Scoping Tests to determine the PrimaryWater Stress Corrosion Cracking of CANDU Steam Generator Tubing

Abstract

Alloy 600 and Alloy 800 tubing, representative of that in CANDU steam generators, was tested at 360 degrees C in pH 10.4 (LiOH) water with additions of H2 (up to 40 cc/kg) and 02 (up to 250 pg/kg). Comparison was made with Alloy 600 tubing known to be susceptible to primary water stress corrosion cracking. of the CANDU materials failed by intergranular stress corrosion cracking, whereas the susceptible lot of Alloy 600 did. The results may be interpreted to mean that CANDU steam generator tubing has a very low susceptibility to primary water stress corrosion cracking.