Primary water stress corrosion cracking (PWSCC) of Alloy 600 materials and Alloy 182/82 welds has become a top industry concern for PWR plants. PWSCC has produced significant availability losses and has attracted considerable regulatory attention.

The nuclear industry is currently focusing on short-term mitigation plans directed towards the reactor vessel head (RVH) and the Alloy 600 weld joint between the RVH and hot leg piping. However, there are many additional locations within the reactor coolant pressure boundary (RCPB) that contain Alloy 600 base metal or weld metal that could be susceptible to PWSCC over time.