Nuclear Weapons Latency

A novel nuclear weapons proliferation assessment method has been developed to determine a state’s Nuclear Weapons Latency, the expected time to be taken by a non-nuclear weapons state to develop a conventionally deliverable nuclear weapon given the state’s position on a path toward or away from a nuclear weapon and accounting for the state’s motivations and intentions. Potential proliferation time is taken as a representation of the latent proliferation capacity of a non-nuclear weapons state. An assessment of proliferation time is critical to crafting an effective policy response within a useful time frame. Current proliferation assessments either neglect proliferation time or are static case-specific assessments frequently built on restricted information and opaque assumptions. The Nuclear Weapons Latency computational tool has been developed to determine a state’s Nuclear Weapons Latency and embodies a stochastic Petri net proliferation simulation. The tool makes only three simple assumptions: a decision to proliferate has been made, the proliferation pathway network is known, and the associated pathway activity times are estimable. Beyond the quantification of a state’s latency, the tool provides a transparent, efficient, adaptable, and highly repeatable platform which allows for extensive sensitivity analysis to better inform the nonproliferation discussion and policy decisions. Functionality of the tool was verified and inherent sensitivities determined through historical analysis with the U.S. case of proliferation in the Manhattan Project. Network and operational parameters were found that drove expected Latencies high while others increased the Latency distribution variance. Further confidence was built with historical analyses of the Pakistani and South African cases of proliferation. These verifications were done in lieu of experimental validation which is impossible for future event simulations like the Latency tool. Analysis revealed that while A.Q. Khan altered the Pakistani proliferation pathway, his impact on proliferation time may have been minimal. A Multi-Attribute Utility Analysis (MAUA) function was implemented for proliferation pathway selection. This function might increase the accuracy of the most-likely Latency estimate in certain cases. However, use of MAUA for adversary modeling also significantly increased the number of assumptions necessary. A Latency investigation of South Korean nuclear fuel cycle facility development, a current nonproliferation policy concern, demonstrates how Nuclear Weapons Latency can help characterize the proliferation risk of different policy options for decision makers. Analysis showed that development of any one of pyroprocessing, PUREX, or especially commercial uranium enrichment technologies reduces South Korean Latency. This risk characterization ability through policy option sensitivity enables the Latency tool to help fill a void of useful proliferation risk information provided by technical assessments to policy makers identified by the 2013 National Academies study Improving the Assessment of Proliferation Risk of Nuclear Fuel Cycles

Reactor power history from fission product signatures

The purpose of this research was to identify fission product signatures that could be used to uniquely identify a specific spent fuel assembly in order to improve international safeguards. This capability would help prevent and deter potential diversion of spent fuel for a nuclear weapons program. The power history experienced by a fuel assembly is distinct and could serve as the basis of a method for unique identification. Using fission product concentrations to characterize the assembly power history would limit the ability of a proliferator to deceive the identification method. As part of the work completed, the TransLat lattice physics code was successfully benchmarked for fuel depletion. By developing analytical models for potential monitor isotopes an understanding was built of how specific isotope characteristics affect the production and destruction mechanisms that determine fission product concentration. With this knowledge potential monitor isotopes were selected and tested for concentration differences as a result of power history variations. Signature ratios were found to have significant concentration differences as a result of power history variations while maintaining a constant final burnup. A conceptual method for implementation of a fission product identification system was proposed in conclusion

Use of Costas arrays in subpixel metrology

Subpixel methods increase the accuracy and efficiency of image detectors, processing units, and algorithms and provide very cost-effective systems for object tracking. A recently proposed method permits micropixel and submicropixel accuracies providing certain design constraints on the target are met. In this paper, we explore the use of Costas arrays - permutation matrices with ideal auto-ambiguity properties - for the design of such targets.JJH acknowledges the support of the National University of Ireland (NUI) Post-doctoral Fellowship in the Sciences. DM acknowledges the support of the Spanish Ministerio de Economía y Competitividad through the project BIA2011-22704, the Generalitat Valenciana through the project PROMETEO/2011/021, and the University of Alicante through the project GRE10-09. The authors also would like to acknowledge the support of Science Foundation Ireland and Enterprise Ireland under the National Development Plan

Engaging Empirical Dynamic Modeling to Detect Intrusions in Cyber-Physical Systems

Modern cyber-physical systems require effective intrusion detection systems to ensure adequate critical infrastructure protection. Developing an intrusion detection capability requires an understanding of the behavior of a cyber-physical system and causality of its components. Such an understanding enables the characterization of normal behavior and the identification and reporting of anomalous behavior. This chapter explores a relatively new time series analysis technique, empirical dynamic modeling, that can contribute to system understanding. Specifically, it examines if the technique can adequately describe causality in cyber-physical systems and provides insights into it serving as a foundation for intrusion detection

Performance of an environmental test to detect Mycobacterium bovis infection in badger social groups

A study by Courtenay and others (2006) demonstrated that the probability of detecting Mycobacterium bovis by PCR in soil samples from the spoil heaps of main badger setts correlated with the prevalence of excretion (infectiousness) of captured badgers belonging to the social group. It has been proposed that such a test could be used to target badger culling to setts containing infectious animals (Anon 2007). This short communication discusses the issues surrounding this concept, with the intention of dispelling any misconceptions among relevant stakeholders (farmers, policy makers and conservationists)

Trust \u3ci\u3eThe Key to Leading When Lives Are on the Line\u3c/i\u3e

The Hostage Rescue Team (HRT) of the Federal Bureau of Investigation was called in to assist the bureau\u27s Special Weapons and Tactics (SWAT) team in Memphis to apprehend a married couple wanted on drug trafficking charges. The fugitive couple and an adult son, all with criminal records, were believed to be living in trailers in a mountain valley where outsiders would be easily noticed. The fugitives were known to stockpile weapons and had vowed never to be taken alive by law enforcement. Thus the FBI considered them to be armed and extremely dangerous. Two HRT snipers along with two SWAT snipers were given the mission of positively identifying the fugitives and providing security and containment for the assault force. The snipers would have to travel several kilometers through wooded, mountainous terrain using night vision goggles (NVGs). The SWAT snipers did not have nighttime, overland movement capability, which is why HRT was brought in

Effects of rapid thermal annealing on GaAs 1-x

The effects of rapid thermal annealing on the optical and structural properties of GaAs1-xBix alloys for x ranging from 0.022 to 0.065 were investigated. At room temperature, the annealed GaAs1-xBix showed modest improvement (∼3 times) in photoluminescence (PL) while the PL peak wavelength remained relatively unchanged. It was found that bismuth related defects are not easily removed by annealing and the PL improvement may be dominated by the reduction of other types of defects including arsenic and gallium related defects. Also, the optimum annealing temperature is Bi composition dependent. For samples with x < 0.048, the optimum annealing temperature is 700 °C but reduces to 600 °C for higher compositions

Long-term stability of RNA in post-mortem bovine skeletal muscle, liver and subcutaneous adipose tissues

peer-reviewedBackground: Recovering high quality intact RNA from post-mortem tissue is of major concern for gene expression studies in animals and humans. Since the availability of post-mortem tissue is often associated with substantial delay, it is important that we understand the temporal variation in the stability of total RNA and of individual gene transcripts so as to be able to appropriately interpret the data generated from such studies. Hence, the objective of this experiment was to qualitatively and quantitatively assess the integrity of total and messenger RNA extracted from bovine skeletal muscle, subcutaneous adipose tissue and liver stored at 4°C at a range of time points up to 22 days post-mortem. These conditions were designed to mimic the environment prevailing during the transport of beef from the abattoir to retail outlets. Results: The 28S and 18S rRNA molecules of total RNA were intact for up to 24 h post-mortem in liver and adipose tissues and up to 8 days post-mortem in skeletal muscle. The mRNA of housekeeping genes (GAPDH and ACTB) and two diet-related genes (RBP5 and SCD) were detectable up to 22 days post-mortem in skeletal muscle. While the mRNA stability of the two housekeeping genes was different in skeletal muscle and liver, they were similar to each other in adipose tissue. After 22 days post-mortem, the relative abundance of RBP5 gene was increased in skeletal muscle and in adipose tissue and decreased in liver. During this period, the relative abundance of SCD gene also increased in skeletal muscle whereas it decreased in both adipose tissue and liver. Conclusion: Stability of RNA in three tissues (skeletal muscle, subcutaneous adipose tissue and liver) subjected to long-term post-mortem storage at refrigeration temperature indicated that skeletal muscle can be a suitable tissue for recovering biologically useful RNA for gene expression studies even if the tissue is subjected to post-mortem storage for weeks, whereas adipose tissue and liver should be processed within 24 hours post-mortem.This research was part funded by the Irish Government under the National Development Plan 2000-2006. Support to BB under the Walsh Fellowship Programme of Teagasc is acknowledged