NSUF 24-4962: High Temperature Testing of Fully Ceramic Microencapsulated Fuel

Fully ceramic microencapsulated (FCM) fuel forms have been developed to improve upon the long, successful history of tristructural-istotropic (TRISO) fuel by replacing the graphite matrix with SiC. In addition to the advantages SiC offers in terms of strength and oxidation resistance, recent advances have shown the ability to 3D print complex SiC shapes and increase particle packing fractions by up to ~50%. The fabrication process uses chemical vapor infiltration (CVI) to densify the matrix and deposit a thin (tens to ~100 µm) dense SiC layer on the outer surfaces, which has been postulated to offer enhanced radionuclide retention and has even been credited in some radionuclide retention strategies. Today there are no quantitative data regarding the enhanced radionuclide retention of FCM fuel compared to conventional TRISO fuel forms. This RTE will provide valuable information regarding fission product retention of the SiC matrix by measuring the radionuclide inventories of existing irradiated FCM fuel forms before and after high-temperature thermal safety testing. A total of 12 irradiated FCM samples were previously irradiated in MiniFuel targets in the High Flux Isotope Reactor under the Transformational Challenge Reactor program. Prior to thermal safety testing, radionuclide inventories will be measured using gamma spectroscopy to provide a reference to which post-heating inventories can be compared to determine fractional releases. The samples will be heated in the Furnace for Irradiated TRISO Testing (FITT) at Oak Ridge National Laboratory, similar to what has been done for many years under the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program. The proposed test matrix will allow for the comparison of the fission product retention of UN TRISO particles with reference UCO TRISO as well as UN and UCO TRISO particles in a SiC matrix fabricated using multiple processing routes to confirm whether certain matrices offer any measurable improvements.

Informație Adițională

Cîmp	Valoare
Awarded Institution	Oak Ridge National Laboratory
Embargo End Date	2026-06-06
Facility Tech Lead	Kory Linton
NSUF Call	FY 2024 RTE 2nd Call
PI	Jason Harp
PIE Facilities	Irradiated Fuels Examination Laboratory
Project Member	Dr. Jason Harp, Group Leader - Oak Ridge National Laboratory (https://orcid.org/0000-0002-5345-8440)
Project Member	Dr. Tyler Gerczak - Oak Ridge National Laboratory (https://orcid.org/0000-0001-9967-3579)
Project Member	Dr. Christian Petrie, Group Leader - Oak Ridge National Laboratory (https://orcid.org/0000-0003-1167-3545)
Project Type	RTE