Preliminary results of the XR2-1 experiment
- Sandia National Labs., Albuquerque, NM (United States)
- SAIC, Albuquerque, NM (United States)
The XR2-1 (Ex-Reactor) experiment, investigating metallic core-melt relocation in boiling water reactor geometry, was performed on October 12, 1995, following two previous simpler XR1-series tests in August and November of 1993. The XR2-1 test made use of a highly detailed replication of the lower region of the BWR core, including the control blade and channel box structures, fuel rods, fuel canister nosepieces, control blade velocity limiter, and fuel support pieces, in order to investigate a key core melt progression uncertainty for BWR Station Blackout type accidents. The purpose of this experiment program is to examine the behavior of downward-draining molten metallic core materials in a severe reactor accident in a dry BWR core, and to determine conditions under which the molten materials drain out of the core region, or freeze to form blockages in the lower portion of the core. In the event that the draining metallic materials do not form stable blockages in the lower core region, and instead erode the lower core structures such as the lower core plate, then the subsequent core melt progression processes may proceed quite differently than was observed in the TMI-2 accident, with correspondingly different impact on vessel loading and vessel release behavior. The results of the Ex-Reactor tests are preliminary. All of the tests conducted have shown a significant degree of channel box destruction induced by the draining control blade materials. The XR2-1 test further showed that the draining zircaloy melt causes significant disruption of the fuel rod geometry. All of the tests have shown tendencies to form interim blockages as the melts temporarily freeze, but that these blockages re-melt, assisted by eutectic interactions, resulting in the sudden draining of accumulated metallic melt pools.
- Research Organization:
- US Nuclear Regulatory Commission (NRC), Washington, DC (United States). Office of Nuclear Regulatory Research; Brookhaven National Lab. (BNL), Upton, NY (United States)
- OSTI ID:
- 269689
- Report Number(s):
- NUREG/CP-0149-Vol.2; CONF-9510156-Vol.2; ON: TI96007985; TRN: 96:016795
- Resource Relation:
- Conference: 23. water reactor safety information meeting, Bethesda, MD (United States), 23-25 Oct 1995; Other Information: PBD: Mar 1996; Related Information: Is Part Of Twenty-third water reactor safety information meeting: Volume 2, Human factors research; Advanced I and C hardware and software; Severe accident research; Probabilistic risk assessment topics; Individual plant examination: Proceedings; Monteleone, S. [comp.] [Brookhaven National Lab., Upton, NY (United States)]; PB: 514 p.
- Country of Publication:
- United States
- Language:
- English
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