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Division Spotlight
Robotics & Remote Systems
The Mission of the Robotics and Remote Systems Division is to promote the development and application of immersive simulation, robotics, and remote systems for hazardous environments for the purpose of reducing hazardous exposure to individuals, reducing environmental hazards and reducing the cost of performing work.
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.
Claude Mounier, Pietro Mosca
Nuclear Science and Engineering | Volume 179 | Number 2 | February 2015 | Pages 130-147
Technical Paper | doi.org/10.13182/NSE13-63
Articles are hosted by Taylor and Francis Online.
The fast neutron fluence is an important parameter for the reactor pressure vessel (RPV) lifetime. The uncertainty estimation of this parameter is crucial to manage the RPV with a suitable safety margin. This work focuses on a facet of the problem that concerns the uncertainty contribution of the spectrum of the fission source for different burnups in a thermal neutron reactor. The main goal of this paper is to assess the effect of a possible uncertainty correlation among the spectra of the fissile nuclei, involved in the fission source, on the response uncertainty. Two main simplifications are assumed to reduce the complexity of the problem. The first simplification concerns the geometry of the transport problem that is chosen to calculate as fast as possible the sensitivities and the different responses. The second simplification is related to the way by which one can take into account the correlations among spectra of different fissile nuclei. Simple ENDF-6 models of the fission spectrum (Maxwell, Watt, and simplified Madland-Nix) are used to define correlations among the fissile spectra through the mean neutron energy of the prompt fission spectrum. Results are given to quantify the effect of these postulated correlations on response uncertainties and are compared to the ones using JENDL-4.0 covariances.