Abstract
A CANDU reactor core comprises several hundred horizontal fuel channels spanning a calandria vessel. Loss of sufficient cooling during a severe accident could result in collapse of the core to the bottom of the calandria. A simple computational tool for simulating, in two dimensions, the resulting build-up of a terminal debris bed is described. The tool is used to model a variety of core collapse scenarios. Computed debris beds are generally lower in the middle, ∼10 fuel channels deep, and have higher decay power in their interiors. The initial debris bed porosity is estimated to be 0.65 ± 0.15. High porosity could augment in-vessel hydrogen generation and fission product release during subsequent debris bed heat-up.
Funding source: Atomic Energy of Canada Limited
Award Identifier / Grant number: Federal Nuclear Science & Technology Program
Acknowledgments
I thank M.J. Brown, J.H. Spencer, and R.C. Bowden for review of the manuscript, and Z. Liang for review of the code.
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Author contributions: The author has accepted responsibility for the entire content of this submitted manuscript and approved submission.
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Research funding: This work was supported by Atomic Energy of Canada Ltd. under the Federal Nuclear Science and Technology program.
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Conflict of interest statement: The author declares no conflicts of interest regarding this article.
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