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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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U.K.’s NWS gets input from young people on geological disposal
Nuclear Waste Services, the radioactive waste management subsidiary of the United Kingdom’s Nuclear Decommissioning Authority, has reported on its inaugural year of the National Youth Forum on Geological Disposal forum. NWS set up the initiative, in partnership with the environmental consultancy firm ARUP and the not-for-profit organization The Young Foundation, to give young people the chance to share their views on the government’s plans to develop a geological disposal facility (GDF) for the safe, secure, and long-term disposal of radioactive waste.
Zhaopeng Zhong, Thomas J. Downar, Yunlin Xu, Mark D. DeHart, Kevin T. Clarno
Nuclear Science and Engineering | Volume 158 | Number 3 | March 2008 | Pages 289-298
Technical Note | doi.org/10.13182/NSE06-24TN
Articles are hosted by Taylor and Francis Online.
The coarse-mesh finite difference (CMFD) formulation is applied as an efficient means of acceleration of the heterogeneous whole-core transport calculation. The CMFD formulation enables dynamic homogenization of the cells during the iterative solution process such that the heterogeneous transport solution can be preserved. Dynamic group condensation is also possible with a two-level CMFD formulation involving alternate multigroup and two-group calculations. The two-dimensional discrete ordinates (SN) method is used as the kernel to generate the heterogeneous solution; the CMFD solution provides the SN kernel with much faster convergence of fission and scattering source distributions. In this paper, the two-level CMFD acceleration has been tested using the VENUS-2 two-dimensional whole-core model; it is shown that the number of SN transport sweeps can be reduced by a factor of about 10 while exactly reproducing the original transport solution. The second level of CMFD acceleration is also significant in reducing the computation time. The application of the CMFD formulation in arbitrary geometry demonstrates that CMFD also works well for irregular geometries.