LAUSR

Abstract The thermal behavior of reactor channels is of prime concern for a postulated scenario of LOCA along with the un-availability of ECCS as the integrity of the fuel bundle may be challenged and slumping of fuel pins is expected. The present study is aimed to analyze the thermal characteristics of a large capacity Indian PHWR specific fuel bundle with disassembled fuel pins configuration. The configuration considers the collapse of 37-fuel pins of a bundle from the endplate and rearranges at the bottom surface of the PT. The paper further investigates the influence of PT-CT contact on the channel. The results show that a significant circumferential temperature gradient is developed in the PT due to the slumping of fuel pins. The maximum temperature is obtained at the bottom sector of the PT, which is in contact with the fuel pin. However, PT-CT contact causes a sudden temperature drop at the bottom nodes of the PT.