Potential impact of enhanced fracture-toughness data on fracture mechanics assessment of PWR vessel integrity for pressurized thermal shock

Conference · Mon Dec 31 23:00:00 EST 1990

OSTI ID:6031090

Dickson, T L; Theiss, T J

The Heavy Section Steel Technology (HSST) Program is involved with the generation of enhanced fracture-initiation toughness and fracture-arrest toughness data of prototypic nuclear reactor vessel steels. These two sets of data are enhanced because they have distinguishing characteristics that could potentially impact PWR pressure vessel integrity assessments for the pressurized-thermal shock (PTS) loading condition which is a major plant-life extension issue to be confronted in the 1990's. A series of large-scale fracture-mechanics experiments have produced crack-arrest (K{sub Ia}) data with the distinguishing characteristic that the values are considerably above 220 MPA {center dot} {radical}m. The implicit limit of the ASME Code and the limit used in the Integrated Pressurized Thermal Shock (IPTS) studies. Currently, the HSST Program is planning experiments to verify and quantify for A533B steel the distinguishing characteristic of elevated the distinguishing characteristic of elevated initiation-fracture toughness for shallow flaws which has been observed for other steels. The results of the analyses indicated that application of the enhanced K{sub Ia} data does reduce the conditional probability of failure P(F{vert bar}E); however, it does not appear to have the potential to significantly impact the results of PTS analyses. The application of enhanced fracture-initiation-toughness data for shallow flaws also reduces P(F{vert bar}E), and does appear to have a potential for significantly affecting the results of PTS analyses. 19 refs., 11 figs., 1 tab.

• Research Organization: Oak Ridge National Lab., TN (USA)
• Sponsoring Organization: NRC; Nuclear Regulatory Commission, Washington, DC (USA)
• DOE Contract Number: AC05-84OR21400
• OSTI ID: 6031090
• Report Number(s): CONF-910602-14; ON: DE91009554
• Country of Publication: United States
• Language: English

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36 MATERIALS SCIENCE
360103 -- Metals & Alloys-- Mechanical Properties
ACCIDENTS
ALLOYS
CARBON STEELS
CONTAINERS
CRACK PROPAGATION
FRACTURE MECHANICS
FRACTURE PROPERTIES
HEAT RESISTANT MATERIALS
IRON ALLOYS
IRON BASE ALLOYS
LOSS OF COOLANT
MATERIALS
MATERIALS TESTING
MECHANICAL PROPERTIES
MECHANICAL TESTS
MECHANICS
MITIGATION
NUCLEAR FACILITIES
NUCLEAR POWER PLANTS
POWER PLANTS
PRESSURIZATION
PWR TYPE REACTORS
REACTOR ACCIDENTS
REACTOR SAFETY
REACTOR VESSELS
REACTORS
SAFETY
SERVICE LIFE
STEEL-ASTM-A533-B
STEELS
TESTING
THERMAL POWER PLANTS
THERMAL SHOCK
TRANSIENTS
WATER COOLED REACTORS
WATER MODERATED REACTORS