As a political issue, nuclear power has everything going for it.

The facts are nearly all in dispute, and where they are not, their meaning is. Nuclear energy is second in complexity only to the strategic arms limitation treaty, but nearly everyone has an opinion about it. Best of all, the experts are in total disagreement, so the field is clear for the politicians to take over.

This, at least, is the gloomy view at the Nuclear Regulatory Commission, where most of the people see their futures shadowed by looming political decisions that cannot be anything but bad.

Legislation pending in Congress variously would speed up the NRC's licensing process for new reactors or halt such licenses for a year or more. Some bills give the NRC a club with which to force state governments into coming up with complete evacuation plans; others give the states a club with which to force the NRC to keep reactors outside their borders.

And antinuclear organizers nationwide have promised to make nuclear politics a major factor in the 1980 elections.

"You get driven first one way and then the other way," complained NRC Chairman Joseph Hendrie in a recent interview. "What you try to do is take some kind of a middle road."

The still-developing NRC response to the near-disaster at the Three Mile Island nuclear plant is probably crucial to the future of nuclear politics."That really scared people . . . the tougher they (the NRC) are on the industry now, the more they can reassure people and defuse the fear a little," said a Capitol Hill staff member involved in the issues.

Industry leaders tend to agree. "We're only as credible as the NRC is," said one prominent spokesman. "We try to maintain a good working relationship with them."

In the past, however, that has meant the kind of low-pressure, non-aggressive monitoring that nuclear critics now condemn.

More than 250 NRC inspectors made 3,000 visits to operating reactors last year, and in 40 percent of those checks they found health and safety violations, NRC figures show. Yet only six civil penalties or fines were levied. The other cases either still are pending or were resolved after oral or written notice to the utility.

This is partly because "the laws that set up the NRC are a mess," said Leonard Bickwit, the NRC's general counsel. Endless legal wrangles inevitably follow any stiff NRC action, and the only alternative to the wrist-slap of a fine (maximum penalty: $258000) is a total plant shutdown.

When asked whether the NRC would like Congress to give it more flexible weapons, however, several staff members said no. "The industry will move mountains to avoid a shutdown . . . All we have to do is be a little more willingg to go that far," said one.

But a shutdown makes the industry look bad to the public. Convinced as most NRC personnel are that nuclear power is essential if the country is to have enough electricity in the coming years, they are working overtime to make both the NRC and nuclear power look strong and responsible.

Not many in the NRC are yet sure it can be done.

The NRC was not set up to control accidents but to license nuclear facilities and check their safety. No other regulatory commission does more than spot-check its targets, assume honesty in most cases after an accident, checking the debris for clues.

But as the Three Mile Island incident wore on, it became evident that the public expected more from the NRC*. "We relied on quality control systems of the manufacturers and the (utility) operators for the simple reason that we didn't have the resources to do otherwise," said Commissioner Richard T. Kennedy in an interview. "Now we have to invent machinery for crises whether we like it or not."

If the NRC is to become both a tough watchdog over every aspect of nuclear power and also a SWAT team capable of defusing any reactor crisis, it will require an internal overhaul that is only just beginning.

More than 3,000 "events" at reactors are reported to the NRC every year. Some are trivial: burned-out fuses or frozen pipes, leaky valves or other problems of the sort that afflict every power generating unit, whether it burns coal or splits atoms.

Others signal deeper problems and are more important especially with the benefit of 20-20 hindsight. But studying these reports is a task the NRC has never managed to organize.

The valve that stuck open at Three Mile Island, allowing cooling water to escape and uncover the core, for example, previously had stuck open in other reactors. A consultant's report that said a misleading water gauge might cause trouble in the future was never circulated in the NRC - until the gauge misled the operators at Three Mile Island.

The NRC has a list of 130 safety issues that it thinks apply to all its nuclear plants. These range from sudden bursts of water pressure that can fracture pipes to the effect that warm water discharged from cooling plants may have on surrounding land.

The list was divided in January, after years of delay, into high and low risk items, but little has vet been done to deal with the issues.

In the past, those witthin the NRC who brought up succh problems and others with political repercussions faced social ostracism as traitors to the nuclear cause and occasionaly were hounded from their jobs. One, who calls himself a gadfly, said that, under Hendrie, dissenters have been encouraged to come forward. But he noted: "A lot of the same people are in the same places and still resent any challenge . . . Things don't change overnight."

A major worry is that the nuclear industry and the reactors themselves already may be too much like juggernauts rolling beyonnd the capacity of any agency to control.

"I think the plants are too big," said Robert Minogue, chief of the NRC's standards division. Nuclear technology invented for 100 to 300 megawatts of power generation has been stretched to build giant reactors turning out 1,000 megawatts and more.

"Eventually you stretch beyond a line in which the thing becomes a different object altogether," Minogue said. "I think the industry crossed that line . . . at about 600 megawatts."

The NRC limited reacttor size to 1,100 megawatts long ago, but the larger units are notorious for difficulties. The solution, said Minogue, is to "regulate the hell out of them . . . but the agency is way too small in view of the complexity of the industry."

In reply, industry spokesmen say a NRC does not have enough people who understand the balance sheet problems of utilities. Floods of trivial instructions bury the crucial ones, and changes in requirements frustrate attempts to comply, according to one respected industry source.

"There's no objection to serious people questioning what they (the utilities) do . . . but the NRC has knuckled under to the most frivolous questions raised by people who only want to delay everything possible and kill any nuclear efforts whatever," said Milt Copulos, a nuclear energy analyst for the conservative Heritage Foundation.

Yet no one denies that objections from outside the circle of experts have improved reactor safety over the years. The question is how the NRC will respond to all these conflicting pressures.

Minogue said there will be "more emphasis on an army of inspectors and hardware engineering standards." Hendrie said operator training and procedures, mostly left in the past to individual utilities, are "core matters" in which the NRC will become involved.

Telephones linking each reactor to NRC headquarters already have been set up to speed communications "and as a signal that we intend to have a role in any emergency," said Commissioner Victor Gilinsky. Industry teams are testing procedures and reactor design systems to come up with improvements before the NRC orders them to do it.

"It's clear the tolerance of the machine for goof-ups has declined over the years," said Edson Case, deputy director of nuclear regulation.

"Congress wants us to issue licenses faster but it wants the reactors cheaper and safer at the same time . . . I think getting along with Congress is impossible until there's a consensus on nuclear power among the people.

"Until then," Case said, "We're going to get the blame for whatever happens, so we might as well take over as much as possible." CAPTION: Picture, CHAIRMAN JOSEPH HENDRIE . . . "driven one way and the other"