A progress update on selected AREVA NP advanced BWR methodologies

Conference · Fri Jul 01 04:00:00 EDT 2016

OSTI ID:22750094

Quick, K. S.; Tinkler, D.; Schnepp, R.; Charlot, L. ^[1]; Ellger, T. ^[2]; Farawila, Y. ^[3]

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1. AREVA Inc, 2101 Horn Rapids Road, Richland, WA (United States)
2. AREVA GmbH, Paul-Gossen- Strasse 100, 91052 Erlangen (Germany)
3. Farawila et al Inc., Richland, WA (United States)

This article presents an overview of select advances in AREVA NP methods concerning 3 topics: Analytical fuel rod model, Transient and accident simulation, and ATWSi post dryout treatment. Concerning the first topic, the analytical fuel rod model relies heavily on first-principles closed-form solutions instead of ever finer nodalization and higher dimensions of standard numerical methods such as finite differences or finite elements. This analytical fuel rod model takes full account of the complications that made numerical analysis necessary, e.g. variation of pellet thermal conductivity with temperature and burnup, and the radial dependence of fission power deposition in pellets. The model also calculates thermo-mechanical parameters such as clad stress and strain, fission gas release, pellet sintering and swelling, and pellet-clad gap size and thermal resistance. The model is suited for innovative fuel designs such as doped pellets. Concerning the second topic, the BWR evaluation model, AURORA-B, is an advanced transient and accident simulator including SRELAP5, a two fluid thermal hydraulic code comprehensively reviewed by international safety authorities for BWR and PWR applications; RODEX4, a best estimate fuel performance code used to evaluate the local thermal-mechanical behavior of fuel rods during postulated transients and accidents; and MB2-K, a neutron kinetics extension of the steady state core simulator MICROBURN-B2. The analytical domains will include transients as well as control rod drop and loss of coolant accidents. Extension of RODEX4 have been made to accommodate analysis of chromium-doped fuel. Concerning the third issue,The new AREVA post-dryout models can accurately predict dryout/re-wet followed by an ultimate failure to re-wet under oscillatory ATWSi (Anticipated Transient Without SCRAM with core instability) conditions. These models, while not a boiling curve based method, can qualitatively reproduce the characteristics of the boiling curve.

• Research Organization: American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22750094
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
ATWS
BWR TYPE REACTORS
DOPED MATERIALS
DRYOUT
FUEL RODS
LOSS OF COOLANT
NUMERICAL ANALYSIS
PWR TYPE REACTORS
REACTOR ACCIDENT SIMULATION
THERMAL CONDUCTIVITY
THERMAL HYDRAULICS