In an information notice, the NRC said Comanche Peak 1 did not pick up on several indications of freespan outside diameter stress corrosion cracking in either primary or secondary bobbin analyses conducted last year during an outage investigating the source of a primary-to-secondary leak. NRC said that the flaws were found "fortuitously", because the plant operator had undertaken a more comprehensive examination. NRC said Comanche Peak’s experience underscores the need for PWRs to review their data analysis procedures, analyst training and process controls. However, it said that its suggestions were not mandatory.