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Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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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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Powering the future: How the DOE is fueling nuclear fuel cycle research and development
As global interest in nuclear energy surges, the United States must remain at the forefront of research and development to ensure national energy security, advance nuclear technologies, and promote international cooperation on safety and nonproliferation. A crucial step in achieving this is analyzing how funding and resources are allocated to better understand how to direct future research and development. The Department of Energy has spearheaded this effort by funding hundreds of research projects across the country through the Nuclear Energy University Program (NEUP). This initiative has empowered dozens of universities to collaborate toward a nuclear-friendly future.
Bojan G. Petrovic, Alireza Haghighat
Nuclear Science and Engineering | Volume 122 | Number 2 | February 1996 | Pages 167-193
Technical Paper | doi.org/10.13182/NSE96-3
Articles are hosted by Taylor and Francis Online.
An accurate prediction of the reactor pressure vessel (PV) fast neutron fluence (E> 1.0 MeV or E> 0.1 MeV) is necessary to ensure PV integrity over the design lifetime. The discrete ordinates method (SN method) is the method of choice to treat such problems, and the DORT SN code is widely used as a standard tool for PV fluence calculations. The SN numerics and the corresponding DORT numerical options and features offer alternative choices that increase flexibility but also impact results. The effects of SN numerics based on PV fluence calculations for two pressurized water reactors are examined. The differencing schemes [linear, zero-weighted (ZW), and θ-weighted (TW)] and their interactions with spatial and angular discretization are also examined. The linear and TW ( θ = 0.9) schemes introduce unphysical flux oscillations that for certain groups and positions may exceed 10%. The ZW scheme produces smooth results; however, its results differ from the other two schemes. A good compromise for PV fluence calculations is a TW scheme with a small θ value (i.e., θ = 0.3), which reduces the uncertainty to ∼3%. Angular discretization and spatial mesh size employed in typical calculations introduce another ∼3 and ∼2% uncertainty, respectively. The analysis further shows that the fixup is not necessary for the negative scattering source. The pointwise convergence criterion is also not a critical issue in the fast energy range because of a relatively fast convergence rate. Similarly, acceleration parameters impact mainly the execution time and only marginally the results. The root-mean-square combined uncertainty for standard PV fluence calculations due to the options analyzed is ∼5%.
