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Division members promote the advancement of mathematical and computational methods for solving problems arising in all disciplines encompassed by the Society. They place particular emphasis on numerical techniques for efficient computer applications to aid in the dissemination, integration, and proper use of computer codes, including preparation of computational benchmark and development of standards for computing practices, and to encourage the development on new computer codes and broaden their use.
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Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
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NRC engineers share their expertise at the University of Puerto Rico
Robert Roche-Rivera and Marcos Rolón-Acevedo are licensed professional engineers who work at the U.S. Nuclear Regulatory Commission. They are also alumni of the University of Puerto Rico–Mayagüez (UPRM) and have been sharing their knowledge and experience with students at their alma mater since last year, serving as adjunct professors in the university’s Department of Mechanical Engineering. During the 2023–2024 school year, they each taught two courses: Fundamentals of Nuclear Science and Engineering, and Nuclear Power Plant Engineering.
Drew E. Kornreich
Nuclear Technology | Volume 181 | Number 2 | February 2013 | Pages 282-302
Technical Paper | Reactor Safety | doi.org/10.13182/NT13-A15784
Articles are hosted by Taylor and Francis Online.
This work involved estimating the homogeneous metal-water mixture critical mass curves of 34 fissionable nuclides from thorium to einsteinium. Calculations were performed using the discrete ordinates code PARTISN with ENDF/B-VII.0 69-group cross sections. Sample MCNP5 test cases indicate reasonable agreement between the two transport codes. In general, the results confirmed that there are three "forms" of the critical mass curves: (a) the traditional curve most well known as characterizing the "big 3" nuclides (233U, 235U, 239Pu), where the minimum critical mass is found in a dilute solution; (b) a simple monotonic curve characterized by a monotonically increasing critical mass as water is added to the metal, where the minimum critical mass is a metal system; and (c) a hybrid curve where the shape is similar to the traditional curve but the minimum critical mass is the pure metal. In general, the traditional and monotonic curves follow the "odd-even" rule of thumb that a nuclide with an even Z and an odd A or vice versa will have a traditionally shaped curve and that the other nuclides will have a monotonically shaped curve. The violations of this rule of thumb, i.e., the hybrid curves, in the set of nuclides analyzed are comprised of 232U and 252Cf. Plutonium-236 is especially interesting because it is a traditionally shaped curve with the minimum critical mass in a relatively dilute solution, but it violates the "odd-even" rule of thumb.