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Hypothetical Accident Analyses of the Proposed Split Core at NIST using ANL-Paret Code



Zeyun NMN Wu, Robert E. Williams, J. Michael Rowe


Preliminary design basis accident analyses have been performed on the proposed split core to examine the thermal-hydraulics (T/H) safety characteristics of the new design. The multi-channel T/H safety analysis code PARET, developed by Argonne National Laboratory, is employed to perform the transient analyses with the power and kinetics parameters provided by neutronics calculations. Two important transient overpower phenomena, control rod withdrawal accident during the core start-up and maximum reactivity insertion accident at the full power operation condition, are investigated in the paper. The accident scenarios are investigated at both the start-up (SU) and end-of-cycle (EOC) core status in an equilibrium cycle to examine the T/H performance characteristics at different stages of the cycle. The postulated accidental transients are simulated in PARET with real-time monitoring of the cladding temperature, a power rate and mass flow rate. Reasonable T/H safety margins of the new design are achieved by comparing the minimum critical heat flux ratio and the peak cladding temperature to the safety criteria specified for typical low enriched uranium (LEU) test reactors.
Conference Dates
March 13-17, 2016
Conference Location
Conference Title
International Group Operating Research Reactors Conference


, Z. , , R. and , J. (2016), Hypothetical Accident Analyses of the Proposed Split Core at NIST using ANL-Paret Code, International Group Operating Research Reactors Conference, Berlin, -1, [online], (Accessed April 21, 2024)
Created March 13, 2016, Updated February 19, 2017