Evaluation of aging degradation of structural components

Conference · Sun Mar 01 04:00:00 EST 1992

OSTI ID:10154053

Chopra, O K; Shack, W J

Irradiation embrittlement of the neutron shield tank (NST) A212 Grade B steel from the Shippingport reactor, as well as thermal embrittlement of CF-8 cast stainless steel components from the Shippingport and KRB reactors, has been characterized. Increases in Charpy transition temperature (CTT), yield stress, and hardness of the NST material in the low-temperature low-flux environment are consistent with the test reactor data for irradiations at < 232{degrees}C. The shift in CTT is not as severe as that observed in surveillance samples from the High Flux Isotope Reactor (HFIR): however, it shows very good agreement with the results for HFIR A212-B steel irradiated in the Oak Ridge Research Reactor. The results indicate that fluence rate has not effect on radiation embrittlement at rates as low as 2 {times} 10{sup 8} n/cm{sup 2}{center_dot}s at the low operating temperature of the Shippingport NST, i.e., 55{degrees}C. This suggest that radiation damage in Shippingport NST and HFIR surveillance samples may be different because of the neutron spectra and/or Cu and Ni content of the two materials. Cast stainless steel components show relatively modest decreases in fracture toughness and Charpy-impact properties and a small increase in tensile strength. Correlations for estimating mechanical properties of cast stainless steels predict accurate or slightly conservative values for Charpy-impact energy, tensile flow stress, fracture toughness J-R curve, and J{sub IC} of the materials. The kinetics of thermal embrittlement and degree of embrittlement at saturation, i.e., the minimum impact energy achieved after long-term aging, were established from materials that were aged further in the laboratory. The results were consistent with the estimates. The correlations successfully predict the mechanical properties of the Ringhals 2 reactor hot- and crossover-leg elbows (CF-8M steel) after service of {approx}15 y.

• Research Organization: Argonne National Lab., IL (United States)
• Sponsoring Organization: Nuclear Regulatory Commission, Washington, DC (United States)
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 10154053
• Report Number(s): ANL/CP--75790; CONF-920375--23; ON: DE92014849
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
210100
210200
36 MATERIALS SCIENCE
360103
360106
AGING
CHARPY TEST
EMBRITTLEMENT
FRACTURE PROPERTIES
MECHANICAL PROPERTIES
NEUTRON FLUENCE
PHYSICAL RADIATION EFFECTS
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
BOILING WATER COOLED
POWER REACTORS
NONBREEDING
LIGHT-WATER MODERATED
NONBOILING WATER COOLED
RADIATION EFFECTS
REACTOR COMPONENTS
RWE-BAYERNWERK REACTOR
SHIPPINGPORT REACTOR
STAINLESS STEELS
STEEL-ASTM-A212
TENSILE PROPERTIES