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Division Spotlight
Reactor Physics
The division's objectives are to promote the advancement of knowledge and understanding of the fundamental physical phenomena characterizing nuclear reactors and other nuclear systems. The division encourages research and disseminates information through meetings and publications. Areas of technical interest include nuclear data, particle interactions and transport, reactor and nuclear systems analysis, methods, design, validation and operating experience and standards. The Wigner Award heads the awards program.
Meeting Spotlight
ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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
Norway’s Halden reactor takes first step toward decommissioning
The government of Norway has granted the transfer of the Halden research reactor from the Institute for Energy Technology (IFE) to the state agency Norwegian Nuclear Decommissioning (NND). The 25-MWt Halden boiling water reactor operated from 1958 to 2018 and was used in the research of nuclear fuel, reactor internals, plant procedures and monitoring, and human factors.
Blair P. Bromley, Bronwyn Hyland
Nuclear Technology | Volume 186 | Number 3 | June 2014 | Pages 317-339
Technical Paper | Fission Reactors | doi.org/10.13182/NT13-85
Articles are hosted by Taylor and Francis Online.
New reactor concepts to implement thorium-based fuel cycles have been explored to achieve maximum resource utilization. Pressure tube heavy water reactors (PT-HWRs) are highly advantageous for implementing thorium-based fuels because of their high neutron economy and online refueling capability. The use of heterogeneous seed/blanket core concepts in a PT-HWR where higher-fissile-content seed fuel bundles are physically separate from lower-fissile-content blanket bundles allows more flexibility and control in fuel management to maximize fissile utilization (FU) and conversion of fertile fuel. The lattice concept chosen was a 35-element bundle made with a homogeneous mixture of reactor-grade PuO2 (∼67 wt% fissile) and ThO2, with a central zirconia rod to reduce coolant void reactivity. Several annular and checkerboard-type heterogeneous seed/blanket core concepts with plutonium-thorium–based fuels in a 700-MW(electric)–class PT-HWR were analyzed, using a once-through thorium cycle. Different combinations of seed and blanket fuel were tested to determine the impact on core-average burnup, FU, power distributions, and other performance parameters. WIMS-AECL Version 3.1 was used to perform lattice physics calculations using two-dimensional, 89-group integral neutron transport theory, while RFSP Version 3.5.1 was used to perform the core physics and fuel management calculations using three-dimensional two-group diffusion theory. Among the different core concepts investigated, there were cores where the FU was up to 30% higher than that achieved in a PT-HWR using natural uranium fuel bundles. There were cores where up to 67% of the Pu was consumed, cores where up to 43% of the energy was produced from thorium, and cores where up to 363 kg/year of 233U was produced in the discharged fuel.