In an article in yesterday's editions, an Argentine official incorrectly identified nuclear reactors in Cuba as being of the "Chernobyl-type." In fact, the Cuban reactors are of a design similar to those built in the United States. (Published 8/15/87)

ZARATE, ARGENTINA, AUG. 13 -- Like nuclear-energy programs almost everywhere, Argentina's ambitious plans to harness the atom have fallen on hard times. But the slowdown here is especially significant in view of the vast scope and stunning achievements reached in the program's heyday.

Argentina led Latin America into the nuclear age, with the region's first research reactor, first commercial reactor, first plutonium-reprocessing capability, first productions of fuel elements, and first export of a reactor.

Now, the atomic energy plan is marked by retrenchment and uncertainty. Despite a government pledge to sustain it, the once lavish program is shaken by budget cuts, labor disputes, project delays and an exodus of trained personnel.

Here in Zarate, giant cranes stand idle above the concrete skeleton of a half-completed nuclear power station -- the product of dreams that got far ahead of budgets. The electrical generating complex, called Atucha II, is six years behind schedule and already a projected $1 billion over its original $1.5 billion price tag.

"The worst thing that has happened here in the last few years," said Edgardo Ventura, adviser to the president of Argentina's nuclear energy commission, "is that people have lost the sense of mystique they used to have about the nuclear program."

Launched erratically by Juan D. Peron after World War II, the atomic push enjoyed more than three free-spending decades and a degree of administrative independence unmatched by any other state institution. Navy officers ran and protected it. Some of the best minds in the country contributed to it.

Many suspected -- although officials always denied -- that one aim was to build an atomic bomb. Foreign fears of this were heightened four years ago when Argentina announced that its researchers had secretly demonstrated the ability to enrich uranium, a requisite for production of a nuclear weapon.

Few doubt that Argentina is capable of making the bomb. But concerns that it might actually do so have eased since popularly elected President Raul Alfonsin took power in December 1983, ending nearly eight years of military rule. Alfonsin's actions have increased the credibility of longstanding government claims that Argentina will use nuclear technology solely for peaceful purposes.

Alfonsin has placed the nuclear program under civilian management, slashed its annual budget from $1.2 billion to $700 million and tightened financial controls. As a member of the so-called Group of Six formed in 1984, he has joined with the heads of state of Greece, India, Mexico, Sweden and Tanzania to appeal for an international ban on nuclear tests and for eventual nuclear disarmament.

Nevertheless, uneasiness persists abroad. This stems from Argentina's refusal to sign international nonproliferation treaties and from its development of the plutonium-reprocessing and uranium-enrichment technologies that are crucial to weaponry.

The worry is not that the current government would ever go the weapons route, but that a less democratic one could do so in the future.

Secrecy still shrouds part of Argentina's nuclear research. "It's a carry-over from the military period," said Naren Bali, president of the Argentine Physics Society, who has urged nuclear commission officials to open up facilities that are still off-limits. "They've never been able to shake off that sense of original sin."

Argentina continues to resist U.S. pleas that it ratify the 1968 worldwide Nuclear Nonproliferation Treaty and the 1967 Latin American Treaty of Tlatelolco. Under both treaties, nations that do not have nuclear weapons agree not to build them. They also accept international inspection.

The Alfonsin government, like past administrations, contends that the nonproliferation treaty discriminates against nations trying to develop their own nuclear industries. It regards the Tlatelolco pact as more fair but objects to certain operational aspects.

The issue, in any case, has lost some of its former urgency now that Argentina no longer appears locked in a nuclear race with neighboring Brazil. The ex-rivals have begun a series of meetings to coordinate nuclear development in a widening framework of economic and political accords.

The new amity was highlighted last month when Alfonsin took his Brazilian counterpart, Jose Sarney, on a tour of one of this country's most secret nuclear installations -- the uranium-enrichment facility at Pilcaniyeu, about 1,100 miles southwest of Buenos Aires. Although largely symbolic, this first visit by a foreign head of state reinforced hopes that the two South American powers would develop a system of mutual inspection that could substitute at least partially for international oversight.

Of growing concern to U.S. officials is Argentina's stepped-up effort to sell nuclear technology to Third World countries. A $5.5 million contract that Argentina signed with Iran earlier this year particularly irked some U.S. officials.

The deal seems militarily harmless. It calls for reshaping a 20-year-old, U.S.-made research reactor at Tehran University to run on 20 percent enriched uranium instead of 90 percent, weapons-grade enriched uranium. But the Reagan administration would prefer that the facility not operate at all.

"We very much frown on the deal," said a U.S. Embassy official in Buenos Aires. "We do not favor cooperation between Argentina and Iran at this time. The U.S. government has expressed to Argentina its opposition to the cooperation in no uncertain terms."

The complaint has made little difference. In consortium with West German and Spanish firms, the Argentines are bidding to complete Iran's 1,293-megawatt nuclear power plant begun by France.

Argentina has also agreed, according to a government source, to train Cubans to operate two Chernobyl-type reactors under construction in Cuba. Requests, though, from Pakistan and Libya for nuclear assistance were spurned.

"We do want to be considered responsible exporters, and we're working hard on that," said Adolfo Saracho, director of the Foreign Ministry's nuclear affairs office.

Building on its Third World political ties and its First World atomic technology, Argentina hopes to increase nuclear sales to developing countries. Last March, engineers here unveiled designs for a new medium-sized reactor called the Argos 380, which boasts lower capital costs, quicker construction time and better safety features than competitive models.

In a speech about the nuclear program last year, Alfonsin said "the difficulties of today must not annul our possibilities for tomorrow." But industry analysts say Argentina is in danger of losing its technological edge as scientists and other highly trained personnel, upset by low salaries, abandon the field.

"Some time ago, we transferred computer codes to the Argentines for our Candu reactor," said Raul Palou, local representative for Atomic Energy of Canada Ltd., which designed one of Argentina's two operating nuclear power stations. "Now they're asking us to update the codes and retrain people in them. That suggests a lack of continuous support and development."

Labor unrest forced Argentina to close its Atucha I and Embalse atomic power stations temporarily last June. Technical committees had warned that poor morale and unfinished maintenance work had raised the risk of human error at both facilities.

Alberto Constantini, an Alfonsin appointee, angrily quit last April as head of the National Atomic Energy Commission in a budget dispute with Economy Ministry officials. He was widely accused of failing to scale down the commission's program. His successor, a respected physicist named Emma Perez Ferreira, faces the same challenge.

For the next decade and a half, Argentina plans to rely on expanded hydroelectric and natural-gas programs to serve a projected doubling of demand for electricity. Nuclear power is slated to retain a 15 percent share of total energy production through the end of the century. This calls for completion of Atucha II by 1993 and construction of another 700-megawatt reactor by 2000.