21 research outputs found
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Application of the Controllable Unit Approach (CUA) to analyzing safeguards measurement systems
CUA is a material control and accountability methodology that takes into account the system logic and statistical characteristics of a plant process through the formulation of closure equations. The study evaluated CUA methodology to meet performance oriented regulations. The criterion is defined as the detection of a material loss of two kilograms of SNM with 97.5% confidence. Specifically investigated were the timeliness of detection, the ability to localize material loss, process coverage, cost/benefits, and compatibility with other safeguards techniques such as diversion path analysis and data filtering. The feasibility of performance-oriented regulations is demonstrated. To fully use the system of closure equations, a procedure was developed to formally integrate the effect of both short-term and long-term closure equations into an overall systems criterion of performance. Both single and multiple diversion strategies are examined in order to show how the CUA method can protect against either strategy. Quantitative results show that combined closure equations improve the detection sensitivity to material loss, and that multiple diversions provide only diminishing returns
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Statistical problems arising from simulation of a high-throughput nuclear facility
Shortages in traditional energy sources, such as oil and natural gas, have placed greater emphasis on alternative fuel sources. With an already developed technological base and cost history, nuclear power is an attractive option. However, the public's attitude toward recent terrorism has generated strong demands for improved safeguards measures to deter, detect, and protect against diversion of special nuclear material (SNM). To encourage improved safeguards accountability, the Nuclear Regulatory Commission (NRC) has been considering the use of performance oriented regulations to supplement those currently used. A study, sponsored by NRC/Office of Standards Development, was conducted to evaluate the controllable unit approach (CUA) to meeting performance oriented regulations. The study results are used to provide the NRC with a methodology that systematically and iteratively compares the actual situation to the need before additions or refinements are imposed. And because the existing or proposed system is mathematically modeled, modifications to the process for any reason can be tested quickly for their effect on material control before implementation. A summary flow diagram of the CUA methodology is shown and described