Debris and pool formation/heat transfer in FARO-LWR: Experiments and analysis
The FARO-light water reactor (LWR) experiments examine the debris and pool formation from a pour of core melt materials (UO(2)/ZrO(2) and UO(2)/ZrO(2)/Zr) into a pool of water at prototypic accident conditions. The experiments give unique data on the debris bed initial conditions, morphology and heat transfer after the core melt has slumped and (partly) quenched into the water of the lower head. Quantities of up to 170 kg of corium melt are poured by gravity into water of depth between 1 m and 2 m through a nozzle of diameter 0.1 m at different system pressures. The debris is collected in a flat bottom catcher of diameter 0.66 m. It reaches heights up to 0.2 m depending on the melt quantity. In general, the melt reaches the bottom only partially fragmented. The debris which forms consists of a conglomerate (a cake) in contact with the collecting structure and overlaying fragments (loose debris). The mean particle size of the loose debris is in the range 3.5 mm - 4.8 mm. The upper surface of the debris is flat. A gap is present between the cake and the bottom plate. This paper reviews the debris formation and heat transfer to the bottom steel structure from these tests and describes the development of a model to predict the debris and pool formation process. Sensitivity analyses have been performed by the COMETA code to study the behaviour of the ratio between the cake mass and the total mass.
Bibliographic Reference: Paper presented: OECD/CSNI Workshop on In-Vessel Core Debris Retention and Coolability, Garching (DE), 3-6 March 1998
Availability: Available from (1) as Paper EN 41254 ORA
Record Number: 199810778 / Last updated on: 1998-07-02
Original language: en
Available languages: en