BWR LOCA Research and Development of SAFER Code

Abstract

Many integral and separate effect experiments have been carried out cooperatively by the Japanese BWR utilities and vendors. Through these results, various counter-current-flow limitation phenomena occurring inside the BWR core, steam and mist cooling effect, multibundle effect etc. have been identified effectively to cool down the core during LOCA transients. Based on these findings and with other aids, SAFER code, which can better estimate the thermal-hydraulics of the BWR transient by the simple one-dimentional method, has been developed by the BWR vendors to replace with the existing SAFE-REFLOOD-CHASTE code system. The new code predicts the peak-cladding-temperature for the standard jet-pump BWR LOCA transients to be as high as 500~600°C, which is well below the current regulatory limitation. LOCA/ECCS constraints will be reduced for future BWR core managements and ECCS equipments surveillance etc. by the use of new code. © 1986, Atomic Energy Society of Japan. All rights reserved.