None of the debris that fell from the stricken Soviet satellite over Canada Jan. 24 has come from the dangerously radioactive nuclear power plant that provided the spy satellite with its electricity.

The only things that have been spotted or recovered on the ground are structural pieces of the satellite or the container housing the nuclear fuel," said one White House source close to the search and recovery operation said Friday. "No parts of the uranium fuel or its fission products have been seen on the ground anywhere in Canada and we now believe the fuel burned up in the upper reaches of the atmosphere."

On Friday a Canadian C-130 Hercules flew a lead box weighing 300 pounds to the eastern edge of Great Slave Lake, where searchers found a highly radioactive piece of metal that came from the Soviet satellite. Three inches wide and 10 inches long, the metal was to be placed in the box and packed in lead bricks for a flight back to the Whiteshell Nuclear Research Establishment in Manitoba.

The piece of satellite debris is emitting between 100 and 200 roentgens of radiation per hour, which is 40 times the dosage permitted an atomic worker in one year. Still, the fragment is not considered radioactive enough to be a piece of the 100 pounds o fspent uranium fuel that was abroad the Cosmos 954 satellite.

"It could be a piece of the stainless steel or nickle-copper alloy that surrounded the fuel," one source said, "but it's nowhere near hot enough to be the fuel itself."

Sources said the Soviets told the White House, that the uranium core that powered the satellite was signed to burn up quickly at an attitude no lower than 300,000 feet. The core was built of either metallic uranium or uranium carbide in contact with traces or oxygen in the atmosphere.

The uranium fuel bundle was also built to allow the heat of the satellite's re-entry into the atmosphere to penetrate the core. Since the uranium core was already presumed to be as hot as 2,000 degrees Fahrenheit from its own fission products, the additional heat of friction would guarantee a quick and complete burn-up of the fuel before it reached the lower regions of the earth's atmosphere.

"We were told that was very little cladding around the fuel," a White House source said. "I'm not going to tell you how it was designed to break up but we and the Canadians both were quite satisfied with the Soviet explanation of how the break-up would happen."

In Moscow yesterday, Soviet space scientist Leonoid Sedov said the satellite could have been struck by another object in space that caused it to drop out of orbit.

"It may be assumed that the satellite collide in flight with some other object of natural or artificial origin." Sedov told the news agency Tass. "As a result, the satellite's onboard system went out of operation, it lost orientation and it began uncontrollable descent."

Sources said the United States first believed the five-ton satellite was in trouble in December when the Soviets could no longer command it to maneuver in space. On Jan. 6, one of the satellite's fuel tanks apparently exploded and caused it to begin tumbling out of control.

In the next 10 days, the satellite continued to tumble and fell almost 50 miles to where it was dangerous close to falling out of orbit. Twice during those 10 days, White House security officials spoke with their counterparts in Moscow asking for assurance that uranium fuel would rot return to Earth with pieces of the satellite when it finally broke up.

Once the White House had these assurances, it notified the member nations of the North Atlantic Treaty Organization so they would not think they'd been attacked by an errant nuclear missile if the satellite fell in them. Japan and China were informed privately of the approaching satellite accident.

During this time of crisis, staff members of the National Security Council discussed daily the possibility of announcing the impending accident to the world. It was not announced because the council felt the most dangerous parts of the satellite would burn up in the atmosphere and because an announcement might trigger panic in some of the world's people.

"We panned that as soon as we knew where this thing was coming down we'd immediately notify the countries along the re-entry path", a White House source said. "I think the president would even have called Albania if we felt the thing might fall on them."

White House sources said that Cosmos 954 was the only satellite with an atomic power plant aboard that was anywhere near falling from the sky. There are 15 other Soviet satellite in space with nuclear power plants but they're all at least 570 miles above the Earth where they will stay for 500 years longer.

Sources said President Carter plans to ask the Soviets that if they orbit any more satellites with atomic power plants that they be built with redundant rocket engines to carry them to a safer orbit or that they be fitted with explosive devices that can blow them up if they fall from space.

The pieces of the satellite that are being recovered from the tundra of the Northwest Territory will all be examined by intelligence officials, but sources gave the impression tht they already knew all they needed to know about this type of satellite, which was first flown by the Soviets in 1967.

Sources said the U.S. has known the ocean-surveillance satellite carries an atomic plant to feed power to huge onboard radar that tracks the movement of American warships at sea. Sources denied published reports that the satellite is able to peer below the ocean surface and identify Polaris submarines.

"That's pure nonsense," one source said."There is no radar that can track submerged submarines."