Eastern Europe's communist-ruled nations, deeply committed to a Soviet-led program for development of nuclear energy, will face strong economic pressures to continue rapid construction of nuclear power plants despite the recent accident at Chernobyl, western analysts and industry experts say.

The Soviet Union's reported decision to suspend operation of graphite-type nuclear plants like the one at Chernobyl is unlikely to have a significant impact on Eastern Europe, officials here said tonight. The electricity-generating nuclear plants now operating in four Soviet Bloc nations are of a different design and technology and should be unaffected by the measure, they said.

However, the accident at Chernobyl has called into question ambitious plans by Eastern European countries to build or expand dozens of Soviet-designed nuclear plants between now and 2000. All six countries united with Moscow in the Council for Mutual Economic Assistance, or Comecon, are now constructing large nuclear complexes with Soviet assistance and most have committed huge investments to the program as well as to factories building reactor parts.

The nuclear drive, begun in 1979, has been mandated by cutbacks in Soviet oil supplies and other energy sources and is vital to the plans of most Eastern European countries for economic growth. Already, Romania, Bulgaria and Poland are suffering from serious energy shortages and bottlenecks, and every East Bloc country is facing the need for major energy savings.

As a result, any cutback in nuclear building plans, or even a substantial delay in construction schedules, could seriously damage the ability of Eastern European governments to expand their economies in coming years and trigger enduring energy crises, analysts say.

Government officials around the region have played down the Chernobyl accident this week, and Poland's top nuclear official insisted tonight that there was no need to slow the construction program here or throughout the bloc.

"The accident should have no effect on carrying out Poland's nuclear program," said Mieczyslaw Sowinski, chairman of the state atomic energy commission, "because the reactors we install are of a completely different construction and design."

Most of the Soviet reactors now operating or under construction in Eastern Europe are Soviet models whose design and technology is based on that developed by Westinghouse in the 1960s, according to East European specialists. The reactors, which use enriched uranium, come in two sizes, 440 or 1,000 megawatts, and are usually grouped in blocks of three or four.

Until now, Eastern European officials have invariably dismissed concerns about the safety of nuclear plants as a western media phenomenon. Two accidents, in Czechoslovakia and Bulgaria, have been reported since 1970 by western sources, but East Bloc officials have never provided full information about them.

In a recent interview, Vassil Tzvetkov, the deputy vice president of Bulgaria's energy corporation, said concerns about radiation emissions were so low that neighboring Romania had shut its monitors.

Other Eastern European officials have said that their safety concerns are alleviated by the practice of shipping all of their spent fuel rods to the Soviet Union, which uses them to make plutonium in reprocessing plants. However, western experts say East European countries will soon have to create their own nuclear disposal sites as the number of plants rapidly expands.

Moscow's allies already depend heavily on Soviet technology. The capacity of nuclear generators in the region doubled between 1978 and 1983 as Bulgaria, Czechoslovakia, East Germany and Hungary opened or expanded nuclear plants. In addition, Eastern European countries have invested in the construction of two huge Soviet complexes in the Ukraine, at Pribuzhiye and Khmelnitsky, in exchange for a share of the power they generate.

Czechoslovakia, which has five 440-megawatt plants operating and has plans to build seven more, produces the Soviet-designed reactor for export around the region. Bulgaria has doubled its nuclear power capacity since 1980 and now produces 31 percent of its electricity in nuclear plants.

Throughout the region, nuclear power generation is planned to increase by at least another 500 percent by 2000, when the six Eastern European countries expect to produce between 20 and 60 percent of their energy in reactors. In addition, Comecon countries recently agreed to develop new kinds of nuclear technology, such as nuclear-powered heating plants for cities.

The Comecon program also has been slowed by construction delays. Some industry specialists say that nuclear energy is coming too slowly and at too high a cost and argue that the mandatory ties of each country to Soviet uranium supplies and outdated technology are a sure recipe for increasing the region's economic dependence.