Quenching Test of SiC_f-SiC_m Composite Cladding

摘要

The nuclear fuel cladding undergoes severe thermal shock during reflooding of the nuclear core after a loss of coolant accident (LOCA). The purpose of this work is to evaluate the resistance of SiC_f-SiC_m composite cladding to such thermal shock events. In order to achieve this goal, a nuclear grade SiC_f-SiC_m composite tube, manufactured by General Atomics (GA), was quenched from an outer surface temperature of 1000 °C into room temperature (RT) water and hot water. The composite tube was heated by a tungsten rod placed inside the tubular sample to simulate the fuel pellet. The tungsten rod was heated to a centerline temperature of 1400 °C by an induction coil. To monitor the progressive damage of the SiC_f-SiC_m composite tube, the acoustic emission (AE) technique is used to acquire the acoustic signals during the test. The samples quenched into RT water showed visible cracks while the sample quenched in hot water did not. Some of the AE signals are related to cracks in the material during quenching. After quenching, the burst strength of the SiC_f-SiC_m composite tube is measured using a bladder technique. Results show that the SiC_f-SiC_m composite tube retains more than 88% of its strength after quenching.