Experiments on the high temperature graphite and steam reaction under LOCA condition

Conference · Sat Dec 31 04:00:00 EST 1994

OSTI ID:197119

Uda, T; Ogawa, M; Seki, Y ^[1]

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1. Japan Atomic Energy Research Inst., Ibaraki-ken (Japan); and others

The results of conceptual design activity of ITER (International Thermonuclear Experimental Reactor) gave graphite as a primarily candidate for the plasma facing materials in the first physics phase. In safety analysis of the fusion experimental reactor, release of radioactive tritium and activation product in the plasma-facing materials caused by a loss of coolant accident (LOCA) in a vacuum vessel is one of the severest accident scenarios. It is presumed that loss of coolant flow will generate an extremely high temperature spot, above 1000{degrees}C, on plasma-facing components such as armor tiles of the first wall and divertor plates. Thus coolant pipe made of copper will break or melt, then coolant water will blow out as steam into the vacuum vessel. High temperature graphite will react violently with the steam pouring into the vacuum vessel. Then safety analysis necessitate that the reactivity of the graphite materials should be precisely evaluated. To obtain fundamental data for safety analyses considering loss of coolant inside of the vessel, the rate of reaction between high temperature graphite and steam has been experimentally measured between 1000 and 1600{degrees}C. For experiments isotopic graphite and C/C composite ones were used. Reaction rate to a unit surface area was measured dividing the weight loss by inner surface area of tube type graphite specimen, and product gases were analyzed by gas-chromatography.

• OSTI ID: 197119
• Report Number(s): CONF-940664--
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
CHEMICAL REACTION KINETICS
GRAPHITE
ITER TOKAMAK
LOSS OF COOLANT
SAFETY ANALYSIS
STEAM
TEMPERATURE RANGE 1000-4000 K
TRITIUM