Nuclear Engineering ETDs

Publication Date

Spring 5-16-2026

Abstract

Accident Tolerant Fuels (ATFs) such as FeCrAl are being developed to enhance safety margins in light water reactors during transients like Reactivity Initiated Accidents (RIAs). This dissertation evaluates the accuracy and representativeness of TRACE thermal hydraulic models for predicting FeCrAl C36M cladding behavior under steady state and transient flow boiling conditions. Benchmarking against University of New Mexico separate effects experiments shows that TRACE reproduces key thermal trends but underpredicts cladding temperatures near CHF by approximately 25 to 30%. A calibrated uncertainty and global sensitivity analysis, using Sobol indices, demonstrates that CHF and cladding temperature variability are dominated by mass flux, inlet subcooling, and a single CHF scaling parameter, with negligible influence from FeCrAl thermophysical property uncertainties. Comparison with PWR RIA simulations confirms consistent thermohydraulic regime dependence and supports the representativeness of the experimental loop. These findings strengthen confidence in TRACE’s predictive capability and inform future improvements to FeCrAl specific CHF correlations for ATF deployment.

Keywords

Accident-tolerant fuel, FeCrAl cladding, reactivity-initiated accidents, critical heat flux, uncertainty quantification, TRACE system code

Sponsors

Nuclear Regulatory Commission

Document Type

Dissertation

Language

English

Degree Name

Nuclear Engineering

Level of Degree

Doctoral

Department Name

Nuclear Engineering

First Committee Member (Chair)

Christopher Perfetti, PhD

Second Committee Member

Nicholas Brown, PhD

Third Committee Member

Adam Hecht, PhD

Fourth Committee Member

Christopher Murray, MS

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