$$\mathrm{REX}$$: An analytical tool for reactor operating envelope expansion through fuel-clad thermo-mechanics

Journal Article · 24 December 2021 · Nuclear Engineering and Design

DOI: https://doi.org/10.1016/j.nucengdes.2021.111625 · OSTI ID:1977507

Fassino, Nicholas J. ^[1]; Erickson, Anna ^[2]

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1. Georgia Institute of Technology, Atlanta, GA (United States); OSTI
2. Georgia Institute of Technology, Atlanta, GA (United States)

Here REX, an analytical reactor design tool for the identification and expansion of reactor operating envelopes, is introduced and detailed. Written in MATLAB, REX takes core geometries and axially discretized detector and depletion output from the Serpent neutron transport code and performs full-core, pin-specific thermal-hydraulic and thermo-mechanical calculations. REX identifies the operating envelopes of advanced, solid-fuel nuclear reactors on the basis of their fuel-cladding, fuel-gas, and coolant-cladding interfacial thermo-mechanics. It iteratively pushes coolant inlet temperatures and modifies fuel pin geometries to induce mechanical failure in their original cladding materials at the fullest extent of their fuel cycle lengths and permissible coolant inlet temperatures. It then attempts to expand their operating envelopes by determining the mechanical responses of alternative cladding materials under the same geometric conditions. The result of the REX calculation sequence is a set of 5-D variables describing the temperatures, pressures, geometries, and mechanics of the core as functions of assembly, fuel pin, axial zone, depletion step, and coolant inlet temperature for each candidate cladding material with the limiting fuel pin geometry for the original material.

• Research Organization: Georgia Institute of Technology, Atlanta, GA (United States); Massachusetts Institute of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: USDOE Advanced Research Projects Agency - Energy (ARPA-E)
• Grant/Contract Number: AR0001066
• OSTI ID: 1977507
• Journal Information: Nuclear Engineering and Design, Journal Name: Nuclear Engineering and Design Journal Issue: C Vol. 387; ISSN 0029-5493
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English