Triggering and energetics of a single drop vapor explosion: The role of entrapped non-condensable gases
2009 (English)In: Nuclear Engineering and Technology, 2009, Vol. 41, no 9, 1215-1222 p.Conference paper (Refereed)
The present work pertains to a research program to study Molten Fuel-Coolant Interactions (MFCI), which may occur in a nuclear power plant during a hypothetical severe accident. Dynamics of the hot liquid (melt) droplet and the volatile liquid (coolant) were investigated in the MISTEE (Micro-Interactions in Steam Explosion Experiments) facility by performing well-controlled, externally triggered, single-droplet experiments, using a high-speed Visualization system with synchronized digital cinematography and continuous X-ray radiography. The current study is concerned with the MISTEE-NCG test campaign, in which a considerable amount of non-condensable gases (NCG) are present in the film that enfolds the molten droplet. The SHARP images for the MISTEE-NCG tests were analyzed and special attention was given to the morphology (aspect ratio) and dynamics of the air/ vapor bubble, as well as the melt drop preconditioning. Energetics of the vapor explosion (conversion ratio) were also evaluated. The MISTEE-NCG tests showed two main aspects when compared to the MISTEE test series (without entrapped air). First, analysis showed that the melt preconditioning still strongly depends on the coolant subcooling. Second, in respect to the energetics, the tests consistently showed a reduced conversion ratio compared to that of the MISTEE test series.
Place, publisher, year, edition, pages
2009. Vol. 41, no 9, 1215-1222 p.
, Nuclear engineering and technology, ISSN 1738-5733
Fuel-Coolant Interactions, Non-Condensable Gases, Preconditioning, X-ray Radiography
IdentifiersURN: urn:nbn:se:kth:diva-28208ISI: 000272496800010OAI: oai:DiVA.org:kth-28208DiVA: diva2:385217
7th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, Operation and Safety (NUTHOS-7) Seoul, SOUTH KOREA, OCT 05-09, 2008
QC 201101112011-01-112011-01-112011-01-11Bibliographically approved