Heavy-section steel irradiation program: Embrittlement issues

Conference · Tue Jan 01 04:00:00 EST 1991

OSTI ID:5914673

Corwin, W R

Maintaining the integrity of the reactor pressure vessel (RPV) in a light-water-cooled nuclear power plant is crucial in preventing and controlling severe accidents and the potential for major contamination releases. The RPV is one of only two major safety- related components of the plant for which a duplicate or redundant backup system does not exist. In particular, it is vital to fully understand the degree of irradiation-induced degradation of the RPV's fracture resistance which occurs during service, since without that radiation damage it is virtually impossible to postulate a realistic scenario which would result in RPV failure. For this reason, the Heavy-Section Steel Irradiation (HSSI) Program has been established by the US Nuclear Regulatory Commission (USNRC) to provide a thorough, quantitative assessment of the effects of neutron irradiation on the material behavior, and in particular the fracture toughness properties, of typical pressure vessel steels as they relate to light-water reactor pressure-vessel integrity. Effects of specimen size, material chemistry, product form and microstructure, irradiation fluence, flux, temperature and spectrum, and postirradiation annealing are being examined on a wide range of fracture properties including fracture toughness crack arrest toughness ductile tearing resistance Charpy V-notch impact energy, dropweight nil-ductility temperature and tensile properties. Models based on observations of radiation-induced microstructural changes using the field on microprobe and the high resolution transmission electron microscopy provide improved bases for extrapolating the measured changes in fracture properties to wider ranges of irradiation conditions. The principal materials examined within the HSSI program are high-copper welds since their postirradiation properties are most frequently limiting in the continued safe operation of commercial RPVs.

• Research Organization: Oak Ridge National Lab., TN (United States)
• Sponsoring Organization: NRC; Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 5914673
• Report Number(s): CONF-911079-19; ON: DE92005424
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
360106 -- Metals & Alloys-- Radiation Effects
AGING
ALLOYS
AUSTENITIC STEELS
BWR TYPE REACTORS
CARBON STEELS
CHARPY TEST
CHROMIUM ALLOYS
CHROMIUM-NICKEL STEELS
CONTAINERS
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CRACK PROPAGATION
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DESTRUCTIVE TESTING
DUCTILITY
EMBRITTLEMENT
ENRICHED URANIUM REACTORS
FRACTURE PROPERTIES
HEAT RESISTANT MATERIALS
HEAT RESISTING ALLOYS
HIGH ALLOY STEELS
IMPACT TESTS
IRON ALLOYS
IRON BASE ALLOYS
JOINTS
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
NICKEL ALLOYS
PHYSICAL RADIATION EFFECTS
POINT DEFECTS
POWER REACTORS
PRESSURE VESSELS
PWR TYPE REACTORS
RADIATION EFFECTS
REACTORS
STAINLESS STEEL-308
STAINLESS STEELS
STEEL-ASTM-A533-B
STEEL-CR20NI11
STEELS
TENSILE PROPERTIES
TESTING
THERMAL REACTORS
VACANCIES
WATER COOLED REACTORS
WATER MODERATED REACTORS
WELDED JOINTS