Monju: Safety measures not sufficient

March 5, 2015

Nuclear regulator says preventive measures lacking for Monju fast-breeder reactor

http://mainichi.jp/english/english/newsselect/news/20150305p2a00m0na014000c.html

The Nuclear Regulation Authority (NRA) said on March 4 that the Japan Atomic Energy Agency (JAEA) had not taken sufficient measures to prevent its Monju fast-breeder reactor in Fukui Prefecture from experiencing trouble.

In May 2013, the NRA issued an order to effectively halt the operation of the Monju fast-breeder reactor because JAEA failed to inspect a huge number of reactor components. JAEA, the operator of the reactor, then submitted reports seeking the lifting of the order. In response to JAEA's reports, the NRA said on March 4, "Preventative measures have not been fully taken." It now has become difficult for the NRA to lift the order by the end of this year because the nuclear regulatory agency, the NRA's secretariat, says the Monju reactor should go through at least three quarterly inspections to have the ban lifted.

It came to light in November 2012 that JAEA had failed to conduct inspections on nearly 10,000 components. In May 2013, the NRA ordered JAEA to suspend preparatory work for restarting the reactor until it rebuilds a maintenance and management system for the facility. In December 2014, JAEA submitted three reports in a bid to have the order lifted, but it was subsequently found to have erred in tallying the number of components it had yet to inspect. JAEA then amended and resubmitted some of the documents in February this year.

At the NRA's regular meeting on March 4, the nuclear regulatory agency revealed that it had instructed JAEA to recheck 4,967 components the operator had put off inspecting on the grounds that they "do not affect the reactor facility." Regarding the errors in tallying the number of inspected components, the agency also said that it had instructed JAEA to "verify the fundamental cause and take necessary measures."

JAEA had sought the lifting of the order by the end of this month, but it will be delayed for a considerable period of time because the NRA needs to check the credibility of JAEA's reports and it must conduct on-site work to check the safety of the facility. NRA Chairman Shunichi Tanaka said at the March 4 regular meeting, "There is still a long way to go (before lifting the order). We are not in a situation where we can say in a carefree fashion that it cannot be lifted within the current fiscal year."

The Monju fast-breeder reactor is believed to produce more plutonium than it consumes after using plutonium extracted from spent fuel as nuclear fuel. It first started operations in 1994, but it has remained offline for a long time due to a string of accidents and trouble. In the government's basic energy program, the Monju reactor is regarded as a research facility designed to reduce radioactive waste.