05000250/FIN-2017008-01
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Finding | |
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| Title | Potential Failure of Fire Detection Capability on Credited Train of Equipment Following High Energy Arc Flash Event |
| Description | Inspection Scope The team reviewed the fire brigade response after an explosion and smoke was reported coming from the Unit 3 safety -related 3A 4kV switchgear to determine and assess whether : (1) the brigade response was adequately staffed ; (2) there was timely arrival of the required amount of dressed- out fire brigade members ; (3) the required firefighting equipment and communication equipment and procedures were taken to and or available at the scene to adequately plan and execute a fire fighting strategy; and (4) that the brigades fire -fighting actions and communications were appropriate in accordance with the established procedures and the licensees fire brigade program requirements. The team also reviewed whether the licensees fire brigade had requested assistance from the Miami -Dade Fire and Rescue Department , the basis for assistance and if Miami -Dade Fire and Rescue provided any firefighting assistance. The team interviewed the responsible fire brigade team leader and the SRO that responded to the switchgear room to obtain the details regarding the as found conditions and actions taken by the brigade to address the smoke and potential fire in the switchgear room . The team reviewed the licensees fire pre -plan to assess whether the licensee adequately ventilated the smoke from the Unit 3A switchgear given the circumstances. Specifically , the Unit 3 EDG had automatically started and was blowing high velocity air from the radiator exhaust into the direction of the 3A and 3B switchgear room door entrances. The team walked down the Unit 3 4kV switchgear rooms with the responsible SRO that had assisted in decision making to direct smoke ventilation during the incident, to understand the circumstances regarding the strategy used for ventilation. The team reviewed the licensees fire risk management actions implemented after the licensee identified the fire door had been damaged, including the establishment of a fire watch in the 3A 4kV switchgear room. The team reviewed the licensees fire brigade response report and CAP database to determine if the licensee was adequately addressing any unresolved issues identified during the fire brigade response. 12 b. Findings and Observations On March 18, 2017 , at approximately 11: 07 a.m. EDT , as a result of an arc f lash in switchgear room 3A, eleven out of eleven spot detectors and two out of two very early warning detectors activated in switchgear room 3B. The spot detectors activated spatially from the first detector closest to Fire Door D070- 3, which separates switchgear Room 3A and 3B , to the last spot detector activating closest to the exit door on the east side of the room. The licensee acknowledged the alarms at Fire Alarm Control Panel 3C286 after the incident; however, the licensee did not reactivate the smoke detectors until sixty two hours later on March 21, 2017 , at 12:51 a.m. EDT. The team confirmed with the licensee that the detectors would not have activated between the times they were acknowledged and reactivated. The 3B 4kV switchgear was the protected train after the arc f lash in the 3A 4kV switchgear. Procedure 0 -ADM -016, Fire Protection Program , Rev . 19, Table 5.6.3 -1, denotes Fire Zone 70 ( 3B 4kV switchgear) to include fire detection instruments in the maintenance rule (a)(4) monitored fire zone and specified required risk -informed interim compensatory actions for degraded equipment. Section 5.6.3.3. d outlined these compensatory actions as the following: ...all detection instruments must be in service when required to be functional. If any single detector instrument is declared out of service, within one hour, a continuous fire watch shall be established and maintained until the detection instrument is returned to service... Smoke removal activities immediately after the inc ident credits personnel in the switchgear room 3B for nearly four hours. Thereafter, based on the security access logs, at 2 :43 p.m. EDT, two maintenance personnel were placed on fire watch duty until 5:22 p.m. EDT . However, these individuals monitored switchgear room 3A and were not placed inside the room with the credited train, 3B. The following fire watch shift arrived at approximately 6:00 p.m. EDT and maintained presence outside of both switchgear rooms 3A and 3B with the entry doors closed. The licensee informed the team that the crew was fearful of the persistent odor that was emanating after the incident in switchgear 3A. Since this crew did not maintain logs nor access the doors, the licensee confirmed to the team they were present outside. AR 2194579 was generated to document fire watches located outside the room do not meet the intent of 0 -ADM -016.4, Fire Watch Program. The first documented log of a continuous fire watch occurred at 1:15 p.m. EDT on March 19, 2017. This log continues until the smoke detectors were reactivated at 12:51 a.m. EDT on March 21 , 2017 ; however these individuals were located in switchgear room 3A. The team interviewed fire watch personnel and determined that the individuals , which did not maintain fire watch logs and stationed themselves outside the switchgear rooms , were Florida Power and Light (FP&L) employees who recently started fire watch activities; whereas, the individuals that maintained logs and placed themselves inside switchgear room 3A were experienced contractors. The team did not have an opportunity to interview FP&L fire watch employees; the contractors that were interviewed were trained and experienced to sufficiently perform the duties. In addition, the single smoke detector in the 480V Load Center 3A, 3B room (Fire Zone 95) located directly above the switchgear rooms did activate during the incident and was not reactivated until 12: 51 a.m. EDT on March 21, 2017 . The detector is assumed to have activated by smoke travelling from switchgear room 3A to switchgear room 3B to 13 the fire door located on the second level of switchgear room 3B. According to 0- ADM - 016.4, Fire Watch Program, for a deactivated detector in the 480V Load Center 3A, 3B room, the following requirement applies: ...restore the non- functional instruments to functional status within 14 days or within the next 1 hour1.157407e-5 days <br />2.777778e-4 hours <br />1.653439e-6 weeks <br />3.805e-7 months <br /> establish a fire watch patrol to inspect the zones with the non- functional instruments at least once per hour. The licensee maintained an hourly roving fire watch in switchgear rooms 3A, 3B and 3 A/B/C/D 480V Load Centers rooms before the incident that was temporarily suspended for the 11:00 a.m., 12:00 p.m., 1:00 p.m. & 2:00 p.m. hours on March 18, 2017, due to scene safety and subsequent investigation. The hourly rove was reinstated in switchgear rooms 3A, 3B and 3 A/B/C/D 480V Load Center rooms for the 3:00 p.m. hour. The team interviewed licensee fire managers regarding the fire response activities after the incident. The managers were cognizant of the issues and attributed them partly to the false fire alarms in other areas of the plant that occurred shortly after the event . AR 2194706 was generated to enhance fire procedures that would address functionality of suppression, detection and barriers; and consideration of compensatory measures post incident. Overall, the team concluded that the licensees fire brigade response and communications were adequate following the event. However, the team identified issues with regards to the establishment of a fire watch for the 4kV switchgear rooms following the event and therefore opened an Unresolved Item (URI) as documented below . URI 05000250, 251/ 2017008- 01, Potential Fai lure of Fire Detection Capability on Credited Train of Equipment Following High Energy Arc Flash Event Introduction: The team identified an URI associated with the licensees actions to implement fire watches following the 3A 4kV switchgear high energy arc flash . These actions potentially resulted in inadequate fire detection capability in the 3B 4kV switchgear room for a period of up to 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> following the event on March 18, 2017. Description : The arc flash in the 3A 4kV switchgear room activated all spot type and early warning smoke detectors in the 3A 4kV switchgear, 3B 4kV switchgear and 3/A/B 480V Load Center rooms. These detectors were not reactivated until 62 hours7.175926e-4 days <br />0.0172 hours <br />1.025132e-4 weeks <br />2.3591e-5 months <br /> later on March 21, 2017, (58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> following completion of smoke removal activities) . After the event , the 3B 4kV switchgear was the protected train of equipment. Due to the risk significance of switchgear room 3B, Procedure 0 -ADM -016.4, Fire Watch Program, require d a continuous fire watch with one smoke detector out of service. For the 3/A/B 480V Load Center, Procedure 0 -ADM -016.4 required an hourly fire rove for detectors out of service. The licensee had established an hourly fire rove before the incident for all the affected rooms that was temporarily suspended for scene safety and subsequent investigation. The licensee was unable to document a continuous fire watch for 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> following the smoke removal activities in switchgear room 3B until the detectors were reactivated. Fire watches were posted after the incident to cover switchgear room 3A , which was the non- credited train of equipment. In addition, for approximately 22 hours2.546296e-4 days <br />0.00611 hours <br />3.637566e-5 weeks <br />8.371e-6 months <br /> following smoke removal activities, the individuals covering switchgear room 3A did not keep fi re watch 14 logs and for a period of time the individuals stayed outside the room with the entry door closed. The team noted the cause of this deficiency was primarily due to lack of training and guidance for individuals performing the fire watches. As a result of inactive smoke detectors and no fire watches in switchgear room 3B, the credited train was without smoke detection for approximately 58 hours6.712963e-4 days <br />0.0161 hours <br />9.589947e-5 weeks <br />2.2069e-5 months <br /> following smoke removal activities. Due to the risk significance of the room, licensee procedures required a continuous fire watch with one detector out of service. An URI has been opened for additional review to identify whether a performance deficiency existed related to the licensees fire watch actions following the arc flash event on March 18 . (URI 05000250, 251/2017008- 01, Potential Failure of Fire Detection Capability on Credited Train of Equipment Following High Energy Arc Flash Even |
| Site: | Turkey Point  |
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| Report | IR 05000250/2017008 Section 4OA5 |
| Date counted | Mar 31, 2017 (2017Q1) |
| Type: | URI: Green |
| cornerstone | Mitigating Systems |
| Identified by: | NRC identified |
| Inspection Procedure: | IP 2201/004 |
| Inspectors (proximate) | E Stamm G Crespo J Patel J Reyes L Suggs N Mellyj Orrj Reyes N Hobbs R Carrion A Butcavage T Morrissey J Patel A Wilson |
| CCA | H.9, Training |
| INPO aspect | CL.4 |
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Finding - Turkey Point - IR 05000250/2017008 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Finding List (Turkey Point) @ 2017Q1
Self-Identified List (Turkey Point)
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