U.S. to Stop Production of H-Bombs : Defense: Bush decision will mark the first time since dawn of the Atomic Age that nation will have no nuclear warheads being manufactured or on order.

President Bush has decided to halt further assembly of the W-88 hydrogen warhead, the last nuclear bomb the United States still has in production, senior Administration officials said Saturday.

U.S. officials said the decision reflects the sharply diminished threat following the breakup of the Soviet Union late last year. Cancellation of the W-88 marks the first time since the start of the Nuclear Age the United States has no nuclear warheads either in production or on order.

The move also will mean major cuts in operations at the controversial Rocky Flats nuclear-weapons plant just outside Denver, which was to have manufactured plutonium triggers for the warhead. The facility has been beset by serious environmental and safety problems. Officials said the Colorado facility would probably lose about 1,000 jobs.

The White House signaled last week that Bush planned to negotiate with the former Soviet republics for a reduction or elimination of arsenals of multiple-warhead missiles, possibly including those in missile-carrying U.S. submarines.

Experts said the decision to stop production of the W-88 suggests that the deal may be further along than had been thought, and that Bush wants to use the cancellation to help prod the republics into going along. The W-88 is the principal bomb used in such missiles.

Bush is expected to seek a reciprocal gesture in a meeting at Camp David with Russian President Boris N. Yeltsin, now scheduled for next weekend. They say leaders of the former Soviet republics generally have been receptive to such suggestions.

The Times reported Thursday that a Pentagon plan to be unveiled when the 1993 defense budget is submitted this month would freeze virtually all future defense programs after the research and engineering stage, putting off actual production of the new weapons indefinitely.

Officials called the proposal a response to changes in the world that give planners a least a year’s warning of any significant need for advanced combat capability.

Officials said the Administration expects cancellation of the W-88, reported by the Washington Post on Saturday, to save about $1 billion, most of which would be used instead to help clean up the environmental damage that has resulted from decades of nuclear bomb manufacturing.

The government already has spent more than $1 billion to repair environmental and safety problems at Rocky Flats.

Although cancellation of the W-88 warhead is expected to curtail most work at the plant, officials said Saturday that some operations, not related to the manufacture of plutonium triggers, probably would be continued when the plant reopens later this year.

Significant as it may be in historic terms, the decision on the W-88 is only the latest in a series of such cancellations.

As a result of earlier arms-control measures, the Administration already has canceled production or development of at least 10 other warhead designs. And with the Rocky Flats plant closed for repairs, the United States has not produced new nuclear warheads since mid-1990.

News of the decision was one of a spate about coming policy changes--both large and small--that have been made public by the Administration in advance of Bush’s State of the Union address Tuesday.

The W-88 warhead, which was to have been used with the Trident II ballistic missile deployed on strategic submarines, has an explosive force equivalent to 475,000 tons of TNT--about 32 times as powerful as the bomb the United States dropped on Hiroshima.

Pentagon officials say with the W-88 no longer available, the United States’ strategic submarines are now expected to use the W-76, a far less-powerful warhead that would be less able to destroy some of the more heavily reinforced targets in the former Soviet Union.

News of the decision to halt production of the W-88 was greeted favorably, both on Capitol Hill and among military experts here. Sen. Sam Nunn (D-Ga.), chairman of the Senate Armed Services Committee, called the matter “a good development.”

Bush’s decision had been expected. As early as mid-December, top Administration officials suggested publicly that the White House may speed up the cancellation of nuclear weapons now that the Soviet threat has diminished.

Energy Secretary James D. Watkins told reporters then that the stoppage would provide an opportunity for the nation to spend the money “in the private sector . . . in a more-productive way.”

Meanwhile, U.S. officials indicated that the Bush Adminsitration would not press Russia or the other former Soviet republics to adhere to the 1972 Anti-Ballistic Missile (ABM) Treaty, which bars most forms of defenses against missile launches.

The Administration has stated that it wishes to renegotiate the treaty to permit limited defenses against accidental or third-country missile launches. Russia and the three other former Soviet republics that have nuclear weapons have not indicated if they are willing to reopen the treaty.

In communications with the former republics, the Adminstraiton has said it expects them to adhere to various weapons pacts, including the Non-Proliferation Treaty and the Strategic Arms Reduction Treaty (START) but has pointedly left the ABM treaty off the list.