23 Juillet 2016
July 23, 2016
THE ASAHI SHIMBUN
The prototype fast-breeder reactor Monju in Tsuruga, Fukui Prefecture (Asahi Shimbun file photo)
Yet another lapse in safety checks has come to light at the Monju prototype fast-breeder reactor at a time when the government is looking for a new entity to operate the problem-plagued facility.
The Nuclear Regulation Authority, the nation's nuclear watchdog, has already recommended to the science ministry that a new operator be appointed after repeatedly pointing out that the Japan Atomic Energy Agency (JAEA) is incapable of following proper maintenance procedures.
In the latest wrinkle, it emerged that a newly assigned worker failed to check a key piece of equipment at the Monju reactor in Fukui Prefecture for two months or so, sources said July 22.
The individual ignored a warning sign which showed that the device in question had not been looked at.
According to the NRA, the JAEA by the end of March was supposed to have checked the equipment to control the temperature of sodium used to cool the reactor. But when the JAEA investigated May 27, it found that nothing had been done.
Screens in the control room at the JAEA had shown since late February that the equipment had gone unchecked.
However, as other pieces of equipment had been scrutinized, the worker in charge may have thought that colleagues had done so but neglected to input the information into the control system, the sources said.
The JAEA is trying to determine whether the person's predecessor conveyed the job procedures adequately.
In 2012, it emerged that maintenance work at Monju had been insufficient at more than 10,000 portions.
After that scandal, the NRA repeatedly pointed out in its inspections that the JAEA was not observing maintenance rules.
In November 2015, the NRA concluded that the JAEA does not have ability to operate Monju safely and advised the science ministry to either look for a new operator or take drastic measures to reduce the risk of a disaster.
The science ministry is now considering handing over Monju's operations to a new entity.
This new instance of slipshod work could reflect badly on the JAEA.
“A much stricter view will be taken with regard to Monju," said a high-ranking science ministry official. "Why is the JAEA unaware that the actions of just one person can have a huge influence on the entire organization?”
July 22, 2016
The Japan Atomic Energy Agency again failed to conduct checks on a device at its experimental Monju fast-breeder reactor and overlooked a warning signal from a maintenance management system for about three months, it was learned Friday.
The state-affiliated agency, which recently came under fire for failing to inspect thousands of devices at Monju, is investigating the cause of the latest mishap and devising measures to prevent a recurrence.
According to sources familiar with the matter, the device in question controls the temperature of sodium coolant for the prototype reactor, which is situated in Tsuruga, Fukui Prefecture.
The JAEA was slated to complete the inspection by the end of March, after moving up the previous deadline, which was set at the end of May.
Around the end of February, the maintenance management system installed at Monju started to display a warning signal. But it was not until May 27 that agency officials noticed it, the sources said.
JAEA reported the problems to the Nuclear Regulation Authority and completed the inspection of the temperature-controlling device on May 31, the sources said.
A massive sodium leak and coverup bid in December 1995 caused Monju’s operations to be suspended. It was eventually brought back online in May 2010, but halted again by a different problem in August the same year.
In November 2012, it was found that JAEA failed to carry out maintenance checks on more than 10,000 devices at Monju. After that, the NRA effectively banned the JAEA from operating the reactor.
In November last year, the NRA recommended to science and technology minister Hiroshi Hase that JAEA be replaced as Monju’s operator. The ministry is studying the matter.