The challenge of balancing the benefits of nuclear energy against the risks of nuclear proliferation has been recognized since the dawn of the nuclear age (Barnard et al. 1946 [Acheson–Lilienthal Report]; Eisenhower 1953). In the last 10 years, interest in nuclear energy has increased significantly, and the number of countries with interest in nuclear power reactors is still expected to increase despite the events at Fukushima (Amano 2013). This expansion has provoked renewed concern about nuclear proliferation and efforts among nuclear supplier states to revise nonproliferation policies and to develop new fuel cycles that do not increase proliferation risks. Much of the focus has been on technologies that can be used to produce nuclear weapons material from natural uranium and spent nuclear fuel, widely referred to as enrichment and reprocessing (E&R) technology. A number of E&R facilities (approximately 10 enrichment facilities and half a dozen reprocessing facilities; IPFM 2011) currently exist. Limiting the future expansion of E&R technology is a widely accepted nonproliferation goal (NRC 2009).
As the primary source of funding for nuclear fuel cycle research and development (R&D) in the United States the Department of Energy Office of Nuclear Energy (DOENE) makes decisions about how to invest its resources to develop cost-effective and environmentally sustainable fuel cycles that do not have increased proliferation risks. The DOE National Nuclear Security Administration (NNSA) is a major player in the U.S. interagency team that makes decisions about U.S. nonproliferation policy, including international nuclear cooperation and nuclear export control. The NNSA also funds R&D in nuclear safeguards technology to detect and impede misuse of civilian nuclear technology and material for military purposes.
The missions of DOE-NE and NNSA occasionally can be in conflict because DOE-NE is focused on developing and deploying future nuclear energy systems and technologies whereas the NNSA is focused on minimizing and managing proliferation risks of nuclear energy. Over the years, both DOE-NE and NNSA have invested in developing nonproliferation assessment tools to help evaluate and compare proliferation factors between different future fuel cycles. As they consider further development and use of these tools, they have requested advice from the National Academy of Sciences.
The sponsors requested that the study be carried out in two consecutive phases. Phase 1 was a workshop that was held August 1-2, 2011, at the National Academies’ Keck Center in Washington, D.C. It focused on encouraging discussion between policy makers and the technical assessment community but was not designed to produce
Statement of Task
- Identify key proliferation policy questions capable of being answered by a technical assessment of the host state proliferation risk posed by a given nuclear fuel cycle, and discuss the utility of these questions for informing international nonproliferation policy decisions;
- Assess the utility for decision makers of existing and historical methodologies and metrics used by DOE and others (such as the International Atomic Energy Agency) for assessing proliferation risk, both for considering the deployment of these facilities domestically as well as the implications of deployment outside the United States;
- Assess the potential for adapting risk assessment methodologies developed in other contexts (such as safety and security) to host state proliferation risk assessments—including both qualitative and quantitative approaches—their benefits, limitations, and the challenges associated with adapting these methodologies to proliferation risk assessment;
- Identify R&D and other opportunities for improving the utility for decision-makers of current and potential new approaches to the assessment of proliferation risk; and
- Identify and assess options for effectively communicating proliferation risk information to government and industry decision-makers, as well as the public and the NGO community both within the United States and internationally.
This study will not address the risk associated with the physical security of the facility or materials against attack, theft, or diversion of nuclear materials. The study may examine policy options but will not make specific policy recommendations.
consensus findings or conclusions. A summary of the briefings and discussions was released as a workshop report in January 2012 (NRC 2011a). Phase 2, a study completed by a separately constituted committee, addresses the full statement of task (Box 1.1) and produces findings and recommendations agreed by consensus.
The study was carried out by a committee of experts appointed by the National Research Council (NRC). The committee’s 12 members have a breadth of experience, including risk assessment and communication methods, proliferation metrics and research, nuclear fuel cycle and power plant design and engineering, international nuclear nonproliferation and national security policy, and nuclear weapons design. Special attention was given to including diverse perspectives on methods for assigning values to risk or approaches for quantifying critical aspects of complex systems; a balance of
nuclear fuel cycle research knowledge and real-world nonproliferation security expertise; and practical program evaluation experience with an understanding of how metrics could be applied to policy decisions. Biographical sketches of the committee members are provided in Appendix A.
SCOPE, DEFINITIONS, AND TERMINOLOGY
The focus of this study is on methods to assess the “host-state proliferation risk” of a given nuclear fuel cycle. In other words, the committee was not asked to evaluate methods for assessing the risks that a terrorist organization or non–state actor will acquire and use a nuclear fuel cycle for purposes of proliferation, nor that they will attack a nuclear facility to acquire material or technology. Although the risk associated with the physical security of the facility or materials against attack, theft, or diversion is an important challenge, and clearly related to host-state proliferation risk, it is outside the request and hence beyond the scope of this study. We note that these two types of risk cannot be separated completely, and attempting to do so may lead to overlooking or minimizing significant factors. In fact, a host state could easily access any material that would be plausible for non–state actor diversion scenarios. Any material that non–state actors could potentially steal, a host state could more easily divert.
The committee notes that the terminology widely used to discuss the concept of proliferation risk is subject to inconsistency. In particular, the terms “proliferation risk” and “proliferation resistance” frequently are used interchangeably and incorrectly when discussing nuclear energy systems. Proliferation resistance is one factor among many that contribute to proliferation risk, and most technical assessment methodologies assess proliferation resistance, rather than risk.
The International Atomic Energy Agency defines proliferation resistance as the characteristics of a nuclear energy system that impede the diversion or undeclared production of nuclear material or misuse of technology by states in order to acquire nuclear weapons or other nuclear explosive devices. . . . The degree of proliferation resistance results from a combination of, inter alia, technical design features, operational modalities, institutional arrangements and safeguards measures. (IAEA 2002)
Proliferation resistance assessments focus on the engineering-aspects of the fuel cycle under consideration. Often, these assessments follow a specified framework that defines a given fuel cycle by individual processing steps, assesses a predefined list of detailed attributes against a proliferation threat, and uses a predetermined approach for scoring and combining the attributes to determine the cycle’s overall proliferation resistance. They can also be used to identify the steps within the cycle with the least resistance. The committee has termed these methodologies “predefined frameworks.”
Proliferation risk is a more complex concept and includes, among other things, analysis of country specific issues. Although it does not have an internationally accepted definition, some analysts in the proliferation resistance assessment community have attempted to define proliferation risk through an equation that relates proliferation risk to
three terms: the probability that an adversary will choose to proliferate along a particular pathway (L), the probability of success along that path (P), and the consequences of proliferation (C) (NSSPI 2010, NRC 2011a, Charlton 2012). A full risk assessment sums over all possible pathways. The committee notes that this is a difficult and evolving task for situations in which a motivated host state may continuously invent new pathways (including illegal acquisition) or regional stability alters that motivation; both examples affect the probabilities that attach to the terms above. Country-specific factors such as motivation, technical capability, access to technology, and intent clearly are needed to assess L. Proliferation resistance could contribute to both P and L. Because proliferation resistance is one component to the problem of proliferation risk and because it is not infinite (there is no proliferation-proof fuel cycle), other country-specific factors will determine whether and how a host state proliferates.
The report is organized into five chapters that correspond to the five tasks in the study charge.
Chapter 2 describes the types of proliferation-related topics faced by decision makers and identifies questions that can be informed by a broad range of technical assessments. It ends with a discussion of the types of questions that can be addressed by technical assessment of proliferation resistance.
Chapter 3 describes historical and existing methods for assessing proliferation risk, with a particular focus on predefined framework methodologies, identifies their strengths and weaknesses, and discusses their utility to decision makers.
Chapter 4 considers how risk assessment methodologies from other fields might be applied to the problem of proliferation risk assessment. It also discusses how application of these approaches could be applied to address deficiencies in implementation of predefined framework assessments.
Chapter 5 addresses needs for future R&D to improve assessments of proliferation risk, based on the findings of Chapters 3 and 4. Chapter 6 focuses on approaches for better communicating results of technical assessments to different audiences, including policy makers, the international community, and the public.