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Canada begins regulatory approval process for spent fuel repository
Canada has formally initiated the regulatory process of licensing its proposed deep geological repository for spent nuclear fuel, with the country’s Nuclear Waste Management Organization (NWMO) announcing that it has submitted an initial project description to the Canadian government.
According to the NWMO, the initial project description is a foundational document, detailing the repository’s purpose, need, and expected benefits and explaining how the project will be implemented. It also provides a preliminary assessment of potential impacts and describes measures to avoid or mitigate them. The NWMO is the not-for-profit organization responsible for managing Canada’s nuclear waste.
M. L. Williams, B. L. Broadhead, C. V. Parks
Nuclear Science and Engineering | Volume 138 | Number 2 | June 2001 | Pages 177-191
Technical Paper | doi.org/10.13182/NSE00-56
Articles are hosted by Taylor and Francis Online.
A method is presented to compute sensitivity coefficients for the eigenvalue of a critical assembly, including implicit effects associated with changes in resonance-shielded multigroup cross sections. Two alternative approaches, based on a forward and an adjoint solution, respectively, are developed to determine the effect of perturbations on the weight function used in group averaging of resonance cross sections. The forward method uses an automated methodology to compute the flux derivative with respect to various cross-section processing parameters. The adjoint method introduces adjoint equations for a multigroup cross-section functional and presents adjoint slowing-down equations for two common methods of resonance self-shielding. Expressions are presented for sensitivity coefficients of self-shielded group cross sections. These sensitivity coefficients are combined with conventional eigenvalue sensitivity coefficients to obtain a general perturbation expression for the multiplication factor. An example application determines the sensitivity of the critical eigenvalue to hydrogen density changes in a homogeneous sphere containing low-enriched uranium. It is shown that changes in 238U-shielded cross sections caused by perturbations in hydrogen concentrations are important components in the overall eigenvalue sensitivity coefficient, which is predicted well by the developed method.
