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Underwater plasma arc cutting in Three Mile Island's reactor

Journal Article · · Welding Journal (Miami); (USA)
OSTI ID:5273434
;  [1];  [2]
  1. PCI Energy Services (US)
  2. GPU Nuclear, Parsippany, NJ (US)

On March 28, 1979, the Pennsylvania Three Mile Island nuclear power plant Unit 2 (TMI-2) suffered a partial fuel-melt accident. During this accident, over 20,000 lb of molten fuel flowed through holes melted through the baffle plates and through the lower-core support assembly (LCSA). The molten fuel subsequently resolidified in the bottom of the reactor vessel. The lower-core support assembly of the TMI-2 reactor was not structurally damaged during the accident. In order to permit defueling of that region of the core, the LCSA was cut to permit access. A five-axis teleoperator was developed to deliver plasma arc cutting, rotary grinding and abrasive waterjet cutting of end effectors to the LCSA. Complex geometry sectioning was completed in a mock-up facility at chemistry and pressure conditions simulating those of the vessel, prior to actual in-vessel operations. In-vessel activities began in early May 1988 and were completed on April 11, 1989. This paper presents the details of the in-vessel cutting efforts.

OSTI ID:
5273434
Journal Information:
Welding Journal (Miami); (USA), Journal Name: Welding Journal (Miami); (USA) Vol. 68:7; ISSN 0043-2296; ISSN WEJUA
Country of Publication:
United States
Language:
English