05000353/FIN-2017004-01
From kanterella
Jump to navigation
Jump to search
Finding | |
|---|---|
| Title | Unplanned HPCI Inoperability Due to Isolating All Suction Sources During Post-Maintenance Te s t i n g |
| Description | The inspectors identified a self-revealing Green non-cited violation (NCV) of 10 Code of Federal Regulations (CFR) 50, Appendix B, Criterion V, Instructions, Procedures, and Drawings, for Exelons failure to adequately establish post-maintenance testing instructions for a relay replacement for the Unit 2 high pressure coolant injection (HPCI) system. Specifically, implementing the instructions caused a loss of all suction sources and unplanned inoperability of the Unit 2 HPCI system. Exelon initiated a condition report (issue report (IR) 4036417) and conducted a technical human performance (THU) workshop with the maintenance planning department to increase awareness of THU tools and added THU behavior discussion topics to weekly maintenance planning department all hands meetings.This finding is more than minor because it adversely affected the configuration control attribute of the mitigating systems cornerstone to ensure the availability of systems that respond to initiating events to prevent undesirable consequences (i.e. core damage). Specifically, HPCI was made inoperable when it was planned to remain operable. Using IMC 0609, Appendix A, Exhibit 2, the inspectors determined that this finding required a detailed risk assessment because it represented a loss of the single train systems function. The Regional Senior Reactor Analyst performed a detailed risk evaluation using the Limerick Generating Station (LGS) Unit 2 Standardized Plant Analysis Risk Model. The issue was modeled with a HPCI failure to start due to the suction valves being closed. The change in core damage frequency per year was determined to be in the low E-9 range due to the very short duration that both suction sources were isolated. Therefore the issue was determined to be of very low safety significance (Green). The inspectors determined that this finding has a cross-cutting aspect in the area of Human Performance, Work Management, because the work process did not ensure individuals were aware of plant status and the changes in the plan of work were not effectively implemented. [H.5] |
| Site: | Limerick  |
|---|---|
| Report | IR 05000353/2017004 Section 4OA3 |
| Date counted | Dec 31, 2017 (2017Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71153 |
| Inspectors (proximate) | S Rutenkroger M Fannon H Anagnostopoulos C Bickett K Mangan J D'Antonio E Carfang |
| Violation of: | 10 CFR 50 Appendix B 10 CFR 50 Appendix B Criterion V |
| CCA | H.5, Work Management |
| INPO aspect | WP.1 |
| ' | |
Finding - Limerick - IR 05000353/2017004 | ||||||||||||||||||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Finding List (Limerick) @ 2017Q4
Self-Identified List (Limerick)
| ||||||||||||||||||||||||||||||||||||||||||||||||