Shaun Burnie with Mycle Schneider
Japan's Nuclear Regulatory Authority on 4th November 2015 decided that a new entity would be required to manage the MOX fueled Monju Prototype Fast Breeder Reactor (FBR) at Tsuruga in Fukui prefecture. The new body would be tasked with demonstrating that the reactor can be operated safely. The NRA has asked that Government to identify a new agency, or, if that proves not possible, take a decision to permanently shut down the reactor. Any decision to shutdown Monju would have major implications for Japan's long-standing nuclear fuel chain policy.
The 280 MW reactor, which began operation in April 1994, has not operated since an accident in 1995 in which liquid sodium leaked from cooling pipes - with the exception of a limited period of operation between May and August 2010, when it was shut down following another accident.
A safety inspection of Monju in 2012 showed that more than 9,000 of about 49,000 parts had not received necessary checks. Subsequently, the NRA recognized seven instances in which Monju violated safety regulations, including equipment malfunctions and failure to properly manage documents. In May 2013, the NRA ordered JAEA not to embark on preparations for its restart. In March 2015 the JAEA provided assurances to the NRA that it had implemented reforms, however further revelations had emerged during the previous two years that the agency had violated safety regulations and committed errors by not conducting thorough checks of other pieces of equipment.
The 4th November 2015 decision by the NRA Commissioners was their first ever "admonition", in this case against the Japan Atomic Energy Agency (JAEA), a government body under the Education, Culture, Sports, Science and Technology Ministry, deeming it not qualified to run the Monju reactor. Shunichi Tanaka, the NRA chairman stated at an emergency meeting on 2nd November: "Our assessment is that the agency is unfit to manage and operate the Monju...The agency cannot solve its problems on its own, and we will make our own judgment." JAEA President, Toshio Kodama, told NRA officials that the JAEA is taking measures to review its inspection regime, and seeking the NRA's understanding by stating: "No entities other than the JAEA can manage Monju." Asahi newspaper noted in an editorial that "pulling the plug on the Monju program is the only reasonable option. The decision to do so should be the government's answer to the NRA's recommendation."
The Monju FBR is one of the few such reactors worldwide, and as such is central to both Japan's domestic and international research and development program on sodium cooled fast reactors. In May 2014 extended cooperation was announced by the Governments of France and Japan, with Monju playing a central role, including in the testing of fuel for France's new demonstration breeder ASTRID (Advanced Sodium Technological Reactor for Industrial Demonstration).
On 7th October 2015, a panel of the NRA concluded that a seismic fault line beneath the Monju prototype fast-breeder reactor is likely inactive, after finding the fault line would not move in tandem with an active geological fault 500 meters away. A full report will be prepared for NRA Commissioners.