Implementation of a Spacer Grid Rod Thermal-Hydraulic Reconstruction (ROTHCON) Capability into the Thermal-Hydraulic Subchannel Code CTF

Journal Article · Mon Apr 08 00:00:00 EDT 2019 · Nuclear Technology

DOI:https://doi.org/10.1080/00295450.2019.1585734· OSTI ID:1545233

Salko, Jr., Robert K.  ^[1]; Pointer, William D.  ^[1]; Delchini, Marc -Oliver  ^[1]; Gurecky, William L. ^[2]; Clarno, Kevin T.  ^[1]; Salttery, Stuart R.  ^[1]; Petrov, Victor ^[3]; Manera, Annalisa ^[3]

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1. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
2. Univ. of Texas at Austin, Austin, TX (United States)
3. Univ. of Michigan, Ann Arbor, MI (United States)

The Consortium for Advanced Simulation of Light Water Reactors is developing a core simulator capability known as the Virtual Environment for Reactor Applications (VERA) to address nuclear industry challenge problems such as crud-induced power shift (CIPS). The CTF thermal-hydraulic (T/H) subchannel code provides thermal feedback in the coupled neutronics, T/H, crud chemistry simulation that VERA performs. It has been discovered that the coarse meshing approach used by CTF (in which fuel rods are discretized into four azimuthal segments) can be a source of error in predicting crud growth and boron distribution in VERA CIPS calculations. Spacer grid effects lead to complex rod-to-fluid heat transfer behavior that, when not resolved, can lead to error in the prediction of crud growth and boron deposition. A higher-fidelity computational fluid dynamics approach can be used instead of CTF, but this leads to excessive simulation times. This paper presents an approach for using high-fidelity computational fluid dynamics data to create shape functions that are used in CTF to reconstruct rod surface heat transfer behavior as a function of spacer grid geometry. The approach is demonstrated for a 5 × 5 rod bundle facility with five mixing vane grids under a range of operating conditions encountered in nominal pressurized water reactor conditions. Furthermore, it is demonstrated that the grid heat transfer maps are successful at introducing a higher-fidelity heat transfer modeling capability into CTF.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1545233
• Journal Information: Nuclear Technology, Journal Name: Nuclear Technology; ISSN 0029-5450
• Publisher: Taylor & Francis - formerly American Nuclear Society (ANS)
• Country of Publication: United States
• Language: English

Related Subjects

Rod thermal-hydraulic reconstruction
CTF
CFD-informed
subchannel