The Three Mile Island nuclear accident appears to have left the public sharply divided about the future of nuclear energy but pretty much certain abourt one aspect of it: most people don't want nuclear plants built in their communities. These are the chief findings of a nationwide Washington Post poll on nuclear energy taken in May, five to seven weeks after the March 28 accident. The poll suggests that the near-meltdown in pennsylvania has added scarcely anyone to those opposed in principle to the continuing development of nuclear power as an energy source. Instead, a relatively large number of people who had considered themselves suppoters of nuclear power are now uncertain about it. In their uncertainty, the poll indicates, they are opposed to making themselves and their neighbors potential victims of some new accident. By a two-to-one majority among those who have made up their minds, people living in areas that don't now have nuclear plants say they don't want any to be built there. That ratio holds, with little change, in every region of the country and among virtually all segments of the population. It is maintained in small towns and rural areas, as well as in big cities and their suburbs. While public opinion has no formal role in deciding where nuclear plants will go, such opposition could, nevertheless, prove crucial to the future of nuclear energy in the United States. Currently, the Nuclear Regulatory Commission holds public hearings while considering applications from utility firms for nuclear power plant and construction permits. There has long been some outspoken opposition expressed at such hearings, but no plant permit has yet been denied because of it. However, until now, opposition to local plants has often been led by anti-nuclear activists who have been branded as a small, unrepresentative part of the population. Whether nuclear plants will be built amidst the widespread opposition that was uncovered in The Post's poll is quite another question. Before Three Mile Island, a variety of polls showed a majority in favor of continued nuclear development, often by margins of two-to-one or more, with a hard core of 25 percent opposed. The Post poll, conducted May 3 to May 17, asked a random sample of 1,000 people whether they would describe themselves as supporters or opponents of nuclear power plants as a means of providing electricity, or whether they hadn't made up their minds. The opposition was virtually the same as in the years before Three Mile Island: 26 percent. But only 36 precent described themselves as supporters, and 38 percent said they hadn't made up their minds -- a sharp change from the past. Strikingly, men are twice as likely as women to support nuclear power. Among men, 49 percent said they were supporters, 24 percent were opponents and 27 percent were uncertain. Among women, 24 percent said they were supporters, 27 percent opponents and 49 percent uncertain. The poll also uncovered another sharp difference in attitudes toward nuclear power: people who are now served by nuclear power plants, or who think they are, tend to be far more supportive of it. Twenty-two percent of those interviewed thought their areas got power from nuclear plants. Among them, half described themselves as supporters of nuclear power plants, one quarter said they were opponents and another quater said they hadn't made up their minds. Among the other 78 percent of the population, 32 percent described themselves as supporters of nuclear power plants, 26 percent said they were opponents and 42 percent said they were uncertain. The Post asked people who thought they were not served by nuclear power plants whether they would approve or disapprove construction of a nuclear plant in their area -- "that is, within a five-mile radius of where you live." The question was based on a similar one asked by the Gallup Poll in 1976, when 45 percent said they would be against such construction, 42 percent said they would not be against it, and 13 percent said they were not sure. In the Post poll, 56 percent said they would disapprove construction of a plant near then, 28 percent said they would approve and 16 percent were uncertain. Most of the opposition, of course, came from people who said they were opponents of nuclear power. Almost universally, they also were opposed to having a plant installed near them. But those who have not made up their minds about the future of nuclear power were also overwhelmingly against having a nuclear plant in their midst. Only 15 percent of them said they favored such plants, 57 percent said they were opposed, and 28 percent said they were not sure Even among supporters of nuclear power, 26 percent said they would oppose a plant near them. Seven percent were undecided and 67 percent said they would approve. Representatives of the electric power and nuclear industries, appraised of The Post's findings, said that reluctance about local nuclear plants may be largely unrelated to fears of nuclear mishaps. "The fact that people don't want a major installation in their neighborhood is not surprising," said Scott Peters, a spokesman for the Atomic Industrial Forum, trade association of the nuclear power industry. "It's consistent with general reluctance to get some kind of big operation, an industry, going up in your backyard." Bill Morris, vice president for communications of the Edison Electric institute, trade association of the electric utility industry, said, "We're not surprised . . . people don't want to live near airports, don't want offshore drilling rigs to mar their views off the beaches . . . it's just anti-facility, not anti-nuclear." However, those views do not account for the change over time -- the sharp rise of opposition to local nuclear plants between 1976 and the aftermath of Three Mile Island in 1979. Peter Franchot, of the Union of Concerned Scientists, a Massachusetts-based group critical of nuclear energy, said, "Every poll taken since Three Mile Island shows that the public has soured on nuclear power . . . Its not true that people oppose any kind of a facility. Several polls have shown they make a clear distinction between nuclear plants and other kinds."