Experiments and theoretical modelling for a core catcher concept for future light water reactors
- Forschungszentrum Karlsruhe (Germany). Inst. fuer Angewandte Thermo-und Fluiddynamik
- Univ. Stuttgart (Germany). Inst. fuer Kernenergetik und Energiesysteme
The COMET concept of corium cooling is proposed to be integrated into future reactors. The concept is based on spreading of the ex-vessel core-melt on a sacrificial concrete layer and, after erosion of this layer, flooding the melt by totally passive water ingression from below through a multitude of melt plugs. The resulting evaporation and interaction processes should lead to a fragmented and porously solidified melt, rapidly coolable through open flow channels. The important processes of melt fragmentation and heat transfer from the melt at direct water contact are investigated with thermite melts in medium scale experiments, and with decay heat simulation in large scale experiments in the modified BETA facility. The experiments show fast cool-down of the melt and solidification of the metallic and oxidic fraction of the melt as a porous structure which, due to its high permeability for the steam-water flow, ensures short-term and long-term coolability. As the experiments are 1-dimensional representations of the central section of the core catcher in the characteristic scale, they should be directly applicable to reactor conditions. Specific tests on the possibility of steam explosions at the initial melt water contact showed very low mechanical loads. The conceptual and experimental work at FZK is accompanied by theoretical investigations at IKE, Stuttgart. Main aims are to optimize the cooling behavior and to evaluate the possible threat by strong steam explosions. Penetration of water jets into an overlying melt layer and resulting phenomena of fragmentation, coolant channel and porous medium formation constitute the key physical processes. Basic models have been developed and applied to the experiments.
- OSTI ID:
- 485005
- Report Number(s):
- CONF-960815-; TRN: 97:010843
- Resource Relation:
- Conference: 31. national heat transfer conference, Houston, TX (United States), 3-6 Aug 1996; Other Information: PBD: 1996; Related Information: Is Part Of Heat transfer -- Houston 1996; El-Genk, M.S. [ed.] [Univ. of New Mexico, Albuquerque, NM (United States)]; PB: 385 p.; AIChE symposium series, Number 310, Volume 92
- Country of Publication:
- United States
- Language:
- English
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