Methodology for Vulnerability Assessments of Material Control and Accounting Systems at NRC Nonreactor Nuclear Facilities

In 2003, the U.S. Nuclear Regulatory Commission (NRC) requested that Los Alamos National Laboratory perform independent vulnerability assessments of material control and accounting (MC&A) systems at NRC-regulated nonreactor nuclear facilities. The facilities that will be evaluated may include conversion plants, enrichment facilities, and fuel fabrication facilities. This paper discusses the methodology developed for these vulnerability assessments. The methodology utilizes diversion scenarios and diversion path analysis as well as incorporating typical auditing procedures. The purpose of each assessment is to evaluate the overall effectiveness of the facility’s existing MC&A system. The work is significant because of recent interest in considering a broader range of threats to nuclear facilities, including terrorism and the potential of diversion of nuclear material for purposes of radiological sabotage. MC&A systems, regulations, and licensing procedures have been designed to account for special nuclear material (SNM) of various levels of significance as defined in 10 CFR 74 (Code of Federal Regulations) to a set of prescribed limits. The extent to which the current system designs can address broader issues, such as attempts to divert nuclear material of lower significance or waste material may be an emerging priority.