Tests to determine whether any radioactivity is in the water have not been concluded, according to Michael Armacost, the under secretary of State for political affairs who appeared on NBC's "Meet the Press."

Armacost said there was a report that at one point the sub "had been under way at a very slow speed under its own power, perhaps auxiliary diesel power." But "other difficulties apparently developed," or the sub "had been stopped briefly," he said.

Sen. Sam Nunn (D-GA), the ranking Democrat on the Senate Armed Services Committee, said, "The chances of any kind of nuclear detonation are very, very low."

He added, "You're always apprehensive when you have a vessel that is under considerable disress and this one is."

Shultz and Nunn also said the Soviets, apparently mindful of the criticism after the nuclear disaster at Chernobyl, seemed to be cooperating in providing information about the accident.

"I think they got badly burned at Chernobyl because you can hide these things no matter what," said Shultz, referring to the Soviets' delay in reporting that accident.

He said Gorbachev's decision to notify Reagan about the fire on the sub 24 hours after the fact was "pretty good."