Criticality Safety and Sensitivity Analyses of PWR Spent Nuclear Fuel Repository Facilities
| Autor: | Marko Maucec, Bogdan Glumac |
|---|---|
| Přispěvatelé: | KVI - Center for Advanced Radiation Technology |
| Rok vydání: | 2005 |
| Předmět: |
Nuclear and High Energy Physics
Nuclear fuel Nuclear engineering Pressurized water reactor CASKS Nuclear reactor Condensed Matter Physics REACTIVITY Spent nuclear fuel Monte Carlo simulations law.invention Nuclear Energy and Engineering Criticality law Nuclear power plant criticality safety Environmental science PWR spent fuel BURNUP CREDIT Neutron moderator STORAGE Burnup |
| Zdroj: | Nuclear Technology, 149(1), 1-13 |
| ISSN: | 1943-7471 0029-5450 |
| DOI: | 10.13182/nt05-a3575 |
| Popis: | Monte Carlo criticality safety and sensitivity calcu- lations of pressurized water reactor (PWR) spent nuclear fuel repository facilities for the Slovenian nuclear power plant Krsko are presented. The MCNP4C code was de- ployed to model and assess the neutron multiplication parameters of pool-based storage and dry transport con- tainers under various loading patterns and moderating conditions. To comply with standard safety requirements, fresh 4.25% enriched nuclear fuel was assumed. The im- pact of potential optimum moderation due to water steam or foam formation as well as of different interpretations, of neutron multiplication through varying the system boundary conditions was elaborated. The simulations indicate that in the case of compact (all rack locations filled with fresh fuel) single or "double tiering" loading, the supercriticality can occur under the conditions of enhanced neutron moderation, due to accidentally re- duced density of cooling water. Under standard opera- tional conditions the effective multiplication factor (keff ) of pool-based storage facility remains below the speci- fied safety limit of 0.95. The nuclear safety require- ments are fulfilled even when the fuel elements are arranged at a minimal distance, which can be initiated, for example, by an earthquake. The dry container in its recommended loading scheme with 26 fuel elements rep- resents a safe alternative for the repository of fresh fuel. Even in the case of complete water flooding, the keff remains below the specified safety level of 0.98. The criticality safety limit may however be exceeded with larger amounts of loaded fuel assemblies (i.e., 32). Additional Monte Carlo criticality safety analyses are scheduled to consider the "burnup credit" of PWR spent nuclear fuel, based on the ongoing calculation of typi- cal burnup activities. |
| Databáze: | OpenAIRE |
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