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Bowman & Smith on NRC security programs
Greg Bowman and George Smith work for the Nuclear Regulatory Commission in implementing programs that deal with risk, whether to nuclear power plants or from nuclear materials, such as radiological sabotage and theft or diversion of materials. Bowman is the director of the NRC’s Division of Physical and Cybersecurity Policy in the Office of Nuclear Security and Incident Response. Smith is the senior project manager for security in the Source Management & Protection Branch of the Division of Materials Safety, Security, State, and Tribal Programs in the Office of Nuclear Material Safety and Safeguards.
The three initiatives Bowman and Smith discussed with Nuclear News editor-in-chief Rick Michal are the Insider Threat Program, the Cybersecurity Program, and the Domestic Safeguards Program.
Rakesh Chawla, Om Parkash Joneja, Marc Rosselet, Tony Williams
Nuclear Technology | Volume 139 | Number 1 | July 2002 | Pages 50-60
Technical Paper | Reactor Safety | doi.org/10.13182/NT02-A3303
Articles are hosted by Taylor and Francis Online.
Although high-temperature reactors (HTRs) are endowed with a number of inherent safety features, there are still aspects of the design that need particular attention. For concepts in which shutdown rods are situated outside the core region, as is the case in contemporary modular pebble bed designs, accurate calculations are needed for the worth of these shutdown rods not only in normal operation but also under accident conditions in which significant changes occur, for instance, due to inadvertant moderation increase in the core (ingress of water or other hydrogeneous compound). Corresponding validation experiments, employing a variety of reactivity measurement techniques, were conducted in the framework of the HTR-PROTEUS program employing low-enriched uranium pebble-type fuel. Details of the experimental configurations, along with the measurement results obtained, are given for two different HTR-PROTEUS cores, in each of which four different shutdown rod combinations were investigated. Comparisons made with calculations, based on both approximative deterministic models and geometrically "near-to-exact" Monte Carlo analyses, have clearly brought out the sensitivity of the experimental results to calculational correction factors when conventional (thermal) techniques are used for reactivity measurements in such systems. Considerably greater systematic accuracies are reflected in the experimental shutdown rod values obtained using specially developed epithermal techniques, and it is these results that are recommended for benchmarking purposes.