05000289/FIN-2014002-02
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Finding | |
|---|---|
| Title | Loss of Air Intake Tunnel Sump Pump Function due to Inadequate Work Execution |
| Description | The inspectors identified a finding of very low safety significant (Green) for Exelons failure to follow work order instructions in accordance with MA-AA-716-011, Work Execution and Close Out, during planned maintenance activities on the air intake tunnel (AIT) deluge sump pump (SD-P-7). Specifically, in May 2013, a maintenance worker applied epoxy to the sump pumps float switch contrary to work order instructions. Inspectors identified that the float switch was fixed in the OFF position, rendering the pump unavailable, during a system walkdown in March 2014. Exelon documented this as issue report 1628577 and performed prompt corrective actions to remove the epoxy coating from the float switch. In addition, corrective actions were performed to replace the float ball that likely was submerged and filled with water as a result of the float switch being stuck. Exelon successfully postmaintenance tested the float switch and pump on March 6, 2014, and returned it to service. The inspectors determined the performance deficiency associated with this finding involved Exelons failure to follow work order instructions in accordance with MA-AA-716-011, Work Execution and Close Out, during planned maintenance activities on SD-P-7 was more than minor because it was associated with mitigating systems cornerstone adversely affected the cornerstone objective to ensure the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. Specifically, in May 2013, a technician applied epoxy to SD-P-7s float switch, contrary to work order instructions, rendering the pump non-functional. The inspectors evaluated the finding using IMC 0609, Attachment 4, Initial Characterization of Findings, and Appendix A, The Significance Determination Process for Findings At-Power, Exhibit 4, External Events Screening Questions, and determined, based on operator response to an air intake tunnel deluge alarm, this finding to be of very low safety significance (Green). This finding has a cross-cutting aspect in the area of Human Performance because the worker did not follow work order instructions and incorrectly applied epoxy to the SD-P-7 float switch assembly, rendering the pump non-functional and unavailable (H.8). |
| Site: | Three Mile Island  |
|---|---|
| Report | IR 05000289/2014002 Section 1R05 |
| Date counted | Mar 31, 2014 (2014Q1) |
| Type: | Finding: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 71111.05 |
| Inspectors (proximate) | C Cahill D Werkheiser E Burket J Heinly K Mangan R Rolph S Barr T O'Hara W Cook |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
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Finding - Three Mile Island - IR 05000289/2014002 | |||||||||||||||||||||||||||||||
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Finding List (Three Mile Island) @ 2014Q1
Self-Identified List (Three Mile Island)
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