Ground Zero Week, which ends today, caused a loud detonation in some communities and fizzled in others, while extraordinary national media attention brought the issue of nuclear war into tens of millions of American living rooms.

The success of this unprecedented attempt to educate America on the risks of nuclear weapons was not easy to measure, as its organizers acknowledged. "We never offered this course before," said Roger C. Molander, the former National Security Council official who dreamed up Ground Zero in the aftermath of the Soviet invasion of Afghanistan in December, 1979. "We had no idea what to expect."

There were Ground Zero activities in more than 600 communities around the country, from New York City and San Francisco to Marinette, Wis., the town where Molander grew up. The Washington area had a range of activities. More than 350 college campuses staged events, and altogether, hundreds of thousands of Americans took part.

In some communities where organizers had expected impressive events, the results were disappointing. In Albuquerque, N.M., a full schedule of rallies, lectures and slide shows was poorly attended. One event on the University of New Mexico campus attracted two participants.

Similarly, in New Orleans, Baton Rouge, Houston and Austin, Ground Zero events drew only small audiences.

In other communities, Ground Zero activities drew more attention. A rally in Detroit attracted 2,000 people; in Los Angeles County, 400 mayors and county officials met to consider the impact of a nuclear attack in their area.

Nowhere did Ground Zero provoke huge rallies or protests, but that was never its purpose, according to organizers. "We're not talking about big demonstrations in the street," said Josh Baran, the San Francisco Bay Area coordinator of Ground Zero. "We're talking about educating the public, and that's better done in small groups."

Some Bay Area events were deliberately kept small. More than 400 people were turned away from a lecture by activist Daniel Ellsberg at Diablo Valley College, special correspondent Debbie Prager reported.

Molander said it might take a long time to measure the impact of Ground Zero and related efforts. "I'm looking forward to some polls" in the weeks and months ahead, he said.

Molander intends to keep the Ground Zero organization operating, and has begun to plan next spring's activities. He said that the paperback book he and his brother, Earl, wrote as part of their educational campaign, "Nuclear War, What's In It For You" is now in its fourth printing, with 250,000 copies in circulation.

Six months ago the Molanders wondered if anything at all would materialize during Ground Zero week, and they considered abandoning it. Two months ago the whole project, short of funds, almost collapsed.

But interest in the nuclear issue has burgeoned in the last two months. Calls for a Soviet-American freeze on nuclear weapons backed by a mushrooming grassroots organization have attracted wide attention. A doctors' group called Physicians for Social Responsibility has been proselytizing widely on the dangers of nuclear war.

The sudden prominence of the nuclear issue was a boon to Ground Zero, particularly because it produced so much media attention. In recent weeks Time and Newsweek have devoted cover stories to the nuclear issue, and major newspapers have covered it extensively.

During Ground Zero week the television networks gave wide coverage to nuclear matters, bringing them to the attention of a huge audience. The ABC and NBC evening news programs gave substantial coverage, and morning television on all three networks did long segments on the issue. Thursday night, ABC's Nightline devoted an expanded program to a discussion of nuclear issues involving live satellite hookups to Moscow and Munich as well as American cities.

All this attention on nuclear matters is a dramatic departure from recent times, as Sen. Daniel Patrick Moynihan (D-N.Y.) noted in a Ground Zero speech Friday at Cornell University. During the Senate debate on the second Strategic Arms Limitation Treaty (SALT II) in 1979, Moynihan said, he got more mail from consituents about an endangered species of wildlife than about the arms treaty.