05000315/FIN-2014005-04
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Finding | |
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| Title | Inadvertent Trip of the Unit 1 TDAFW Pump |
| Description | A finding of very low safety significance, with an associated non- violation of TS 5.4, Procedures, was self-revealed on November 1, 2014, when the Unit 1 TDAFW pump tripped during an emergent dual-unit shutdown. Both units were taken offline by operators due to debris intrusion from Lake Michigan into the cooling water screenhouse. The TDAFW pump started as expected but shutdown after a few minutes of operation. Investigation by the licensee revealed that a cover for the trip solenoid had been installed incorrectly. The cover was relatively loose and had been placed near components involved with the proper latching of the Trip and Throttle valve (TTV) (the valve which opens to let steam in to turn the pump on). After refuting several possible causes and running the pump several times for testing, the licensee determined the likely cause of the trip was the misplaced enclosure, which could have interfered with the proper latching of the TTV. Technical Specification 5.4, Procedures, states, in part, that written procedures shall be established, implemented, and maintained covering the applicable procedures recommended in Regulatory Guide 1.33. Regulatory Guide 1.33 states, in part, that maintenance that can affect the performance of safety-related equipment should be properly preplanned and performed in accordance with written procedures, documented instructions, or drawings appropriate to the circumstances. Contrary to these requirements, the cause of the misplaced enclosure was due to a lack of detailed instructions regarding the installation and removal of the enclosure. The enclosure was most recently affected by maintenance performed during the fall 2014 refueling outage. The licensee worked with the vendor and reinstalled the enclosure correctly. The Unit 2 TDAFW pump trip solenoid enclosure was also found out of position and corrected. The licensee entered the issue into the CAP. The performance deficiency was more than minor because it adversely impacted the Configuration Control attribute of the Mitigating Systems cornerstone, whose objective is ensuring the availability, reliability, and capability of systems that respond to initiating events to prevent undesirable consequences. The inspectors utilized IMC 0609 Appendix A, The Significance Determination Process for Findings at Power, to assess the significance of the finding. Per Exhibit 2, the finding represented a loss of function for one train of Auxiliary Feedwater (AFW) for greater than the TS allowed outage time. Therefore, the inspectors consulted the regional Senior Reactor Analyst for a detailed risk evaluation. The inspectors considered the Unit 1 TDAFW pump inoperable since the last successful surveillance on October 23, 2014. Given the evidence available, this was the likely opportunity for the conditions to be established to set-up the improper engagement between the TTV and the trip hook. In the detailed analysis, the finding screened as Green, or very low safety significance. The finding had an associated cross-cutting aspect in the area of human performance, specifically, H.8, Procedure Adherence. During maintenance, work proceeded on the trip enclosure despite a lack of detailed instructions on the removal/installation of the enclosure. |
| Site: | Cook  |
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| Report | IR 05000315/2014005 Section 1R19 |
| Date counted | Dec 31, 2014 (2014Q4) |
| Type: | NCV: Green |
| cornerstone | Mitigating Systems |
| Identified by: | Self-revealing |
| Inspection Procedure: | IP 71111.19 |
| Inspectors (proximate) | E Sanchez J Cassidy J Ellegood J Lennartz K Riemer M Garza M Mitchell M Phalen T Go T Taylor |
| Violation of: | Technical Specification - Procedures Technical Specification |
| CCA | H.8, Procedure Adherence |
| INPO aspect | WP.4 |
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Finding - Cook - IR 05000315/2014005 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Cook) @ 2014Q4
Self-Identified List (Cook)
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