Detection of special nuclear material (SNM) being smuggled into the US through ports of entry has been identified as a crucial capability for ensuring the safety and security of the US from radiological threats. Programs such as the NNSA's Second Line of Defense aim to deploy detection systems, both domestically and abroad, in an attempt to interdict the SNM before it reaches its destination. Active interrogation (AI) is a technique that relies on the detection of emitted particles which are produced when SNM is bombarded with a source of high energy photons or neutrons. This work presents a general framework that allows for fast radiation transport modeling of AI scenarios by generating families of response functions which depict neutron, gamma, or electron radiation exiting various regions within the problem, per unit source of radiation entering the region. The solution for a given scenario, typically the detector count rate, is computed by injecting a source term into the first region and applying the appropriate response functions, in sequence, for each subsequent region. For the AI systems modeled in this work, the source is an electron beam in a linear accelerator. Subsequent response functions create and transport bremsstrahlung photons into the SNM, and transport neutrons born in the problem to a detector. The computed solution is comparable to that of a full Monte Carlo simulation, but is assembled in orders of magnitude less time from pre-computed response function libraries. The ability to rapidly compute detector spectra for complicated AI scenarios opens up research and analysis possibilities not previously possible, including conducting parametric studies of scenarios spanning a large portion of the threat space and generating detector spectra used for conditioning and testing of alarm algorithms. / text

This work presents a computational tool that calculates optimally efficient safeguarding strategies at and across nuclear fuel cycle facilities for a cost-constrained inspector seeking to detect a state-facilitated diversion or misuse. The tool employs a novel methodology coupling a game theoretic solver with a probabilistic simulation model of a gas centrifuge enrichment plant and an aqueous reprocessing facility. The simulation model features a suite of defender options at both facilities, based on current IAEA practices, and an analogous menu of attacker proliferation pathway options. The simulation model informs the game theoretic solver by calculating the detection probability for a given inspector-proliferator strategy pair and weighting the detection probability by the quantity and quality of material obtained to generate a scenario payoff. Using a modified fictitious play algorithm, the game iteratively calls the simulation model until the equilibrium is reached and outputs the optimal inspection strategy, proliferation strategy, and the equilibrium scenario payoff. Two types of attackers are modeled: a breakout-willing attacker, whose behavior is driven by desire for high value material; and a risk-averse attacker, who desires high-value material but will not pursue a breakout strategy that leads to certain detection. Results are presented demonstrating the sensitivity of defender strategy to budget and attacker characteristics, for an attacker known to be targeting the enrichment or reprocessing facility alone, as well as an attacker who might target either facility. The model results indicate that the optimal defender resource allocation strategy across multiple facilities hardens both facilities equitably, such that both facilities are equally unattractive targets to the attacker. / text

The U.S. has implemented a two-track nuclear policy since the Cold War. The first track is non-proliferation and the second track involves securing all nuclear materials. The two-track nuclear policy has been effective, but at times non-proliferation efforts are contradicted by the US supporting nuclear programs by securing nuclear materials. The current greatest threat to nuclear security is the acquisition of nuclear materials by an extremist or terrorist organization. Can the US combat the current growing threat of loose nukes with the two-track policy? / text

Between 1957 and 1963, both Anglo-American discussions of nuclear cooperation and the wider debate on nuclear strategy within NATO were often dominated by the question of whether Britain’s deterrent would be amalgamated or integrated into a wider NATO or European force, such as the proposed MLF (Multilateral Force). This dissertation discusses the development and impact of competing British and American proposals for “nuclear sharing” within the context of European economic and political integration as well as that of discussions within NATO of the appropriate strategy for the alliance in an age of mutual nuclear vulnerability between the superpowers. Particular attention is paid to the context of successive nuclear crises in world politics during this period, from Sputnik to the Soviet ultimatum over Berlin through the Cuban missile crisis. The divergent opinions among the leaders of the major powers over the appropriate responses to these crises shaped the debate over nuclear sharing and form a previously neglected dimension of this topic.

Between 1957 and 1963, both Anglo-American discussions of nuclear cooperation and the wider debate on nuclear strategy within NATO were often dominated by the question of whether Britain’s deterrent would be amalgamated or integrated into a wider NATO or European force, such as the proposed MLF (Multilateral Force). This dissertation discusses the development and impact of competing British and American proposals for “nuclear sharing” within the context of European economic and political integration as well as that of discussions within NATO of the appropriate strategy for the alliance in an age of mutual nuclear vulnerability between the superpowers. Particular attention is paid to the context of successive nuclear crises in world politics during this period, from Sputnik to the Soviet ultimatum over Berlin through the Cuban missile crisis. The divergent opinions among the leaders of the major powers over the appropriate responses to these crises shaped the debate over nuclear sharing and form a previously neglected dimension of this topic.

Thesis (M.A. in Security Studies (Defense Decision-Making & Planning))--Naval Postgraduate School, December 2007. / AD-A475 821. "December 2007." Description based on title screen as viewed on January 17, 2008. Thesis Advisor(s): Russell, James A. ; Kadhim, Abbas. Includes bibliographical references (p. 67-71). Also available via the World Wide Web.

Zugl.: Koblenz, Landau (Pfalz), Univ., Diss., 2008

Thesis (Ph.D.)--Pennsylvania State University, 2007. / Mode of access: World Wide Web.

Thesis (M.A. in Security Studies (Defense Decision-Making and Planning))--Naval Postgraduate School, Sept. 2004. / Thesis Advisor(s): Peter R. Lavoy. Includes bibliographical references (p. 85-89). Also available online.

Thesis (M.A. in National Security Affairs)--Naval Postgraduate School, Sept. 2004. / Thesis Advisor(s): Peter R. Lavoy, Mikhail Tsypkin. Includes bibliographical references (p. 51-56). Also available online.