Contamination on Soviet Sub Thought Likely

OSLO —  A leak in the nuclear power system of a Soviet submarine probably contaminated the vessel but not the environment outside, a Norwegian expert said Tuesday.

The submarine, built in the 1960s, billowed smoke and steam when its reactor’s cooling system broke down Monday, 70 miles from the coast of Norway.

Soviet officials say there was no radiation leak. They say the reactor was shut down and no one was injured.

But Knut Gussgard, acting chairman of Norway’s Committee on Peacetime Nuclear Accidents, said pieced-together details of the accident aboard the submarine show a reactor cooling circuit most likely leaked radioactive water and steam into the vessel.