A reactor at Sweden's Forsmark plant was shut down for checks overnight after a problem was detected in a rubber seal, one of the owners said today.
The reactor was the third to be shut down in a week of problems for the Nordic country's troubled nuclear industry.
State-owned power group Vattenfall said the decision to shut down the Forsmark 1 reactor was taken after tests yesterday showed a rubber seal on an outer wall had lost some of its elasticity.
"At Forsmark 1, it was judged that further analysis was necessary," the firm said in a statement. "The seals have no security function during normal operations, but would function to keep the right pressure in case of a broken pipe inside the reactor casing."
The reactor was taken off line gradually overnight and brought to a complete halt this morning, the firm said. The Ringhals 3 reactor was shut down this week to check and adjust instruments after some anomalous readings. Its sister reactor, Ringhals 1, has been off line since Monday after a problem with its cooling system.
Earlier this week, a leaked report pointed to safety failings at the Forsmark plant, which had to make an emergency shut-down in July last year due to an electrical short circuit. The plant is jointly owned by Vattenfall, Mellansvensk Kraftgrupp and Germany's E.ON.
Sweden's Nuclear Power Inspectorate (SKI), which this week complained to prosecutors over Forsmark's handling of the emergency shutdown last year, said separately it would hold a meeting today to assess the situation.