Analysis of buffer-IPyC separation in TRISO fuel particles

Journal Article · Tue Jan 09 00:00:00 EST 2024 · Annals of Nuclear Energy

DOI:https://doi.org/10.1016/j.anucene.2023.110338· OSTI ID:2346154

Krajewska, Zuzanna M. ^[1]; Hales, Jason D. ^[2]; Jiang, Wen ^[2]

---

1. National Centre for Nuclear Research, Otwock (Poland)
2. Idaho National Laboratory (INL), Idaho Falls, ID (United States)

During High Temperature Gas-cooled Reactor (HTGR) operation, and due to the neutron irradiation in the reactor core, damage of the nuclear fuel coating layers occurs. The mechanism of damage formation in the TRISO fuel is explored by the Advanced Gas Reactor (AGR) Fuel Development and Qualification Program, in which the debonding process between coating layers was also investigated. The purpose of this paper is to report simulation results for two models. Firstly, the debonding restricted model, where no gap formation between buffer and IPyC layers is permitted. Secondly, a debonding enabled model, where the gap between those layers is created. The simulations were performed with the Bison code. The inputs of the simulated models are based on data from the AGR-1 experiment. Further, the research included simulations on spherical and aspherical fuel types. The simulations match results obtained by the AGR-1 experiment, which as such shows that the Bison code is a good computational method for simulating the behavior of the gap between buffer and IPyC layers in TRISO fuel. Based on the irradiation experiments, and the Bison simulations, it was concluded that the most common scenario is a gap formation along the buffer-IPyC interface, while the least possible scenario is the situation where there is no gap formation at the buffer-IPyC junction. The computational results confirmed that the sphericity of the fuel influences the thickness of the gap that occurs at the buffer-IPyC junction, in a way that with increasing aspect ratio the gap thickness increases. In addition, the fuel sphericity does not influence the Weibull failure probability. The results obtained for spherical and aspherical fuel are nearly identical.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 2346154
• Report Number(s): INL/JOU--24-77694-Rev000
• Journal Information: Annals of Nuclear Energy, Journal Name: Annals of Nuclear Energy Vol. 199; ISSN 0306-4549
• Publisher: Elsevier
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
Bison Code
Buffer-IPyC Interface
Debonding
Gap Formation
TRISO Particle