ABC correspondent Tom Schell surveyed the sleeping bags and tents scattered about a gentleman farmer's field, a disappointing first turnout for the big nuclear blockade. "I've worked on farms where there were more people," he said.

Members of the Abalone Alliance, one of the antinuclear coalitions here, have been philosophical about the slow start for the plan to field thousands in a blockade of the Diablo Canyon Nuclear Power Plant. "It takes a while to get a big car rolling," one said. By yesterday, about 1,400 had arrived, but it was unclear if they would exceed the estimate of 1,500 compiled by the state attorney general whose staff called many of the state's antinuclear groups and asked how many they were sending.

That is more than enough for the San Luis Obispo County Board of Supervisors, who remember that it cost them an extra $100,000 just for the arrests and trials of 400 demonstrators at the plant in 1978. This agricultural county of oak trees, dry grass and coastal fog, about 150 miles northwest of Los Angeles, now has more than 150,000 residents, its numbers swollen by retirees and vacationers from San Francisco and Los Angeles who care less about the $7 million in taxes the nuclear plant has brought in and worry more about its potential safety hazards.

Board Chairman Steve MacElvaine, leader of a three-man pro-plant Republican majority, approved an antinuclear rally in 1979 on the grounds of free speech, but wondered about his decision after his constituents complained bitterly about the 20,000 people who jammed the main roads with automobile traffic.

The numbers will be nowhere near that great this time, for the antinuclear groups are insisting protesters take anti-violence training and many of the thousands or so already here are only providing support and will not participate in the actual blockade. "I'll take care of child care, pets and things like that for people who are arrested," said Paul English, a naturalist from Santa Barbara.

If the demonstrators fall short, the numbers of reporters, cameramen and photographers should more than make up for them. That is just as well for the demonstration, since the workers and nuclear fuel the blockade is supposed to keep out are already safely inside the plant and fuel loading will eventually proceed whether the demonstrators surround the plant or not. The only thing left is a media victory.

More than 100 news people fill the motels already, fighting for space with parents here to settle their children in for the fall semester at California Polytechnic State University.

News organizations have been anticipating this event for months. Sheriff George Whiting met media representatives in July and arranged a complex pool for reporting any arrests inside the plant's outer fences. The demonstrators have promised not to try to penetrate the inner fences, which are eight feet high and patrolled by dogs anyway. The television networks spent $8,000 of two microwave units to get pictures from inside the plant perimeter and transmit them to Fresno.

Beside the networks, television stations from San Francisco, Los Angeles, Santa Maria, Fresno and other cities have sent crews, sometimes lining the side of the demonstrator's camp like carnival barkers as they do their evening "live" feeds.

When the demonstration happens, Whiting said, he will have to worry about the helicopters.

Every TV channel in the state seems to have one, ready to rattle over the plant to catch action from the air. "We've also got National Guard choppers, Pacific Gas & Electric Co. choppers," he said, noting the hazard they present when the fog comes in. He said: "It'll look like 'Apocalypse Now' if they all swoop down."

The Abalone Alliance took its name from the accidental death of about a thousand of the beautiful mollusks during construction of the plant in 1974. John Sumner, a nuclear engineer with Pacific Gas & Electric, shakes his head at the memory of the event. About 5 percent of the abalone in Diablo Cove died from exposure to small amounts of copper which had accumulated in seawater flushed out of the plant's cooling system.

Pacific Gas & Electric spent $10 million to replace the copper piping with titanium. Then the abalone, supposedly safe at last, were wiped out by sea otters that chose that moment to migrate from the south, Sumner said.

"They were very expensive abalone," he said.