Japan Shuts Research Nuclear Reactor after Glitch
The Japan Atomic Energy Research Institute's 3.5 MW nuclear reactor in Tokaimura, north of Tokyo, was shut down manually at 11:29 a.m. (0229 GMT), due to a glitch with one of the reactor's five control rods, the ministry said in a statement.
Nuclear safety officials at the site were making checks, it said.
A science ministry official said the incident was not serious.
"The reactor has been shut down safely," said Terumi Aoki, director at the Education and Science Ministry's office for nuclear regulation.
"It's more of a malfunction than an accident," Aoki said, adding that the reactor would eventually be restarted once officials ascertain what caused the problems with the control rod.
One of the worst accidents at any nuclear facility in Japan occurred at a uranium-processing plant in Tokaimura on Sept. 30, 1999, when an uncontrolled nuclear chain reaction was triggered after three poorly trained workers used buckets to mix nuclear fuel in a tub.
The resulting release of radiation killed two workers and forced the evacuation of thousands of nearby residents.
Last August, hot water and steam leaking from a broken pipe at Kansai Electric Power Co.'s Mihama No. 3 nuclear power generator killed five workers in Japan's worst-ever nuclear power plant accident.