Russian Officials Deny Testing Nuclear Weapons Finns, U.S. Say Seismic Readings Indicate Blast On Remote Island; Russian Says Country Is Working To Improve Its Arsenal But No New Warheads In Works

Denying that they had broken their moratorium on nuclear testing, Russian officials said Thursday that whatever seismic activity the United States and Finland detected two weeks ago on a Russian island was not from an atomic test.

A Pentagon spokesman in Washington said a “seismic event with explosive characteristics occurred” Aug. 16 in the area of a Russian nuclear proving ground at Novaya Zemlya, a remote Arctic site about 600 miles east of Finland’s northern tip. Finnish officials also said they picked up evidence of a blast.

“Where the Pentagon got this information from I have no idea,” a spokesman for the Atomic Energy Ministry told Reuters news service. “There are special channels for the exchange of information on these issues between the two countries, and they are working perfectly.

“No nuclear tests were carried out at Novaya Zemlya. Russia has voluntarily given up nuclear testing and sticks to this position.”

A White House spokesman in Massachusetts, where President Clinton is vacationing on Martha’s Vineyard, said U.S. officials are discussing the event with their Russian counterparts.

“We have not reached a conclusion on what the seismic event is and its exact nature,” the spokesman said.

The incident comes at a time when some Russians are growing more nervous about the widening gap between Russia’s military capabilities and those of the West, particularly the United States.

Last week, responding to reports in the U.S. news media, Deputy Atomic Energy Minister Lev Ryabev said Russia was aware of U.S. efforts to improve some nuclear bombs so that they burrow into the ground before detonating, posing a threat to buried bunkers, depots and command centers.

While Ryabev said this advance did not constitute a new weapon and thus did not violate any nuclear treaties, the news unsettled some Russians.

“If this is true, then we would lose the last factor that is supporting our position as a great nuclear power,” said Viktor Sokirko, writing in the Moscow newspaper Komsomolskaya Pravda. “And while the Americans will not start to openly flaunt their nuclear superiority, they will probably not pass up the opportunity to ‘flex their muscles.”’

Ryabev said Russian scientists also are working to improve the nation’s nuclear arsenal, but he denied that any new warheads, which would require nuclear testing, were in the works.

Russia declared an end to nuclear testing in 1992 and has focused on trying to consolidate its far-flung, underfunded and aging forces. With U.S. financial help, the Russians are dismantling many of the warheads they once pointed at Europe and the United States.

If Moscow is trying to hide something in Russia’s Arctic area, such news will come as little surprise to those Western officials and analysts who see the Atomic Energy Ministry as a bit of a throwback to the secretive days of the Soviet Union. How much eventually becomes known depends on the evidence gathered not only by the Americans but by the Finns.

“According to the information we received from the Seismological Institute, it was an explosion and not an earthquake,” said Hannele Aaltonen of the Finnish Center for Radiation and Nuclear Safety. “We have no knowledge of whether it was a nuclear charge.”

Aaltonen, who spoke by telephone with Reuters, said the event did not affect radiation levels in Finland.

The Atomic Energy spokesman in Moscow added that a recent nuclear test would make no sense.