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flexible and agile so that it will be able to deal with surprises, which are sure

to come. My testimony amplifies on these points. First, I discuss the need for a sustained. balanced Stockpile Stewardship Program and efforts under way to enhance NNSA's capabilities to develop and execute a balanced program. Second, I highlight selective accomplishments of the program to illustrate that considerable progress is being made on many fronts. Finally, I discuss the challenges that lie ahead.

A SUSTAINED, BALANCED PROGRAM EFFORT The Stockpile Stewardship Program continues to be extremely challenging. It needs both strongly sustained support and balance for continued success in the long term. There are competing demands on the program. The central focus of the Stockpile Stewardship Program is on stockpile readiness-maintaining the weapons, monitoring their condition, and refurbishing or replacing weapon components as necessary. To meet these needs, the program is expeditiously putting into place a set of vastly improved scientific tools and modern manufacturing capabilities, which are crucial for stockpile readiness in the near- and long-term. These capabilities include 100-teraops supercomputers, advanced radiography capabilities to take three-dimensional images of imploding mock primaries, a high-energy-density experimental facility (the National Ignition Facility) to study the thermonuclear physics of primaries and secondaries, and efficient and flexible manufacturing facilities.

These investments in the capabilities for stockpile stewardship are very demanding of resources. So is the need to meet the near-term requirements of the Department of Defense (DoD) through stockpile life extension programs. In addition, as pointed out in the 2002 Nuclear Posture Review, new weapons capabilities, not present in the current stockpile, may be needed to meet future post-Cold War threats. Accordingly, exploratory work on advanced weapons concepts should be part of the overall program. Finally, on top of all these specific demands on the program, we need some flexibility in the Stockpile Stewardship Program to respond to surprises. The history of the weapons programs is that every so often something unanticipated arises that puts an extra demand on resources.

General John Gordon, Administrator of NNSA, is taking a number of actions to enhance NNSA's performance and improve processes for long-term planning and budgeting, which are critically important to the development and execution of a balanced Stockpile Stewardship Program. One key change is the annual development of the integrated Future-Year Nuclear Security Plan (FYNSP). With this five-year plan, NNSĂ is better able to make program trade-offs, which involve adjustments to future-year budgets, and it helps our Laboratory in resource, workload, and facility planning by providing a more reliable future program base. In addition, we expect that the organization changes in NNSA, clarification of lines of authority and responsibility, and steps to reduce inefficiencies and excessive administrative workload will improve the effectiveness of programmatic efforts.

As the two nuclear design laboratories, Lawrence Livermore and Los Alamos are working with our contractor, the University of California, to strengthen management accountability, institute more uniform best practices in operations at the two laboratories, and better integrate our efforts in the Stockpile Stewardship Program. While it is essential to preserve the independent assessment capability of a two-laboratory system, there are many aspects of stockpile stewardship where we share capabilities and load-level the work. It is our joint responsibility to ensure that there are no significant gaps in nuclear design capabilities and expertise, that important program milestones are met, and that inefficiencies in effort are minimized.

PROGRAM ACCOMPLISHMENTS To date, the Stockpile Stewardship Program has many accomplishments—we are largely on track. It has been a team effort that has benefited from capabilities, ex. pertise, and hard work across the NNSA complex-headquarters and the field, the three laboratories, the production facilities, and the Nevada Test Site. My testimony describes several example accomplishments where the Laboratory's efforts were directly involved. The W87 Life Extension Program

In April 2001, Lawrence Livermore and Sandia national laboratories completed Kumal certification of the W87 ICBM warhead, which is undergoing a life-extension wwwgram (LEP) so that it may remain part of the enduring stockpile beyond the year

3 and meet anticipated future requirements for the system. The W87 in the 21 reentry vehicle is planned as a single RV option for the Minuteman III ICBM.

The first production unit was completed at the Pantex Plant in February 1999, and production is proceeding on schedule for completion early in 2004.

This first completed certification of a warhead refurbished through an LEP is a groundbreaking milestone for the Stockpile Stewardship Program. The program was an outstanding team effort with the Air Force, and it demonstrated effective partnership of the laboratories and the production facilities to overcome physics, engineering, and manufacturing challenges to meet Department of Defense requirements without conducting a nuclear test. The development activities for this program included extensive flight testing, ground testing, and physics and engineering analysis. High-fidelity flight tests, incorporating the latest technological advances in onboard diagnostic instrumentation and telemetry, provided added confidence in the reliability of the design modifications. Assessment of nuclear performance is based on computer simulation, past nuclear tests, and new above-ground experiments that addressed specific physics questions raised by the engineering alterations and computer simulations.

The W87 certification process was detailed and thorough. It included extensive formal peer and expert reviews by laboratory, NNSA, and DoD personnel. Confidence in the results was greatly strengthened by the use of a rigorous quantitative methodology as a basis for the certification. This methodology is discussed below. Certification and Assessments

To maintain the nuclear stockpile and to be responsive to evolving policy, we must be able to ensure with confidence the safety and performance of aged and/or refurbished warheads against their military requirements. One vital process to build this confidence is Annual Certification. It is based on advice from the laboratory directors, the commander-in-chief of the U.S. Strategic Command, and the Nuclear Weapons Council to the Secretaries of Energy and Defense developed from the technical evaluations made by the NNSA laboratories. The sixth Annual Certification cycle was completed in 2001. We are well into the seventh and find ways to improve the process each cycle.

In the course of Annual Certification, our Laboratory collects and reviews all available information about each stockpile weapon system for which LLNL has design responsibility, including physics, engineering, and chemistry and materials science data. This work is subjected to rigorous, in-depth review by scientists, engineers, and managers throughout the program-including the use of “red teams.” În addition, the Laboratory's work is reviewed by USSTRATCOM's Stockpile Assessment Team, which provides a very valuable critique, and several other DoD groups.

For the assessments underpinning Annual Certification and the formal certification required for modified units of previously certified and tested weapons, the key question has transformed from “will it work?” to “when does it fail?”. When nuclear testing is not available, these certifications will be based on a much more extensive range of above-ground testing, together with a vastly improved simulation capability. The existing nuclear test database is a crucial resource for challenging the validity of these improved codes. Ultimately, expert judgment informed by the best available data will always be at the core of the certification process.

Quantification of Margins and Uncertainties (QMU). For these certification actions, it is essential that we use a rigorous set of quantitative standards, which is technically sound—to establish our own confidence and which provides transparency to the government and military—to build their trust and confidence in us. The methodology used in this process is called the quantification of margins and uncertainties (QMU).

These standards are based on ensuring that adequate margins exist against limited uncertainties for each sensible way that the warhead can fail to function properly (analogous to the engineering safety factors used in building a bridge). Margins must be adequate whether the concerns are driven by aging, remanufacturing, possible design or manufacturing flaws, or new requirements for the warhead.

For each issue, we gather data and conduct simulations to determination how close we are to the margin of failure and estimate uncertainties. This process entails the efforts of many experts, extensive peer group review, and careful scrutiny by “red teams”. The outcome is quantitative confidence factors that can be used as a basis for judgments. Livermore first applied the QMU methodology to the certification of the W87 life extension program. It is being further developed and jointly implemented by Livermore and Los Alamos as a single national certification proc

QMU can also help provide prioritization for the laboratory's technical efforts and for the overall Stockpile Stewardship Program, for example where to invest in capabilities to raise confidence in weapon performance. That is, QMU can help provide

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firsnon fe efforts to improve weapon surveillance and for the Science and Bee

The Laboratory Director's Responsibility. As mentioned the use of QM neipe to tross attention on aspects of weapon desig ni gineering the case moet to metall performance. The methodolog and considerable - o data zathers that is required for its implementation are amendable to the gre TEN-Egert opinion and a multiplicity of viewpoints are a absolzely necessary sent of the process. However, in the end, certification is a jodgment issue that suite musly resta on my shoulders. It is my responsibility as laboratory &rector. Enhanced Surveillance

Our stockpile surveillance efforts focus on assessing the condition of reapons in the stockpile and on understanding the effect of aging on them. Aging is peras because it affects the physical characteristics of materials, and we was determine bon these changes impact weapon safety and performance. With a better sodes standing of aging, we can help to avoid surprise. More predictive stockpile surveillance makes possible systematic refurbishment and preventative maintenance ativities to correct developing problems when necessary. The workload a the production facilities can be better managed if burdensome refurbishment of components that are not in danger of failing can be avoided. An important factor here is to be able to detect subtle changes to the weapon system well in advance of the change causing a safety, reliability, or performance issue. This is essential to prepare for and balance the workload for upgrades or life extension efforts that may take many years to fully implement.

We continually review and upgrade our surveillance programs as we gather more data, gain experience, and refine sampling plans. We also measure additional attributes as new tools become available and the need for more information arises. We are now taking on responsibility for surveillance of pits from Livermore-designed weapons in the stockpile to better balance the workload. These activities had been conducted at Los Alamos.

In addition, we are making major improvements to the sensors and techniques used to inspect weapons. Newly emerging diagnostics-including some that do not require destruction of the weapon-are enabling us to better quantify the condition of the stockpile and to identify aging characteristics at the earliest possible time. Better surveillance capabilities can help avoid unnecessary refurbishment work at the plants. For example, Livermore, in cooperation with Y-12, has completed the development of an analytical model and the development and deployment of a suite of diagnostic tools that enable us to understand the aging behavior of secondary assemblies. We are also completing development of high-resolution x-ray tomography for imaging weapon pits; first phase deployment at the Laboratory is complete, and deployment at Pantex is continuing. Furthermore, development continues on highenergy neutron radiography for nondestructively detecting small voids and structural defects in weapon systems. Understanding Plutonium

One of the major success stories of the Stockpile Stewardship Program is the significant improvement we are making in understanding the properties of plutonium. This is a very important issue-we need to understand aging in plutonium and the effect of aging-related changes on the performance of an imploding pit of a stockpiled weapon. The required capacity of the production complex depends on the anticipated lifetime of plutonium pits in the stockpile. An accurate assessment is necessary. If we underestimate the lifetime of pits, we may overinvest in facilities to remanufacture plutonium parts. If we overestimate the lifetime of pits, the nation could find itself critically short of capacity for plutonium operations when it is vitally needed.

To study the highly complex properties of plutonium, we have combined advances in theoretical modeling with the use of sophisticated experiments. For example, we are using advanced materials characterization tools such as our Transmission Electron Microscope, the most powerful such instrument in the NNSA complex, to study how aging plutonium accommodates the helium that is created through self-irradiation. We are also using old pits and accelerated-aging alloys to determine the lifetime of pits. Accelerated-aging samples are plutonium alloys with a mixture of isotopes to increase the

rate of self-irradiation damage so that the material "ages” faster. Furthermore, Livermore is conducting sub-critical experiments at the Nevada Test Site (NTS) to investigate the properties of plutonium shocked and accelerated by high explosives. NTS is also site of the Joint Actinide Shock Physics Experimental Research (JASPER) Facility, a two-stage gas gun for performing shock tests on special or materials. Now that construction is completed, JASPER will com

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plement other experimental and modeling activities by providing scientists more precise equation-of-state data at extreme conditions than can be obtained from other types of experiments. Capabilities for Weapon Assessments and Certification

Assessments of weapon performance and certification of weapon refurbishments must be based on scientific and engineering demonstration to be credible. In the absence of nuclear testing, we rely on data from past nuclear tests as a benchmark, component-level experiments and demonstration, and advanced simulations for an assessment of weapon performance and safety that is integrated through use of the QMU methodology: This approach has enabled us to successfully certify the W87 life-extension refurbishment and address stockpile issues that have emerged to date. However, as the stockpile ages, we anticipate that more difficult issues will arise.

These needs—to be able to assess and certify both weapon performance and refurbishment actions—drive the Stockpile Stewardship Program's investments in much more capable experimental facilities, such as the National Ignition Facility (NIF), the Dual Axis Radiographic Hydrodynamic Test Facility and even more advanced hydro-test capabilities, and greatly enhanced numerical simulation tools developed through the Advanced Simulation and Computing (ASCI) program. Here, the discussion focuses on three areas where significant improvements in capabilities are completed or under way at Livermore: the Contained Firing Facility, ASCI, and NIF.

The Contained Firing Facility. Hydrodynamics testing is the most valuable experimental tool we have for diagnosing device performance issues for primaries in stockpiled weapons. Through hydrodynamics experiments conducted at Livermore's Site 300 and the Dual-Axis Radiographic Hydrodynamic Test Facility (DARHT) at Los Alamos, weapon scientists are able to characterize the energy delivered from the high explosives to a mock pit, the response of the pit to hydrodynamic shocks, and the resulting distribution of pit materials when they are highly compressed. This information is critical for baselining weapons, certifying stockpile performance, and validating hydrodynamics simulation codes.

Over the past decade, we have made tremendous advances in diagnostics capabilities and experimental techniques used in hydrodynamic testing. We are now able to gather far more revealing data from hydrodynamic tests than was possible when We developed the weapons that are now in the stockpile. The most sophisticated type of hydro experiment is the "core punch,” in which scientists use high-energy radiography to record a digital image of the detailed shape of the gas cavity inside a pit when it is highly compressed. In 1998, we carried out at Livermore's Flash X-Ray Facility the first core punches on two important stockpile primary devices: the W76 SLBM warhead and the B83 strategic bomb.

An upgrade of the Flash X-Ray Facility was completed last year with the addition of the Contained Firing Facility. The project was completed on time, on budget. Qualification testing has been completed to assure its ability to contain debris from experiments that use up to 60 kilograms of high explosives. The first stockpile-related experiment was executed in March 2002. Livermore is now able to conduct these critically important experiments with isolation from the surrounding environment.

ASCI and the ASCÌ White Computer. The Advanced Simulation and Computing (ASCI) program is central to many of the success stories of the Stockpile Stewardship Program. ASCI has steadily progressed from efforts to develop weapons physics and engineering codes that run efficiently on the new computers to a resource that the LEPs are counting on to meet important milestones. As we continue to get larger and faster machines and better simulation models, the ASCI capabilities we have are "deployed” in support of a wide range of Stockpile Stewardship Program deliverables.

In summer 2000, we took delivery from IBM of ASCI White, at the time the world's most powerful computer, capable of 12.3 teraops (trillion operations per second). This machine has been successfully used and shared since early 2001 by all three NNSA laboratories-Sandia and Los Alamos were extremely effective in using it by computing at a distance. To meet each laboratory's requirements to run problems, calculations were interleaved in an integration schedule for the machine.

Both Livermore and Lost Alamos used ASČI White to complete in late 2001 the first-ever prototype fully three-dimensional simulations of a complete warhead explosion. The size and scale of ASCI White allowed the two laboratories to employ a level of spatial resolution and depth of physics models that were heretofore completely beyond reach in 3D. Sandia also used ASCI White to perform structural dynamics calculations for different environments that weapons might encounter. One terabyte of core memory was used on each structural dynamics calculation in simulations that were completed in late September 2001 and set many world records.

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