Metallurgical Evaluation of an 18-Inch Feedwater Line Failure at the Surry Unit 2 Power Station.

摘要

A metallurgical failure analysis was performed on pieces from a catastrophically failed 18-inch diameter feedwater line from the Surry Unit 2 Nuclear Power Station. The failed pipe had been globally thinned and had a scalloped appearance on the inside surface. All fracture surfaces examined showed a ductile failure mode. The materials of construction met the appropriate specification requirements (both mechanical and chemical). The report has as its final conclusion that the pipe failed due to excessive thinning by an erosion-corrosion mechanism.