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Fuel Cycle & Waste Management
Devoted to all aspects of the nuclear fuel cycle including waste management, worldwide. Division specific areas of interest and involvement include uranium conversion and enrichment; fuel fabrication, management (in-core and ex-core) and recycle; transportation; safeguards; high-level, low-level and mixed waste management and disposal; public policy and program management; decontamination and decommissioning environmental restoration; and excess weapons materials disposition.
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ANS Student Conference 2025
April 3–5, 2025
Albuquerque, NM|The University of New Mexico
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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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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.
M. Assawaroongruengchot, G. Marleau
Nuclear Science and Engineering | Volume 155 | Number 1 | January 2007 | Pages 37-52
Technical Paper | doi.org/10.13182/NSE07-A2643
Articles are hosted by Taylor and Francis Online.
Most perturbation theory calculation methods for neutron transport problems are based on the assumption that the solution to the adjoint transport problem is known. Here we develop an adjoint transport solution based on the method of cyclic characteristics (MOCC) for two-dimensional fuel assembly problems with isotropic scattering. The main advantages of the MOCC method are (a) it requires lower computing time and memory spaces than the collision probability (CP) method and (b) it does not require the boundary surface currents as for the method of characteristics with isotropic tracking. In the MOCC the adjoint characteristics equations associated with a cyclic tracking line are formulated in such a way that a closed form for the adjoint angular function can be obtained. The mathematical relationship between the adjoint function obtained by CP method and the adjoint function by MOCC is also presented. In order to speed up the MOCC solution algorithm, group-reduction and group-splitting techniques based on the structure of the adjoint scattering matrix are implemented. In addition, a combined forward flux/adjoint function iteration scheme, based on the group-splitting technique and the common use of large numbers of variables storing tracking-line data and exponential values, is proposed to reduce the computing time. To demonstrate the efficiency of these algorithms, calculations are performed on a 17 × 17 pressurized water reactor lattice, a 37-pin CANDU [Canada deuterium uranium reactor] cell, and the Watanabe-Maynard benchmark. Comparisons of adjoint function and keff results obtained by the MOCC and the CP method are presented.
