Inspections at the Palisades Nuclear Plant in Michigan found that its steam generator tubes had indications of stress cracking that “far exceeded estimates” based on the plant’s previous operating history, according to a report published October 2 by the Nuclear Regulatory Commission (NRC). Of the more than 16,000 tubes in the plant’s two steam generators, 1,163 had indications of cracking.
Pressurized water reactors like Palisades use steam generators (see photo below) to convert water into steam using the reactor core's heat. Steam generators can be up to 70 feet long, weigh as much as 800 tons and include 3,000 to 16,000 tubes, each about three-quarters of an inch in diameter, according to the NRC.
