Bomb Design Bars Test Ban, Pentagon Says

The Reagan Administration is opposed to the comprehensive test ban proposed by the Soviets because the National Weapons Laboratories have designed nuclear bombs of such fragile sophistication that they must be constantly tested, according to a Defense Department official.

Although President Reagan’s five predecessors in the White House sought a complete ban on nuclear testing, the Defense Department now maintains that the design of America’s strategic weapons precludes such an agreement.

According to Frank Gaffney, deputy assistant secretary of defense for nuclear forces and arms control policy, the designers of the United States’ current nuclear arsenal “did not emphasize aspects of warhead design which would enhance weapon endurance in a no-test environment.”

Gaffney’s explanation of the Administration’s lack of enthusiasm for the Soviets’ proposal appeared in a letter he recently sent to Rep. Edward J. Markey (D-Mass.), who made the document available to The Times.

“I find it incredible,” Markey said, “that they have never taken account of the possibility of a test ban when they’re designing warheads.”

Markey, a proponent of such an agreement, charged that, “after reviewing this letter, I can only conclude that the Pentagon and the weapons labs are now trying to torpedo prospects for negotiation of a test ban by trying to convince people that there are insurmountable technical obstacles to a comprehensive test ban agreement.”

The Gaffney letter fuels a long- simmering dispute over the feasibility of such a moratorium, which has been opposed by the federal weapons laboratories at Los Alamos, N.M., and Livermore, Calif. The debate has flared recently as the result of the Soviets’ unilateral moratorium on testing, which was announced before the Geneva summit conference and then extended until April 1.

Both superpowers have agreed to observe a ban on atmospheric testing and a restriction holding underground tests below a 150-kiloton threshold. When they signed the Limited Test Ban Treaty in 1963, both sides pledged to pursue a ban on all nuclear testing.

Argument Used With Carter

When the Jimmy Carter Administration came close to concluding such an agreement with the Soviets, however, the directors of Livermore and Los Alamos met with the President to argue for the necessity of continued testing. The Reagan Administration broke off talks with the Soviets on the issue, but according to Arms Control and Disarmament Agency spokesman Robert Shields, negotiating a comprehensive test ban is “a long-term goal of the United States.”

In his letter, Gaffney agreed that “a comprehensive test ban, or CTB, that strengthens global stability and enhances security has been a long-term objective of the United States for some time,” but he added: “A CTB in the foreseeable future would not strengthen stability but rather lead to a less secure and more dangerous world as the nuclear nations, unsure of the reliability of their nuclear weapons, increased their stockpiles to compensate for this uncertainty.”

Gaffney was expanding on views presented to Congress earlier by representatives of the Livermore Laboratory and challenged by Markey in a letter to the Pentagon.

‘Assumption’ of Testing

Last September, Roger E. Batzel, director of the Livermore Laboratory, told a panel of the House Armed Services Committee that nuclear weapons “were designed under the assumption that nuclear testing would continue.” Batzel added that “the designs would have been very different if the guidelines from the government had placed primary emphasis on stockpile longevity.”

Paul Brown, Batzel’s assistant for arms control, advanced the same argument in an internal Livermore memo.

Aims of Earlier Policy

If America’s current nuclear arsenal could not survive a test ban, its construction represents a departure from earlier U.S. policy, according to Glenn Seaborg, who headed the Atomic Energy Commission from 1961 to 1971. In a letter to Markey, Seaborg wrote: “Our national policy was to seek a verifiable Comprehensive Test Ban Treaty, and the development and building of nuclear weapons were conducted with this objective in mind.”

Seaborg, a Nobel Prize winner in chemistry, added: “I do not recall that the proof testing of stockpiled nuclear weapons was ever an issue in this connection. It is my impression that the same situation prevailed during most of the 1970s.”

Designs of the 1960s

Seaborg’s views were communicated to Gaffney, who disagreed in his letter to Markey: “The consensus to maintain vigorous nuclear testing and weapons development programs and strong weapons laboratories provided the context for national decisions of the 1960s which determined the structure and characteristics of the nuclear forces we have today. Those decisions did not emphasize aspects of warhead design which would enhance weapons endurance in a no-test environment.”

Markey, however, challenged Gaffney’s assertion that an adequate defense requires the testing of nuclear explosives. “We have never conducted any statistically significant number of explosive proof tests of the warheads in our arsenal. . . . We already rely on non-nuclear testing to provide most of our information on the performance of our warheads. Proof tests are very, very rare.”

Just what is tested at the Nevada test grounds operated by the two labs for the Energy Department is classified information. The directors of Livermore and Los Alamos lobbied Carter against a test ban on the grounds that testing was essential, but others familiar with the program, such as former Los Alamos Director Norris Bradbury, deny the necessity of such tests.

Political Motive Charged

Livermore physicist Hugh E. DeWitt charged in an article in the November issue of the Bulletin of the Atomic Scientists that nuclear-weapons design once was compatible with a comprehensive test ban, but that, “by the summer of 1978, the policy--or the weapons laboratories’ understanding of the policy--had changed.” He argued that it was changed to provide political ammunition against the test ban treaty then being considered by the Carter Administration.

Some proponents of an end to testing argue that non-nuclear testing combined with remanufacture of weapons according to original specifications will ensure stockpile reliability. Others say that unreliability of the arsenal is itself desirable, because if the superpowers do not trust their weapons to explode on command then they will not trust them in a nuclear first strike.