Abstract
SiC-fiber–reinforced SiC matrix composite cladding for light water reactor fuel elements must withstand high-temperature steam oxidation in a loss-of-coolant accident scenario (LOCA). Current composite designs include an outer monolithic SiC layer, in part, to increase steam oxidation resistance. However, it is not clear how such a structure would behave under high-temperature steam in the case when the monolithic layer cracks and carbon interphases and SiC fibers are exposed to the environment. To fill this knowledge gap, stress-rupture tests of prototypic SiC composite cladding at 1000°C under steam and inert environments were conducted. The applied stress was ∼120 MPa, which was beyond the initial cracking stress. The failure lifetime under steam was 400–1300 s, while 75% of the composite specimens did not fail after 3 h of total exposure under inert gases. Microstructural observations suggest that steam oxidation activated slow crack growth in the fibers, which led to failure of the composite. The results from this study suggest that stress rupture in steam environments could be a limiting factor of the cladding under reactor LOCA conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 1658-1666 |
| Number of pages | 9 |
| Journal | International Journal of Applied Ceramic Technology |
| Volume | 20 |
| Issue number | 3 |
| DOIs | |
| State | Published - May 1 2023 |
Funding
This study was supported by the US Department Energy (DOE), Office of Nuclear Energy, for the Advanced Fuels Campaign of the Nuclear Technology R&D program and the Westinghouse Electric Corporation/General Atomics FOA program under contact DE‐AC05‐00OR22725 with ORNL, managed by UT Battelle, LLC. Analysis of the specimens tested in helium was supported by the US DOE, Office of Nuclear Energy, Nuclear Energy University Program, under contract DE‐AC05‐00OR22725 with ORNL, managed by UT Battelle, LLC. Adam Willoughby developed the custom steam generator. The authors wish to thank Xiang Chen, Mackenzie Ridley, Erica Heinrich, and Charlie Horak at ORNL for reviewing and editing this paper. This paper has been authored by UT‐Battelle, LLC, under contract DE‐AC05‐00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid‐up, irrevocable, worldwide license to publish or reproduce the published form of this paper, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe‐public‐access‐plan ). This study was supported by the US Department Energy (DOE), Office of Nuclear Energy, for the Advanced Fuels Campaign of the Nuclear Technology R&D program and the Westinghouse Electric Corporation/General Atomics FOA program under contact DE-AC05-00OR22725 with ORNL, managed by UT Battelle, LLC. Analysis of the specimens tested in helium was supported by the US DOE, Office of Nuclear Energy, Nuclear Energy University Program, under contract DE-AC05-00OR22725 with ORNL, managed by UT Battelle, LLC. Adam Willoughby developed the custom steam generator. The authors wish to thank Xiang Chen, Mackenzie Ridley, Erica Heinrich, and Charlie Horak at ORNL for reviewing and editing this paper.
| Funders | Funder number |
|---|---|
| Westinghouse Electric Corporation/General Atomics | DE-AC05-00OR22725 |
| U.S. Department of Energy | |
| Office of Nuclear Energy | |
| Oak Ridge National Laboratory | |
| Nuclear Energy University Program | DE‐AC05‐00OR22725 |
| UT-Battelle |
Keywords
- composites
- corrosion/corrosion resistance
- oxidation
- silicon carbide