The A station
service water traveling screen was out of service from June 20 through 26, 2003 to perform corrective maintenance. This work was completed under
work order 60037345 and included replacement of the screen head-shaft and sprockets. The screen was returned to service on June 26. On June 28 the shear pin on the A
service water screen motor failed and was replaced. On July 1 a self-revealing finding occurred when the A
service water traveling screen stopped rotating due to the head-shaft shifting laterally and binding the screen. The screen was out of service for replacement of the damaged head-shaft and returned to service on July 9, 2003.
PSEG performed an apparent cause evaluation of the A
service water traveling screen failure under order 70032466 and concluded the head-shaft shifted laterally while in operation due to maintenance personnel improperly cutting a vendor supplied shaft key in June 2003 without instructions or procedure guidance.
PSEG identified a contributing cause regarding inadequate tensioning of the traveling screen carrier chains because of repeatability problems with the installed load cells used for this task. The inspectors identified an additional casual factor regarding screen tensioning, in that although
PSEG procedure HC.MD-PM.
EP-0001(Q) provided qualitative and quantitative acceptance criteria for leveling the screen head-shaft and tensioning the screen carrier chains, the applicable section of this procedure was not included and completed in June 2003 under
work order 60037345 to ensure the A
service water traveling screen chains were tensioned correctly. Also, the description of work completed under
work order 60037345 did not indicate this tensioning criteria was considered.
PSEG initiated notification 20160886 to address this problem in their corrective action process. NRC Inspection Report 50-354/2003-006 dated February 11, 2004 described an apparent violation of NRC requirements regarding inadequate maintenance work practices.
10 CFR 50 Appendix B, Criterion V, Instructions, Procedures and Drawings requires that activities affecting quality be accomplished in accordance with documented instructions, procedures or drawings appropriate to the circumstances, and that these documents shall include appropriate quantitative or qualitative acceptance criteria for determining that important activities have been satisfactorily accomplished. Contrary to this, maintenance was completed under
work order 60037345 from June 20 though 26 that trimmed a vendor supplied key without procedure guidance and tensioned the A
service water traveling screen chains without using applicable acceptance criteria
