Although more Americans now favor caution in the construction of nuclear power plants, a solid majority continues to feel it is important to develop nuclear power to meet the future energy needs of the nation.

These are among the key findings to emerge from a nationwide survey completed Monday, in which certain questions were repeated from a 1976 Gallup survey for comparison purposes.

The percentage of Americans who favor a cutback in nuclear plant operations until stricter safety regulations can be put into practice has increased from 40 percent in the 1976 survey to 66 percent in the current survey.

Helping to explain the sharp change in attitudes are findings from the current survey which show that among the remarkably high proportions (96 percent) of Americans who had heard or read about the Three Mile Island situation at the time of the survey:

Three in 10 (four in ten in the East) were "extremely" (12 percent) or "quite" (16 percent) worried about their own and/or their family's safety in the immediate aftermath of the reactor incident.

As many as four persons in 10 (41 percent) felt the situation was, in general, not handled as well as possible, reflecting the confusing early reports regarding the seriousness of the situation.

Three in every four in the survey (75 percent) think a situation such as the Three Mile Island plant accident is likely to happen again.

While most Americans continue to attach considerable importance to the development of nuclear power, as many as six in 10 (62 percent) say they would object to having a nuclear plant constructed near their home (within a radius of five miles).

This proportion represents a sharp increase since the 1976 survey, when only 45 percent said they would have a similar objection.

Yet, despite these worries, the American people are not ready to reject the use of nuclear power for future energy needs.

In fact, only one American in four (25 percent) favors shutting down all nuclear plants at this time.