A Japanese company said Saturday it shut down a nuclear reactor after detecting a problem, but there was no radioactive leakage.
Tohoku Electric Power Co., based in the northern part of the largest Japanese island of Honshu, said it urgently halted reactor number three at its Onagawa plant in Miyagi prefecture, north of Tokyo, at 3:19 (0619 GMT).
An inspection had detected a rise in the hydrogen level in part of the reactor, but there was no radioactive leakage, the company said in a statement.
The company said it was still investigating the cause of the problem.
Japan, which has virtually no natural energy resources, relies on nuclear plants for about one-third of its power needs despite repeated safety scares.
In July, a deadly earthquake caused a fire and a small radioactive leak at the Kashiwazaki-Kariwa plant northwest of Tokyo.
No one was injured at the Kashiwazaki-Kariwa plant and UN inspectors said there were no safety risks. But its operator, Tokyo Electric Power Co., plans to keep the facility closed at least until the end of the year for checks.
