The operator of a nuclear power plant in western Japan says it has found a crack on the welded joint of a metal cover inside an offline reactor, but that no radiation has leaked.
Chugoku Electric Power Company says it analyzed imagery showing the interior of the No.2 reactor's pressure vessel at the Shimane plant in Matsue City. The crack is roughly 55 centimeters long, it says.
The footage was taken by an underwater camera for a mandatory inspection within 30 years of the start of the reactor's operation, the company says. The check was the first of its kind since the reactor went online in 1989, it says.
The company says the cover closes a hole that was created for workers to use during the construction of the reactor. The hole is about 50 centimeters across.
The utility plans to determine the detailed status of the crack and its cause. It will also assess whether the crack will have adverse effects if the reactor comes back online.
In December, holes apparently caused by corrosion were spotted in ventilation ducts in the central control room of the reactor. The holes could lead to contamination of the room in the event of a serious accident.