Material property effect in steam explosion energetics: Revisited
2007 (English)In: Proceedings - 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-12, 2007Conference paper (Refereed)
Steam explosion, as a threat to LWR reactor vessel and containment integrity, has been postulated to occur during a hypothetical severe accident with relocation of molten core materials to a water pool either in-vessel or ex-vessel. Studies of molten fuel-coolant interactions (FCI) conducted over the past decades have not resolved the controversy about whether, when, and how melt material properties influence steam explosion energetics. Crucial questions persist about safety significance of experimental evidence about corium low explosivity in various reactor accident scenarios. In this paper, taking into consideration results from recent FCI experiments and analyses, we revisit the study of Dinh et al (1998) and hypotheses proposed therein about mechanisms by which corium physical properties may influence steam explosions. Corium high density, high melting point and low conductivity are found to be central to mechanisms in premixing that govern corium low explosivity. For micro-interactions, three processes, namely drop surface undercooling, nucleation and growth of solid phases, and interfacial instability and breakup are evaluated with respect to their role in fine fragmentation. The paper provides a new hypothesis for rationalizing the effect of corium composition (eutectic vs. non-eutectic) on its triggerability and energetics.
Place, publisher, year, edition, pages
Coremelt accident, Energetics, Fuel-coolant interactions, Material property, Mushy, Non-eutectic, Radiation, Solidification, Steam explosion
IdentifiersURN: urn:nbn:se:kth:diva-155266ScopusID: 2-s2.0-42249093642ISBN: 0894480588ISBN: 978-089448058-4OAI: oai:DiVA.org:kth-155266DiVA: diva2:761378
12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH-12, 30 September 2007 through 4 October 2007, Pittsburgh, PA, United States
QC 201411062014-11-062014-11-042014-11-06Bibliographically approved