Abstract
Verification and validation of the Monte Carlo particle transport code Serpent 2 depletion calculation capabilities in the context of tristructural isotropic (TRISO) particles was performed against available data from the second Advanced Gas Reactor irradiation campaign (AGR-2), which was irradiated in the Advanced Test Reactor (ATR) at Idaho National Laboratory. The AGR-2 test train contained both uranium oxycarbide (UCO) and uranium dioxide (UO2) TRISO particles, which were irradiated for 12 ATR power cycles over a period of 3.5 years. For this study, the AGR-2 test train was reconstructed in full detail using Serpent 2, and depletion calculations replicating the experimental irradiation conditions were performed. The fast neutron fluence and AGR-2 fuel burnup resulting from the depletion calculations for the 12 irradiation cycles are compared with the corresponding reported MCNP-computed data. The total AGR-2 fuel burnup accumulated by the end of the AGR-2 test train irradiation is also compared with available experimental data. The fission product inventory at the end of the AGR-2 irradiation obtained from the Serpent 2 depletion calculations is compared with the reported computational data. The Serpent 2 results for the fast neutron fluence (En > 0.18 MeV) differ on average by 5.10% from the MCNP-computed results. Similarly, the Serpent 2 model underpredicts the AGR-2 fuel burnup at the end of the irradiation by 5.13%, on average for all capsules, when compared with the MCNP-computed results and by 2.01% when compared with the experimental results. Last, the fission product inventory calculated by Serpent 2 is underpredicted by 5.27%, on average for all capsules, in comparison with the reference MCNP data. Serpent 2 is generally in satisfactory agreement with the AGR-2 reported values. These results provide confidence in the performance of Serpent 2 depletion calculations for TRISO fuel particles.
| Original language | English |
|---|---|
| Pages (from-to) | 1774-1808 |
| Number of pages | 35 |
| Journal | Nuclear Technology |
| Volume | 211 |
| Issue number | 8 |
| DOIs | |
| State | Published - 2025 |
Funding
This research was performed using funding received from the DOE Office of Nuclear Energy’s Nuclear Energy University Programs under IRP Project 20-22094, “Multiphysics Fuel Performance Modeling of TRISO-Bearing Fuel in Advanced Reactor Environments.” This work was also supported by a U.S. Nuclear Regulatory Commission Graduate Fellowship.For the computational calculation, this research used the Savio computational cluster resource provided by the Berkeley Research Computing program at the University of California, Berkeley (supported by the University of California Berkeley Chancellor, Vice Chancellor for Research, and Chief Information Officer). This research was performed using data provided by INL. We thank B. P. Collin, M. Plummer, K. Wilson, J. W. Sterbentz, and P. A. Demkowicz for the help and support provided for this work.
Keywords
- AGR-2
- Serpent 2
- TRISO fuel performance
- depletion calculations
- verification and validation