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September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The when, where, why, and how of RIPB design
The American Nuclear Society’s Risk-informed, Performance-based Principles and Policy Committee (RP3C) held another presentation in its monthly Community of Practice (CoP) series.
Watch the full webinar here.
B. R. Merk, D. G. Cacuci
Nuclear Science and Engineering | Volume 151 | Number 2 | October 2005 | Pages 194-211
Technical Paper | doi.org/10.13182/NSE05-A2540
Articles are hosted by Taylor and Francis Online.
Closed-form expressions for three-timescale approximations are developed for the one-group time-dependent P1 and P3 equations for a homogeneous multiplying medium in planar geometry with two effective groups of delayed neutrons. The development of these three-scale approximations does not rely on imposing separation of space and time. The differences between the three-scale approximations for the P1, P3, and diffusion equations, respectively, are analyzed in detail. In particular, the results obtained using the three-scale approximations for the P1 and P3 equations underscore their efficiency and accuracy, particularly for the shortest timescales and in the presence of large reactivity insertions.
