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Division Spotlight
Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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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Latest News
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.
Tracy E. Stover, Dennis Mennerdahl, Dominic D. Winstanley, Christopher Tripp, Kermit Bunde, Douglas Bowen
Nuclear Technology | Volume 208 | Number 4 | April 2022 | Pages 644-687
Technical Paper | doi.org/10.1080/00295450.2021.1938910
Articles are hosted by Taylor and Francis Online.
Calculated critical and subcritical data for systems of mixed oxides of plutonium and uranium are presented for review and subsequent incorporation into a revision of ANSI/ANS 8.12. The system specifications were prepared in parallel with the ISO standard ISO 11311:2011, involving experience from international mixed oxide fuel fabrication facilities. Data are presented for two mass fractions of plutonium to uranium plus plutonium (at 12.5% and 35%), damp mixed oxide density up to a theoretical density of 11.03 g/cm3 (for the 12.5% mass fraction, ignoring the variation due to plutonium isotopic content) and up to a density of 3.5 g/cm3 (for the 35% mass fraction), three plutonium isotopic mass fractions (100% 239Pu, 95% 239Pu with 5% 240Pu, and a reactor grade composition with 20% 240Pu and the balance 239Pu, 241Pu, and 242Pu), systems at two moderation conditions (water mass fractions at 3% and at optimal conditions) and systems at two water reflector conditions (nominal 2.5 cm and full 30.0 cm). Parameters of interest presented are values of volume (L), infinite cylinder diameter (cm), infinite slab thickness (cm), mass (kg), cylinder linear density (g/cm), and slab areal density (g/cm2). Values are presented at calculated multiplication factors of 1.000, 0.980 and 0.950. Calculations were made by various subject matter experts with various computational programs and cross section libraries. Validation methods were reviewed and discussed herein though data propagated to revision of ANSI/ANS 8.12 will reflect a conservative subcritical margin selected based on expert judgment.