Boundary layer boiling on the external bottom surface of a hemispherical vessel
In recent years, the concept of passive cooling of core melt in a reactor vessel has been considered a desirable means of decay heat removal during a severe accident. In this concept, water is made available on the bottom side of the reactor vessel by flooding the reactor cavity. As the reactor vessel is heated by the core melt resulting from the accident, the decay heat generated in the melt is removed from the external bottom surface of the reactor vessel by downward-facing boiling of the water in the flooded cavity. If this mode of external cooling is effective throughout the postaccident stage, then failure of the reactor vessel due to high-temperature creep rupture or melt-through can be prevented, and the core melt will remain in-vessel. In spite of its practical importance, very little is known about the boiling phenomenon on the external bottom surface of a reactor vessel, which is downward facing and curved. The reported results on the influence of surface configuration are limited to those for nucleate boiling from inclined flat plates or disks with no curvature on the surface. In this study, the boiling phenomenon and critical heat flux on the external surface of a heated hemispherical vessel are investigated experimentally using the method of transient quenching.
- OSTI ID:
- 89357
- Report Number(s):
- CONF-941102--
- Journal Information:
- Transactions of the American Nuclear Society, Journal Name: Transactions of the American Nuclear Society Vol. 71; ISSN TANSAO; ISSN 0003-018X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Observation of Downward Facing Pool Boiling on a Hemispherical Vessel under External Reactor Vessel Cooling
Large-scale testing of in-vessel debris cooling through external flooding of the reactor pressure vessel in the CYBL facility