The Reagan administration's policy of strongly supporting nuclear power while dismantling many government conservation programs is unlikely to attract widespread public support and may actually be solidifying opposition to nuclear power, a new Washington State University study suggests.

"Devoting major efforts toward nuclear power at the expense of conservation may very well prolong the high level of opposition to nuclear power," warn researchers Eugene Rosa and Marvin Olsen.

Based upon an extensive survey of attitudes in the western states and a review of trends in recent national polls, they conclude that the public climate for nuclear expansion is less favorable now than at any time since the period immediately following the 1979 accident at Three Mile Island.

And, they note, the administration's proposal to speed up licensing of nuclear plants flies in the face of increasing local opposition to having such plants in their own communities.

In general, they found a "low level" of support for nuclear power and a "high level" of support for conservation and suggested that a policy which "makes room for both options" might be most successful.

But "the public has been almost completely ignored" by policy makers, the Washington researchers complained in a presentation yesterday at the annual meeting of the American Association for the Advancement of Science.

A survey they conducted this year of nearly 10,000 American households concentrated largely in 10 western states found that solar energy enjoys the largest support--over 90 percent of those surveyed--while nuclear is the choice of less than 50 percent.

"Nuclear power comes out dead last every time," said Rosa in a press conference on the session.

The survey revealed, however, that the public was not polarized into simple "pro" and "anti" categories. Instead, said Olsen, the western survey found four groups of attitudes over a wide range.

While there was an even split, at 30 percent each, between those who were essentially pro- or anti-nuclear, the rest of the population showed mixed reactions. About 20 percent favored both nuclear and conservation policies, while the other 20 percent said they were not in favor of either option.

The survey also found that there were strong differences among the pro- and anti-nuclear groups. The nuclear proponents were more likely to be male, older, homeowners, longtime residents of their communities and in the highest income category. They tend not to view the energy situation as serious, said Rosa and Olsen.

Regardless of policy preference, they found that three-fourths of those sampled favored energy conservation practices, including mandatory programs.