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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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ITA to work with IAEA on advance geologic repository knowledge
The International Tunnelling and Underground Space Association (ITA), a nongovernmental organization made up of 81 member states working to advance the safe, beneficial use of subsurface spaces, is working with the International Atomic Energy Agency to support the advancement of geologic disposal facilities for high-level radioactive waste.
Clifton R. Drumm, Wesley C. Fan, Leonard Lorence, Jennifer Liscum-Powell
Nuclear Science and Engineering | Volume 155 | Number 3 | March 2007 | Pages 355-366
Technical Paper | Mathematics and Computation, Supercomputing, Reactor Physics and Nuclear and Biological Applications | doi.org/10.13182/NSE07-A2668
Articles are hosted by Taylor and Francis Online.
Charged-particle transport is characterized by scattering cross sections that are extremely large and forward-peaked, requiring specialized treatment as compared with neutral-particle transport. The extended-transport correction (ETC) is known to be an effective method to treat elastic scattering of electrons. We apply the ETC to inelastic downscattering of electrons, and evaluate the effectiveness of the method by comparing the scattering moments for the screened Rutherford scattering kernel and for scattering with a deterministic cosine. The ETC approximation results in a -function in angle downscatter source term, for energy loss without direction change, which has been incorporated into the CEPTRE discrete ordinates code in a manner that is compatible with general quadrature sets, not requiring a specialized Galerkin quadrature. The ETC approximation also makes it possible to develop a first-collision source technique that is effective for charged-particle transport, by including particles that have downscattered in energy without direction change in the uncollided-flux solution. We demonstrate the effectiveness of these techniques for problems involving electron beam sources incident on infinite and finite water cylinders and compare the energy- and charge-deposition distributions with ITS Monte Carlo results with good agreement.