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Division Spotlight
Mathematics & Computation
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.
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
Vogtle-3 shuts down for valve issue
One of the new Vogtle units in Georgia was shut down unexpectedly on Monday last week for a valve issue that has since been investigated and repaired. According to multiple local news outlets, Georgia Power reported on July 17 that Unit 3 was back in service.
Southern Company spokesperson Jacob Hawkins confirmed that Vogtle-3 went off line at 9:25 p.m. local time on July 8 “due to lowering water levels in the steam generators caused by a valve issue on one of the three main feedwater pumps.”
Emilio Fuentes, Dale B. Lancaster, Meraj Rahimi
Nuclear Technology | Volume 125 | Number 3 | March 1999 | Pages 271-291
Technical Paper | Fission Reactors | doi.org/10.13182/NT99-A2947
Articles are hosted by Taylor and Francis Online.
The calculation of isotopic concentrations in spent nuclear fuel (SNF) assemblies and the subcritical multiplication factor of SNF packages are two of the essential requirements of the actinide-only burnup credit methodology. To justify the accuracy of the computed values, the code systems used to perform the calculations must be validated. Here, the techniques used for actinide-only burnup credit isotopic and criticality validation are presented and demonstrated.Fifty-four chemical assays are included in the isotopic validation benchmark set. To perform the validation, the samples are analyzed to obtain isotopic concentrations for each of the isotopes included in the methodology (234U, 235U, 236U, 238U, 238Pu, 239Pu, 240Pu, 241Pu, 242Pu, and 241Am). Correction factors are computed based on the measured and calculated values, which are then used to conservatively bias computed isotopic concentrations.For the criticality validation, 57 critical experiments are included in the benchmark set. The set is composed of 21 UO2 and 36 mixed-oxide experiments, which are analyzed to determine the bias and corresponding uncertainty, ultimately resulting in an upper safety limit. This limit represents the maximum computed keff value that would be considered subcritical.