Capitol Hill's star player in the growing drama of Clinch River and the plutonium breeder is Sen. Frank Church (D-Idaho), whose liberal past led the White House two months ago to think he would back their move against Clinch River.

If anything, Church has been the most vocal and effective spokesman for Clinch River. He has astonished the White House, which has tried to paint Church as an unwitting victim of industry lobbying for Clinch River. At which Church bristles and to which Church replies: "That's ridiculous."

Church points out that two experimental breeders (EBR-1 and 2) have quietly been making plutonium and power in his home state for 20 years. Church doesn't believe the notion that plutonium is "the most dangerous substance known to man." Church also believes that stopping Clinch River will not stop plutonium breeders in other countries. He calls the closing of Clinch River a "step toward nuclear isolationism."

Ever on the attack, White House aides point out that Church's Idaho stands to receive $500 million over the next seven years in research grants if Clinch River stays on the books. They also point out that 200 breeder jobs will come to Idaho on top of 7,800 nuclear jobs already in place at the Idaho National Engineering Laboratory in Idaho Falls.

White House aides also point the finger at Church's long friendship with Orval Hansen, a former Idaho Republican congressman now with the law firm of Doub, Purcell, Muntzing and Hansen. William Doub and Manning Muntzing are former associates at the Atomic Energy Commission and Nuclear Regulatory Commission and their clients include the pronuclear government of Iran and members of the nuclear industry.

So strong is Church's friendship with Hansen that one lobbyist had this to say: "Hansen is the key guy in getting to Church. The time you get with Church depends on Hansen."

Church points out that it would be odd if he were not friends with Orval Hansen, who served three terms as one of Idaho's two congressmen and who spent part of that time on the Joint Committee on Atomic Energy.

"He's an informed man whose judgment I've always respected," Church said of Hansen. "I have discussed the Clinch River breeder with Hansen as I have with many other people, including Ralph Nader's group, Jim Cubie and Friends of the Earth. I've tried to see everybody on both sides of this issue and discuss it with all of them."

Finally, Church says with some dismay that the White House has solicited few of his views on the topic. He said he met once with Deputy Under Secretary of State Joseph Nye at Church's request and had a very unsatisfactory discussion with Nye about it.

"It was a hurried affair because he had to go somewhere else," Church said of his meeting with Nye. "I do know that if I were persuaded that the President's program was drected at solving the problem of weapons proliferation I would favor it. I don't think that has been the case."