Fault under Tsuruga 2 active

 March 25, 2015

Regulator concludes fault under Tsuruga reactor is active

http://mainichi.jp/english/english/newsselect/news/20150325p2g00m0dm055000c.html

TOKYO (Kyodo) -- The nation's nuclear regulator determined Wednesday that a reactor at Japan Atomic Power Co.'s Tsuruga nuclear plant on the Sea of Japan coast sits right above an active geological fault, a conclusion that may force the operator to permanently shut down the unit.

The Nuclear Regulation Authority's decision-making panel approved a report compiled by experts that says at least one of the faults running under the No. 2 reactor, including one called "D-1," could move in the future.

Despite the move, Japan Atomic Power is expected to apply for the regulator's safety screening to resume operation of the unit in Fukui Prefecture.

But the regulator's decision is unlikely to be overturned unless the operator can submit enough new data.

In quake-prone Japan, building reactors or other important safety-requiring facilities directly above active faults is prohibited.

The regulator acknowledged in 2013 that "D-1" is an active fault. But it conducted an additional probe after Japan Atomic Power submitted more data in trying to have that evaluation overturned.

Also Wednesday, the Nuclear Regulation Authority concluded that at least two key geological faults running under the premises of Tohoku Electric Power Co.'s Higashidori plant in northeastern Japan could move in the future.

Unlike with the Tsuruga reactor, the decision would not immediately force Tohoku Electric to scrap the sole reactor at the Pacific coast plant in Aomori Prefecture, as the faults do not run directly beneath the reactor.

But the facility could remain offline for quite a while, as Tohoku Electric will likely be required to take further measures to enhance the plant's safety before restarting it.

The assessment report also said the experts were not able to obtain enough data to judge whether another fault, which runs directly beneath an important facility at the plant, is active or not.

Tohoku Electric has already applied for the Higashidori plant's safety screening, a process necessary for any reactor to be allowed to go back online. The regulator is expected to resume a full-fledged review of the plant taking the report into account.

Currently, all of Japan's 48 commercial reactors remain offline amid heightened safety concerns following the Fukushima nuclear crisis triggered by a massive earthquake and tsunami in 2011.

The government of Prime Minister Shinzo Abe is seeking to restart reactors that have cleared the Nuclear Regulation Authority's safety review, which is based on new regulations introduced after the crisis.

March 25, 2015(Mainichi Japan)

Report: Fault under Tsuruga reactor may be active

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

Mar. 25, 2015 - Updated 07:39 UTC+1

An expert panel of Japan's nuclear regulator has maintained its assessment that a fault just below a nuclear reactor in central Japan could move.

The panel submitted a report to the Nuclear Regulation Authority on Wednesday, concluding its 3-year study of the fault under the No. 2 reactor at the Tsuruga plant in Fukui Prefecture. The report follows 2 others that said the fault may move.

After the 2011 Fukushima Daiichi nuclear disaster, Japan adopted tougher regulations that ban construction of reactor buildings and other key structures above such faults.

NHK reporters say the idled reactor may be scrapped. But the plant's operator, Japan Atomic Power Company, is disputing the experts' assessment and plans to apply for a restart.

Nuclear Regulation Authority Chairman Shunichi Tanaka suggested that the regulators will fully respect the assessment when they discuss the possible application.

The company recently decided to decommission the plant's aging No.1 reactor.