Fuel cladding integrity analysis during beam trip transients for China lead-based demonstration reactor

Frequent beam trips as experienced in the existing high-power proton accelerators may cause thermal fatigue in Accelerator-Driven System (ADS) components, which may lead to degradation of their structural integrity and reduction of their lifetime. In this paper, we focus on the strength and integrity of fuel cladding during the beam trip transients of China Lead-based Demonstration Reactor (CLEAR-III). Typical frequent beam trips and fuel burn-up are addressed to investigate the acceptable beam trip frequency limitation. Correspondingly, the variation magnitude of temperature and thermal stress of fuel cladding are simulated by ANSYS code. Besides, the behavior of cladding material T91 under irradiation, creep and Lead Bismuth Eutectic (LBE) corrosion conditions has been discussed. It shows that beam trips have little influence on the cladding integrity and the acceptable beam trip frequency of the fuel cladding within 10 s of the beam trip time duration is more than 2.5 × 105 times per year, consequently the CLEAR-III's fuel claddings are expected to have a good resistance to the thermal-mechanical effects induced by beam trips.