Technical Specification 5.4.1 requires that written procedures be established and implemented for activities provided in
Regulatory Guide 1.33, Revision 2, Appendix A, dated February 1978. Procedures specified in
Regulatory Guide 1.33 include procedures for performing surveillance tests on the Standby Gas Treatment (
SBGT) System which are provided by licensee procedure
DOS 7500-02,
SBGT System Surveillance and
IST Test, Revision 46. Contrary to this requirement, on September 18, 2009, operations personnel failed to follow the instructions in procedure
DOS 7500-02 to fill the 2/3 A
SBGT loop seal as part of an in-service testing (
IST) surveillance. Operations personnel misread step I.22 of
DOS 7500-02 and failed to close an isolation valve associated with filling the 2/3 A train of
SBGT loop seal. The valves had similar equipment part numbers (EPN), one was 2/3-7513A-500 and the other was 2/3-7513A-500TV. Step I.22 of
DOS 7500-02 instructed the individual to close valve 2/3-7513-A-500. The individual did not question the fact that the valve thought to be correct (2/3-7513-A-500TV) was already in that position. The failure to close the isolation valve associated with this task may have resulted in introducing water into the 2/3 A
SBGT filter which could make the system
inoperable. The inspectors determined that this issue was more than minor because the licensee had to declare the 2/3 A train of
SBGT inoperable and take the system out-of-service to perform an inspection to verify that water was not introduced into the system. In addition, online risk changed to Yellow during this evolution. This incident was identified in the licensees corrective action program as Issue Report 966877. This finding was determined to be of very low safety significance because the inspections performed demonstrated that water was not introduced into the system.
