April 15, 1987

April 15, 1987 | Backgrounder on National Security and Defense

U.S. Nuclear Testing: Enhancing Deterrence Mackubin Thomas Owens


(Archived document, may contain errors)

576 April 15,1987 J U.S. NUCLEAR TESTING ENHANCING DETERRENCE INTRODUCTION The United States detonated its first nuclear test of 1987 on February

3. Three weeks later, the Soviet Union triggered its first test of the ye ar. And Britain, France, and China are continuing their nuclear weapons test programs As nuclear testing continues, so do debates over banning or limiting it. Pending in Congress is legislation that would deny funds to test nuclear weapons with a yield in excess of one kiloton, that is with an explosive force e ual to 1,000 tons of TNT (current testing is limited by the Threshold Test Ban Treaty to yie 7 ds of 150 kilotons).

Proposals to halt or limit underpound nuclear tests have been discussed for years. They have not been approved because significant and persuasive objections have been raised.

For one thing, any testing agreement with Moscow requires foolproof verification of Soviet com liance so far, Moscow has refused to agree to such verification pro cedures. For arms control. To the contrary. Until strategic defense systems replace the current deterrent based on offensive weapons, testing will be essential to ensure the effectiveness and reliability of these weapons. Doubts about weapons reliability d estabilizes the U.S.-Soviet nuclear relationship Testing Warhead Reliability. So long as the U.S.-and Western world therefore depend on the nuclear deterrent for their security, it will be necessary that the weapons com rising the warheads in the inventor y . In addition, and as important, testing is the only means to modernize U.S. weapons and improve nuclear weapon safety, security, and survivability including strategic defenses, communications and e uipment. U.S. national security and anot K er thing, it is not at all certain that halting or limiting nuclear testing would advance that deterrent work as designed. Nuclear testing is the only way to verify the reliabi P ity of continued deterrence thus depend on continued nuc P ear testing.

WHY THE UNITED STA TES MUST TEST Assess Weapons Flaws Instead of exploding nuclear devices, say some experts, it would be sufficient to test nonnuclear components of nuclear weapons and use computer simulations of nuclear explosions. This, in fact, can prodde useful informa t ion. But because of the extreme complexity of nuclear weapons, no simulation can provide the results that are obtained from the actual testing of their nuclear components. Nuclear weapons are fabricated from chemically active materials which may possess m u tual1 incompatible properties. As *a needed to ensure that these changes do not lead to weapons failure. result of subtle changes, the behavior of these materia r s is often unpredictable. Tests are Experience also shows that all flaws cannot be accounted for by design, extrapolation, or inspection alone. Only testing can assess the impact of unpredicted deterioration of nuclear materials and ensure that ro osed design changes will work. Testing alone ensures that the U.S. nuclear stocLig is reliable and c a n serve as a nuclear deterrent Undiscovered Problems. Since 1958, over one third of all weapons designs introduced into the U.S. stockpile have suffered reliability roblems. Without nuclearl reliability problems have affected, among other systems, the W47 warhead percent of these problems would have gone un dp iscovered and uncorrected submarine-launched ballistic missile (SLBM the W68 warhead for the Poseidon SYM and the W56 warhead for the Minuteman Intercontinental Ballistic Missile (ICBM).

Some claim t hat a decline in stockpile reliability is a good thing, reducing the likelihood of a disarming first strike, since reduced stockpile reliability increases uncertainty, which is the basis of deterrence. In fact, the opposite is 'ust as likely to be true: a decline in nuclear weapon reliability could rompt a first strike. dormer Acting Assistant Secreta of Energy degradation. As reliabili declines, the attacker ains a significant advantfge by launching Donald Kerr has testifie B that suMval favors the attack e r after a certain level o 7 stockpile a first strike, since he has 7 ess to fear from the de B ender's retaliatory force etrically. Because of differences in weapons 2 esigns and materials, the reliability of ST economize on the use of special nuclear mat eria P (enriched uranium, lutonium, and emphasize throwwei ht (a measure of what a &si 'r e can launch at a target) and volume.

The Soviets have a d ve-to-one advanta e in ICBM throwweight over the U.S which also a higher yeld longer than smal f er U.S. we apons Five-to-One Soviet Edge. U.S. and Soviet stoc iles in any event would not degrade t e U.S. stockpile is likely to decline faster. The reason: U.S. desi ners emphasize smaller, more accurate mssiles, and warheads o timized for each elivery system. Th e y tritium and give hiEh priority to safety and securi devices. Soviet esigners, by contrast means they have developed lar er and eavier ICBM warheads. These are likely to retain 8 a a 1. Roger E. Batzel, Director, Lawrence Livermore National Laboratory, b e fore the Senate Foreign Relations Committee, January 15,1987 2. Jack Rosengren in Report of the Special Panel on Arms Control and Disarmament, House Armed Services Committee, January 1986, pp. 127-157 3. House Armed Services Committee, Effects of a COmDre h enSiVe Test Ban Treav on United States National Securitv InterestL August 1415,1978 (HASC No. 95-89 p. 30 2As reliability declines, moreover, military planners would seek to counter increasin shifting to hi her yield weapons Thus, in the absence of testin the downward trend in U.S. again would have to begin uilding monster-sized missiles and warheads uncertainty about warhead reliability by assigning more warheads to a given target an d by B numbers an t yields of U.S. wea ons since the early 1960s wou d h a ve to be reversed. The g Modernize Nuclear Stockpile Testing is needed to modernize the. U.S. nuclear arsenal. This modernization has four 1) Ensure objectives to the U.S. nuclear weapons ro am. nuclear explosions, to prevent t K8 e ispersal of whi f e no t causin a nuclear detonation, still could scatter nuclear materials. Such accidents and finally to mnimize radiation exposure to personnel handling weapons I Consider the use of Insensitive High Explosive (IHE) in nuclear weapons. A nuclear explosion is i n itiated b means of a high explosive charge. There always has been the dan er that in an acci 2 ent involving nuclear weapons the detonation of the high explosive occurred in 196 near Palomares, Spain, and in 1968 over Thule, Greenland. In neither incident was there a nuclear detonation, but plutonium was dispersed over a wide area.

These events led to the development of IHE as an explosive that would not detonate in an accident. Without nuclear testing such a major safety improvement could not have been ac hieved t 2) Improve effectiveness. U.S. strategic doctrine has evolved from massive nuclear retaliation to flexible res onse, re uiring a more diverse stockpile composed of a variety of warheads with a range oryelds. 3esting has enabled development of new warheads for small, low-flying cruise mssiles; for the fast, low-flying B-1 bomber; for the mobile Pershing II missile; and for other weapons designed for purposes other than a massive nuclear exchange wea om designed for one articular set of targets ma n o t be as effective against another have buried deeply their command and control centers. One potential U.S. response to this would be to develop warheads designed to penetrate the earth before exploding. To do so requires testing. And it was testing which ermitted develo ment of the development of new bombs for the low-flying B-

1. Bombs desi ned for the high-flying substantially different warhead design 3) Respond to the changing threat. Soviet targets and defenses change constantly. U.S kin B of target. E xample: t K e Soviets have hardened t B eir missile silos with concrete and nuclear-tipped Air-Launched Cruise Missile A& M) for the B-5 s bomber and the B-52 cannot be used on the B-1, because the speed and angle o 9 delivery requires a of the weapons in the stockpile. Testing has ena E led the U.S. to develo smaller warheads testing claim to want a more survivable and stable deterrent, yet wit B out testing 4) Preserve strategic stability. A critical com onent of strategic stability is survivability that ennit smaller delivery systems, such as cruise missiles and mobile CBMs. These smal P er systems are harder for the Soviets to locate, more easily hardened, and better hidden. Mobile nuclear missiles are more survivable and less destabilizing than missile s in fixed silos. Testing is required to develop the warheads for mobile s stems. Opponents of H 3survivability would be more difficult to op onents of testing claim to What is puzzling, moreover, is that many warheads for those new systems mobile missile o r the Trident su g marine, yet they oppose the Ensure Equipment Functioning in a Nuclear Environment function in a nuclear environment. The Defense the vulnerability of cratering and ground shock; 3 Electromagnetic Pulse (EMP 4 electrical and optical nucl ear effects; and 5) weapons and defenses to directed-energy weapons developed nonnuclear simulation techniques.

SDI weapons, communications, and systems, especially space-based systems, is critical to an effective strategic defense. Testing those systems a gsunst nuclear explosions is the only way to make them as survivable as possible against attack by nuclear armed weapons Testing subjects military equipment to nuclear effects to determine whether it will effects Other thinti

an radiation of nuclear Such tests have uncovered vulnerabilities in U.S. military systems undetected by highly Testing is very important for the Strategic Defense Initiative (SDI The survivability of Avoid Technological Surprises of any claim facilities , and plutonium and other the concepts that have usually identified with scientists. Consequently and to prevent the U.S. from being is critical that the U.S. keep have made Kennedy's Complaint. This the U.S. failed to do durin the 1958-1961 U.S.-Soviet nu c lear testing moratorium. Complained President John F! Kennedy on March 2,1962 Some may urge us to try [a moratorium] again, keepin our preparations to test in a constant state of readiness. fut in actual practice, particularly in a society of free choice w e cannot kee topflight scientists concentrating on the on an uncertain date in the future. Nor can large technical laboratories be kept fully alert on a standby basis waiting for some other nation to break an agreement. This is not merely preparation o P a n experiment which may or may not take place 4. This is an important but little discussed aspect of testing. The limited U.S. capacity to produce spekial nuclear materials has forced U.S. weapon laboratories to economize in thekdesigns. This results in ex t remely close tolerances and specifications in U.S. weapons, requiring that they be tested more often than if U.S. designers were unconstrained by materials' availability, as is the case with the Soviets 4difficult or convenient-we have explored this altgm ative thoroughly, and found it impossible of execution.

During the three year moratorium the Soviets maintained their technical base and repared in secret to conduct the most intensive series of nuclear tests in history before greaking out of the moratorium in 19

61. By contrast, it took the U.S. nearly a year to restore its testing capabilities.

Kennedy's advice remains valid today OTHER ISSUES In 1986, the House of Representatives Passed legislation prohibiting tests over 1 kiloton.

The Senate is expec ted to ass similar legislation this year. Some see such proposals 'as a kilotons. This already im oses serious constraints ample: high yield earth penetrators first step toward a compre K ensive test ban. Current1 U.S. testing is limited to.150 cannot be t ested against B eeply buried targets In testimony last January before the Senate Forei Relations Committee, the directors of the Lawrence Livermore and Los Alamos nationa P laboratories said that slashing the testin threshold to 10 kilotons or even 1 kilo t on, the most frequently pro osed linuts function of on some systems; and tests of the x-ray laser, including defenses a ainst it, would be recluded. At 1 kiloton the function of fission triggers (primaries! could not be verified kgh explosive primaries co uld not be put on old secondaries; and most x-ray laser research could not be conducted woul*ce unrealistic demands on weapons designers and lead eventu aK y to a serious degra ation of ile reliability. At 10 kilotons, testing that is necessary to veri

th e warheads such as those designed for the ICBM missile, the Trident 11 missile, would not be possible; fission triggers could not be tested VERIFICATION AND COMPLIANCE As part of his compromise with Con ess prior to last October's Reyk'avik summit Ronald R ea an agreed to submit the Xeshold Test Ban Treaty TI'Bd and the Peaceful needed for ratification. Xouph sir treaties have never been ratified testing limit that the treaties would impose U.S. e erts believe, however, that the Soviets Reagan sent the two t reaties to the Senate this January, accompanied by a "reservation ed in the mid-1970s by the U.S. and the 5 SSR, these Nuclear Exp f osions Trea (PNET) to the Senate for the advice and consent rocess have exceeded the 150 kiloton limit on as many as 2 occ a sions Fish with certainty whether a Soviet test yields '3E 5 'lotons, 150 kilotons, or even 300 ki otons 0th countries claim to have observed the 150 kiloton that would prevent them from taking effect until a more effective verification method is accepted by the Soviets. Seismographic e ui ment is not precise enough to distin If the test ceiling were reduced below 150 kilotons, verification would be even more difficult while the relative benefits derived from cheating would be far greater 5. Department of E nergy, Policy Paper 5 Nuclear Weapons Testing January 1987, p. 15 5THE 1958-1961 MORATORIUM I The history of the test ban teaches a valuable lesson. In the expectation that a testing halt would be the initial step toward negotiations ending nuclear testin g permanently, the Eisenhower Administration on October 31,1958, a eed with the Soviets jointly to observe became stalemated, Eisenhower declared that the U.S. would not be bound by the moratorium when the year's term expired in 19

59. He did promise, howe ver, that the U.S. would not resume testing without pnor notice. Soviet leader Nikita Khrushchev replied that the USSR would not test either, adding that the country to resume testing first would be acting "illegally and immorally The moratorium remained i n effect for another twenty months a one year moratorium on nuclear testing. When t lr e talks on a comprehensive test ban On Au st 30,1961 the Soviet Union announced its resumption of testin Just two days later oscow triggered the most intensive series o f nuclear tests in wor f d history. In U.S. for t R e Soviet breakout, th t it was months before the Atomic Energy Commission test two weeks after t f e Soviet breakout, by which time the Soviets already had exploded 10 60 days the Soviets conducted 40 tes ts, including numerous multi-megaton tests in the atmosphere, and the largest single explosion ever conducted, a massive 58 megaton blast.

So scru ulously had Washington observed the moratorium and so ill-prepared was the rh could conduct a high 'eld test or 11 atmospheric blasts with a total yield of nine megatons e U.S. conducted a miniscule two kiloton underground U.S. POLICY LESSONS The experience of the 1958-1961 moratorium provides lessons which proponents of a new moratorium should heed. Among them W hen not testing, the U.S. technological ar'id scientific base deteriorates ra idly and technical work, virtual1 came to a complete halt. In the Soviet Union, apparentl the Soviet breakout confirms preparation effectively extra olate performance from alrea d y known information. There alwa s are war 'R eads suffered unanticipated deterioration and showed serious reliability problems when testing was resumed after 1961 The Soviets test episodically and can afford sustained breaks in testing once a series has b e en com leted. Evldence sugjgests that when the Soviets declared their moratorium in test series. The situation was the same when Moscow announced its unilateral moratorium During the 1958-1961 moratorium, many peo le critical to the nuclear pro am le K th e national laboratories. Activities at the Neva B a test site, including test rea f iness activities laboratories continued wor h 'ng and the test sites were ready for action. The extent o I the su rises," whic K only testing can discover and correct. Seve r al different types of L.S 1958 they ha 2 just completed a major series of tests, but the U.S. was just about to begin a Without testing, many weapons problems go undetected. Scientists cannot 6. It has recently been revealed that the US. conducted small n u clear experiments for safety reasons during the 1958-1961 moratorium. By no stretch of the imagination can these be called nuclear testing. They certainly did not prepare the U.S. to respond to the massive Soviet breakout. Robert N. Thorn and Donald R. We s tervelt Hydronuclear Experiments Los Alamos National Laboratory Report LA-10902-MS, February 1987 6- I in August 1985, which lasted until the Soviet tests this year. Before proclaiming the 1985 moratorium, the Soviets conducted a flurry of tests CONCLUSIO N Nuclear weapons are the cornerstone of the U.S. nuclear deterrent and will continue to fulfill this role as long as the Soviets maintain their current superiori in conventional limitations before these goals are accomplished damages U.S. security and con t ributes nothing to arms control. A test ban, after all, does not eliminate a single warhead Achilles Heel. The nuclear testing issue is potential1 the Achilles Heel of U.S defended by the administration. Other national security issues have been given prio r ity over testing. This situation is improving, but until Ronald Reagan unequivocally declares that the U.S. nuclear testing program is essential to the national security, testing o ponents essential relationship between nuclear testing and U.S. security f o r the foreseeable future wea 011s. If a future arms control a reement significantly reduces o 2 ensive weapons and can fl e verified, then further testing f imits may be pursued. But to push for testing national security, because until recently U.S. testi n g PO r icy has not been adequately will have a chance of seriously curtailing or even ending it. Reagan should make c f ear the I Prepared for The Heritage Foundation by Mackubin Thomas Owens, Ph.D Dr. Owens, a former congressional and Energy Department a ide, soon will join the faulty of The Naval War College 7-

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