Validation of the MEWA code agsinst POMECO-HT experiments and cool ability analysis of stratified debris BEDS
2015 (English)In: International Topical Meeting on Nuclear Reactor Thermal Hydraulics 2015, 2015, Vol. 4, 3279-3291 p.Conference paper (Refereed)Text
Motivated by qualification of the MEWA code for coolability analysis of debris beds formed during severe accidents of light water reactors, the present work presents a validation of the code against the experimental data obtained on the POMECO-HT facility for investigation of two-phase flow and heat transfer limits in particulate beds with various characteristics. The volumetrically heated particulate beds used in the POMECO-HT experiment are packed in various configurations, including homogeneous bed, radially stratification, triangular stratification, axial stratification, and multi-stratification. To investigate coolability enhancement by bottom-fed induced natural circulation, a downcomer is employed. Besides, the influence of the interfacial drag is also studied. The results show that simulation results of the MEWA code is overall comparable with the experimental data in term of dryout conditions of the particulate beds. For the 1-D top-flood case, the dryout heat flux is mainly determined by counter-current flow limit. While for certain cases the multidimensionality may help to break CCFL. Besides, the debris bed’s coolabiltiy can be significantly improved due to the natural circulation flow from the bottom induced by using downcomer. The interfacial drag affects the coolability by means of varying the pressure field inside the bed. For the top-flood case, the dryout condition deteriorates since the vapor and coolant flow reversely and thus the interfacial drag increases the flow resistance. Whereas for the bottom-fed case, the dryout heat flux rises remarkably when considering the interfacial drag, because the vapor and coolant flow in the same direction and the interfacial drag helps to pull coolant upward from the bottom.
Place, publisher, year, edition, pages
2015. Vol. 4, 3279-3291 p.
Coolability, Debris bed, Interfacial drag, MEWA code simulation, Severe accident
Fluid Mechanics and Acoustics Energy Engineering
IdentifiersURN: urn:nbn:se:kth:diva-187435ScopusID: 2-s2.0-84962626362OAI: oai:DiVA.org:kth-187435DiVA: diva2:930153
16th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2015; Chicago
QC 201605232016-05-232016-05-232016-05-23Bibliographically approved