3

Systems Engineering and Aging

Three critical engineering-based elements of the laboratories’ efforts in support of their nuclear weapons mission are (1) systems engineering, especially as it applies to integration of efforts from multiple laboratories; (2) execution of nuclear weapons life-extension programs (LEPs); and (3) understanding aging effects, with an emphasis on aging effects on plutonium, but including aging in non-nuclear components for use in control, arming, fuzing, and firing.

The three national security laboratories, Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), and Sandia National Laboratories (SNL), have a strong focus on systems engineering, which integrates advances in R&D, engineering, and component manufacturing.

The systems engineering staff deal with some of the nation’s most demanding and exacting high-technology systems, which must be extremely safe, secure, and highly reliable. These goals must be accomplished in the absence of the ability to fully test the system. The laboratories are also required to interface effectively with the NNSA production sites to ensure that the weapons they produce will perform as designed under all of the conditions specified by the military.

High-quality S&E expertise and performance are essential to modernizing both the stockpile and the nuclear weapons complex. A strong systems engineering function is the core integrating activity for the results of high-quality scientific research, development, engineering, and manufacturing. High-quality systems engineering underpins the success of the recent W-76 LEP and is essential to the B-61 LEP that is currently underway.

Within the nuclear weapons complex, SNL is generally regarded as the “engineering” laboratory with responsibility for entire weapons systems. However, both LANL and LLNL have significant engineering capabilities to turn designs into functioning physics packages. A strong foundational capability in systems engineering in a multidisciplinary team environment is, therefore, a requirement at each of the laboratories, and systems engineers at all of the laboratories constitute a significant percentage of the professional staff. The laboratories have a history of innovatively solving complex systems development and engineering challenges. In general, they have a unique base of people with the critical experience, skills, and integrated knowledge to rapidly design and engineer large, complex national security systems. This institutional experience base has been developed over decades, and stockpile stewardship at the nuclear weapons laboratories requires maintenance of the requisite skills.

HIGH-QUALITY SYSTEMS ENGINEERING

In general, the quality of systems engineering within the national security laboratories is very high. Based on its extensive discussions with staff working in systems engineering, the committee was impressed by the quality of the systems engineering capabilities. It is encouraging that early-career scientists and engineers expressed excitement at, and appreciation of, the opportunity to do exciting work on the nuclear weapons mission and, more generally, on key national security missions.

The laboratories have a unique base of people with critical experience, skills, and integrated knowledge to rapidly architect and engineer large, complex national security systems. However, in the



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 19
3 Systems Engineering and Aging Three critical engineering-based elements of the laboratories’ efforts in support of their nuclear weapons mission are (1) systems engineering, especially as it applies to integration of efforts from multiple laboratories; (2) execution of nuclear weapons life-extension programs (LEPs); and (3) understanding aging effects, with an emphasis on aging effects on plutonium, but including aging in non- nuclear components for use in control, arming, fuzing, and firing. The three national security laboratories, Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), and Sandia National Laboratories (SNL), have a strong focus on systems engineering, which integrates advances in R&D, engineering, and component manufacturing. The systems engineering staff deal with some of the nation’s most demanding and exacting high- technology systems, which must be extremely safe, secure, and highly reliable. These goals must be accomplished in the absence of the ability to fully test the system. The laboratories are also required to interface effectively with the NNSA production sites to ensure that the weapons they produce will perform as designed under all of the conditions specified by the military. High-quality S&E expertise and performance are essential to modernizing both the stockpile and the nuclear weapons complex. A strong systems engineering function is the core integrating activity for the results of high-quality scientific research, development, engineering, and manufacturing. High-quality systems engineering underpins the success of the recent W-76 LEP and is essential to the B-61 LEP that is currently underway. Within the nuclear weapons complex, SNL is generally regarded as the “engineering” laboratory with responsibility for entire weapons systems. However, both LANL and LLNL have significant engineering capabilities to turn designs into functioning physics packages. A strong foundational capability in systems engineering in a multidisciplinary team environment is, therefore, a requirement at each of the laboratories, and systems engineers at all of the laboratories constitute a significant percentage of the professional staff. The laboratories have a history of innovatively solving complex systems development and engineering challenges. In general, they have a unique base of people with the critical experience, skills, and integrated knowledge to rapidly design and engineer large, complex national security systems. This institutional experience base has been developed over decades, and stockpile stewardship at the nuclear weapons laboratories requires maintenance of the requisite skills. HIGH-QUALITY SYSTEMS ENGINEERING In general, the quality of systems engineering within the national security laboratories is very high. Based on its extensive discussions with staff working in systems engineering, the committee was impressed by the quality of the systems engineering capabilities. It is encouraging that early-career scientists and engineers expressed excitement at, and appreciation of, the opportunity to do exciting work on the nuclear weapons mission and, more generally, on key national security missions. The laboratories have a unique base of people with critical experience, skills, and integrated knowledge to rapidly architect and engineer large, complex national security systems. However, in the 19

OCR for page 19
absence of full-system testing, the opportunities to exercise the needed skill sets are decreasing and, frequently, are unavailable. The laboratories currently have unique and critical high-quality expertise and capabilities in the areas of materials, including plutonium aging expertise, and device processing. They also maintain important specialized capabilities, such as for the production of certain nuclear weapons components (e.g., neutron generators), for plutonium processing and experimentation, and for producing radiation- hardened microelectronic, photonic, and related electronic components. In order to ensure that essential S&E capabilities are maintained by the laboratories, the NNSA should consider assigning them more scientific and programmatic development autonomy and responsibility. These topics are addressed later in this chapter. The committee saw evidence supporting the observation in the phase I report that NNSA continues to direct not just the “what” of the laboratories’ activities, but also the “how”—in spite of the fact that these laboratories were established to provide technical expertise that the government does not have. If the government goes beyond setting policy and imposes technical judgments on the laboratories, the basis of the federally funded research and development center model is called into question. An example is the set of rules that must be followed for all laboratory work that involves plutonium, which appear to make it very difficult for the laboratories to carry out their programmatic responsibilities. The imposition of these rules appears to have been done without adequately accounting for the fact that the laboratories have great expertise in working with plutonium. WEAPONS SURVEILLANCE Nuclear weapons surveillance is critical for measuring, evaluating, and understanding the aging of weapon components, not only for annual stockpile assessments but also for LEPs. Moves were begun in the 2007 timeframe to transform the weapons surveillance program by increasing emphasis on S&E through destructive and non-destructive non-nuclear testing and by decreasing the emphasis on flight testing of Joint Test Assemblies. The current surveillance program continues to identify potential S&E enhancements that would lead to an improved understanding of component aging effects, along with adding predictive capability, and retains the information traditionally gained from Joint Test Assembly flight tests. The envisioned transformed surveillance program assumes that the best approach to modern component aging assessment and management should be based on a sampling of components and materials; examination of a superset of that sample to determine the extent of age-related conditions and appropriate corrective actions; and eventual system recommendations, including a system de-rating if weapon reliability is partially compromised. Such an approach is necessary in order to maintain high quality. PLUTONIUM AGING Addressing the issue of plutonium aging is crucial for maintaining the reliability and safety of the stockpile. The laboratories have invested substantial resources to understand this important phenomenon. Although the stockpile is considered to have a sufficient margin to operate reliably in spite of the anticipated effects of aging, there are scientific unknowns. Experimental data is crucial for this field, and these data can often be extremely difficult to obtain. The laboratories are making progress toward understanding aging. Investments are being made in important areas, and the quality of the staff and facilities is high. However, progress is hindered by reduced budgets and a risk-averse culture that impedes the conduct of experiments involving plutonium and some other important materials used in weapons. It is necessary to compare the risk of not understanding plutonium aging versus the risk of performing experiments that may involve some (well-understood) risk to safety. 20

OCR for page 19
Construction of the CMRR (Chemical and Metallurgical Research Replacement) at LANL has been deferred. 1 Because of cost and siting requirements, there is a possibility that the CMRR will be deferred further, and perhaps never built. In addition to providing facilities for a range of research, the CMRR would support pit production in the plutonium facility (PF-4) in LANL’s Technical Area 55. However, only a limited number of pits have been built there. As pits continue to age, it is essential to maintain a vigorous surveillance program to ensure their integrity and predict if and when they must be replaced. For this, it will be necessary to continue to develop a fundamental understanding of the long-term behavior of plutonium. The Science and Engineering Campaigns and the Advanced Simulation and Computing program are also spurring attention to aging impacts in essential areas, including corrosion. Addressing this will involve an integrated program in experimentation, theory and modeling, and simulation. To consider these issues, significant collaborative studies have been undertaken by LANL and LLNL on the topic of plutonium aging leading to the milestone 2007 plutonium aging report, 2 which was an effort to determine a minimum pit-lifetime estimate to support decisions on the need, timing, and capacity for pit-production capability. That study summarized the physics and materials issues surrounding aging of stabilized, delta-phase plutonium alloy based on data from naturally aged samples up to 46 years of age and through an accelerated aging experiment that extended the equivalent age to 65 years. The conclusion was that these plutonium pits could last at least 85 years.3 As a result, additional studies that had been planned (such as examination of other alloys) were never undertaken, leaving unanswered some questions about plutonium aging. However, the conclusion that pits may be reliable for 85 years or more has renewed dialog on the possibility of pit reuse for extended timeframes for the dominant alloy, as well as for alloys for which there is only limited information. Since the 2007 study, some additional areas of concern have been identified, including surface reactions, phase stability and dimensional changes, additional self-irradiation effects not considered in the study, lattice damage, helium in-growth, and void swelling. Continued understanding of these effects requires experimentation. Recommendation 3.1. In view of the constrained budgets, researchers should prioritize efforts that contribute to quantifying uncertainties in the information that led to the 2007 report and identify the key hallmarks of aging to ensure the long-term viability and performance of the stockpile. SELECTED SUPPORTING DISCIPLINES Materials Science and Engineering Understanding irradiation effects and other materials issues, especially corrosion, is increasingly important in the aging stockpile, and several experts with whom the committee interacted expressed uneasiness, in particular, about the level of interest and support for materials science research to support understanding of plutonium aging. More generally, several presentations to the committee highlighted the reduction in the laboratories’ work on materials science over the past several years. While the reduction in support in this area has been offset to some degree by related research done under work for others (WFO) and by the availability of non-nuclear materials scientists to support WFO, no single office at NNSA Headquarters has “ownership” of materials research. Possibly as a result of this situation, it does not appear that headquarters program managers regard materials research as a priority. Absent such a focus, 1 The September 2012 6-month Continuing Resolution for fiscal year 2013 appropriations contained no funding for the CMRR. This at least delays CMRR construction and possibly ends it. 2 The MITRE Corporation, Pit Lifetime, JSR-06-335, McLean, Va., January 11, 2007. 3 A more recent article (A. Heller, Plutonium at 150 years: Going strong and aging gracefully, S&TR, December 2012, LLNL, Livermore, Calif., available at https://str.llnl.gov/Dec12/pdfs/12.12.2.pdf) provides updated accelerated aging data that suggest no precipitous degradation at least until the alloy in question is 150 years old. 21

OCR for page 19
funds for materials research must be assembled piecemeal from other budget lines. The laboratories need the flexibility to continually develop the research and technology base to respond to future problems, especially in view of the aging of the stockpile. Chapter 4 contains some discussion about the quality of materials science and engineering research at the laboratories more generally. Recommendation 3.2. NNSA, working with the laboratories, should support materials research at a level that adequately meets strategic materials research needs. Nanodevices and Microsystems SNL has established a focused “research foundation” program to advance its capabilities in nanodevices and microsystems. These capabilities play a strong role in SNL’s mission and strategy for nuclear weapons, national defense, energy, and scientific excellence and are critical for nuclear weapons stockpile maintenance and LEPs. While advancing the scientific and engineering frontiers of nanodevices and microsystems and enabling advances in other research areas at SNL, the research foundation program for nanodevices and microsystems develops, designs, and produces tens of thousands of components while specifying and procuring a much larger number of components required for the nuclear weapons LEPs for the B61 and W88 weapons as well as for future LEPs. Because of the centrality of nanodevices, optoelectronics, microelectronics, and microsystems to SNL’s mission and the nuclear weapons program, it is important that this research foundation be adequately supported by SNL’s strategic recapitalization project and operating plans. Funding streams for recapitalization should not be interrupted, and budgets should be identified for future deliverables, from research to product. Because of continuing rapid advances in technology in the microelectronics, photonics, sensors, and information technology areas, the research foundation program in this area needs to retain its current strong connections with the broader electronics R&D community so that it can continue to be well- informed about S&E advances in these fields. It also needs to develop strong partnerships with technical leaders from other organizations in that broader community. Neutron Generators The reliability of the neutron generators in weapons systems directly affects the reliability of the stockpile. SNL is responsible for all aspects of the neutron generators, including design, manufacturing, and testing, and for addressing any issues that arise from surveillance and inspection. As with many components in the stockpile, it is difficult, if not impossible, to build neutron generators identical to those that are being replaced, whose performance is reflected in weapons test data. This is due to unavailability of certain materials, the inability to replicate many manufacturing processes because of, say, changes in allowable practices, and the loss of expertise as the workforce ages. To address this issue, SNL is engaged in a major effort to put the design and manufacture of neutron generators on a stronger S&E basis. This transition is key for assessing the reliability of neutron generators when missions change or there are changes to the extreme environments that are faced. SNL has been applying an impressive, disciplined approach to understanding the S&E of neutron generators in which every aspect of the neutron generator design and operation is modeled and subjected to testing to validate the models. 22

OCR for page 19
TRANSITIONING TECHNOLOGY FOR ENGINEERING: LDRD AND TECHNOLOGY READINESS LEVELS The Laboratory Directed Research and Development (LDRD) program 4 is critical for the laboratories to maintain their needed S&E edge. It is a major source of cutting-edge S&E and appears to be a robust program. For example, at SNL approximately half of the intellectual property generated by the laboratories, as measured by patent disclosures and copyrights generated, comes from LDRD projects. The process by which LDRD projects related to systems engineering, aging, and LEPs are reviewed, modified as necessary, and eventually selected is impressive. Proposed LDRD projects are categorized by potential application and by funding level. Among projects with smaller funding requirements, a substantial number are focused on advancing S&E capabilities that are important to systems engineering, aging, and LEP work in support of the primary mission. Other LDRD funding is allocated to such areas as grand challenges (projects that have the potential to address major issues that could be mission- transforming), early-career projects aimed at nurturing the next generation of scientists and engineers, and capability sustainment and enhancement. Technology developed under LDRD funding often has direct and sometimes immediate application to current or near-future programs related to systems engineering, aging, and LEPs (for example, in creating a new option of potential value to an LEP for an existing weapon system). However, LDRD is explicitly designated for generating new scientific and engineering understanding and concepts that have the potential for major advances in S&E for future use; LDRD funds may not be used to augment existing programs. LDRD funding is often—but not always—limited to maturing a new technology option only to a technology readiness level (TRL) of 2 or 3—that is essentially a laboratory or bench-top demonstration—well short of TRL 5 or 6 (or higher) that would generally be needed by mission program managers. Transforming LDRD results to appropriate technology maturation levels that can be incorporated into the stockpile stewardship program is a continuing challenge. SNL staff told the committee that this gap can occasionally be bridged during the engineering phase of a new project, but such attempts tend to fall short and leave project managers with no choice but to opt for an existing design solution, rather than a more advanced solution deriving from LDRD results that are assessed to have the potential to offer substantial improvements. Lack of technology maturation investment results in an inability to use some innovations that would be more responsive and more efficient than existing technologies. Some potential mitigating efforts have been suggested (e.g., establishment of a continuous 6.3 program 5) in which funds are allocated specifically for maturation of new technology based on discoveries or inventions from the LDRD program. In 2011, NNSA launched a Component Maturation Framework “to serve as a long-term planning tool [that] includes the maturation plans for development and production of stockpile sustainment components.” 6 These steps indicate that this issue is recognized and appreciated by all three laboratories and by NNSA management, but there is no apparent process addressing it systematically. 4 LDRD annual reports for all three national security laboratories can be found at http://tri-lab.lanl.gov/. 5 NNSA manages life extension efforts using a multipart nuclear weapon refurbishment process, referred to as the 6.X Process, which separates the life extension process into phases. The first three phases—6.1 Concept Assessment; 6.2 Feasibility Study and Option Down-Select; and 6.2A Design Definition and Cost Study—are primarily R&D activities and studies that determine what changes are needed to ensure that a weapon system remains a safe and reliable part of the nation’s nuclear stockpile. The next three phases—6.3 Development Engineering; 6.4 Production Engineering; and 6.5 First Production—convert the R&D designs into final designs and manufacturing processes in order to produce refurbished weapons that meet the military requirements set by the Department of Defense (DOD). The last phase—6.6 Full-Scale Production—manufactures and installs the components needed to refurbish the weapons undergoing life extension and returns refurbished weapons to the stockpile. See GAO-02-889R. 6 U.S. Department of Energy, “FY 2012 Stockpile Stewardship and Management Plan: Report to Congress,” April 15, 2011, p. 26, available at http://www.fas.org/programs/ssp/nukes/nuclearweapons/SSMP-FY2012.pdf. 23

OCR for page 19
Recommendation 3.3. The laboratories and NNSA management should take steps to ensure that the gap between the low technology readiness level (TRL) achieved by Laboratory Directed Research and Development projects and the higher TRL required by program managers can be bridged, as necessary, to exploit improved technologies. A more strategic approach, which recognizes the 5- to 10-year timeframe often needed to bring new technologies to readiness levels required to support the mission, would be very positive. Some efforts have been made in this regard through the Advanced and Exploratory Program and the Stockpile Transformation Program. 7 However, the potential of these programs to develop new technologies is limited. With regard to systems engineering, the committee was told that, in a recent year, 60 proposals for new technologies were suggested at SNL, all of which were determined to be valuable for inclusion into one or more LEPs. The list of 60 new technologies with good potential had to be pared down to seven candidates, and only three of those could be pursued. The committee does not know the appropriate fraction of promising technologies that should be matured, but such a large-scale paring down should not be done based on available budget alone but approached more strategically. WORK ENVIRONMENT AND STAFFING The three NNSA national security laboratories appear to have taken aggressive approaches to replace retiring S&E personnel high-quality hires, as gauged by standard metrics such as prior academic performance and class standing. These aggressive approaches have no doubt been aided by the economic downturn, which has created a talent-buyers’ market since 2009. All three laboratories indicated that no significant problems have been encountered in hiring outstanding systems engineering personnel over the past five years. SNL has implemented strategies at an early stage to anticipate impending demand by hiring and training on a more accelerated schedule. However, continuing budgetary uncertainties are causing uneasiness at the laboratories about the continued prospects for the aggressive hiring, with SNL perhaps less uneasy than the other two laboratories because of its larger diversity of funding sources and WFO. WFO activities have come to play increasingly important roles in the intellectual development at the laboratories. At SNL, for example, it was reported that the laboratory could not sustain its systems engineering talent without the infusion of funds and programs from WFO activities. In the past, the laboratories had sufficient flexibility in their core mission funding to pursue new technology directions. For example, SNL embarked years ago on pioneering work in the area of microelectronics, which not only stimulated a major new technological field for the laboratory, but also became of fundamental importance in modernizing the nuclear stockpile and for the LEPs. While the laboratories are able to take advantage of robust postdoctoral programs to bring in new science researchers, on the engineering side postdoctoral training is less common and new hires tend to enter the laboratories more directly. The national security laboratories also hire many staff at the master’s degree level. In many cases, the laboratories are able to take advantage of strong ties with universities, and especially with professors working in fields related to the laboratories’ activities, to attract well- qualified new hires. Nonetheless, the laboratories are facing continuing workforce challenges. LANL, for example, has gone through two voluntary separation programs in the last 4 years. And the laboratories’ ability to access the expertise of retirees is constrained by limitations on contracts with individuals who have left 7 See, for example, (1) SNL publication “Sandia’s Nuclear Weapons Mission” (http://www.sandia.gov/news/publications/fact_sheets/_assets/documents/NW_mission_2012_FNL.pdf); (2) SNL webpage for “materials aging and surveillance” (http://www.sandia.gov/materials/science/people/corrosion.html) [Technical Basis for Stockpile Transformation Planning (TBSTP)]; and (3) LLNL FY13 25 year site plan, September 2012, UCLR-AR-143313-12. 24

OCR for page 19
the laboratories. Conversely, SNL has been hiring in anticipation of the B-61 LEP. Timing of the funding for the program will be critical to providing work for the staff that has been brought into the lab. In general, the laboratories continue to invest in the staffing pipeline, but sustaining the human infrastructure for S&E excellence is continually challenging. Without new weapons to design and build, there is less full-systems work through which early- career systems engineers can learn the full range of skills required to design and develop a nuclear weapons system, including inserting products from R&D into new weapons systems. The pipeline of personnel possessing capabilities (possibly new) needed for the next generation of systems is extremely important. Candidates within some disciplines that are critical to weapons systems, such as metallurgy, are becoming increasingly scarce and difficult to recruit because these disciplines have declined as fields of study at universities. These challenges, which are recognized by the laboratories, along with uncertainty in federal funding and program direction, could negatively impact the laboratories’ ability to continue to attract and retain talent, especially as the economy recovers and the laboratories face increasing competition from other sectors to hire new graduates. The situation is exacerbated by an aging workforce, a significant fraction of which is now eligible for retirement. Knowledge preservation and knowledge transfer—succession planning—are important issues. A deliberate strategy is needed to maintain sufficient systems engineering core capabilities for future missions. The “120-day study” discussed in the next section is a good example of an activity designed to help facilitate the passage of experience and knowledge from older staff to early- and mid- career engineers and scientists. THE 120-DAY STUDY The three laboratories recently worked together to carry out a novel “120-day study” as a means of exposing early-career engineers and scientists to the challenges of weapons design. 8 This study did not design new nuclear weapons, but it did consider advanced options for the nuclear physics package and various approaches on how to configure the stockpile using existing components and systems with an emphasis on raising the levels of safety, security, and reliability. The study ranged from basic concepts to engineering and examined the type of experimental capabilities needed to support the future stockpile. It also exercised the systems engineering skills needed to integrate the design into the intended delivery system. The study teams took appropriate considerations of re-use, refurbishment, and replacement established by the surrogate customer for a particular LEP. The staff assembled to address these considerations consisted of a few experienced designers, several mid-career designers, and a relatively large number of near-entry-level designers who were given an opportunity to work together within the customer constraints to develop timely and workable solutions. The S&E skill sets represented in this “design-subject-to-constraints” study were impressive. The study provided a clear demonstration that the quality of the S&E expertise available at the three laboratories continues to be extremely high and able to do excellent work within customer constraints. Recommendation 3.4. NNSA should continue the approach used for the 120-day study as one means of developing and maintaining a new generation of well-trained weapons designers and the concomitant systems engineering capability. 8 On January 10, 2012, NNSA officially requested that LANL, LLNL, and SNL perform a 120-day study to evaluate alternative warhead designs and to inform NNSA on potential options for future LEPs. 25