Russian nuclear plant closes again

The Chernobyl tragedy in 1986 was the world's worst civilian nuclear disaster

MOSCOW, Russia -- Russia's newest nuclear reactor, the first to open since the 1986 explosion at Chernobyl, has been shut down.

The closure -- the reactor's second since it entered service last year -- occurred automatically on Wednesday after a steam valve failed.

No excess radiation was recorded at or near the Rostov plant in southern Russia, its spokesman Yegor Obukhov told The Associated Press.

The cause of the problem was unclear, and engineers were waiting for the reactor to cool down so they could examine it more closely.

The reactor, which took nearly 20 years to build, has been heavily opposed by environmental groups.

The Chernobyl accident in Ukraine sent a large radiation cloud over much of Europe and contaminated large areas of then-Soviet Ukraine, Russia and Belarus. More than 4,000 people died.

According to the Ukraine Health Ministry 400,000 adults and 1.1 million children are entitled to state aid for illnesses contracted as a result of the disaster.

Levels of thyroid cancer in Ukraine and Belarus are abnormally high, and experts are predicting that the incidence of cancer and other disabling diseases will continue to rise for at least another 30 years.

The reactor involved in the Chernobyl accident was encased in a huge steel and concrete tomb to prevent more radiation leaking out.

The plant's other three reactors continued operating until December 2000, when they were closed down.