Life nearly imitated art a decade ago in a nuclear technology that supposedly couldn't fail.

In nearby Harrisburg, a theater showed "China Syndrome," a movie in which a nuclear accident threatened to wipe out an area "the size of Pennsylvania."At 4 a.m. on March 28, 1979, movie fantasy turned horribly real at the Three Mile Island power plant as a series of human and mechanical failures nearly triggered a nuclear disaster along the Susquehanna River.

By 8 a.m., after cooling water was lost and temperatures soared above 5,000 degrees, the top half of a reactor's 150-ton radioactive core collapsed and melted. Contaminated coolant water escaped into a nearby building, releasing radioactive gases.

Frightened by reports of uncontrolled radiation releases and a potentially explosive hydrogen bubble in the damaged reactor, as many as 200,000 people living within 50 miles of the plant fled. Women and children within five miles were advised by Gov. Dick Thornburgh to leave.

The accident was contained, but it intensified fears about the potential dangers of nuclear power, killed plans for new U.S. plants, and left a once-complacent nuclear power industry defensive about its abilities.

Robert Long, director of planning and nuclear safety at Three Mile Island, recalled that before 1979 people in the industry were confident a serious accident was all but impossible.

"All of us felt it was just really remote," he said. "There are still people in the industry who think, `It couldn't happen to us.' We're constantly trying to remind people it could happen to anybody."

The health effects continue to be debated. The utility says radiation doses outside the plant during the accident were less than background radiation, and 10 national and state studies found no evidence of increased human cancers or other serious problems in animals or plants. Anti-nuclear activists claim the studies were flawed and say they have seen evidence of increased cancers, medical problems in animals and vegetation mutations. Studies will continue for years.

General Public Utilities Corp., the New Jersey based owner of the plant, suffered greatly. It lost a nearly $1 billion investment in the just-opened Unit 2, was vilified for mangling the region's psyche and teetered on the edge of bankruptcy until a cleanup financing plan was put in place in 1985 and its other reactor at Three Mile Island returned to service later that year.

After overcoming both financial and technical pitfalls, the nearly $1 billion cleanup should be completed late next year. Seventy-one percent of the core has been shipped to federal research laboratories in Idaho, and GPU is being hailed by the industry as a model utility.

"We're trying to recognize people do make mistakes, but we're going to do what we can to learn from those mistakes," said Michael Roche, director of Unit 2.

For most of those who live near Three Mile Island, this week's anniversary will be just another day. But local activists will hold a vigil outside the plant, talk with reporters and recall those eerie days of 1979.

Two citizen groups, Three Mile Island Alert and Susquehanna Valley Alliance, have doggedly monitored plant activities and called attention to shortcomings in cleanup and operations. They also tried to block the 1985 restart of the Unit 1 reactor.

"This is a utility that has lied, cheated and was convicted of a felony," said Eric Epstein, a spokesman for Three Mile Island Alert. "In our opinion, it lacks the requisite competence and character to operate a nuclear plant."

He referred to a guilty plea in 1984 for the use of false leak test results at Unit 2's cooling system before the accident, to accusations the company made false statements to the Nuclear Regulatory Commission and to a cheating scandal involving operating personnel who took licensing tests in 1981.

"I think there are still underlying concerns, but people are getting on with their lives," said Joel Roth, a former chairman of Three Mile Island Alert.

"Underlying it, there is still quite a bit of feeling . . . the utility is going to do what it wants to do regardless of what anybody else does," he said.

One of the surprises of the accident was that the China Syndrome - a chain of events in which molten fuel burns through a reactor and containment building and spews radioactive steam into the air - can be stopped once started.

Although 50 percent of the uranium fuel melted and 20 tons of molten material flowed within minutes to the bottom of the steel reactor vessel, the remaining water cooled it and held it in place.

"As a result of TMI-2, there has been a rethinking of severe accident consequences and it's still going on today," said Roche, the Unit 2 director.

Harold Denton, the agency's director of government and public affairs, said that without the addition of cooling water three to four hours into the accident, "it would have penetrated the reactor vessel and that would have been a really severe accident."

Denton, whose calm, knowledgeable style calmed many of the region's fears during the accident, was regarded as something of a hero.

Over the years, the owner of Three Mile Island has mounted extensive public relations campaigns, telling people it has learned the accident's lessons and has demonstrated since 1985 it can safely operate the Unit 1 reactor while continuing the cleanup.

The company says it has retrained operators, given them better designed controls and helped develop state-of-the art cleanup techniques. Operators now have monitors that, if in place during the accident, would have alerted them within two minutes that the core had lost cooling water, Long said.

One remaining issue is GPU's plan for long-term monitoring of Unit 2. About 290 pounds of nuclear fuel will remain in hard-to-reach places, but the company says there will be no chance of any chain reaction or other dangerous condition occurring.

Another issue is what to do with 2.3 million gallons of once-contaminated water left from the accident and its aftermath.

The company was blocked from dumping the filtered water into the Susquehanna and now proposes spending $7 million to boil it away over two years. Small amounts of radioactive cesium, carbon and strontium in the water would be removed and packaged before evaporation. Traces of radioactive tritium would remain in the water and be released to the atmosphere, but the company says that would pose no threat to the public.

Despite the passage of time, many people remain anxious.

Thomas Bailey, 28, a lawyer whose family fled the area during the accident, said he is so concerned about what he feels are hazards from the evaporation plan that he and his wife have decided not to have children.

"People are getting apathetic," he said. "They don't think they have any effect or can have any effect. They feel the NRC and GPU can do whatever they want."

People "don't perceive the crisis because the utility says there is no problem," he said. "I think there is a problem anytime they want to release additional radiation."