It seemed at first glance that the mighty atom might be in trouble. In a national referendum last week, Swiss voters showed strong regional opposition to building the nation's sixth atomic power facility. But they rejected proposals that would have scrapped the country's nuclear power plants by the turn of the century. The vote did not give the government a green light, conceded Dr. Leon Schlumpf, who is federal President and energy minister.
Growing public unease over attempts to recover 30 containers of mildly radioactive uranium hexafluoride from the French freighter Mont Louis, which sank off the Belgian coast more than a month ago, also made some wonder whether the atom's future might be doomed.
There is little doubt that the continued development of nuclear power in Western Europe faces serious obstacles: rising costs, slowed energy demand, public unrest over safety, and repeated construction snags.
Yet few will dispute that the atom, already a prime mover on the world energy scene, appears headed for a bright if not glorious future on this side of the Atlantic.
''I'm confident the obstacles will be overcome,'' a senior European Community energy official said.
Plans for expanding Western Europe's nuclear power capability remain highly optimistic, although they are less ambitious today than they were in the economic boom years of the 1960s and in the oil-shocked 1970s.
Austria has decided to ban the construction of nuclear power plants, and Sweden is gradually bringing such construction to a halt. The rest continue to pursue the development of atomic power with anything from caution to a vengeance even though some countries have postponed nuclear projects or lengthened construction timetables.
From 1977 to 1981 the 10 EC countries doubled the amount of electricity they generated with nuclear reactors (to 202,291 million kilowatts). Conservative forecasts show that by 1990, they will have more than doubled it again.
Even in France, where Socialist President Francois Mitterrand has been less enthusiastic about nuclear power than was his predecessor, the proportion of electricity produced by the atom is due to rise from 48 percent last year to 75 percent by 1990 - easily the highest in the world. During the first four months of this year it jumped to 62 percent.
In the United Kingdom, where nuclear power generates about 18 percent of the electricity, nuclear power is the cornerstone of Prime Minister Margaret Thatcher's energy strategy. Nuclear plants are to provide 20 percent of electricity production by the end of this year and are projected to contribute up to 30 percent by the end of the century. Figuring in Mrs. Thatcher's thinking is a desire to reduce the clout of the leftist-led coal miners' union, political analysts point out.
The Bonn government, for its part, does not appear to have been fazed by the country's powerful antinuclear movement - the strongest in Western Europe. Some 80,000 demonstrators once stormed a nuclear construction site north of Hamburg.
Still, Chancellor Helmut Kohl's government is pressing ahead with new plant construction and EC energy experts predict that nuclear power will provide 32 percent of the country's electricity by 1990, up from only 18 percent today.
The Socialist government in Spain, meanwhile, has pledged to increase nuclear capacity significantly over the next few years - although some of the projected capacity is in doubt.
Belgium has always been a leader in the field. Last year, about 35 percent of the nation's electricity came from the atom (fourth highest in the 24-nation Organization for Economic Cooperation and Development, behind France, Finland, and Sweden). By 1990, according to the EC, that figure is due to grow to 56 percent.
Analysts say that Western Europe's seemingly unstoppable rush to the nuclear camp will have nothing to do with rising energy demand.
According to the economic information service DRI Europe, energy consumption in Western Europe will grow by only 1.2 percent a year between now and 2005, compared with a more than 2.5 percent average annual growth rate of the country's gross national product.
Oil demand, in fact, is expected to fall to almost 20 percent below its 1979 peak level by 2005, DRI Europe says. Of all the fuels, nuclear power will be the main gainer, according to the information service, with capacity more than doubling by the end of the century.