Fault at Higashidori seems to be active according to NRA

September 4, 2013

NRA team still seems leaning toward ruling fault under Aomori nuke plant is active

JIJI, Kyodo

http://www.japantimes.co.jp/news/2013/09/04/national/nra-team-still-seems-leaning-toward-ruling-fault-under-aomori-nuke-plant-is-active/#.UigvmX9Sb9k

HIGASHIDORI, AOMORI PREF. – A team of experts from the Nuclear Regulation Authority finished its second study Wednesday of underground crush zones at Tohoku Electric Power Co.’s Higashidori nuclear power plant to determine if they are active faults.

The nuclear watchdog has so far kept unchanged its earlier assessment that the faults under the plant in Aomori Prefecture are active, but NRA Commissioner Kunihiko Shimazaki told reporters the NRA may conduct yet another study before announcing a conclusion.

Shimazaki lead the two-day study of suspected active faults beneath the plant.

Following the first study in December, the team said in May the crush zones under the plant are active faults.

Tohoku Electric claims they are inactive and has performed its own study of the underground crush zones, including boring into them. The two-day study by the NRA viewed the utility’s findings.

If they are judged to be active, Tohoku Electric would be forced to decommission the plant’s reactor 1.

Even if there are no active faults under key facilities, Tohoku Electric may need to conduct seismic reinforcement work if the NRA concludes there are active faults beneath the premises of the plant.

2nd survey at Higashidori nuclear plant ends

http://www3.nhk.or.jp/nhkworld/english/news/20130904_33.html

A member of Japan's nuclear power regulator says the result of its second survey at the Higashidori nuclear plant in northeastern Japan will not change its conclusion that faults under the facility appear to be active.

Nuclear Regulation Authority Commissioner Kunihiko Shimazaki was speaking to reporters on Wednesday after the 2-day survey by a panel of experts at the plant in Aomori Prefecture.

In February, the authority compiled a draft report based on its first survey last December in which it said the faults appeared to be active.

On Wednesday the panel investigated a cross section of a trench dug by the plant's operator, Tohoku Electric Power Company, along a fault called F-3.

Tohoku Electric claimed that the faults were not active. The utility has been conducting its own additional survey.

Shimazaki indicated that the authority will examine Tohoku Electric's extra research before compiling a final report.