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.

It went on for nearly four hours, a continuous stream. Knots of arrested protesters at just inside the fence, singing or chanting anti-nuke slogans, or chatting amiably with police while waiting to be taken to precinct headquarters in Yaphank for booking. "If any of you people would like a piece of gum I have some in my back pocket," offered one teen-ager, her bands bound behind her back. "I can't get it, of course...."

BUT IF YOU watched the news that night--the 20 seconds or so devoted to Shoreham by the networks--those aren't the scenes that hit the screens. The focal point of the occupation attempt was the plant's front gate, right in front of most of the press, LILCO officials and police. That's where the only violence of the day took place, when about 15 youths (apparently unconnected with SHAD) decided they would like to storm the place. So they charged the gate repeatedly, kicking and bloodying the hands of LILCO employees who tried to hold it up, and eventually knocked it over. Curiously, though, a no-man's land opened up as the youths backed off instead of entering, and the fence was repaired.

"They're nice people," muttered a LILCO security man sarcastically as he went for first aid, "they didn't mean no harm." The incident gave LILCO spokesman Jan Hickman a chance to lash out at SHAD: "I don't know if SHAD was directly involved, but this is not 'nonviolence' and it wouldn't have happened if it weren't for the kind of emotional garbage SHAD has been putting out."

Informed of the violence, some SHAD protesters worried about the adverse publicity it might generate. Said a man from New York, "we're not here to piss people off or alienate them, we're here to make a point."

By the end of the day, most seemed satisfied that they had. As the cameras continued to roll and dusk approached, the last groups went over the main gate. They had debated for two hours whether doing so might prove an unnecessary provocation because of the earlier incident. Almost all of the final 100 went limp and had to be dragged off are carried away on strechers. The crush of onlookers artificially heightened the tension, as policemen occasionally knocked down ladders or pushed protesters. But by then, people were more tired and wet than angry.

Security for the protest cost LILCO an estimated $250,000, and the Suffolk Co. police $150,000 more; the expenses, naturally, would be passed on to ratepayers and taxpayers. The occupation attempt brought construct on, normally light on a Sunday, to a one-day halt, a short-lived moral victory. Proceedings for the arrested clogged District Court in Hauppauge for a week, and about half of the protesters have turned down an offer to have the charges dismissed in six months and instead opted to plead not guilty and demand a jury trial. Self-defense, they'll say, and repeat their case to all who will listen when the trials open in September. Maximum penalty for criminal tresspassing is 90 days in jail and a $500 fine, but no one expects any prison sentences.

Asked at her arraignment bearing how far she thought the protests would go, whether she thought they would remain non-violent, a middle-aged woman who had just joined the movement said," I don't know, but I'll do whatever it takes to stop that plant from opening.

"Wow," she added after a moment, somewhat "I never thought I'd be saying stuff like that."