CFD analysis of blockage length on a partially blocked fuel rod

• Autor(a) principal: SCURO, NIKOLAS L.
• Data de Publicação: 2018
• Outros Autores: ANGELO, GABRIEL, ANGELO, EDVALDO, ANDRADE, DELVONEI A. de, INTERNATIONAL NUCLEAR ATLANTIC CONFERENCE
• Tipo de documento: Artigo de conferência
• Título da fonte: Repositório Institucional do IPEN
• Texto Completo: http://repositorio.ipen.br/handle/123456789/28205
• topic: boundary conditions; computerized simulation; flow blockage; fluid mechanics; fuel rods; heat transfer; loss of coolant; numerical analysis; steady-state conditions; turbulence

In LOCA accidents, fuel rods may balloon by the increasing of pressure difference between fuel rod and core vessel. With the balloon effect, the swelling can partially block the flow channel, affecting the coolability during reflood phase. In order to analyze the influence of blockage length after LOCA events, many numerical simulations using Ansys-CFX code have been done in steady state condition, characterizing the final phase of reflood. Peaks of temperature are observed in the middle of the fuel rod, followed by a temperature drop. This effect is justified by the increasing of heat transfer coefficient, originated from the high turbulence effects. Therefore, this paper considers a radial blockage of 90%, varying just the blockage length. This study observed that, for the same boundary conditions, the longer the blockage length originated after LOCA events, the higher are the central temperatures in the fuel rod.