FARO Test L-14 on fuel coolant interaction and quenching

1 - Description of test facility: The FARO test facility became operational in 1987. It is an experimental installation which in its present configuration is dedicated to the investigation of the interaction process of a large mass of corium with water under realistic melt composition and prototypical accident conditions. On the basis of contingent reactor safety research requirements, the test facility was then reconfigured in the early 90's for the investigation of fuel coolant interaction and quenching phenomenologies pertinent to the progression of severe accidents in water cooled reactors. The FARO test facility consists of 5 main major components which include the furnace, the intersection valve unit, the interaction test section TERMOS and the venting system which are properly instrumented to characterize the evolution of the interaction processes. The FARO facility consists of a furnace capable to handle up to 200 kg oxide fuel simulant at temperatures up to 3,270 K; metallic components can be processed as well - orifice/valve system provided to control release mode of the melt (gravity or forced) into test vessel - release vessel designed for a pressure of 10 MPa at 570 K combined with a debris catcher on the lower part of the vessel - release vessel connected to a steam/water separator and a venting system with a set of 4 pressure relief valves - test vessel trace-heated to control heat losses and initial test conditions 2 - Description of tests: The FARO test L-14 consists of a non-energetic fuel coolant interaction and quenching test in which 125 kg of a dioxide mixture was released by gravity in a 2.05 m deep pool of saturated water at a system pressure of 5.1 bar. A number of 15 calculations have been provided using 8 codes or code versions. The major research objectives assigned to test L-14 included the characterization of the fuel coolant interaction and quenching process under the relevant experimental conditions with emphasis on pre-mixing aspects, debris formation and cooling as well as thermal response of the debris catcher bottom plate. FARO test L-14 run with 125 kg of a dioxide mixture (80% UO2 and 20% ZrO2) released by gravity in 2 m deep pool of saturated water at 5.1 MPa