Abstract
Reflood phenomena of 2-loop PWR with upper-plenum-injection (UPI) type ECCS was studied by examining CCTF experimental data. The major conclusions about the effects of asymmetric UPI and single low-pressure-coolant-injection (LPCI) pump failure on reflood phenomena are as follows: 1. Single failure assumption of LPCI pump is more conservative (worse core cooling) than no failure assumption of LPCI pump under UPI condition. This is consistent with current guide line for reactor safety evaluation.2. The asymmetric UPI promoted a radial ununiformity of the core cooling, although even symmetric UPI lead to the radial ununiformity of the core cooling.3. The asymmetric UPI did not give a local degradation of core cooling in comparison with symmetric UPI but gave an enhancement of core cooling in the upper part of core after the initiation of water fall back.4. The enhancement of core cooling is considered to be caused by increased upward fluid flow due to water fall back and water fall back itself, which are promoted by asymmetric UPI.5. Initiation of water fall back can be predicted with Bankaff's correlation under UPI condition when the fluid temperature is saturated.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
