Scaling of the Erosion of a Thermally Stratified Layer in a Large Water Pool during a Steam Injection Through Spargers
2016 (English)Conference paper (Refereed)
The development of thermal stratification in the pressure suppression pool of a BWR is a safety issue since it reduces its cooling capability and leads to higher containment pressures than in completely mixed conditions. In this work, we analyzed the experiments on pool thermal stratification and mixing performed with spargers in the PPOOLEX facility at Lappeenranta University of Technology (LUT), and in the PANDA facility at the Paul Scherrer Institut (PSI). It was observed that at high momentum injections the mean flow was able to penetrate into the stratified layer and induce complete mixing of the pool. At lower momentum injections, the stratified layer was slowly eroded at the interface by the action of small scale turbulence and the breakup of waves. We demonstrated that the erosion mechanism and erosion velocity can be obtained as a function of a single non dimensional number, the Richardson number. Based on this finding, a preliminary coarse resolution model was implemented in the thermal-hydraulic code of GOTHIC to simulate pool behavior during a steam injection through spargers.
Place, publisher, year, edition, pages
IdentifiersURN: urn:nbn:se:kth:diva-194229OAI: oai:DiVA.org:kth-194229DiVA: diva2:1038901
NUTHOS-11: The 11th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operation and Safety, At Gyeongju, Korea, 9-13 2016
QCR 201610252016-10-202016-10-202016-10-25Bibliographically approved