By David Remnick

Washington Post Foreign Service

MOSCOW, March 3, --The Chernobyl Atomic Energy Station where an explosion and fire in April 1986 led to the world's worst nuclear accident, will be phased out of operation over the next five years and then closed completely, the government of the Ukraine announced.

In a resolution published in the republic's official press, the Ukrainian Supreme Soviet also said it would stop building atomic power plants. It is unclear, however, whether the Ukrainian legislature has final authority over the Chernobyl plant.

In the past, Moscow has had final say over such decision but, as power continues to shift gradually from the Kremlin to the legislatures of the republics, many people in Kiev, the Ukrainian capital, believe that Moscow will let the Ukrainian Supreme Soviet's decision stand.

The Chernobyl accident, which led to at least 31 deaths and hundreds of cases of radiation sickness, remains a powerful issue in the Ukraine and Byelorussia and has been one of the main campaign issues in Sunday's local elections. Candidates from the independent group Rukh and the ecological group Green World have made Chernobyl, where three of the four reactors still are in operation, a target in their speeches and leaflets.

Legislators such as novelist Ales Adamovich and journalist Yuri Shcherbak maintain that officials have conspired since 1986 in a "massive cover-up" hiding evidence from the local population that radiation levels continue to remain high in heavily populated areas such as Gomel and Zhitomir. They say that although there have been efforts to "entomb" damaged Reactor No. 4 with concrete, the other reactors on the Chernobyl site also are dangerous, despite recent design Improvements.

Collective farm directors in regions where the radiation was highest have reported an unusual number of farm animals born dead or deformed. Adamovich said that at least 20 percent of Byelorussia's arable farmland was made unusable, and that farm animals are often fed fodder with high radiation levels. Many children in the region have reported headaches, thyroid problems and other illnesses.

The designer of the Chernobyl-model reactor, Anatoli Alexandrov, recently mocked reports of high radiation readings on collective farms throughout the region west of Chernobyl as "folly, just radiophobia." Alexandrov, one of the most highly decorated Soviet scientists, once wrote in the Leonid Brezhnev era that Chernobyl-style reactors should be built close to heavily populated areas so that they could relieve heating shortages in winter.

Shcherbak, author of a history of the accident, said Alexandrov should have been prosecuted. Shcherbak has campaigned In the Congress of People's Deputies for the Kremlin to spend more money to relocate farm families from areas such as the Narodichi reason of Byelorussia and Zhitomir In the Ukraine where radiation levels remain higher than normal

Until now, authorities in Moscow and the Ukraine have resisted closing the Chernobyl station, saying it would cause energy shortages in the region and would lead to the failure to fulfill contracts for power from East European countries.

The Soviet Union, under pressure from the growing environmental movement here, has shut down nuclear power plants in Armenia the Crimea and some Russian cities The government also has said it would try to make sure that any future projects are built in remote areas and use the latest technology rather than outmoded designs such as the one used at Chernobyl.

Just 60 miles from Kiev, Chernobyl is a ghost town, fenced off from the world. Dozens of apartment building in the village of Pripyat are empty, and "hot" abandoned trucks and railroad cars stand at roadsides awaiting burial. Workers in "the zone" wear special clothes, live in specially cleaned dormitories and are shuttled in and out of the region every two weeks to avoid accumulating too much radiation.

Shutting down the Chernobyl station will not entirely solve the problem. Yuri Solemenko, an official in the clean-up effort, told a reporter on a recent trip to Chernobyl that making a concrete sarcophagus of the damaged reactor is "only a temporary solution" and that engineers must find a safe way of extracting the radioactive materials from the core. Solemenko said the process would take a decade at least. He said the concrete could not safely contain the radioactive core for longer than 25 years.