ANS is committed to advancing, fostering, and promoting the development and application of nuclear sciences and technologies to benefit society.
Explore the many uses for nuclear science and its impact on energy, the environment, healthcare, food, and more.
Division Spotlight
Materials Science & Technology
The objectives of MSTD are: promote the advancement of materials science in Nuclear Science Technology; support the multidisciplines which constitute it; encourage research by providing a forum for the presentation, exchange, and documentation of relevant information; promote the interaction and communication among its members; and recognize and reward its members for significant contributions to the field of materials science in nuclear technology.
Meeting Spotlight
Nuclear Energy Conference & Expo (NECX)
September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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!
Latest Magazine Issues
Jun 2025
Jan 2025
Latest Journal Issues
Nuclear Science and Engineering
August 2025
Nuclear Technology
July 2025
Fusion Science and Technology
Latest News
Take steps on SNF and HLW disposal
Matt Bowen
With a new administration and Congress, it is time once again to ponder what will happen—if anything—on U.S. spent nuclear fuel and high-level waste management policy over the next few years. One element of the forthcoming discussion seems clear: The executive and legislative branches are eager to talk about recycling commercial SNF. Whatever the merits of doing so, it does not obviate the need for one or more facilities for disposal of remaining long-lived radionuclides. For that reason, making progress on U.S. disposal capabilities remains urgent, lest the associated radionuclide inventories simply be left for future generations to deal with.
In March, Rick Perry, who was secretary of energy during President Trump’s first administration, observed that during his tenure at the Department of Energy it became clear to him that any plan to move SNF “required some practical consent of the receiving state and local community.”1
Flavio Dante Giust, Peter Grimm, Rakesh Chawla
Nuclear Science and Engineering | Volume 175 | Number 3 | November 2013 | Pages 292-307
Technical Paper | doi.org/10.13182/NSE12-69
Articles are hosted by Taylor and Francis Online.
Total fission rate measurements have been performed on full-size boiling water reactor fuel assemblies of type SVEA-96 Optima2 in the framework of phase III of the light water reactor (LWR)-PROTEUS experimental program at Paul Scherrer Institute. This paper presents comparisons of calculated, nodal reconstructed, pinwise total fission rate distributions with experimental results. Radial comparisons have been performed for the three axial sections of the assembly (96, 92, and 84 fuel pins), while three-dimensional (3-D) effects have been investigated at pellet level for the two transition regions, i.e., the tips of the short (one-third) and long (two-thirds) partial-length rods. The test zone has been modeled using two different code systems: HELIOS/PRESTO-2 and CASMO-5/SIMULATE-5. The former is presently used for core monitoring and design at the Leibstadt Nuclear Power Plant (KKL). The latter represents the most recent generation of codes constituting the widely applied CASMO/SIMULATE system. For representing the PROTEUS test zone boundaries, partial current ratios - derived from a 3-D Monte Carlo (MCNPX) model of the entire reactor - have been applied to the PRESTO-2 and SIMULATE-5 models in the form of two-group and five-group diagonal albedo matrices, respectively. The MCNPX results have also served as a reference high-order transport solution in the calculation-to-experiment (C/E) comparisons.It is shown that the performance of the nodal methodologies in predicting the global distribution of the total fission rate is very satisfactory. Considering the various radial comparisons, the standard deviations of the C/E distributions do not exceed 1.9% for any of the three methodologies - PRESTO-2, SIMULATE-5, and MCNPX. For the 3-D comparisons at pellet level, the corresponding standard deviations are 2.7%, 2.0%, and 2.1%, respectively.
