Leak forces shutdown of No.3 Genkai reactor

March 31, 2018

March 31, 2018

Steam leak prompts power generation to halt at Japan nuclear plant

https://mainichi.jp/english/articles/20180331/p2g/00m/0dm/002000c

FUKUOKA (Kyodo) -- Kyushu Electric Power Co. stopped generating and supplying electricity at its nuclear reactor in southwestern Japan on Saturday after detecting a steam leak the previous day.

The utility said there has been no radiation leak and that it will inspect the reactor, which resumed operation only a week ago at the Genkai power plant in Saga Prefecture.

According to Kyushu Electric, staff discovered at around 7 p.m. Friday that steam was leaking from the pipe of a device used for the removal of oxygen and other dissolved gases from the feedwater to steam generators.

The No. 3 reactor at the plant resumed operation on March 23 after being offline for over seven years, amid lingering concerns among residents about how to evacuate from islets near the plant in the event of a serious accident. It restarted power generation two days later.

Following the latest incident, Kyushu Electric's plan to restart the No. 4 reactor in May could be delayed, the utility said.

The No. 3 unit was suspended for a regular inspection in December 2010, three months before a massive earthquake and tsunami sparked a crisis at the Fukushima Daiichi nuclear plant.

It cleared the Nuclear Regulation Authority's safety screening in January 2017 under stricter, post-Fukushima regulations and was later approved for reactivation by the Genkai municipal government and Saga prefectural government.

Steam leak found at Genkai nuclear power plant

https://www3.nhk.or.jp/nhkworld/en/news/20180331_09/

The operator of the Genkai nuclear power plant in southwestern Japan has found a steam leak in a reactor just one week after putting it back online. It suspended power generation early Saturday.

Kyushu Electric Power Company says a worker found the small leak at the No. 3 reactor around 7 PM on Friday. The plant is located in Genkai Town in Saga Prefecture.

The utility says the steam does not contain radioactive substances, and that monitoring posts around the plant show no change in radiation levels. It says there has been no harm to the environment.

Kyushu Electric says the leak occurred in a pipe connected to equipment that removes oxygen, carbon dioxide and other substances from the steam.

The reactor was generating power at 75 percent of its capacity at the time. The utility says it gradually lowered output through the night, halting it completely by around 6 AM on Saturday.

Kyushu Electric says it is working quickly to determine the cause and resume operations.

The leak is an unwelcome setback for the utility, which put the reactor back online on March 23rd, ending a break of more than 7 years in operations. The reactor began generating and transmitting power 2 days later.

The reactor was suspended for a regular inspection after the 2011 earthquake and tsunami, which triggered the Fukushima nuclear accident.