Transition Core Modeling for Extended-Enrichment Accident-Tolerant Fuels in Light Water Reactors Using PARCS/Polaris

Abstract

Current plans and efforts of reactor operators and vendors to include extended-enrichment (EE) fuel and accident-tolerant fuel (ATF) in current reactor fleets motivate the study of these changes in reactor physics analysis. This work uses the U.S. Nuclear Regulatory Commission’s core simulator PARCS to do the core calculation and the SCALE Polaris lattice physics code to generate the homogenized, few-group constants. In this work, both pressurized water reactor and boiling water reactor (BWR) colorset models are used to verify the proposed approach. The accuracy presented in the colorset models verified the capability of the PARCS/Polaris procedures for the transition core analysis in light water reactors. For the whole-core calculation, the ATF and EE-ATF transition core models were incorporated, in addition to the nominal core model. The BWR model was chosen to represent the entire core calculation due to its challenging design. The core parameters studied are the core power distribution, power peaking factor, Doppler temperature coefficients, and control rod worth at cold zero power and hot full power. When the core parameters of the transition cores are compared with those of the nominal core in PARCS, the results suggest that there is no drastic change in the core parameters for the implementation of ATF and EE fuels.

Keywords:

• Extended enrichment
• accident-tolerant fuel
• PWR
• BWR
• PARCS

Acknowledgments

We would like to thank Dr. Andrew Ward of the University of Michigan for his help with PARCS usage and his valuable feedback on this work.

Disclosure Statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research was supported in part by an appointment to the Oak Ridge National Laboratory Virtual Graduate Research Summer Internship, sponsored by the U.S. Department of Energy and administered by the Oak Ridge Institute for Science and Education. Support for this work was provided by the Offices of Nuclear Regulatory Research, Nuclear Reactor Regulation, and Nuclear Material Safety and Safeguards.