Sunday, July 29, 2012

Liquid Sodium Leak Alarm at Monju Fast Breeder Reactor But No Leak Found, Says Operator JAEA


Secondary coolant leak alarm was sounded on July 30, but the workers didn't find any actual leak. Or so the Japan Atomic Energy Agency, the operator of Monju Fast Breeder in Fukui Prefecture, says.

From Kyodo News (7/30/2012):

もんじゅでナトリウム漏れ誤警報 福井・敦賀、作動原因調査

False alarm of sodium leak at Monju, in Tsuruga, Fukui Prefecture; JAEA to investigate the cause of malfunction

 日本原子力研究開発機構は30日、高速増殖炉原型炉もんじゅ(福井県敦賀市)で同日午前3時40分ごろ、2次冷却系の冷却材ナトリウムの漏えいを知らせる警報が作動したと発表した。実際のナトリウム漏れや環境への影響はなかった。

Japan Atomic Energy Agency (JAEA) announced on July 30 that an alarm was sounded off at about 3:40AM on July 30 that signaled a leak of coolant (liquid sodium) from the secondary cooling system at Monju Fast Breeder Reactor (Tsuruga City, Fukui Prefecture).

 警報が作動した原因は不明で、同機構が詳しく調べ、結果を経済産業省原子力安全・保安院に報告する。

It is not known why an alarm was triggered. JAEA will investigate, and will report the findings to the Nuclear and Industrial Safety Agency under the Ministry of Economy, Trade and Industry.

 もんじゅは原子炉停止中だが、炉内には核燃料が装荷されており、冷却のために1次系、2次系でナトリウムが循環している。

Monju Reactor is stopped, but the nuclear fuel is loaded in the reactor. To cool the fuel, liquid sodium is being used in the primary and secondary cooling systems.

 警報が作動したのは、原子炉補助建屋にある、2次系配管周辺に設置された検出器の一つ。作業員が現場を目視で点検したりしたが、ナトリウム漏れは確認できなかったという。

The alarm was set off by one of the detectors placed around the secondary cooling system pipes in the reactor auxiliary building. The workers went to the site to do the visual inspection, but no sodium leak was observed, says JAEA.

3 comments:

Atomfritz said...

Japanese nuclearists' logic is amazing.
Leak detector gives alarm, a few workers take a short look, find no white smoke and conclude there is no leak.

Apparently they are playing Russian Roulette, just hoping that Monju's leak won't get larger when starting up, and not result in a big blaze like that one at the Russian BN-350 fast breeder in 1974, or even worse.

In France Superphenix leaked 500 liters of sodium per day over many months. The officials said the leak was harmless, even though the operators searched for the leak origin for months in vain. At least that mysteriuos leak helped to finally shut down Superphenix, as it was not justifiable politically to risk restarting a leaky reactor whose leak(s) couldn't be found.

You see, the Japanese nuclear industry has learnt the lessons from the past.
Instead of thoroughly looking for a leak, just write off the leaked sodium and state that the leak detector instrumentation is defective. Bingo, problem solved.

Anonymous said...

This kind of thinking isn't a national, i.e., Japanese problem. I remember reading in the paper many years ago that San Onofre in CA had a coolant leak, as was indicated by radiation detected in the ocean water. SONGS' management response: nothing for the public to worry about because "the leak is so small, we can't even find it."
*mscharisma*

Anonymous said...

Woop!Woop!Woop!Woop!......

WHAT'S THAT NOISE!!!

>WE DON"T KNOW! IT ALWAYS DOES THAT, DON'T WORRY IT'S NEVER BEEN A PROBLEM BEFORE! JUST STICK YOUR FINGERS IN YOUR EARS!

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