Technical Specification 5.4.1(a) requires the licensee to establish, implement, and maintain applicable written procedures for the systems and activities recommended in
Regulatory Guide (RG) 1.33, Revision 2, Appendix A. Section 9(a), Procedures for Performing Maintenance, of
RG 1.33, Revision 2, Appendix A, further states that these maintenance activities should be properly preplanned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances. Contrary to this requirement, on May 20, 2013, the licensees instructions for replacing power supplies in TDY4950, the
Reactor Coolant System saturation pressure/saturation temperature instrument input to Channel 2 of the
Post Accident Monitoring System, were less than adequate for the work being performed. Specifically, the work instruction details only provided stock code numbers for the power supplies, with no reference to voltage output differences. This omission in the written work instructions contributed to the incorrect installation of physically similar 5 Vdc and 15 Vdc power supplies into the wrong locations within the instrumentation cabinet. Subsequently, the application of the incorrect 15 Vdc power to instrumentation components that were only rated for 5 Vdc caused several of the subcomponents to be damaged, and rendered TDY4950 nonfunctional until replacement parts could be obtained and repairs made on June 3, 2013. The objective of the
Mitigating Systems Cornerstone of Reactor Safety is to ensure the availability, reliability, and capability of systems that respond to
initiating events to prevent undesirable consequences (i.e., core damage). A key attribute of this objective is human performance, and specifically, procedure quality. In accordance with NRC
IMC 0612, Power Reactor Inspection Reports, Appendix B, Issue Screening, the inspectors determined that the violation was of more than minor significance in that it had a direct impact on this cornerstone objective. The licensees failure to provide adequate detail within the written work instructions for the replacement of the TDY4950 instrumentation power supplies resulted in the loss of the
Reactor Coolant System saturation pressure/saturation temperature instrument input to Channel 2 of the
Post Accident Monitoring System, and reduced the overall reliability of the
Post Accident Monitoring System for a period of approximately 14 days. The licensee had entered this issue into their
CAP as CR 2013-07901. Corrective actions planned or completed by the licensee include revisions to the detail included within the applicable maintenance plans and instructions for TDY4950, and the corresponding Channel 1 instrument (TDY4951), to address the specific location requirements within the instrumentation cabinet for the 5 Vdc and 15 Vdc power supplies.
