Advantages gained by Optimized ZIRLO and AXIOM PWR cladding materials

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

OSTI ID:22765207

Pan, G.; Mitchell, D. B.; Garde, A. M.; Norrell, J. L.; Atwood, A. R. ^[1]; Limbaeck, M. ^[2]

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1. Fuel Engineering and Safety Analysis, Westinghouse Electric Company, 5801 Bluff Road, Hopkins SC, 29061 (United States)
2. Fuel Materials Center of Excellence - Methods, Technology and Licensing, Westinghouse Electric Sweden AB, 721 63 Vaesteraas (Sweden)

In support of industry's demands for higher performance cladding alloy materials, the Optimized ZIRLO alloy was developed as an evolutionary improvement of the ZIRLO alloy to obtain a significant improvement in corrosion performance and hydrogen pickup while maintaining the overall robust performance of ZIRLO alloy. Currently with operating experience in over 40 plants and burnup reaching over 70 GWd/MTU, a majority of the Westinghouse-fueled US PWR fleet, covering almost all Westinghouse fuel designs, has adopted full regions of Optimized ZIRLO cladding. Across all of these applications, Optimized ZIRLO cladding has demonstrated greatly improved corrosion performance and structural stability. These demonstrated improvements offer increased operational margin and flexibility, in support of industry trends toward increased core operating fuel duties and evolving regulatory requirements such as accident scenarios. Underpinning these benefits are the extensive post irradiation exam (PIE) data obtained from both pool-side and hot-cell exams for Optimized ZIRLO cladding. Building on the successes of Optimized ZIRLO cladding, and in recognition of increasingly challenging fuel management practices, and revised LOCA regulatory rules restricting cladding hydrogen content, AXIOM cladding is being rolled out for full lead test assembly irradiation. The AXIOM alloy, Westinghouse's next generation robust alloy targeting very high fuel duties, is designed to provide improved corrosion resistance, lower hydrogen pick-up, and lower creep and growth compared to current Westinghouse products. AXIOM cladding has been irradiated in a variety of reactors worldwide, including both commercial and test reactors. Extensive PIE data is available for various burnup levels, with leading rods approaching 75 GWd/MTU. The AXIOM composition was selected to ensure enhanced operating performance on multiple fronts, including the optimum combination of corrosion resistance and wear resistance, reduced hydrogen pick-up, improved dimensional stability, and robustness in aggressive coolant chemistry conditions. The present paper provides high burnup performance data, capturing the advantages gained by introducing Optimized ZIRLO and AXIOM alloy as PWR cladding materials. (authors)

• Research Organization: American Nuclear Society - ANS, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22765207
• Country of Publication: United States
• Language: English

Related Subjects

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
36 MATERIALS SCIENCE
BURNUP
CLADDING
CORROSION
CORROSION RESISTANCE
FUEL MANAGEMENT
FUEL RODS
HOT CELLS
HYDROGEN
IRRADIATION
LEAD
LOSS OF COOLANT
NUCLEAR FUELS
NUCLEAR INDUSTRY
PWR TYPE REACTORS
TEST REACTORS
WEAR RESISTANCE
ZIRCONIUM ALLOYS