Crust formation and mixing in a gassy two-liquid pool

Technical Report · Sun Sep 12 04:00:00 EDT 1976

DOI:https://doi.org/10.2172/7138277· OSTI ID:7138277

Bankoff, S G; Horin, W

Molten fuel pools with an overlying layer of steel can be expected to form in various stages of the post-accident heat removal sequence, either on in-vessel or ex-vessel core catchers, or on a concrete or refractory floor beneath the reactor vessel. Since the boiling point of steel is approximately the same as the freezing point of UO/sub 2/, one can expect that a crust of frozen UO/sub 2/ may form at the interface. However, there may be significant bubbling through the interface, either by boiling within the fuel pool or by gas released from the concrete or sacrificial material. The objective of this work was to study the conditions for crust formation in a two-liquid layer pool with gas evolution. A unique physical phenomenon was observed, however, in the course of operation, consisting of the formation of 'ping-pong' balls of ice formed by water transported by the bubbles entering the cold hexane. These formed a raft of hollow spheres at the top of the hexane layer. By analogy, one might expect considerable mixing of UO/sub 2/ in the form of hollow spheres into the molten steel, with important consequences for the pool geometry and heat transfer.

• Research Organization: Northwestern Univ., Evanston, Ill. (USA)
• Sponsoring Organization: US Energy Research and Development Administration (ERDA)
• OSTI ID: 7138277
• Report Number(s): COO-2554-7
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220900* -- Nuclear Reactor Technology-- Reactor Safety
ACCIDENTS
ACTINIDE COMPOUNDS
ALKANES
ALLOYS
CHALCOGENIDES
CORE CATCHERS
ENERGY TRANSFER
FLUID MECHANICS
HEAT TRANSFER
HEXANE
HYDROCARBONS
HYDRODYNAMICS
HYDROGEN COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
MECHANICS
MELTDOWN
MIXING
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
REACTOR ACCIDENTS
REACTOR COMPONENTS
REACTOR CORES
SIMULATION
STEELS
URANIUM COMPOUNDS
URANIUM DIOXIDE
URANIUM OXIDES
WATER