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Isotopes & Radiation
Members are devoted to applying nuclear science and engineering technologies involving isotopes, radiation applications, and associated equipment in scientific research, development, and industrial processes. Their interests lie primarily in education, industrial uses, biology, medicine, and health physics. Division committees include Analytical Applications of Isotopes and Radiation, Biology and Medicine, Radiation Applications, Radiation Sources and Detection, and Thermal Power Sources.
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Nuclear Science and Engineering
Fusion Science and Technology
Penfield and Enos: Outage planning in the COVID-19 era
Energy Harbor’s Beaver Valley plant, located about 34 miles northwest of Pittsburgh, Pa., was one of many nuclear sites preparing for a scheduled outage as the coronavirus pandemic intensified in March. The baseline objective of any planned outage—to complete refueling on time and get back to producing power—was complicated by the need to prevent the transmission of COVID-19.
While over 200 of the plant’s 850 staff members worked from home to support the outage, about 800 contractors were brought in for jobs that could only be done on-site. Nuclear News Staff Writer Susan Gallier talked with Beaver Valley Site Vice President Rod Penfield and General Plant Manager Matt Enos about the planning and communication required.
Beaver Valley can look forward to several more outages in the future, now that plans to shut down the two Westinghouse pressurized water reactors, each rated at about 960 MWe, were reversed in March. “The deactivation announcement happened in the middle of all our planning,” Enos said. “It’s a shame we haven’t had a chance to get together as a large group and celebrate that yet.”
While the focus remains on safe pandemic operations, the site now has two causes for celebration: an outage success and a long future ahead.
Vincent M. Laboure, Ryan G. McClarren, Yaqi Wang
Nuclear Science and Engineering | Volume 185 | Number 2 | February 2017 | Pages 294-306
Technical Paper | dx.doi.org/10.1080/00295639.2016.1272374
Articles are hosted by Taylor and Francis Online.
In this paper, we derive a method for the second-order form of the transport equation that is both globally conservative and compatible with voids using the continuous finite element method. The main idea is to use the least-squares (LS) form of the transport equation in the void regions and the self-adjoint angular flux (SAAF) form elsewhere. While the SAAF formulation is globally conservative, the LS formulation needs correction in voids. The price to pay for this fix is the loss of symmetry of the bilinear form. We first derive this conservative LS (CLS) formulation in a void. Second, we combine the SAAF and CLS forms and end up with an hybrid SAAF-CLS method having the desired properties. We show that extending the theory to near-void regions is a minor complication and can be done without affecting the global conservation of the scheme. Being angular discretization-agnostic, this method can be applied to both discrete ordinates (SN) and spherical harmonics (PN) methods. However, since a globally conservative and void-compatible second-order form already exists for SN [Wang et al., Nucl. Sci. Eng., Vol. 176, p. 201 (2014)] but not for PN, we focus most of our attention on the latter angular discretization. We implement and test our method in Rattlesnake within the Multiphysics Object Oriented Simulation Environment (MOOSE) framework. The results are also compared to those of other methods.