The uranium business is as potentially volatile as the mineral itself. Public fears, government regulation and shifts in national energy policy cause the price of uranium to be more difficult to predict than, well, who will push the next A-bomb button.

Which is why, if a company gambles big on uranium and happens to win, it takes on a sort of supernatural winner's glow.

The United Nuclear Corp. (UNC) glows from the tinted windows on its new circular headquarters in Falls Church to the faces of executives, company news releases and its 1977 recent annual report, there is reflected a sheen, the victor's gloss that comes from good gambling and lucky politics.

Three years ago UNC showed a net loss of $4.7 million. In the fiscal year which ended last March, net earnings exceeded $21 million. Next year, company officials say, should be even better. Reversals like that don't happen every millenium, in any business.

Try to suggest to Keith A. Cunningham, UNC's 54-year-old lawyer president, that the reason for his company's mushrooming figures is a jump in the price of uranium from $8 per pound in 1973 to around $40 today. Just try it.

"Some people would say the cause of UNC's affluence is that the price of uranium has gone up," Cunningham began. "That's a bunch of crap. We are affluent at this time because we were able to take advantage of earlier opportunities."

Those opportunities go back 21 years and include several mergers, the purchase of five mines in New Mexico from the Phillips Petroleum Co., and the acquisition of the Teton Exploration Drilling Co. in Wyoming.

The big gamble, though, was played over the last three years when UNC - with revenues of $170 million, a small fry by energy industry standards - poured $100 million into new mining facilities and exploration.

"We have invested more, for a company our size, to push capacity and develop reserves than anyone else in the business," said Cunningham. "The capital investment we've made is almost out of proportion to our capacity."

The result is that little UNC is giving such mining giants as Kerr-McGee. Arco's Anaconda and General Electric's Utah International, a run for their geiger counters. It now sits on about 100 million pounds of uranium reserves - nearly a tenth of the U.S. total.

It's not sitting on them literally, of course. Falls Church as far as anyone knows, has no uranium deposits. Which suggests the question: Why last fall did UNC's corporate staff move to suburban Washington instead of, say, to suburban Albuquerque?

The answer which UNC officials sometimes give is that Cunningham wanted to live in Virginia. Cunningham doesn't think that's especially funny, or true, although he admits to liking Virginia.

The reasons he gives for the move are these: He wanted easy accessto financial community in New York. UNC has $78 million in outstanding long-term loans, and expects to ask for more.

He also wanted proximity to the Capital because, in his words, "the uranium industry is uniquely subject to government regulation."

Like many, probably even most, businessmen who come under the government's scrutiny. Cunningham believes politicians and bureaucrats aren't very understanding of business interests. They aren't, he says, because they don't see how business operates.

The way to better relations between government and business, according to Cunningham, is for more corporations to set up headquarters on the outskirts of Washington.

Lately, politics have been breaking in UNC's favor. President Carter's decision to ban plutonium - a blow to the nuclear industry - has meant a boon for unranium producers, for without the more efficient plutonium technology, consumption at nuclear power plants is certain to go up.

This is one reason for the recent jump in uranium prices. The other is the oil embargo.

Until 1969, the price of uranium was controlled by the Atomic Economic Commission and averaged about $8 per pound. The commission began to ease out of the industry and by 1971 its purchases had dropped to zero. But commercial demand was slow to pick up, causing prices to slide a bit. But when oil became a scarce commodity in 1974, values soared.

Rumors that an international cartel were forcing the price up became more than gossip when Westinghouse, which was caught short holding $2 billion worth of long-term uranium supply contracts promising cheap uranium to utilities, filed an antitrust suit against UNC and 28 other uranium producers.

UNC officials say a cartel did exist, but deny they were a part of it.

More important than the Westinghouse suit is a complex legal wrangle UNC has begun against Gulf Oil, whose General Atomic Co. contracted several years ago for what amounts to about a fourth of UNC's unranium reserves at a mere $10 per pound.

UNC wants the contract dissolved and is charging Gulf with fraud, deceit and antitrust violations.