Selection and Qualification of Graphite Grades for IMSR400 Operations

Abstract

For the IMSR400 design, graphite has been selected as the moderator material. Terrestrial Energy Inc. (TEI) has conducted a graphite-grade preselection to identify potential candidates for the IMSR400 moderator material, which were subjected to further qualification activities under the GAIA (Graphite Irradiation Assessment) irradiation project. The GAIA project consists of two irradiations phases and is being conducted using the High Flux Reactor (HFR) at Nuclear Research Group (NRG, Petten), which allows irradiation of the selected grades in different temperature zones and up to the required fluence limits to envelope the operating conditions of the IMSR400. For the design validation purposes, a previously irradiated and well-characterized graphite grade (IG-110) is also included into the test program. This paper describes TEI’s selection and qualification approach to identify the optimal graphite grade based on its mechanical, chemical, nuclear and thermal performances.