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Division Spotlight
Radiation Protection & Shielding
The Radiation Protection and Shielding Division is developing and promoting radiation protection and shielding aspects of nuclear science and technology — including interaction of nuclear radiation with materials and biological systems, instruments and techniques for the measurement of nuclear radiation fields, and radiation shield design and evaluation.
Meeting Spotlight
Utility Working Conference and Vendor Technology Expo (UWC 2024)
August 4–7, 2024
Marco Island, FL|JW Marriott Marco Island
Standards Program
The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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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.
Mark Massie, Benoit Forget
Nuclear Technology | Volume 182 | Number 2 | May 2013 | Pages 207-223
Regular Technical Paper | Special Issue on the Symposium on Radiation Effects in Ceramic Oxide and Novel LWR Fuels / Fission Reactors | doi.org/10.13182/NT13-A16431
Articles are hosted by Taylor and Francis Online.
This work presents a methodology for determining the optimal neutron energy spectrum for meeting user-specified transmutation objectives. A simulated annealing routine is used to find the optimal neutron energy distribution by iteratively modifying the flux spectrum, performing depletion calculations, and computing the value of the cost function.To demonstrate this methodology, we found optimal flux spectra for transmuting used nuclear fuel (UNF) to maximize proliferation resistance and to maximize repository capacity by minimizing decay heat. Multiple cost functions are evaluated for each of the two objectives. For maximizing proliferation resistance, we determined the optimal spectra for minimizing 239Pu mass, maximizing 238Pu mass, maximizing 240Pu mass, and minimizing the mass ratio of 239Pu to 238Pu and 240Pu. The results of this study show that while both fast and thermal neutrons are useful for reducing the amount of 239Pu, a thermal spectrum is best for rendering plutonium from UNF unusable as weapons material.Optimal spectra for maximizing repository capacity are found for minimizing the time-integrated decay heat generated by the transmuted UNF. This study shows that optimal transmutation of the full UNF vector can reduce the amount of decay heat released over 10 000 yr by [approximately]39% and that even more substantial reductions are possible with transuranic element-only transmutation, which can decrease decay energy by >81%. Furthermore, it is shown that a thermal spectrum is substantially more effective than a fast spectrum for reducing decay heat released by UNF over 10 000 yr, thus increasing the capacity of heat-limited waste repositories. Results such as these provide powerful insight into the complicated energy dependence of transmutation and illustrate this methodology's effectiveness as a scoping tool.