THE AMERICAN process seems infinitely capable of creating peculiar exceptions to its own passions, which is part of what makes our nation so much interesting than most others. Europeans, in those choice moments when they express themselves honestly, are apt to explain us away as dingue : There's no accounting for crazy Americans.

This season, the national passion for new energy is launching a thousand position papers and a flood tide of dollars. We shall roll up our sleeves and go get it. Even if we must tear apart the Colorado mountains to squeeze oil from the rocks.

Meanvhile with hardly a nod of public recognition, this nation has effectively put a "stop order" on nuclear power. We reject one technology for its unknown hazards, one which the rest of the industrial world is embracing. And we rush off to develop other technologies which have their own lethal qualities.

I am not attempting to find here the fundamental answer on nuclear power - whether America is leading mankind in the right direction or has taken a wrong turn all alone.

My head tells me it's right to stop nuclear expansion for the moment until all the hard questions are answered satisfactorily, until the industry faces the problem of waste storage convincingly, for instance.

But my bones tell me it's a wrong turn. My hunch is that after a decade of filling our air with coal soot and polluting more rivers with acid mine drainage and killing thousands of miners and threatening the globe's atmosphere with too much carbon dioxide, we will take a second look at nuclear technology and decide that it's not as scary as we thought.

The synfuel warriors, signing up for Jimmy Carter's coal war, ought to read the very scary report on carbon dioxide accumulations in our atmosphere, submitted recently to the Council on Environmental Quality. This pollution has the potential of upsetting the global balance of weather and water within a few decades. Burning plain ol coal and oil is bad - but burning synethetic fuels is nearly twice as bad.

Of course, I could be all wet, as I often am. Perhaps someday a nuclear disaster in France or Japan or Russia will convince the rest of the world that the American process, in its own chaotic way, made the right decision first - to turn away from nuclear.

Meanwhile, I am asking an easier question: How was this decision made? Whom should we thank? Or blame? There was no presidential edict, no decisive roll call in Congress, no popular referendum, not even big black headlines announcing the moratorium. It is a classic example of interlocking powers in the American system, a machine of whirling wheels that interact bbut do not control one another.

A lobbyist for nuclear power puts it starkly, perhaps too starkly: "Nuclear is dead. Forget it. There's no way a utility is going to order one now. You won't see another nuclear plant order until the middle '80s, when we start having rolling brownouts, like the gas lines. That's when the recriminations begin. Who lost our electricity?"

I checked his gloomy forecast with several analysts at investment banking firms - men who are paid to make accurate forecasts on the energy business - and with several political types. They agree with the lobbyist's diagnosis of the present, but believe the pressures for nuclear may come back sooner than 1985, perhaps in two or three years after our recession. To be precise, we ought to say that nuclear development is not exactly dead, but in 1979 it slipped deeper into a death-like coma.

To understand these interlocking wheels, one begins with the creakiest one - the electric utilities industry - which plodded along happily for 25 years on postwar growth, assured profits, no competition and no back talk from the customers.

"If the utility executive makes a mistake, somebody pats him on the head and gives him and 8 percent return," the lobbyist said. "That's what he's used to. He can't operate in this new environment. The utilities are scared witless." Actually, he didn't say witless, he used another word.

The new environment includes post-OPEC conservation by America's electricity consumers, particularly American business, and the compelling critique from anti-nuke scholars and propagandists. Tweny-five years ago, the private utilities demanded and won from the Eisenhower adminstration the right to develop atomic power power generation as a private business. That decision had profound safety implications nsee Alvin Weinberg's account in the summer issue of the Wilson Quarterly), but economic insecurities caught up with nuclear first.

Utilities were accustomed to a robust growth rate of 7 percent in electricity consumption. They ordered new nuclear plants confident that, when the juice started flowing 7 to 10 years hence, a growing market would absorb it. By 1975, in the era of higher energy prices and soaring utility bills, they began to grasp that their world had changed.

Growth in energy consumption fell rather dramatically, down to 4 or 5 percent, and suddenly those long-term commitments to vastly expensive nuclear plants didn't look so assured. All projections became very shaky. Since 1975, only two new nuclear plants have been ordered, both by Commonwealth Edison of Chicago, which is already heavily committed to nuclear. Commonwealth Edison's two orders may have involved a bit of pro-nuke boosterism.

In the same decade, the federal government stepped back a pace. For a generation, the old Atomic Energy Commission played cheerleader and sponsor, providing discreet subsidies and political protection for the atomic wonders. The Nuclear Regulatory Commission, created in 1974, was intended to become an earnest regulator, instead of a rich uncle. Meanwhile, some nuclear scientists were sharpening their questions and the anti-nuke movement began to gain momentum. If these power plants are engines of Armageddon in our midst, it is a righteous cause. Yet it reminds me occasionally of the farm laborers rioting against the steam-driven tractor or newspapers inveighing 80 years ago against the dangers of new-fangled automobiles.

In any case, nuclear growth stopped four years ago - 1979 was going to be the year when the nuclear industry broke out of its moratorium - through political action more than economic factors. If Congress could be persuaded to shorten the regulatory process, sped up the time it takes to build and operate a nuke, then maybe those nervous-Nelly utility execs would start ordering again. That was the industry's implicit political goal, and the campaign was well underway.

Then the gauges went crazy at Three Mile Island. A scary episode indeed. It seems tiresome to keep stating that nobody got killed; obviously public opinion doesn't find that fact ver reassuring. The event seemed to confirm the anti-nuke prophecies of a disaster in our future.

On Capital Hill, senators and representatives began searching for an anti-nuke vote they could take home to show the folks that they are zealous watchdogs. The political backlash will get worse in the next 18 months, the lobbyist predicts.

"Your're going to start seeing Republicans and conservative Democrats opposing nuclear," he said. "They're getting too much heat on it, and they aren't willing to go under for that issue."

The president will proceed as a tepid advocate of nuclear expansion at his own peril. In New Hampshire next winter, a state which just defeated a pro-nuke governor, Jimmy Carter will confront an army of anti-nuke activists knocking on doors in behalf of Jerry Brown and a non-nuclear future.

So now the cautious utility executive faces higher hurdles. If he plunks down a billion dollars or two on a 10-yeear gamble on futurre electricity consumtption, he risks a stockholder lawsuit. Will the public let him turn it on 10 years from now? Beyond that, he will have lots of trouble convincing Wall Street to lend him the capital at a reasonable interest rate. Then he has to ask: where will we build it?

The public opinion polls still show about 46 percent of the people in favor of nuclear, roughly an even split with the opposition. But the crucial point is that most Americans (2-to-1) do not want a nuke in their neighborhood. This is the reverse of popular sentiments two years ago. As Public Opinion magazine put it so felicitously, the atom splits the sexes - women oppose neighborhood nukes much more strongly (66 percent) than men (46 percent).

If the public is scared, can politicians be far behind? Yet thee nuclear industry, more than ever, needs political action in order to revive. Whither America? The de facto moratorium gives both sides an opportunity of sorts. The anti-nuke movement will be pounding nails in the coffin, in the form of additional regulatory safeguards. The industry will be trying to clean up its act and convince us that it has solved the safety problems so long unsettled.

My hunch is that, given the cautious self-interest of private investment decisions, the nuclear question will wind up approximately where the development of synthetic fuels has arrived - directly in the hands of the federal government. This scenario is already popular among some business types, who foresee an ultimate up-or-down political decision someday.

One investment analyst put it thus: "Industry will say: If the government wants these nuclear plants, you're going to have to build them and give them a clean bill of health before we can take the risk."

Maybe a few power brownouts will lower public resistance to nuclear, the way gas lines soften us up for price increases. Or another accident will confirm public fears. It seems a rather crude way for a nation to make its fundamental choices, bruising one another until necessity yields a decision. But that is the American process. Usually, it does produce its own rough reason. Like other human systems, it also makes mistakes. CAPTION: Picture, Three Mile Island nuclear power plant.