Abstract
This paper addresses certain key feasibility issues facing the application of SiC-matrix microencapsulated fuels for light water reactor application. Issues addressed are the irradiation stability of the SiC-based nano-powder ceramic matrix under LWR-relevant irradiation conditions, the presence or extent of reaction of the SiC matrix with zirconium-based cladding, the stability of the inner and outer pyrolytic graphite layers of the TRISO coating system at this uncharacteristically low irradiation temperature, and the state of the particle-matrix interface following irradiation which could possibly affect thermal transport. In the process of determining these feasibility issues microstructural evolution and change in dimension and thermal conductivity was studied. As a general finding the SiC matrix was found to be quite stable with behavior similar to that of CVD SiC. In magnitude the irradiation-induced swelling of the matrix material was slightly higher and irradiation-degraded thermal conductivity was slightly lower as compared to CVD SiC. No significant reaction of this SiC-based nano-powder ceramic matrix material with Zircaloy was observed. Irradiation of the sample in the 320-360 °C range to a maximum dose of 7.7 × 1025 n/m2 (E > 0.1 MeV) did not have significant negative impact on the constituent layers of the TRISO coating system. At the highest dose studied, layer structure and interface integrity remained essentially unchanged with good apparent thermal transport through the microsphere to the surrounding matrix.
| Original language | English |
|---|---|
| Pages (from-to) | 389-398 |
| Number of pages | 10 |
| Journal | Journal of Nuclear Materials |
| Volume | 448 |
| Issue number | 1-3 |
| DOIs | |
| State | Published - May 2014 |
Funding
The authors would like to than Joel McDuffee and Bob Sitterson for their efforst in the design and construction of irradiation capsules. The authors would like to thank Dr. John Hunn for the use of the AGR program TRISO tomography image. Transmission electron microscopy was supported by ORNL’s Shared Research Equipment (ShaRE) User Facility, which is sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, US Department of Energy. Irradiations were carried out in the High Flux Isotope Reactor, and office of Science funded user facility. Surrogate TRISO particles were produced as part of previous work supported by the U.S. Department of Energy, Office of Nuclear Energy, under the Very High Temperature Reactor Technology Development Office Advanced Gas Reactor Fuel Development and Qualification Program. The work presented in this manuscript was supported by the Advanced Fuels Campaign of the Fuel Cycle R&D program in the Office of Nuclear Energy, US Department of Energy.
| Funders | Funder number |
|---|---|
| Office of Basic Energy Sciences | |
| Scientific User Facilities Division | |
| US Department of Energy | |
| Very High Temperature Reactor Technology Development Office Advanced Gas Reactor Fuel Development and Qualification Program | |
| U.S. Department of Energy | |
| Office of Nuclear Energy | |
| Oak Ridge National Laboratory |