An American technician eats his lunch before the nearly lifeless switchboard of Brazil's first nuclear power station, while outside the construction cranes for two other reactors have been idle for a month.

A tour of this reactor complex on the scenic coastline near Rio de Janeiro, the crumbling facade of Brazil's big-power nuclear energy ambitions, makes it difficult to entertain the notion that elsewhere the Brazilian military is embarked on a a secret parallel program to develop a nuclear bomb, as alleged in recent investigative reports based on U.S. intelligence sources.

The deepening economic crisis has forced Brazil to lower its once lofty nuclear expectations. Last month, President Joao Figueiredo announced cuts of 47 percent from this year's nuclear energy program and suspended plans for two new reactors that were to be built with West German technology. Units currently under construction will be delayed to the end of the decade.

Washington Post reports that Brazil was producing plutonium in a secret nuclear bomb program were dismissed as "children's fiction" by former Nuclear Energy Commission president Rex Nazare Alves. The report is the latest in a long line of nuclear tensions between Washington and Brasilia and follows previous charges that Brazil's Institute of Energy and Nuclear Studies was involved in secret uranium shipments.

Mines and Energy Minister Cesar Cals strongly denied the report, but he said some plutonium had been produced using a U.S.-made test reactor as part of the peaceful program to develop the country's nuclear technology. Scientists said it would take many years to produce the quantity needed for a bomb using a test set.

In the 1950s, Adm. Alvaro Alberto secretly tried to buy ultracentrifuge equipment from West Germany. Such equipment would have allowed Brazil to enrich its domestic natural uranium and to develop the capability of making a bomb.

The United States stopped the shipment, but Brazil's aspirations for total autonomy in the nuclear fuel cycle continued. Officials at Nuclebras, the state atomic energy authority, say without the recent budget cuts Brazil could have mastered the cycle by the early 1990s, which would theoretically have made possible the production of plutonium without international safeguards.

Brazil participates in the international atomic energy authority accords but is not a signatory of the Nuclear Nonproliferation Treaty.

In line with a 1971 agreement with the United States, Brazil purchased a pressurized water reactor for use in the first Angra reactor, but it was prevented from access to the technology under conditions of the purchase from Westinghouse.

In 1975, Brazil angered Washington by negotiating a secret nuclear pact with West Germany providing for eight reactors and the transfer of the European ultracentrifuge process. The West German technology would have allowed Brazil to enrich its own uranium and eventually to reprocess spent reactor fuel to yield bomb-grade plutonium.

Under pressure Bonn withdrew the ultracentrifuge offer and substituted the costly and little-tried jet-nozzle process, which previously had been tested by South Africa. Brazil bought the first Angra reactor's fuel load raw material from South Africa.

During the Carter presidency, U.S. pressure combined with domestic military repression threw a veil of secrecy over Brazil's nuclear research. It became known, however, that as many as 200 scientists were working at the nuclear studies institute in Sao Paulo on enrichment technology, including the testing of a new laser method. Research also began at the armed forces' jet propulsion laboratory at San Jose dos Campos.

In June 1981 it was reported that Brazil had agreed to supply Iraq, which had publicly appealed for help in creating an Arab nuclear weapon, with 70 tons of uranium oxide from the nuclear studies institute. The reports, strongly denied by the government, said eight tons were sent before Israel destroyed Iraq's nuclear reactor.

The nuclear studies institute has not commented on the latest charges. Following the election victory of Sao Paulo Governor Franco Montoro, a veteran opponent of the military government's nuclear plans, the institute was transferred from state to federal control.

Figueiredo has moved to consolidate under federal control all nuclear research.

Shortly before resigning, Nuclebras' former president Paulo Nogueira Batista said "we are buying technology, not reactors," from West Germany, as part of the accord budgeted at $24.5 billion. After the cuts were announced, however, the West German contractor, KWU, released a statement suggesting that if Brazil did not continue to build reactors, the sensitive technology it wanted would not be forthcoming.

Whatever the status of the alleged parallel nuclear program, which scientists report to be in very preliminary stages, the public nuclear energy program has been dogged by frustration and incompetence. The first nuclear reactor is crippled by a defect in the steam generator, and Brazilian officials accuse the constructors, Westinghouse, of "lack of care and attention."

The second reactor, which is part of the accord with Bonn, needed $80 million extra foundation work. The third, which will not now be ready until 1990, has had its site moved.