Hydrogen generation during fuel-coolant interactions

Conference · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6541875

Young, M F; Berman, M; Pong, L T

During a severe nuclear plant accident, molten fuel can contact water in the core region, the lower plenum, or in the cavity below the reactor vessel. The interactions that take place can vary from benign boiling to explosive vaporization. If the fuel contains a metallic component, rapid oxidation of the metal can occur during the fuel-coolant interaction (FCI). The hydrogen generated from this reaction can increase the threat to containment integrity. Experiments have been conducted with 10 to 20 kg of two kinds of thermite-generated molten fuel simulants: corium and iron-aluminum oxide. Both saturated and subcooled water were employed as coolants. Explosive and nonexplosive FCIs were observed. Up to 30% of the metal was reacted in some cases. For some of the tests, the extent of reaction appeared to depend more on the water subcooling than on the degree of fragmentation as measured by post-test sieving. Models of hydrogen generation are proposed and compared to a broad range of experiments. Predictions agree qualitatively with many of the experimental observations. A more accurate model of hydrogen generation would have to be coupled to a dynamic thermal-hydraulic calculation of the important phases of an FCI: coarse mixing, fine fragmentation, explosion propagation and vapor expansion.

• Research Organization: Sandia National Labs., Albuquerque, NM (USA); Technadyne Engineering Consultants, Inc., Albuquerque, NM (USA)
• DOE Contract Number: AC04-76DP00789
• OSTI ID: 6541875
• Report Number(s): SAND-86-1067C; CONF-860911-29; ON: DE87009054
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
220400* -- Nuclear Reactor Technology-- Control Systems
ACCIDENTS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CORIUM
ELEMENTS
ENERGY TRANSFER
EXPLOSIONS
FLUID MECHANICS
FUEL ELEMENT FAILURE
FUEL-COOLANT INTERACTIONS
HEAT TRANSFER
HYDRAULICS
HYDROGEN
KINETICS
MATHEMATICAL MODELS
MECHANICS
MELTDOWN
MOLTEN METAL-WATER REACTIONS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
REACTOR ACCIDENTS
REACTOR SAFETY
REACTOR SAFETY EXPERIMENTS
SAFETY