The Nuclear Deterrence Role of the DOE Weapons Laboratories in the Post-Cold War Era
November 27, 1995
The end of the Cold War has brought significant changes to the position that nuclear weapons occupy on the international scene. The reduction of tensions between the United States and the former Soviet Union provided the opportunity to reverse the nuclear arms race and allowed the United States to decrease its reliance on the large number of nuclear weapons in the former stockpile as part of its national security policy. In fact, since 1992 it has been U.S. policy not to develop any new nuclear weapons designs. As a result of unilateral actions and because of existing and pending arms control agreements, the United States and Russia have the possibility of reducing their strategic nuclear arsenals to about 3500 weapons, a significant reduction for both nations. Other states of the former Soviet Union will relinquish all nuclear weapons. However, because the total elimination of nuclear weapons is still many years away, nuclear deterrence will continue to be a part of U.S. national security for the foreseeable future. As recently as August 11, 1995, President Clinton stated, "...the United States must and will retain strategic nuclear forces sufficient to deter any future hostile foreign leadership with access to strategic nuclear forces from acting against our vital interests and to convince it that seeking a nuclear advantage would be futile. " To that end, the President considers "the maintenance of a safe and reliable nuclear stockpile to be a supreme national interest of the United States."
The reduction of the U.S. arsenal of strategic nuclear weapons is based on the START treaties--START I and START II. START I, which entered into force on December 5, 1994, commits the United States and Russia to reducing specific strategic nuclear delivery systems by December 5, 2001, with the result that both countries will have reduced their strategic stockpiles to about 10,000 warheads by that date. In separate agreements resulting from the dissolution of the former Soviet Union, the non-Russian successor states that possessed nuclear weapons at the time of the breakup have pledged to return those weapons to Russia for dismantlement and to become signatories to the Non-Proliferation Treaty (NPT) as non-nuclear weapon states. At the present time, the United States is well along in meeting the requirements under START I, and all indications are that Russia is following suit. In addition, the other states (Ukraine, Belarus, and Kazakhstan) appear to be meeting their obligations.
START II commits the United States and Russia to additional reductions in strategic nuclear delivery vehicles, so that by January 1, 2003, each party will have reduced its deployment to about 3500 warheads. START II also requires that intercontinental ballistic missiles (ICBMs) carry no more than one warhead and that Russian heavy ICBMs be destroyed. START II was signed by Presidents Bush and Yeltsin on January 3, 1993, but to date neither party has ratified the treaty, and currently its ratification seems problematic. There are those in Russia who express the opinion that the treaty should be modified to reflect asymmetries between each country's strategic architecture. Concerns are also expressed about whether the limits on ballistic missile defense contained in the 1972 Anti-Ballistic Missile (ABM) Treaty will be continued and, if not, how this will affect further reductions in strategic ballistic missiles. Consequently, the United States is presently proceeding with dismantlement in anticipation that START II will enter into force, but to hedge against the possibility that the START II goals will not be met, the United States may want to retain a stockpile more consistent with START I.
At the same time that nuclear arsenals in the United States and Russia are being reduced, concerns are increasing about the proliferation of nuclear weapons by other states. The discovery of a clandestine program to manufacture nuclear weapons in Iraq, concerns about plutonium production by North Korean reactors, and the potential for diversion of nuclear material, or even weapons, to rogue states or terrorist groups as a result of deficiencies in the secure and accurate control and accounting of nuclear materials in Russia, heighten U.S. concerns. Curbing the proliferation of nuclear weapons and special nuclear materials has therefore become a key element of U.S. national security policy.
Thus, extending indefinitely the 1970 nuclear Non-Proliferation Treaty, the cornerstone of international nonproliferation efforts, became a major U.S. diplomatic effort. States party to the NPT met in April-May 1995 to determine whether to extend the treaty indefinitely or for a fixed period. In discussions leading up to the Extension Conference, it was made clear by many non-nuclear and nonaligned states that significant progress toward a Comprehensive Test Ban Treaty (CTBT) would have to be demonstrated by the time of the conference in order for indefinite extension to gain a significant majority. As a result, President Clinton made the negotiation of a CTBT of highest priority and negotiations were well underway at the time of the Extension Conference. The NPT was extended indefinitely at the April-May conference and the United States is committed to concluding a multilateral CTBT at the earliest possible date.
Consequently, the Department of Energy (DOE), which has responsibility for certifying the safety, security, and reliability of the nuclear stockpile, is faced with a daunting challenge: to be able to maintain, for the foreseeable future, the safety and reliability of the weapons remaining in the nuclear stockpile, without being able to continue nuclear testing of its enduring stockpile. As laid out by the President, meeting this challenge is a necessary condition for the United States to enter into and abide by the provisions of a CTBT. Furthermore, future reductions in the number of U. S . nuclear weapons will likely be contingent upon continued confidence in the remaining weapons, as provided by an effective stockpile stewardship program. This paper presents an overview of the Department's plan for maintaining a safe and reliable nuclear stockpile, how this enables U.S. participation in a CTBT, and the resulting implications for the weapons laboratories managed by the University of California.
The DOE weapons laboratories continue to play a central role in U.S. national security policy. With the end of the Cold War, this role has changed from that of designing, developing, and testing the weapons that made up the U.S. nuclear deterrent, to assuring that deterrent remains safe and reliable in the absence of nuclear testing. The fact that the latter role is possible will allow the United States to enter into a multilateral CTBT, thereby strengthening the nation's nonproliferation goals and reducing the danger of nuclear weapons. The laboratories are also central to the ability to downsize the U. S . nuclear weapons complex and reduce its cost and impact. Although both of these factors help to move the United States away from the nuclear posture of the Cold War to a leadership role in arms control and nonproliferation, it cannot happen unless the laboratories continue to lead in the science and technology of nuclear weapons for the foreseeable future. Without this vital effort, the United States would be unable to assure its continued security in an uncertain world that still possesses nuclear weapons. In addition, prospects of future agreements for additional reductions in strategic offensive arms would be jeopardized if the United States were unable to assure the safety and reliability of its remaining nuclear deterrent.
Since the beginning of the nuclear weapons era, the stockpile has been maintained by a strategy of surveillance, nuclear and non-nuclear testing, remanufacture, and replacement. A significant element of this strategy was the replacement of older weapons types with new designs, thus limiting the lifetime of any weapon in the stockpile. However, during a weapon's life in the stockpile, samples of that weapon type would be periodically removed from the stockpile, dismantled, and examined for defects and deterioration. Nuclear tests could be used to measure the performance of weapons that had been in the stockpile for some time or to provide confidence that a fix to a problem had enhanced, and not reduced, the weapon's performance or safety margin.
The weapons complex was originally sized for significant production of nuclear weapons during the time when new designs were entering the stockpile and the nation's arsenal was considerably larger. Problems in the stockpile would be uncovered through surveillance and testing. If a problem were such as to require remanufacture of an entire class of weapons, the weapons manufacturing complex had the required capability and infrastructure to handle large numbers of weapons. This complex is largely inoperative today. Hence, a new way must be found to maintain the stockpile in the absence of nuclear testing and new designs, and a new approach to remanufacturing is needed.
To meet these challenges, the DOE, working in concert with the weapons laboratories and other elements of the nuclear weapons complex, has developed a program with the following elements:
The stockpile stewardship and management strategy outlined above has provided the President with confidence that the United States will be able to maintain its nuclear deterrent under a CTBT without nuclear testing. Consequently, the President was able to announce on August 11, 1995, his decision to seek a zero-yield CTBT, that is, a treaty that would ban any nuclear weapon test explosion or any other nuclear explosion. This U.S. position should strengthen the ability to conclude CTBT negotiations in a timely manner so that a treaty could be signed during 1996.
Because the President's announcement has eliminated the possibility of low-yield nuclear testing, the constraints on the program to maintain the stockpile are clearly defined and the program can now be fully developed and implemented. This is underway with the support of the Secretaries of Energy and Defense, plus the Chairman of the Joint Chiefs of Staff. The program will be tied to a new procedure for certifying annually that the nation has high confidence in the safety and reliability of its nuclear weapons stockpile. The Laboratory Directors will play a key role in this annual certification. However, to account for the possibility that the stockpile stewardship program could fall short of its objectives, the President also established concrete specific safeguards that define the conditions under which the United States can enter into a CTBT. These safeguards are:
A: The conduct of a Science Based Stockpile Stewardship program to insure a high level of confidence in the active stockpile, including the conduct of a broad range of effective and continuing experimental programs.
B: The maintenance of modern nuclear laboratory facilities and programs in theoretical and exploratory nuclear technology which will attract, retain, and ensure the continued application of our human scientific resources to those programs on which our continued progress in nuclear technology depends.
C: The maintenance of the basic capability to resume nuclear test activities prohibited by the CTBT should the United States cease to be bound to adhere to this treaty.
D: Continuation of a comprehensive research and development program to improve our treaty monitoring capabilities and operations.
E: The continuing development of a broad range of intelligence gathering and analytical capabilities and operations to ensure accurate and comprehensive information on worldwide nuclear arsenals, nuclear weapons development programs, and related nuclear programs.
F: The understanding that if the President of the United States is informed by the Secretary of Defense and the Secretary of Energy (DOE) -- advised by the Nuclear Weapons Council, the Directors of DOE's nuclear weapons laboratories and the Commander of the U. S. Strategic Command -- that a high level of confidence in the safety or reliability of a nuclear weapon type which the two Secretaries consider to be critical to our nuclear deterrent could no longer be certified, the President, in consultation with Congress, would be prepared to withdraw from the CTBT under the standard "supreme national interests" clause in order to conduct whatever testing might be required.[2]
The program outlined above for maintaining the stockpile in the absence of nuclear testing is a necessary condition to allow the United States to enter into a CTBT. Although the basic elements of the program have been spelled out, much remains to be done to implement it. Consequently, it follows that the weapons laboratories, in particular those managed by the University of California, the Los Alamos National Laboratory (LANL) and the Lawrence Livermore National Laboratory (LLNL), will be a central component of this program. There will be a number of implications for the laboratories as a result.
As part of the strategy of downsizing the weapons complex, the laboratories, as well as other elements of the complex, are being evaluated as sites for surveillance, evaluation, repair, fabrication, and replacement of weapons components. In addition to LANL and LLNL, potential sites are the Nevada Test Site (NTS), the Kansas City Plant (KCP), the Y-12 site at Oak Ridge (Y- 12), the Pantex site (PX), the Savannah River Site (SRS), and the Sandia National Laboratories (SNL). One of the principal considerations will be the ability to integrate the R&D, surveillance, and remanufacturing of weapons. Activities (all of which include surveillance) identified to date and their potential locations are:
Weapon assembly/disassembly, including storage of nuclear components of dismantled weapons (NTS, PX, weapons will neither be assembled or disassembled at the weapons laboratories)
Fabrication and testing of non-nuclear components (KCP, LANL, LLNL, SNL)
Nonintrusive modification and recertification of existing plutonium pits[3] for weapon primary stages (LANL, NTS, PX, SRS)
Fabrication of replacement pits and/or intrusive modification and recertification of existing pits (LANL, SRS)
Fabrication of replacement secondary stages and radiation cases (LANL, LLNL, Y-12)
Fabrication and testing of high explosive components (LANL, LLNL, PX)
The DOE is evaluating the alternatives presented above as part of its preparation of a Stockpile Stewardship and Management Programmatic Environmental Impact Statement (PEIS). The Department has already conducted hearings for public comment on its plans and it is expected that a "preferred alternative" for the downsizing of the complex will be announced in early 1996. A draft PEIS will be completed in January 1996, additional hearings will be held in February, and a final decision on the sites for the stockpile stewardship and management facilities/activities is expected in August 1996.
A variety of factors, including environmental considerations, existing capabilities, costs, and workforce availability, will determine the final selection. As a result, the United States will have reduced considerably the size and cost of its weapons complex.
The basic philosophy of the science-based stockpile stewardship program centers on improved scientific and technical understanding and maintaining the required competency to deal with unforeseen problems for the foreseeable future. The program requires greater emphasis on fundamental understanding of nuclear weapons phenomena. It will require a significant increase in computational power on the order of 10,000 times greater than available now (being addressed by the ASCI program). In addition, it will require new emphasis in the areas of remanufacturing (being addressed by the ADaPT program). In particular, these efforts must reduce the footprint, waste, and environmental burden of manufacturing capabilities. New experimental facilities required by the program are generally large, push the state of the art, provide access to new realms of scientific and engineering research, and, in some cases, may be available for research in areas not directly related to nuclear weapons. All facilities will be subjected to thorough evaluation of potential environmental impacts. At this stage in the development of the program, the DOE has made a commitment to the following new facilities, which are targeted for Congressional line-item funding:
Dual-Axis Radiographic Hydro Test Facility/DAHRT (LANL)[4.] An x-ray facility to generate high-resolution images of very dense materials shocked or imploded by high explosive detonations.
Contained Firing Facility (LLNL). An upgrade of a laboratory for studying high explosive detonations.
National Ignition Facility/NIF (LLNL). A large laser facility for studying small amounts of matter at conditions of pressure and temperature approaching those in a nuclear weapon. The NIF will also be used as a test bed to demonstrate laser-induced ignition of tiny capsules of thermonuclear fuel.
Atlas Facility (LANL). A microsecond pulsed-power machine designed to simulate some of the high-energy density conditions produced in a nuclear weapon.
In addition to these proposed new facilities, LANL is upgrading the Los Alamos Neutron Scattering Facility (LANSCE), an existing accelerator-based neutron scattering facility for materials science studies. The upgrade will provide for evaluation of weapons components and will be the basis of a basic science program in materials and life sciences as well as nuclear physics.
[1]For some time before the President's August 11 announcement, Washington policy makers had been considering the possibility of seeking a CTBT that would not exclude low-yield nuclear tests. A stockpile stewardship program that could take advantage of such tests would be configured differently from one without them.
[2] As is standard in all such treaties to which the U.S. is a party, a CTBT will contain, as the President has emphasized, such a clause for withdrawal if such action is perceived to be "in the supreme national interest."
[3] A pit is the part of a nuclear weapon primary stage that contains the fissle material, generally plutonium, and which undergoes an explosive fission chain reaction when imploded by high explosive.
[4 ] The preferred sites for these new facilities are shown in parentheses.
The body of this paper presents general information about stockpile stewardship and management activities to maintain the nation's nuclear deterrent in the absence of nuclear testing. This appendix provides more detail about the remanufacturing activities that might be conducted at the UC-managed laboratories based on reasonable assumptions about decisions on where they might be sited. For example, in the case of plutonium pit fabrication, Savannah River is presented in the PEIS as an alternate site. However, Savannah River presently does not have the capability to make plutonium pits. Consequently, it is reasonable to conclude that the DOE would assign this activity to LANL, where this capability exists, assuming that the PEIS process uncovered no reasons to prevent it.
The number of pit rebuilds that could be required of LANL in the future is uncertain and will depend on how the different weapon systems in the stockpile age and deteriorate. However, LANL is studying this issue from the point of view of "rolling maintenance", that is, a stockpile management program in which a certain number of weapons would be rebuilt every year. For planning purposes, the PEIS considers two cases for plutonium pit fabrication capacity--a base case of 50 pits per year and a high case of 100 per year. LANL could accommodate 50 new pits per year without requiring new facilities--this level would be less than what has been done in the past at this site. The PEIS study indicated that a rate of 100 per year might be accommodated by modifying existing facilities. However, more than that number per year would require new facilities. A strategy presently being considered is to modify one of the four wings of the LANL Plutonium Facility as a pilot plant for fabrication of up to 50 pits per year. This would then be used as a model for a "production plant" and designs for such a plant would be developed based on experience gained in the existing facility. Should experience show that more than 50 pits per year would be required to maintain the stockpile, a production plant could be built, based on these plans. If such a plant were needed, it would probably be sited at SRS.
With respect to non-nuclear components, LANL is currently engaged in fabricating and testing detonators used for igniting the high explosive in a nuclear weapon. As part of an ongoing R&D effort, LANL has produced as many as 20,000 detonators in a single year. Current estimates are that up to 200 detonators per year may be required as weapon replacement parts, well within LANL's present capability and experience.
Tritium technology is an important element of the stewardship and management of the enduring stockpile. LANL has been involved in tritium technology for over 40 years in the support of nuclear weapons. LANL capabilities include two modern, automated, triply-contained tritium facilities designed primarily for R&D in support of nuclear weapons design and tritium processing research. With the downsizing of the weapons complex, these will be the only two tritium R&D facilities in the complex. They can be used to provide tritium interaction data in materials, safer tritium processing, and engineering data from prototype designs for the stockpile.
LANL is also being considered by DOE to perform some surveillance work on war-reserve tritium gas reservoirs at its own facilities or to use LANL personnel to perform some of these analyses at the Savannah River Site. Therefore, some space may need to be added to the existing facilities at LANL for new surveillance tools and missions. It is anticipated that these additions will only be modest increments.
A possible future mission for LLNL is to be the lead laboratory to develop manufacturing technologies for nuclear weapon secondaries and radiation cases. LLNL has experience with the materials and fabrication processes involved with these components, and has been developing solutions to problems of waste generation and manufacturing efficiency. LLNL would work closely with Y-12 and LANL in order to draw on existing expertise for the formulation and critique of proposed programs. Promising new technologies would be implemented at the production plant, i.e., Y-12.
An additional mission that could be assigned to LLNL and LANL is the production of high explosive components for the weapons in the enduring stockpile which each lab has deployed, and the surveillance/monitoring of these components over their stockpile lifetime. The Laboratories because of their existing facilities and past experience with high explosives, could support this mission with little or no change to their facilities.