A numerical and experimental study of water ingression phenomena in melt pool coolability
2009 (English)In: Nuclear Engineering and Design, ISSN 0029-5493, E-ISSN 1872-759X, Vol. 239, no 7, 1285-1293 p.Article in journal (Refereed) Published
During a postulated severe accident, the core can melt and the melt can fail the reactor vessel. Subsequently, the molten corium can be relocated in the containment cavity forming a melt pool. The melt pool can be flooded with water at the top for quenching it. However, the question that arises is to what extent the water can ingress in the corium melt pool to cool and quench it. To reveal that, a numerical study has been carried out using the computer code MELCOOL The code considers the heat transfer behaviour in axial and radial directions from the molten pool to the overlaying water, crust generation and growth, thermal stresses built-in the crust, disintegration of crust into debris, natural convection heat transfer in debris and water ingression into the debris bed. To validate the computer code, experiments were conducted in a facility named as core melt coolability (COMECO). The facility consists of a test section (200 mm x 200 mm square cross-section) and with a height of 300 mm. About 14 L of melt comprising of 30% CaO + 70% B2O3 (by wt.) was poured into the test section. The melt was heated by four heaters from outside the test section to simulate the decay heat of corium. The melt was water flooded from the top, and the depth of water pool was kept constant at around 700 mm throughout the experiment. The transient temperature behaviour in the melt pool at different axial and radial locations was measured with 24 K-type thermocouples and the steam flow rate was measured using a vortex flow meter. The melt temperature measurements indicated that water could ingress only up to a certain depth into the melt pool. The MELCOOL predictions were compared with the test data for the temperature distribution inside the molten pool. The code was found to simulate the quenching behaviour and depth of water ingression quite well.
Place, publisher, year, edition, pages
2009. Vol. 239, no 7, 1285-1293 p.
Cavity forming, Computer codes, Coolability, Corium melts, Debris beds, Decay heats, Generation and growths, K-type thermocouples, Melt pools, Molten Corium, Molten pools, Natural convection heat transfers, Numerical and experimental studies, Numerical studies, Radial directions, Radial locations, Reactor vessels, Severe accidents, Steam flow rates, Test datum, Test sections, Transient temperatures, Vortex flow meters, Water pools, Core meltdown, Debris, Heat convection, Heat exchangers, Nuclear reactors, Quenching, Temperature measurement, Testing
Engineering and Technology
IdentifiersURN: urn:nbn:se:kth:diva-32512DOI: 10.1016/j.nucengdes.2009.02.016ISI: 000267026100015ScopusID: 2-s2.0-67349087729OAI: oai:DiVA.org:kth-32512DiVA: diva2:410973
QC 201104152011-04-152011-04-152011-04-15Bibliographically approved