Multigroup covariance matrix self-shielding effects for thermal reactors fueled with slightly enriched uranium
Carregando...
Data
2023
Data de publicação:
Autores IPEN
Orientador
Título da Revista
ISSN da Revista
Título do Volume
É parte de
É parte de
É parte de
Annals of Nuclear Energy
Exportar
Resumo
A numerical approach has been successfully developed to treat the self-shielding effects in the multigroup cross
section covariance matrices of thermal reactors fueled with slightly enriched uranium. The procedure employs
the coupled NJOY/AMPX-II systems developed at IPEN and the 238U resonance parameter covariance data from
JENDL 3.3. Only the first two most important 238U resonances are under analyses. The direct and indirect effects
of the 238U resonance self-shielding is taken into account. The effect of the change in the cross section is called
the direct effect and that of the neutron flux due to change in the cross section is called the indirect effect. The keff
uncertainty analyses applied to the IPEN/MB-01 reveal that the self-shielding effects both direct and indirect
have an important bearing on the multigroup covariance matrix as well as on the keff uncertainty. Also, the
indirect effects account for nearly 44% of the total uncertainty. The ERRORR module of the NJOY system is in
severe disagreement to the developed method because it considers only the direct effect in the multigroup cross
section covariance matrix. Such results underline the application dependence of multi-group cross section
covariance matrix, and that ENDF FILE 33 content must be corrected due to the resonance self-shielding effects
mainly for applications in thermal reactor fueled with slightly enriched uranium.
Como referenciar
SANTOS, ADIMIR dos; GALIA, MARCUS V.C.; LEAL, LUIZ. Multigroup covariance matrix self-shielding effects for thermal reactors fueled with slightly enriched uranium. Annals of Nuclear Energy, v. 194, p. 1-20, 2023. DOI: 10.1016/j.anucene.2023.110099. Disponível em: https://repositorio.ipen.br/handle/123456789/47861. Acesso em: 09 May 2024.
Esta referência é gerada automaticamente de acordo com as normas do estilo IPEN/SP (ABNT NBR 6023) e recomenda-se uma verificação final e ajustes caso necessário.