CRDM nozzle inspection/repair

The susceptibility of Alloy 600 to Primary Water Stress Corrosion Cracking (PWSCC) continues to plague nuclear power plants. Recently, the problem PWSCC has manifested itself in Control Rod Drive Mechanism (CRDM) head penetrations in nuclear plants in Europe and the U.S. B and W Nuclear Technologies (BWNT) has been involved in responding to this potentially industry-wide concern through the B and W Owners Group (B and WOG). The program also includes work performed in cooperation with the Nuclear Energy Institute (NEI) Task Force and other Owners Groups. BWNT, building on our parent company's (Framatome) technology, has also developed a fully integrated service package and robotic manipulator to inspect and repair CRDM head penetrations for U.S. utilities. This paper describes the work performed by the B and WOG to address this issue globally, and the overall range of inspection and repair tooling and processes developed by Framatome and BWNT to address this issue. (author). 6 figs