An experimental investigation on rewetting of a 54 pins fuel bundle under steam environment by radial jet injection

Abstract

The 54 pins fuel bundle of AHWR rewetting by radial jet injection has been examined experimentally. The drop of coolant mass flow and vaporization cause heat-up of channel which ends up with the damages of fuel pins. The water carries away decay heat from clad and maintained channel integrity. Experiments have been conducted at clad temperature 450 °C, 500 °C, 550 °C and 600 °C with clad average heat flux 1.40 kW/m2, 1.83 kW/m2, 2.03 kW/m2 and 2.40 kW/m2 respectively. Water supplied at 90 lpm under steam environment. It is observed that the inner rings pin underwent rewetting followed by middle and outer. The clad surface, facing the jet direction have shorter rewetting period than the rear side for all pin with few exceptions. The circumferential position has very significant effect on rewetting whereas; the axial position does not affect much. The designed ECCS flow is found to be adequate as no breach reported.