NSUF 25-5227: Assessing the Irradiation-Assisted Hydrothermal Degradation of Bulk GB Engineered SiC

This project will assess the effectiveness of the GB engineering approach in improving the compatibility of SiC with water under irradiation, thus making SiC/SiC composite ATF claddings fitter for use in LWRs. With this goal in mind, GB engineered SiC bulk ceramics will be subjected to synergistic proton irradiation/aqueous corrosion tests, benchmarking their performance against that of CVD SiC currently deposited on CVI SiC/SiC composite ATF claddings to minimize material losses due to the formation and dissolution of silica in high-temperature/high-pressure water (nominal operation conditions). The proton irradiation/aqueous corrosion tests will be conducted in the irradiation-accelerated corrosion (IAC) cell at the MIBL (Michigan Ion Beam Laboratory). The IAC test conditions are identical with those used previously to test CVD SiC supplied by WH & GA in the framework of RTE project #20-4114. More specifically, three polished discs (diameter 3 mm, about 50 μm-thick) will be irradiated with a 5.4 MeV proton (p+) beam at 320°C, for 48 h, in primary PWR water containing 3 ppm H2 (standard water chemistry); each disc will be made of one of the following three ceramics: (a) monolithic Y2SiO5 (yttrium monosilicate, YS1); (b) SiC GB engineered with YS1; and (c) SiC GB engineered with Y3Al5O12 (yttrium aluminium garnet, YAG). Testing monolithic YS1 aims at benchmarking the performance of SiC GB engineered with YS1. Monolithic YAG, on the other hand, has been previously subjected to synergistic proton irradiation/aqueous corrosion testing in the IAC cell (5.4 MeV p+; 320°C; 48 h; PWR water with 3 ppm H2), showing a significantly improved performance (i.e., only shallow intergranular attack) as compared to CVD SiC, which was severely attacked at GBs and stacking faults (SFs) by water radiolysis species during identical test conditions. Both monolithic YAG & YS1 have been tested in autoclave (360°C; 187 bar; 28 days; PWR water with 1000 ppm B & 2 ppm Li) and steam (1600°C, 1 h), showing almost zero weight loss in all cases; therefore, GB engineering of SiC with YAG or YS1 promises to increase the SiC resistance to radiation-assisted hydrothermal corrosion. Each IAC cell test will last for 2 days, resulting in a total of 6 days of IAC testing for three tests; this adheres with the guideline of maximum 2 weeks of MIBL tests. The tests will be performed within 6 months from the award date. After testing, the discs will be inspected vis-à-vis their overall appearance and structural integrity at the Michigan Centre for Materials Characterization (MC2) by means of SEM/EDS, FIB, and (S)TEM/EDS. Basic sample inspection will be concluded within 6 months from the award date. If the GB engineering approach proves effective in controlling the radiation-assisted hydrothermal degradation of SiC, this will be a scientific/technical breakthrough for the invested technology drivers globally. The project findings will be published – together with the results of the detailed post-irradiation examination (PIE) to be conducted at a later stage at PNNL – in a peer-reviewed Journal article that will compare the degradation behaviour of GB engineered SiC to that of CVD SiC.

Informações Adicionais

Campo	Valor
Award Announced Date	2025-08-06T10:06:42.02
Awarded Institution	University of Huddersfield
Facility Tech Lead	Kevin Field
Irradiation Facility	Michigan Ion Beam Laboratory
PI	Konstantina Lambrinou
PI Email	[email protected]
Project Type	RTE
RTE Number	None