Sendai: Problem solved?

August 25, 2015

Sendai plant to increase output from Thursday

Aug. 25, 2015 - Updated 14:57 UTC+2

http://www3.nhk.or.jp/nhkworld/english/news/20150825_40.html

The operator of Japan's only activated nuclear plant says it will begin increasing the power output on Thursday after solving a problem with reactor equipment.

Workers found seawater leaking into cooling water at the No.1 reactor of the Sendai nuclear plant in Kagoshima Prefecture last Thursday. The reactor had gone back online 9 days earlier.

Kyushu Electric Power Company had initially planned to increase the reactor's output to the maximum level, but delayed the work to identify the cause of the trouble.

Company officials said they found that 5 of about 26,000 narrow pipes carrying seawater in a condenser were damaged and 470 liters of seawater had been leaked.

The condenser is one of the 3 units that convert steam from the power turbines into water, using seawater to cool it down.

The utility said it suspects the 5 pipes were damaged by heat and high pressure in the condenser.

Officials say the damaged parts have not been checked since 2006. They say they will review the inspection procedures to carry out more frequent checks. But they stress that the problem does not affect the safety of the reactor.

The utility plans to plug the 5 damaged pipes as well as 64 surrounding ones to prevent seawater from leaking into the cooling water. The system will undergo inspection by the Nuclear Regulation Authority Secretariat. If approved, the operator will begin increasing the output on Thursday and raise it to 100 percent on Monday or later.

The reactor was the first to go back online under the new regulations introduced after the Fukushima nuclear accident in 2011.