VERA Core Simulator methodology for pressurized water reactor cycle depletion

Journal Article · Thu Jan 12 00:00:00 EST 2017 · Nuclear Science and Engineering

DOI:https://doi.org/10.13182/NSE16-39· OSTI ID:1344991

Kochunas, Brendan ^[1]; Collins, Benjamin ^[2]; Stimpson, Shane ^[2]; Salko, Robert ^[2]; Jabaay, Daniel ^[1]; Graham, Aaron ^[1]; Liu, Yuxuan ^[1]; Kim, Kang Seog ^[2]; Wieselquist, William ^[2]; Godfrey, Andrew ^[2]; Clarno, Kevin ^[2]; Palmtag, Scott ^[3]; Downar, Thomas ^[1]; Gehin, Jess ^[2]

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1. Univ. of Michigan, Ann Arbor, MI (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
3. Core Physics, Inc., Cary, NC (United States)

This paper describes the methodology developed and implemented in the Virtual Environment for Reactor Applications Core Simulator (VERA-CS) to perform high-fidelity, pressurized water reactor (PWR), multicycle, core physics calculations. Depletion of the core with pin-resolved power and nuclide detail is a significant advance in the state of the art for reactor analysis, providing the level of detail necessary to address the problems of the U.S. Department of Energy Nuclear Reactor Simulation Hub, the Consortium for Advanced Simulation of Light Water Reactors (CASL). VERA-CS has three main components: the neutronics solver MPACT, the thermal-hydraulic (T-H) solver COBRA-TF (CTF), and the nuclide transmutation solver ORIGEN. This paper focuses on MPACT and provides an overview of the resonance self-shielding methods, macroscopic-cross-section calculation, two-dimensional/one-dimensional (2-D/1-D) transport, nuclide depletion, T-H feedback, and other supporting methods representing a minimal set of the capabilities needed to simulate high-fidelity models of a commercial nuclear reactor. Results are presented from the simulation of a model of the first cycle of Watts Bar Unit 1. The simulation is within 16 parts per million boron (ppmB) reactivity for all state points compared to cycle measurements, with an average reactivity bias of <5 ppmB for the entire cycle. Comparisons to cycle 1 flux map data are also provided, and the average 2-D root-mean-square (rms) error during cycle 1 is 1.07%. To demonstrate the multicycle capability, a state point at beginning of cycle (BOC) 2 was also simulated and compared to plant data. The comparison of the cycle 2 BOC state has a reactivity difference of +3 ppmB from measurement, and the 2-D rms of the comparison in the flux maps is 1.77%. Lastly, these results provide confidence in VERA-CS’s capability to perform high-fidelity calculations for practical PWR reactor problems.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Consortium for Advanced Simulation of LWRs (CASL)
• Sponsoring Organization: USDOE
• Grant/Contract Number: AC05-00OR22725
• OSTI ID: 1344991
• Journal Information: Nuclear Science and Engineering, Vol. 185, Issue 1; ISSN 0029-5639
• Publisher: American Nuclear Society
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
97 MATHEMATICS AND COMPUTING