A Soviet nuclear-powered submarine sank in the North Pacific this summer with 90 men aboard and has recently been raised from the ocean bottom by a Soviet salvage team, administration officials said last night. The fate of the crew is unknown.

Although the Defense Department refused to comment on a CBS News report last night that the submarine had sunk in June off the Kamchatka Peninsula almost certainly with "substantial loss of life," other government officials with access to top-secret intelligence reports confirmed that there had been a sinking.

These officials said they did not know why the submarine sank or how many crewmen were lost in the waters off the Soviet naval base at Petropavlask. But they said intelligence officials are piecing together a picture of the sinking, apparently from the National Security Agency's interceptions of the radio communications by the salvage team. Satellite photos are not the primary source of U.S. information on this disaster, sources indicated.

The giveaway that there had been a sinking came when Soviet ships sailed to the scene to begin the salvage efforts, officials said.

In 1974 the CIA raised part of a sunken Soviet diesel sub in the Pacific in a top-secret operation, code-named Project Jennifer, using the Glomar Explorer retrieval ship. That effort might have spurred the Soviets to raise this submarine themselves.

The sub that the Glomar Explorer went after was an old model of the Golf class, and thus would have told the United States less about the state of Soviet submarine technology than the nuclear-powered one lost this summer. It could not be learned last night whether the sub was an attack or missile submarine.

A submarine can dive only to certain depths before the pressure of the water crushes its hull. Mechanical failures, ranging from lack of enough propulsion to pull out of a dive to inability to blow the water out of ballast tanks, can doom submarines. There are also undersea mountains to be avoided.

Navy officials have said for years that the Soviets have experienced failures with their nuclear submarine power plants, but have declined to detail them. There was no indication from U.S. officials last night that the nuclear power plant was to blame for this latest Soviet sinking.

The Soviets are believed to have lost a nuclear submarine off Britain in 1970 and experienced a fire in another nuclear sub off Okinawa in 1980. That sub was towed to port.

Two U.S. nuclear-powered attack submarines have sunk, with loss of all hands--the Thresher, which went down off Cape Cod in 1963, carrying 129 men, and the Scorpion, which sank in the mid-Atlantic in 1968, with a crew of 99.