The B and W Owners Group program for microstructural characterization and radiation embrittlement modelling of Linde 80 reactor vessel welds

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:524795

Pavinich, W A ^[1]; Harbison, L S ^[2]

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1. Grove Engineering, Knoxville, TN (United States)
2. B and W Nuclear Technologies, Lynchburg, VA (United States)

The Babcock and Wilcox Owners Group (B and WOG) is embrittlement of Linde 80 reactor vessel welds from a micro-mechanical viewpoint. Previous work that focused on characterizing the large microstructural features indicated that a large portion of the bulk copper content is in precipitate/inclusion/carbide form. This result indicates that copper in solid solution is considerably less than the bulk composition. Field-ion microscope atom probe investigations on unirradiated weld metals with bulk copper contents ranging from 0.22 to 0.38 wt%, also indicate significant amount of copper are tied up in precipitate/inclusion/carbide form. This results is significant since the bulk copper content (which includes both copper in solid solution and copper contained in precipitates, inclusions, and carbides) is used in Regulatory Guide 1.99, Revision 2 to determine radiation damage. This paper reviews these results. Existing radiation embrittlement models superpose the changes in yield strength due to defect clusters and copper-rich precipitates induced by neutron irradiation. Low-copper Linde 80 welds display little or no increase in the 41 joule (30 ft-lb) transition temperature as a result of neutron irradiation which indicates that precipitation is the dominant component of radiation embrittlement for Linde 80 welds. Future work will include further microstructural characterizations of Linde 80 reactor vessel welds and applying the existing radiation embrittlement models to Linde 80 welds. This paper describes the detailed plans for future work.

• OSTI ID: 524795
• Report Number(s): CONF-940657--
• Country of Publication: United States
• Language: English

Related Subjects

22 GENERAL STUDIES OF NUCLEAR REACTORS
EMBRITTLEMENT
FILLER METALS
MICROSTRUCTURE
PHYSICAL RADIATION EFFECTS
PRESSURE VESSELS
REACTOR MATERIALS
SUBMERGED ARC WELDING
WELDED JOINTS