CLAD IN HEAVY, dark blue raincoats, the policemen shifted their feet nervously on the broken asphalt parking lot and peered into the dense forest beyond the barbed wire fence as raindrops splattered about them. Puddles. Lots of them. Cops and reporters, too. Not on mention an 80-per-cent complete atomic power plant. But where were the anti-nuclear protesters, the non-violent commandos who were planning to scale those eight-foot tall barriers and stage a mass-occupation?

Behind the officers--a few of the 500-plus who were bussed in for the occasion--stood the containment building which will enclose the nuclear core, that energy-and-radiation-producing network of fuel rods, uranium pellets and cooling pipes. The containment, looking out over Long Island Sound, its grey exterior matching the thick cloud covering above, was the symbol of the nuclear power plant; to those who had come to protest it, it represented all that was evil about nukes. Though no protesters would actually reach the reactor building that Sunday afternoon (and only one tried), it was visible throughout the 850-sq.-acre enclosed construction site, its presence felt.

Now it was shrouded in mist, as the cops awaited the onslaught to come. "Wait til you see the whites of their eyes," advised one, grinning, continuing the lookout. Despite the battlefield small-talk and virtual siege-mentality that permeated the Shoreham, N.Y., nuclear power plant, June 3 was a day for handcuffs made of clear plastic rather than sharp metal, for mostly friendly rapport between arresters and arrestees that one demonstrator called "surreal," for a day of protest that mixed earnestness and euphoria but, except for one incident of dubious origin, excluded confrontation.

The numbers would appear in the newscasts that night and the papers the next day: nearly 600 charged with criminal tresspassing in the largest act of anti-nuclear in the largest act of anti-nuclear civil disobedience since "the Seabrook 1414" in April 1977, and over 15,000 at a separate legal rally held on a strip of beach a mile from the Shoreham reactor.

Demonstrators had visited the $1.5 billion plant, which the Long Island Lighting Co. (LILCO) plans to open in December 1981, before. In 1978, 40 were arrested in a similar, but much smaller, occupation attempt. At the time, the organizers--the SHAD (Sound/Hudson Against Atomic Development) Alliance--had informed police of the details beforehand, where and when protestors would go over the fence. But SHAD modified its tactics, trying to preserve some element of surprise, and Suffolk County police did not find out about plans for the occupation until a deputy commissioner picked up a leaflet when he went to see The China Syndrome.

ALTHOUGH "non-cooperation" was one of the day's many buzzwords, both sides had taken pains to avoid violence. After joining "affinity groups" of 10 to 20 people, all participants in the occupation attempt had received eight-hour training sessions in civil disobedience, with an emphasis on getting the point of the protest across without provoking police. There were strict groundrules: no alcohol, no drugs; no destruction of LILCO property, and above all, no running--that might cause panic.

Estimates for the number of occupiers ranged from a few hundred to 1000. No one knew quite what to expect. Ira L. Freilicher, a LILCO vice-president, set the tone at a 10 a.m. press conference; if they don't leave, they'll be arrested-we've got a plant to build here and we don't plan to remain occupied." But, he added, "we don't want to see people hurt and we don't intend to get physical if they don't.

Security was tight. If you didn't have one of the laminated photo-identity badges distributed by LILCO, police arrested you (two reporters were taken into custody after their badges were misplaced). Police later said they had received a report that a sniper was planning to hide at the site and pick off protesters. He never showed up.

At the rally, thousands of demonstrators trekked down an access road lined with hawkers trying to sell "No Nuke" t-shirts, and pamphleteers who would attempt to convince you that nuclear power was not only dangerous, it was racist, sexist, militaristic, anti-gay and a tool of imperialist capitalistic corporate exploitation as well. Then past tables filled with anti-nuke and alternative energy literature and finally down a dirt path to the beach, were old reliables like Dave Dellinger, former anti-war activist, and George Wald, Emeritus Professor of Biology, would speak and Pete Seeger and others entertain. Just before noon, a sign reading "Plutonium Is Leaking!" was unfurled, but the only visible emission came from the skies, as the rains began; protesters, police and LILCO personnel alike would get soaked for the rest of the day.

Those at the rally realized that much of the action would be going on down the road at the plant, but listened attentively as speakers condemned nukes and urged their extinction. Then, at about 2:30 p.m., came an electrifying message: "We have a special announcement to make: 560 people have just gone over the fence at Shoreham." The crowd roared out its approval, at the action and at the number.

ITHAD BEGUN, Around the perimeter of the main construction site, but mostly from the east where the terrain was easier, groups of "CD people" carried ladders, ropes and blankets (for protection from the barbed wire). "They're everywhere!" a LILCO official reportedly said as he watched them arrive via closed circuit television monitors in the utility's security trailer. They trudged along the fence until they found a nice spot to go over, wished each other and the support--SHAD lawyers, medics, etc.--good luck, then did what they came to do.

In most spots there was no tension at all. Policemen on the inside assisted protesters to a safe landing, sometimes adjusting ladders to make sure they were secure. "Be careful," they said.

"There, that was easy," chirped a blonde teenager in a raincoat as the bounded to the pavement.

"Hi," smiled the waiting policeman, "welcome to Shoreham." And then he arrested her, still smiles all around. The scene was repeated, with variations, hundreds of times that afternoon. Some of the protesters were grim, earnest in their belief that stopping Shoreham was a realistic possibility: "We can't let it open," said one, "I live near here." A protester explained to the officer who arrested her, "You don't understand that we're doing this for you, it's your kids that we're trying to protest." others said the protest was very nice and all that, but doubted it would have a great effect on Shoreham. "This plant is going to be finished, let's face it," an arrested protester said, "but we have a statement to make and we've gotta make it. We're unalterably opposed to nukes."

While for the most part accepting SHAD's policy of nonviolent protest, some expressed impatience with the American anti-nuclear movement and waned that future protests might not be so peaceful. Many were new to the movement, joining after the Three Mile Island accident in March, and this was their first protest. They mixed with old vets, who wore buttons proclaiming earlier arrests at Seabrook, N.H., or Rocky Flats, Colorado. About half the protesters went limp to emphasize their non-cooperation.