Monju moves closer to restart

23 February 2010

The Monju prototype fast reactor (FBR) in Japan has completed a government-mandated procedure to ensure the reactor is safe to restart following a sodium coolant leak which forced it out of action almost 15 years ago. It could restart as early as next month.


Monju (JAEA)
Monju (Image: JAEA)
The final requirement in the procedure was cleared with a decision by the Cabinet Office's Nuclear Safety Commission (NSC) to support the evaluation by the Ministry of Economy, Trade and Industry's (METI's) Nuclear and Industrial Safety Agency (NISA) that Monju is safe to resume operation.


METI told the NSC on 15 February that it had determined that the Monju FBR was ready for safe operation. NSC announced on 22 February that it had now completed its assessment of METI's evaluation and found it to be "reasonable."


Japan Atomic Energy Agency (JAEA), which operates Monju, will now seek permission from the Fukui prefectural government and the municipal government of Tsuruga to restart the reactor. JAEA said that it hopes to restart the unit by the end of March. The FBR will operate on a trial basis for the first three years after it resumes operation.


However, according to the Daily Yomiuri newspaper, Monju's restart could be delayed as "NISA and other related entities are still in the midst of procedures to confirm Monju's earthquake resistance, which is one of the conditions imposed by local governments."


The prototype fast reactor, which would produce more nuclear fuel than it consumes, is a key part of Japan's national energy strategy and politicians have urged its speedy return. Nuclear reactors already provide 30% of Japanese electricity, and this is expected to grow beyond 40% into the middle of the century when fast reactors like Monju should be ready for widespread deployment. Mitsubishi Heavy Industries has been tasked with developing suitable designs, while Japan as a nation is cooperating in efforts like the Generation IV International Forum.


Monju started up in April 1994 and was meant to generate 280 MWe, but a leak of its liquid sodium coolant during performance tests put it out of action from December 1995.


Only Russia currently has fast reactors that provide power to the grid, the 560 MWe Beloyarsk 3 and a 12 MWe unit at Dimitrovgrad. Other nations that have used the design experimentally in the past include France, Germany, Kazakhstan, the UK and the USA. A further Beloyarsk fast reactor is under construction at the moment and should produce 880 MWe from 2014, while there are plans for a 1200 MWe unit to start at Beloyarsk in the 2020s.


Tsuruga 1 seeks life extension


Meanwhile, local governments have approved Japan Atomic Power Co's (Japco's) plan to continue operating Unit 1 of its Tsuruga nuclear power plant until March 2016, the Japan Times reported. "I have no hesitation in extending its operations if the reactor is safe," said Kazuharu Kawase, mayor of Tsuruga.


Tsuruga 1 (JAPC)
Tsuruga 1 (Image: Japco)
The 341 MWE boiling water reactor (BWR), which began operating in March 1970, is Japan's oldest commercial nuclear power reactor.


Should the Fukui prefectural government also approve the plan, Tsuruga 1 would be the country's first power reactor to operate beyond 40 years. Eight other Japanese reactors will reach the 40-year milestone by 2015.


Japco announced a year ago that it planned to postpone the shutdown of Tsuruga 1 beyond the originally scheduled 2010 due to delays in the construction of two new units at the site. At the end of 2006, Japco announced that construction of the Tsuruga 3 and 4 reactors had been delayed by two years due a revision in construction regulations following the government's new earthquake resistance guidelines. Construction of the two 1538 MWe advanced pressurized water reactors (APWRs) will now begin in October 2010, with commercial operation of unit 3 set to start in March 2016 and unit 4 in March 2017.


Researched and written

by World Nuclear News