Parametric analysis of influence factors to the in-vacuum vessel LOCA for CFETR based on RELAP5

Abstract

The water-cooled blanket and water-cooled divertor located inside the vacuum vessel (VV) are two crucial components of the Chinese Fusion Engineering Testing Reactor (CFETR). The flash vaporization from high temperature and high pressure water pressurizes the VV when in-VV Loss of Coolant Accident (in-VV LOCA) occurs. As the first confinement barrier of the CFETR, the integrity of the VV is required to be guaranteed to contain radioactive materials. Parametric analysis of the in-VV LOCA is carried out to analyze the key influence factors on the pressure increasing rate and leaked water mass so as to provide basis for safety facility designs of the CFETR. The water-cooled components, VV and vacuum vessel pressure suppression system are modeled using RELAP5. The pressure increasing rate and leaked water mass are analyzed under circumstances with different discharge pressures, VV initial pressures and the breach areas. Moreover, the pressure increasing rate increases with the discharge pressure, VV initial pressure and breach area increased. The leaked water mass and its variation both increase with breach area increased.