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The Young Members Group works to encourage and enable all young professional members to be actively involved in the efforts and endeavors of the Society at all levels (Professional Divisions, ANS Governance, Local Sections, etc.) as they transition from the role of a student to the role of a professional. It sponsors non-technical workshops and meetings that provide professional development and networking opportunities for young professionals, collaborates with other Divisions and Groups in developing technical and non-technical content for topical and national meetings, encourages its members to participate in the activities of the Groups and Divisions that are closely related to their professional interests as well as in their local sections, introduces young members to the rules and governance structure of the Society, and nominates young professionals for awards and leadership opportunities available to members.
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2024 ANS Annual Conference
June 16–19, 2024
Las Vegas, NV|Mandalay Bay Resort and Casino
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Securing the advanced reactor fleet
Physical protection accounts for a significant portion of a nuclear power plant’s operational costs. As the U.S. moves toward smaller and safer advanced reactors, similar protection strategies could prove cost prohibitive. For tomorrow’s small modular reactors and microreactors, security costs must remain appropriate to the size of the reactor for economical operation.
Uncheol Shin, Warren F. Miller, Jr.
Nuclear Science and Engineering | Volume 128 | Number 1 | January 1998 | Pages 27-46
Technical Paper | doi.org/10.13182/NSE98-A1943
Articles are hosted by Taylor and Francis Online.
Using an asymptotic expansion, we found that the modified time-dependent simplified P2 (SP2) equations are robust, high-order, asymptotic approximations to the time-dependent transport equation in a physical regime in which the conventional time-dependent diffusion equation is the leading-order approximation. Using diffusion limit analysis, we also asymptotically compared three competitive time-dependent equations (the telegrapher's equation, the time-dependent SP2 equations, and the time-dependent simplified even-parity equation). As a result, we found that the time-dependent SP2 equations contain higher-order asymptotic approximations to the time-dependent transport equation than the other competitive equations. The numerical results confirm that, in the vast majority of cases, the time-dependent SP2 solutions are significantly more accurate than the time-dependent diffusion and the telegrapher's solutions. We have also shown that the time-dependent SP2 equations have excellent characteristics such as rotational invariance (which means no ray effect), good diffusion limit behavior, guaranteed positivity in diffusive regimes, and significant accuracy, even in deep-penetration problems. Through computer-running-time tests, we have shown that the time-dependent SP2 equations can be solved with significantly less computational effort than the conventionally used, time-dependent SN equations (for N > 2) and almost as fast as the time-dependent diffusion equation. From all these results, we conclude that the time-dependent SP2 equations should be considered as an important competitor for an improved approximate transport equation solver. Such computationally efficient time-dependent transport models are especially important for problems requiring enhanced computational efficiency, such as neutronics/fluid-dynamics coupled problems that arise in the analyses of hypothetical nuclear reactor accidents.