Overview of the M5{sup R} Alloy behavior under RIA and LOCA Conditions

Conference · Sun Jul 01 04:00:00 EDT 2007

OSTI ID:21229317

Mardon, J P ^[1]; Dunn, B ^[2]

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1. AREVA NP, 10 Rue Juliette Recamier, 69456 Lyon Cedex 06 (France)
2. AREVA NP, 3315 Old Forest Road, P.O. Box 10935, Lynchburg VA 24506-0935 (United States)

Experience from irradiation in PWRs has confirmed the M5{sup R} possesses all the properties required for upgraded operation including new fuel management approaches and high duty reactor operation. In this paper accident behavior is demonstrated through a comparison of M5{sup R} and Zircaloy-4 cladding behavior under RIA (Reactivity Insertion Accident) and LOCA (Loss Of Coolant Accident) conditions. AREVA NP supports a significant experimental program of analytical and full -scale tests along with comprehensive analyses on both M5{sup R} and SRA low-tin Zircaloy-4. A key presumption in the conduct of such tests is that, for all Zirconium alloys, the primary effects of high burn-up on cladding thermal-mechanical properties arise from the accumulation of hydrogen within the cladding during operation. This hypothesis is supported through a summarisation of the results of the main RIA and LOCA tests performed on virgin, pre-hydrided, and irradiated M5{sup R} and SRA low-tin Zircaloy-4 cladding. The first part of the paper presents the results of recent Room Temperature (RT) and High Temperature High Pressure (HTHP) integral RIA tests, mainly from the NSRR and CABRI programs, and separate effects mechanical properties tests on high burn-up M5{sup R} and Zircaloy- 4 irradiated claddings. In the second part of this paper, studies of cladding performance under LOCA conditions are presented.. The discussion includes high temperature oxidation kinetics, quench behaviour and post quenched mechanical behaviour of virgin, pre-hydrided and irradiated M5{sup R} and Zircaloy-4 cladding tubes after oxidation at LOCA temperatures and various quenching scenarios. The hydrogen concentrations studied are alloy dependent. Included are mechanical tests and in-depth metallurgical investigations developed to understand the failure mechanisms with the differing alloys and hydrogen concentrations. The result is a confirmation that the effect of hydrogen uptake dominates on the RIA and LOCA response of Zirconium based cladding alloys. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 21229317
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
42 ENGINEERING
BURNUP
CLADDING
COMPARATIVE EVALUATIONS
FAILURES
FUEL MANAGEMENT
HYDROGEN
IRRADIATION
KINETICS
LICENSING
LOSS OF COOLANT
MECHANICAL PROPERTIES
MECHANICAL TESTS
NUCLEAR FUELS
OXIDATION
PERFORMANCE
PWR TYPE REACTORS
REACTOR OPERATION
TEMPERATURE RANGE 0273-0400 K
TUBES
ZIRCALOY 4