Soviets May End Moratorium : Arms Reliability an Issue as U.S. Continues A-Tests

When the Defense Department discovered in the 1970s that fully half of the 5,000 nuclear warheads on its Poseidon submarine-launched missiles would not work because the chemical triggers had deteriorated, it ran some nuclear tests to correct the problem.

And when the B-1 bomber was being developed, the Pentagon needed a new nuclear bomb to replace the model carried by the slower and higher-flying B-52 because the old bomb would explode under the B-1 or crash into the ground without detonating. Again, nuclear testing provided the answer.

It is for just such reasons that President Reagan, who has repeatedly refused to join the current Soviet nuclear test moratorium, has approved yet another underground shot today in Nevada. The weapon to be tested is reportedly a small bomb of 1.3 kilotons--equal to 1,300 tons of TNT.

The test--No. 772 since 1945 compared to 564 for the Soviets--will probably trigger the resumption of Soviet testing after a nine-month pause. The Soviets have said that the first U.S. blast after March 31 would halt their unilateral moratorium.

The House tried to head off such an outcome in February when it adopted a resolution calling on Reagan to negotiate an end to nuclear testing. House liberals urged Reagan on Monday to halt the latest test, and a spokesman for Greenpeace, an aggressive anti-nuclear group, said that six of its members will try to prevent the shot by trespassing at the test site.

But to the President, nuclear testing is too important to give up. “A limited level of testing assures our weapons are safe, effective, reliable and survivable,” he told Congress last month, “and assures our capability to respond to the continued Soviet nuclear arms buildup.”

The Reagan Administration also contends that the Soviets “likely” have violated an existing agreement to limit underground weapon tests to 150 kilotons or less. It also argues that verifying compliance with a total test ban, as the Soviets are seeking, is impossible at this time.

“Any limitations on nuclear testing must be compatible with our security interest and must be effectively verifiable,” Reagan told Congress. “Because of the continuing threat that we face now and for the foreseeable future, the security of the United States, its friends and allies, must rely on a credible and effective nuclear deterrent.”

Arguments of Testing Foes

Test ban advocates, such as the Arms Control Assn., dispute the Administration on every count. They contend that non-nuclear testing would provide all the necessary information about the reliability of the U.S. nuclear stockpile, that no certain Soviet violations have occurred and that a total ban could be “adequately verified.”

Soviet leader Mikhail S. Gorbachev, who has sought to seize the high ground on the issue by embarking on his testing moratorium, has loosened the Kremlin’s stand toward on-site inspection of Soviet nuclear test facilities.

“For us,” Gorbachev declared in his Jan. 15 proposal, “verification is not a problem.” If the United States accepted his offer, he said, “appropriate verification of compliance with the moratorium “would be fully assured by national technical means as well as with the help of international procedures, including on-site inspections when necessary.”

This was the first time that the Soviets had accepted on-site inspection of a moratorium, U.S. officials said.

Kennedy Precedent

The Gorbachev proposal recalled President John F. Kennedy’s move in mid-1963, declaring a U.S. moratorium on atmospheric tests as long as the Soviets did the same. Moscow followed suit and agreement was reached within two months to bar all tests in the air, sea and space. It remains in effect.

Two other U.S.-Soviet test ban agreements have been signed but have not been ratified by Congress: the 1974 Threshold Test Ban Treaty, which bars underground tests of weapons with yields of 150 kilotons or more, and the 1977 Peaceful Nuclear Explosion Treaty, which sets the same yield limit on non-weapons tests.

For the last three years, the Reagan Administration has charged that the Soviets have “likely” violated the 150-kiloton limit in “a number of instances.” It reduced the figure on these alleged violations a few months ago when it revised its formula for using seismic data to estimate the strength of Soviet underground nuclear tests. But although the effect was to reduce the estimated yield of past Soviet tests by about 20%, the Administration still insists that 10 Soviet tests have violated the 1974 treaty.

To improve test-monitoring accuracy, Reagan has invited the Soviets to send a team to the Nevada test site to calibrate their seismic measuring instruments during an underground test. The Soviets, presumably knowing that a reciprocal invitation would be expected, have not responded.

Not Just Verification

For all the U.S. charges that the Soviets have refused to allow the United States to verify whether they have lived up to existing treaties, a senior U.S. official conceded that “verification is a necessary but not sufficient condition” for ending nuclear tests. Even if the United States could be certain of detecting Soviet cheating, the Administration would still want to continue nuclear testing.

That is because the Administration insists on guaranteeing the reliability of U.S. nuclear weapons. Under current procedures, one of the first weapons off each production line is detonated, and after that, nuclear tests are conducted when a weapon’s continuing reliability is questioned.

The Administration has supplied a House Armed Services subcommittee with long lists of weapons defects that it says have been detected by nuclear testing.

But opponents such as Jack Mendelsohn, deputy director of the Arms Control Assn., deny that nuclear testing is necessary in most cases. Seven former weapons scientists, led by Nobel Prize-winning physicist Hans Bethe, wrote Congress last year that they could find no case in which “the discovery of a reliability problem (was) dependent on a nuclear test, and in no case would it have been necessary to conduct a nuclear test to remedy the problem.”

Disassemble Samples

The scientists said that “the best way to confirm reliability is to disassemble sample weapons and subject the components to non-nuclear tests. Weapons can also be detonated without their nuclear components to ensure the complete assembly operates correctly.”

The Administration responds that nuclear tests are sometimes critical. Such was the case, officials say, when a new warhead was developed for the submarine-launched Polaris missile to replace a warhead whose safety device failed to release.

One official said that a test ban would leave the Soviets marginally better off than the United States because their new weapons usually represent evolutionary improvements over old ones, while new U.S. weapons more often embody revolutionary advances, the reliability of which requires testing.

Both sides agree that testing is necessary to develop bold new weapons such as the exotic beam weapons for the Administration’s Strategic Defense Initiative, or “Star Wars.” But if a test ban meant that the development of such weapons had to stop, that would be fine with arms-control advocates.