Abstract
SiC/SiC composites are considered among leading candidates for accident tolerant fuel cladding in light water reactors. However, when SiC-based materials are exposed to neutron irradiation, they experience significant changes in dimensions and physical properties. Under a large heat flux application (i.e. fuel cladding), the non-uniform changes in the dimensions and physical properties will lead to build-up of stresses in the structure over the course of time. To ensure reliable and safe operation of such a structure it is important to assess its thermo-mechanical performance under in-reactor conditions of irradiation and elevated temperature. In this work, the foundation for 3D thermo-mechanical analysis of SiC/SiC cladding is put in place and a set of analyses with simplified boundary conditions has been performed. The analyses were carried out with two different codes that were benchmarked against one another and prior results in the literature. A constitutive model is constructed and solved numerically to predict the stress distribution and variation in the cladding under normal operating conditions. The dependence of dimensions and physical properties variation with irradiation and temperature has been incorporated. These robust models may now be modified to take into account the axial and circumferential variation in neutron and heat flux to fully account for 3D effects. The results from the simple analyses show the development of high tensile stresses especially in the circumferential and axial directions at the inner region of the cladding. Based on the results obtained, design guidelines are recommended. For lack of certainty in or tailor-ability for the physical and mechanical properties of SiC/SiC composite material a sensitivity analysis is conducted. The analysis results establish a precedence order of the properties based on the extent to which these properties influence the temperature and the stresses.
| Original language | English |
|---|---|
| Pages (from-to) | 126-143 |
| Number of pages | 18 |
| Journal | Journal of Nuclear Materials |
| Volume | 499 |
| DOIs | |
| State | Published - Feb 2018 |
Funding
This manuscript has been authored by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy 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 material is based upon work supported by the U.S. Department of Energy, Office of Nuclear Energy , under Advanced Fuels Campaign of the Fuel Cycle R&D program, through contract number DE-AC05-00OR22725 . Xunxiang Hu at ORNL provided useful comments. The authors are thankful to the MOOSE and BISON code developers at INL for their technical support. The aid and technical insights of Ryan Sweet and Brian Wirth at University of Tennessee, Knoxville is gratefully acknowledged.
| Funders | Funder number |
|---|---|
| U.S. Department of Energy | |
| U.S. Department of Energy | |
| Office of Nuclear Energy | DE-AC05-00OR22725 |
Keywords
- Accident tolerant fuel
- Cladding
- LWR
- SiC
- Silicon carbide
- Thermo-mechanical analysis