In-reactor measurements of fuel centerline temperature variation during power change

Abstract The thermal response of the experimental fuel elements is examined by thermocouples placed at the centre of the fuel. Such measurements allow the determination of thermal feedback effects induced by simultaneous liberation of fission gases and pellet thermal expansion densification, swelling and relocation of fuel fragments. This paper describes briefly measuring techniques developed and currently used in INR Pitesti, and presents and discusses selected experimental results obtained during in-pile experiments performed in the TRIGA SS reactor of INR Pitesti in order to measure the fuel centerline temperature variation during power change.