基于可视化交互式核动力系统瞬态分析程序的先进压水堆蒸汽发生器传热管破裂事故OA

Steam generator heat transfer tube rupture(SGTR)accidents primarily involve the dynamic response of the re-actor coolant system following tube failure,as well as the associated responses of auxiliary and safety systems.In this study,the visual interactive transient analysis code for reactor system(VITARS)was employed to develop an accident analysis model for an advanced pressurized water reactor(PWR),and SGTR accidents in a U-tube steam generator were simulated.Building upon the analysis of single-tube rupture events,multi-tube rupture accidents were further investigated to evaluate the operational limits of the nuclear power plant.In addition,beyond-design-basis accidents,including SGTR combined with loss of offsite power(LOOP)or complete loss of feedwater,were analyzed.The results indicate that more se-vere consequences occur when the rupture is located at the tube inlet under an initial condition of 5%nominal power(NP).No steam generator overfill is observed when fewer than four tubes are ruptured.Moreover,as the number of failed tubes increases,the total amount of steam discharged to the atmosphere from the affected steam generator decreases.In the case of a single-tube SGTR accident with LOOP,the reactor coolant system parameters remain within safe limits,thereby providing sufficient time for operator intervention.