utility said it has yet to determine the final details on how it plans to proceed or the completion date for the additional work.

"We hope to present details on our plan at the earliest date possible to an NRA screening meeting as soon as we have determined them," a Kansai Electric official said.