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Physical and thermal property changes under uniform oxidation in nuclear graphite

Matthews, Austin C. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)] (ORCID:0000000303806598)·Windes, William E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)] (ORCID:0000000188030885)
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Abstract

Material property changes of fine- and medium-grain nuclear graphite grades were measured after subjection to uniform oxidation. The cores of high temperature reactors are composed of large nuclear graphite block components. Here, these large core components are designed to provide neutron moderation and reflection, create a large thermal sink to assist in operational control, and form the solid core structure containing the nuclear fuel, coolant channels, and the safety critical channels for control rod insertion. Oxidation is a principle degradation mechanism affecting all aspects of the nuclear graphite component functions. This study addresses the underlying physical property changes of nuclear-graphite components for oxidized mass loss ranges beyond the current recommended ASME code rule limits to ensure structural integrity within the graphite components (a maximum mass loss = 10%).

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11 - NUCLEAR FUEL CYCLE AND FUEL MATERIALSadvanced reactorgraphite oxidationgraphite strengthnuclear graphite

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Matthews, Austin C. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)] (ORCID:0000000303806598), Windes, William E. [Idaho National Laboratory (INL), Idaho Falls, ID (United States)] (ORCID:0000000188030885). 2025-12-11. Physical and thermal property changes under uniform oxidation in nuclear graphite. https://doi.org/10.1016/j.jnucmat.2025.156376

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