Semantic search

Jump to: navigation, search
Search

Edit query Show embed code

The query [[Category:ENS Notification]] [[Site::Comanche Peak]] was answered by the SMWSQLStore3 in 0.2898 seconds.


Results 1 – 50    (Previous 50 | Next 50)   (20 | 50 | 100 | 250 | 500)   (JSON | CSV | RSS | RDF)
 Entered dateSiteRegionReactor typeEvent description
ENS 543673 November 2019 09:23:00Comanche PeakNRC Region 4At 0800 CST on November 3, 2019, Comanche Peak began a planned modification on the Unit 2 Plant Computer System. During this modification, the ability to perform emergency assessment in the Technical Support Center (TSC) and the Emergency Operations Facility (EOF) will be impacted. Since the ability to perform emergency assessment is not expected to be restored within 72 hours, this is reportable per 10 CFR 50.72(b)(3)(xiii) as an event that results in a loss of emergency assessment capability. During this modification, the Control Room will continue to have the ability to perform emergency assessment. If an Alert, Site Area Emergency, or General Emergency is declared during this modification, communicators dedicated to performing emergency assessment will be stationed in the Control Room, TSC, and EOF. The Plant Computer System modification is scheduled to be completed on November 24, 2019 and a follow-up ENS notification will be made once the Unit 2 Plant Computer System is declared functional. The NRC Resident Inspector has been informed."
ENS 5432915 October 2019 19:10:00Comanche PeakNRC Region 4At time 0911 (CDT), Main Steamline Radiation Monitor 2-RUK-2325/2327 (MAIN STEAM LINE 2-01/2-03 RADIATION MONITOR) was removed from service for planned maintenance. Compensatory measures were in place prior to removing the monitor from service to assure adequate monitoring capability available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL (Main Steam Line) 2-01 and MSL 2-03. With this radiation monitor non-functional, with compensatory measures in place, and the monitor NOT expected to be returned to service within 72 hours, the condition is reportable as a loss of assessment capability per 10CFR50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is negligible safety significance to the current condition with respect to the public health and safety perspective. Corrective actions are being pursued to complete maintenance and restore 2-RUK-2325/2327 to functional status. The NRC Resident Inspector has been notified."
ENS 5406415 May 2019 02:21:00Comanche PeakNRC Region 4At 2151 CDT, on 14 May 2019, Comanche Peak Nuclear Power Plant (CPNPP) experienced a voltage transient within the onsite 138kV switchyard due to the loss of one of the offsite switchyards supplying power to the CPNPP 138kV switchyard. The reduction in safeguards bus voltage due to the transient caused the Unit 2 safeguard busses to load shed and perform a slow transfer to power supplied from 345kV transformer XST2A. Unit 2 was subjected to actuation of both blackout sequencers causing an automatic start of both motor driven Auxiliary Feedwater (AFW) pumps as well as the turbine-driven AFW pump. No emergency diesel generators started by design. All AFW pumps have been returned to standby status. All other safety systems functioned as designed. Unit 1 is currently defueled, and was unaffected by this event. The licensee has notified the NRC resident inspector."
ENS 539062 March 2019 06:12:00Comanche PeakNRC Region 4At 0317 CST, the Unit 2 Reactor tripped due to Feedwater Isolation Valve (FWIV) 2-04 going closed. All Auxiliary Feedwater Pumps started due to steam generator Lo-Lo levels. Unit 2 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IPO-007B. The Emergency Response Guideline Procedure Network has been exited. Decay heat is being rejected to the Main Condenser via the Steam Dump Valves. The cause of the FWIV going closed is currently under investigation. All control rods fully inserted and the reactor trip was uncomplicated. Unit 2 is in a normal post-trip electrical line-up. There was no impact on Unit 1 due to the Unit 2 reactor trip. The licensee notified the NRC Resident Inspector.
ENS 537673 December 2018 11:15:00Comanche PeakNRC Region 4At 0315 (CST) on 12/3/18, the Comanche Peak Nuclear Power Plant experienced a loss of 138 KV transformer XST1. Unit 1 is currently at 100% power. Unit 2 was subjected to actuation of both blackout sequencers causing an automatic start of both motor driven Auxiliary Feedwater (AFW) pumps as well as the turbine driven AFW pump. No emergency diesel generators started as per design. Train A and B motor driven and the turbine driven AFW pumps have been returned to automatic. All other safety systems functioned per design. The loss of power to 138 KV transformer XST1 resulted in loss of power to both safeguards busses on Unit 2. The busses performed a load-shed and slow transfer to power supplied from 345 KV transformer XST2A as designed and were re-energized and loads sequenced back onto the busses. The emergency diesel generators are not required to start unless the busses are not re-energized by the alternate offsite transformer. All electrical power related actuations functioned as designed. There was no impact on Unit 1. The licensee has notified the NRC Resident Inspector."
ENS 5355014 August 2018 02:18:00Comanche PeakNRC Region 4At 23:58 (Central Daylight Time) Unit 2 Reactor Tripped (automatic reactor trip) due to a Turbine Trip/ Generator Lock Out. All Auxiliary Feedwater Pumps started due to steam generator Lo Lo levels. Unit 2 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IP0-007B. The Emergency Response Guideline Procedure Network has been exited. Decay heat is being rejected to the Main Condenser via Steam Dump Valves. The cause of the Generator Lockout is currently under investigation. All control rods fully inserted in response to the automatic reactor trip. The licensee notified the NRC resident.
ENS 5347226 June 2018 04:26:00Comanche PeakNRC Region 4At time 0003 (CDT), Main Steamline Radiation Monitor 2-RE-2326 (Main Steam line 2-02) reading spiked and (was) declared non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-02 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10CFR50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is negligible safety significance to the current condition (with respect to the) public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL 2-02. Corrective actions are being pursued to restore 2-RE-2326 to functional status. The NRC Resident Inspector has been notified."
ENS 5342323 May 2018 16:10:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

At time 0848 (CDT), Main Steamline Radiation Monitor 2-RE-2328 (Main Steamline 2-04) lost communications and was declared non-functional.

With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-04 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10CFR50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL 2-04. Corrective actions are being pursued to restore 2-RE-2328 to a functional status. The NRC Resident Inspector has been notified.

ENS 533803 May 2018 18:40:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopDuring planned maintenance on Unit 2 Radiation Monitor 2-RE-4270 (Service Water Train B to Discharge Canal Rad Monitor), at 1220 CDT, several other Unit 2 Radiation Monitors that are used for Emergency Action Level evaluation became nonfunctional for about 1 hour. With these radiation monitors non-functional, all of the Emergency Action Levels associated with these monitors could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). A PC11 computer reboot restored the affected radiation monitors to a functional status. The NRC Resident Inspector has been notified.
ENS 5321215 February 2018 05:04:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt time 0306 (CST), Main Steamline Radiation Monitor 2-RE-2326 (Main Steamline 2-02) reading spiked and declared non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-02 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10CFR50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL 2-02. Corrective actions are being pursued to restore 2-RE-2326 to functional status. The NRC Resident Inspector has been notified.
ENS 531546 January 2018 18:14:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1126 (CST), main steamline radiation monitor 2-RE-2326 (Main Steamline 2-02) reading was determined to be erratic and was declared non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 2-02 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. The N16 (Nitrogen-16) radiation monitor serves as a backup with alarm function and Radiation Protection technicians have been briefed on taking local readings with a Geiger-Mueller tube on MSL (Main Steam Line) 2-02. Corrective actions are being pursued to restore 2-RE-2326 to functional status. The NRC Resident Inspector has been notified.
ENS 531432 January 2018 17:17:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1137 CST on January 2, 2018, Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 experienced an unplanned loss of the Plant Computer System (PCS). The loss of the Unit 2 PCS resulted in a loss of emergency assessment capability to the CPNPP Technical Support Center (TSC) and Emergency Operations Facility (EOF) for greater than 60 minutes. This report is being made pursuant to 10 CFR 50.72(b)(3)(xiii), any event that results in a loss of emergency assessment capability, off-site response capability, or off-site communications ability. The NRC Resident Inspector has been informed. Repairs are on-going.
ENS 531056 December 2017 01:55:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 2000 (CST), Comanche Peak experienced a failure of SCADA B of the PC11 Radiation Monitor System. This failure caused a loss of Unit 1 Main Steam Line 1-01 and 1-03 Radiation Monitors (1-RE-2325 and 1-RE-2327) and Train A and Train B Station Service Water Radiation Monitors (1-RE-4269 and 1-RE-4270). With the Main Steam Line Radiation Monitors nonfunctional, all of the emergency action levels for a steam generator tube rupture in steam generators 1-01 and 1-03 could neither be evaluated nor monitored. With the Station Service Water Radiation Monitors non-functional, all of the emergency action levels for a radioactive release through station service water could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity, reactor coolant system integrity, and fuel cladding integrity and there is a negligible safety significance to condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator, reactor coolant system, or the fuel cladding. Until these radiation monitors were restored, Operations implemented compensatory measures to monitor the Condenser Off Gas Radiation Monitor for early signs of a steam generator tube leak/rupture and Radiation Technicians were briefed on taking local readings with a Geiger-Mueller tube on the Main Steam Lines. Chemistry Technicians were performing hourly samples of Station Service Water and reporting results to the Control Room. Corrective actions were pursued to restore the non-functional radiation monitors back to service. Those actions are complete and all radiation monitors have been restored to service. The NRC Resident Inspector has been notified. PC11 is a computer common to both Units. The failure happened during radiation monitor maintenance to a single monitor, which unexpectedly affected multiple monitors.
ENS 5309126 November 2017 00:36:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt time 2025 (CST) on 11/25/17, Unit 2 reactor was manually tripped due to a loss of all Main Feedwater. Operators observed both Main Feed Pumps tripped and SG (Steam Generator) levels decreasing, resulting in the direction for a manual reactor trip. The reactor trip actuated a turbine trip, both Motor Driven Auxiliary Feedwater Pumps started on the loss of both Main Feed Pumps, and Steam Generator Lo Lo levels started the Turbine Driven Auxiliary Feedwater Pump. All systems responded as expected. There was no work in progress at the time of the incident. Currently Unit 2 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IP0-0078 and the Emergency Response Guideline Procedure Network has been exited. Decay Heat is being rejected to the Main Condenser via Steam Dump Valves. The licensee has notified the NRC Resident Inspector.
ENS 529452 September 2017 01:36:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt time 2140 (CDT) on September 1, 2017, CPNPP (Comanche Peak Nuclear Power Plant) Unit 2 experienced two (2) dropped rods, one control, one shutdown. The reactor was then manually tripped. This event is being reported in accordance with 10CFR50.72(b)(2)(iv)(B) for reactor trip and 10CFR 50.72(b)(3)(iv)(A) for an actuation of auxiliary feedwater. Currently Unit 2 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IP0-007B, Emergency Response Guideline Procedure Network has been exited. Decay Heat is being rejected to the Main Condenser via Steam Dump Valves (Turbine Bypass Valves). The NRC Resident Inspector has been notified. All rods inserted into the core during the trip. No relief or safety valves actuated during the plant transient. The electrical grid is stable and supplying plant loads. Unit 1 was not affected by the transient.
ENS 5293730 August 2017 10:35:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0210 CDT on August 30, 2017, Comanche Peak Nuclear Power Plant (CPNPP) Unit 2 experienced an unplanned loss of the Plant Computer System (PCS). The loss of the Unit 2 PCS resulted in a loss of emergency assessment capability to the CPNPP Technical Support Center (TSC) and Emergency Operations Facility (EOF) for greater than 60 minutes. As of 0530 CDT the Unit 2 PCS has been restored. Assessment capability has been verified to be available in the TSC and EOF. This report is being made pursuant to 10CFR50.72(b)(3)(xiii), any event that results in a loss of emergency assessment capability, off site response capability, or off site communications ability. The NRC Resident Inspector has been informed.
ENS 5289811 August 2017 16:12:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1124 CDT on 11 August 2017, CPNPP (Comanche Peak Nuclear Power Plant) Unit 2 experienced an automatic turbine trip and trip of both main feedwater pumps on high steam generator water level (P-14, 81.5 percent level) in steam generator 2-02. Following the turbine trip, the auxiliary feedwater system actuated as required. The plant was stabilized at 2-3 percent reactor power with auxiliary feedwater feeding all steam generators with all levels within their normal bands. The cause of the high steam generator level appears to be a mechanical malfunction of steam generator 2-02 flow control valve bypass valve 2-LV-2163 (SG 2-02 FW BYP CTRL VLV) to close when demanded. Troubleshooting and repair of 2-LV-2163 is in progress. This event is being reported in accordance with 10 CFR 50.72(b)(3)(iv)(A) for an actuation of auxiliary feedwater. The NRC Resident Inspector has been notified.
ENS 5281721 June 2017 16:25:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

During the review of an electrical circuit coordination calculation to support an ongoing revision of the Fire Safe Shutdown Analysis (FSSA), a lack of appropriate circuit protection coordination was identified in the coordination of electrical protective devices on 118 VAC electrical panels operating in bypass mode of operation. One or more of these electrical panels could be lost for various 10 CFR Appendix R III.G.2 fires outside the Control Room at CPNPP (Comanche Peak Nuclear Power Plant) due to circuit coordination issues. This could adversely affect safe shutdown equipment and potentially cause the loss of the ability to conduct a safe shutdown as required by 10 CFR 50 Appendix R. Immediate compensatory actions are being taken to establish (or confirm already existing) fire watches in the Fire Areas containing the associate circuits which can potentially jeopardize the FSSA. This condition is reportable in accordance with 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition. The NRC Resident Inspector has been notified.

  • * * RETRACTION ON 8/2/17 AT 1638 EDT FROM BRIAN MITCHELL TO BETHANY CECERE * * *

On 06/21/2017 Comanche Peak reported an ENS Report (no. 52817) related to the potential loss of 118 VAC electrical panels operating in bypass mode of operation for various 10 CFR (50) Appendix R III.G.2 fires outside the Control Room due to circuit coordination issues. This could adversely affect safe shutdown equipment and potentially cause the loss of the ability to conduct a safe shutdown as required by 10 CFR 50 Appendix R. Subsequent analysis by Engineering has determined that the affected panels remain coordinated for fire generated faults and can be credited as available by the Fire Safe Shutdown Analysis for a fire outside of the Control Room. Based on the above, the condition described in the ENS report no. 52817 is not considered to be an unanalyzed condition as described in 10 CFR 50.72(b)(3)(ii)(B). The licensee notified the NRC Resident Inspector. Notified R4DO (Azua).

ENS 5264629 March 2017 03:28:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

On March 28, 2017 at approximately 1957 CDT, a condition was discovered whereby a postulated moderate-energy line break (MELB) involving three fire protection (FP) pipe segments in the Safeguards Building did not contain MELB shielding. It was subsequently determined a postulated crack in one of the affected FP piping sections could adversely affect circuitry associated with the cooling support system for the train A RHR (Residual Heat Removal) pump room, potentially causing the ventilation system to be unavailable to support operation of the train A RHR pump. This condition is not consistent with the CPNPP licensing basis for the protection of essential safe shutdown RHR equipment. At approximately 1957 CDT train A RHR was declared inoperable but available and the unit entered a seventy-two hour LCO (Limiting Condition for Operation) Action Statement per Technical Specification 3.5.2 B pending completion of mitigative actions. Since Unit 1 train B RHR system components and related supporting equipment have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, given the MELB condition, both trains of RHR and or support equipment could have been inoperable and this represents an unanalyzed condition per 10 CFR 50.72(b)(3)(ii)(B). At the time of discovery, train B RHR and support equipment were operable. Therefore, the identified condition is not reportable as a loss of safety function per 10 CFR 50.72(b)(3)(v). The Senior NRC Resident Inspector has been notified. Compensatory actions will include installing a spray shield on the affected cable trays.

  • * * RETRACTION FROM JOHN ALEXANDER TO VINCE KLCO ON 5/23/17 AT 1720 EDT * * *

On 03/29/2017 Comanche Peak reported an ENS Report (no. 52646) related to the identification of potential moderate-energy line break (MELB) considerations in the Safeguards Building and the potential for adverse interaction with specified Unit 1 electrical equipment. The specific interactions of concern were related to ventilation equipment which would support operation of the Unit 1 A RHR train and several segments of fire protection piping. Subsequent investigations by Engineering have determined: (1) all but one of the suspected potential interactions were determined to not be credible, i.e., the potential MELB would not result in an adverse interaction with the 'target' equipment, and (2) for the remaining potential interaction, an assessment of piping stresses determined there was not a credible MELB source in the affected piping segment and therefore there was not a potential for adverse interaction with the ventilation support equipment. Based on the above, the condition described in ENS report no. 52646 is not considered to be an un-analyzed condition as described in 10 CFR 50.72(b)(3)(ii)(B). The licensee informed the NRC Resident Inspector. Notified the R4DO (Groom).

ENS 5248411 January 2017 16:56:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopOn September 16, 2016, Comanche Peak reported an unanalyzed condition and potential loss of safety function per 10 CFR 50.72(b)(3)(ii)(B) and 10 CFR 50.72(b)(3)(v) related to Teflon (PTFE) installed in the pressure gauge diaphragm seal assemblies for all four of the Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2 (EN#52244). On November 14, 2016, this event was subsequently retracted. On December 12, 2016, during the ongoing extent of condition review, Teflon was also found to be installed in the suction and discharge pressure gauge diaphragm seal assemblies for the Unit 1 and 2 Containment Spray Pumps. On January 11, 2017 at approximately 1500 CDT, the reportability evaluation determined that reasonable assurance did not exist that the Containment Spray system would have been able to fulfill its design function of removing heat from the containment environment without impacting the applicable dose limits. Teflon (PTFE) is a restricted material normally prohibited from use in contact with reactor coolant or in radiation environments. Teflon (PTFE) is not radiation tolerant and degrades in a radiation environment. The Teflon (PTFE) used in these diaphragm seal assemblies could fail during a postulated Loss of Coolant Accident (LOCA) which could cause the Containment Spray Pumps on Units 1 and 2 to be inoperable, and exceed system leakage limits. This could challenge dose limits and in plant post-accident accessibility. This represents an unanalyzed condition. The pressure gauges and diaphragm seals for all of the Unit 1 and 2 Containment Spray Pumps have been isolated and the Unit 1 and 2 Containment Spray Pumps are operable. The Teflon (PTFE) has likely existed in these diaphragm seals since initial plant licensing. Luminant Power is continuing to investigate the extent of this condition and potential repair techniques. The NRC Resident Inspector has been notified.
ENS 5236313 November 2016 17:39:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1012 (CST), Unit 1 Main Steam Line 1-01 Radiation Monitor (1-RE-2325) failed high. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 1-01 could neither be evaluated nor monitored. This unplanned condition is reportable as a loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. Until this radiation monitor can be restored, Operations has implemented compensatory measures to monitor the main steamline 1-01 N-16 (Nitrogen-16) radiation monitor for early signs of a steam generator tube leak/rupture and pre-brief radiation protection technicians on taking local readings with a Geiger-Muller tube on Main Steam Line 1-01 and reporting the reading to the Control Room. Corrective actions are being pursued to restore 1-RE-2325 to functional status. The NRC Resident Inspector has been notified. Radiation monitor 1-RE-2325 is not in the plant technical specifications but is important to safety and the Emergency Plan.
ENS 5224416 September 2016 00:14:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

During a review of commercial grade dedication records for a Unit 1 (Emergency Core Cooling System ECCS) Centrifugal Charging Pump discharge pressure gauge, it was identified that the process side of the diaphragm seal utilizes a Teflon (PTFE) gasket. Further review found Teflon (PTFE) to be installed in the pressure gauge seal assembly for all four of the Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2. Teflon (PTFE) is a restricted material normally prohibited from use in contact with reactor coolant or in radiation environments. Teflon (PTFE) is not radiation tolerant and significantly degrades in a radiation environment. The Teflon (PTFE) used in these pressure gauges could fail during a LOCA (Loss of Coolant Accident) which could cause the (ECCS) Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2 to be inoperable, and exceed system leakage limits. Excessive leakage from systems which would contain post-LOCA recirculation fluid would challenge onsite and offsite dose estimates and in-plant post-accident accessibility. This represents an unanalyzed condition. Currently, the pressure gauges for all four of the (ECCS) Centrifugal Charging Pumps and both of the Positive Displacement Charging Pumps on Units 1 and 2 have been isolated until this issue can be further evaluated. Luminant Power believes that the Teflon (PTFE) has existed in the pressure gauges since initial plant licensing. Luminant Power is currently investigating the extent of the condition and repair techniques. The NRC Resident Inspector has been notified.

  • * * RETRACTION AT 1634 EST ON 11/14/16 FROM DANNY BRADFORD TO JEFF HERRERA * * *

On 09/16/2016, Comanche Peak reported an ENS Report (no. 52244) related to the identification of teflon-containing pressure-seal assemblies installed on the suction and discharge sides of the centrifugal charging pumps and on the suction side of the positive displacement pump. The technical concern was the potential for the teflon-containing assemblies to leak if subjected to post-LOCA recirculation fluid and associated radiation levels. Subsequent investigations by Engineering have determined: (1) the centrifugal charging pumps were operable for all postulated non-LOCA design bases events which required their operation and (2) for postulated LOCA scenarios which would involve radiation levels sufficient as to call into question the ability of the teflon-containing assemblies to maintain system pressure boundary, the ECCS function would be fulfilled in the event one or all of the charging pumps had to be removed from service (due to system leakage) and limiting (control room) doses would have remained below applicable regulatory limits. Based on the above, the condition described in ENS report no. 52244 is not considered to be an un-analyzed condition as described in10 CFR 50.72(b)(3)(ii)(B), nor is it considered to be a condition which could have led to a potential uncontrolled radiation release per 10CFR 50.72(b)(3)(v)(C), nor is it considered to be a condition which could have prevented fulfillment of a safety function under 10 CFR 50.72.(b)(3)(v)(D). The NRC Resident Inspector has been notified. Notified the R4DO (Azua).

ENS 5223913 September 2016 22:28:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

Based on a walk down in the Service Water Intake Structure (SWIS) with the NRC Resident (Inspector), it was observed that a vertical section of 4 inch Fire Protection pipe that provides a normally pressurized source of fire water supply to the overhead sprinkler system in the SWIS is not Moderate Energy Line Break (MELB) shielded similar to the horizontal segment of the same line near the ceiling. In the event of a MELB crack along any portion of the unshielded pipe, the MELB has a potential impact to the function of any one of the 4 Service Water pumps. Only one train at a time would be affected during the event. This is due to the physical characteristics of the postulated MELB and the configuration/separation relative to the source line and target pumps and/or associated Motor Control Centers (MCCs) that support pump operation. Since the Service Water trains have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, if the MELB were to have occurred during these times and affected the opposite train, then two Service Water trains could have been inoperable and this represents an unanalyzed condition. At the time of discovery, all four Service Water trains were operable, therefore, this condition is not reportable as a loss of safety function per 10 CFR 50.72(b)(3)(vi). Currently, Service Water Train B on each Unit has been declared inoperable per Technical Specification (TS) 3.7.8. This condition will be corrected within the 72-hour Completion Time of TS 3.7.8. Currently, Emergency Diesel Generator B on each Unit has been declared inoperable per Technical Specification (TS) 3.8.1. This condition will be corrected within the 72-hour Completion Time of TS 3.8.1. The NRC Resident Inspector was informed.

  • * * UPDATE ON 10/6/2016 AT 2009 EDT FROM DAMON SCHROEDER TO DONG PARK * * *

This is an update to Event Number 52239. On September 13, 2016 at 2228 EDT, Comanche Peak reported an unanalyzed condition involving station service water trains per 10CFR50.72(b)(3)(ii)(B). Specifically, the reported condition involved a vertical section of 4 inch Fire Protection pipe in the SWIS that was not adequately shielded for a Moderate Energy Line Break (MELB). In the event of a MELB crack along any portion of the unshielded pipe, the MELB had a potential impact to the function of any one of the 4 Service Water pumps. On October 6, 2016 at 1410 hours CDT, a section of eyewash station pipe in the Unit 2 Safeguards Building was identified as a result of extent of condition walkdowns that was not adequately shielded for a Moderate Energy Line Break (MELB). In the event of a MELB crack along any portion of this unshielded pipe, the MELB had the potential to impact Unit 2 Train B 480V Motor Control Center (MCC) 2EB2-1. This MCC provides power to Unit 2 Train B Emergency Core Cooling, Battery Charger, Containment Spray, and Containment Isolation Valve equipment. The affected eyewash station pipe was isolated shortly after it was discovered to not be adequately shielded for a MELB. Since 480V MCC 2EB1-1 and the Unit 2 Train A Emergency Core Cooling, Battery Charger, Containment Spray, and Containment Isolation Valve equipment trains have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, if the MELB were to have occurred during these times and affected the opposite train, then 2EB1-1, 2EB2-1 and both trains of the Unit 2 Emergency Core Cooling, Battery Charger, Containment Spray, and Containment Isolation Valve equipment could have been inoperable and this represents an unanalyzed condition. At the time of discovery, 2EB1-1 and the Unit 2 Train A Emergency Core Cooling, Battery Charger, Containment Spray, and Containment Isolation Valve equipment was operable. Therefore, this condition is not reportable as a loss of safety function per 10 CFR 50.72(b)(3)(vi). The NRC Resident Inspector was informed. Notified R4DO (Werner).

  • * * UPDATE FROM ROBERT DANIELS TO DONALD NORWOOD AT 2233 EDT ON 10/10/2016 * * *

This is an additional update to Event Number 52239. On September 13, 2016 at 2228 EDT and again on October 6, 2016 at 2009 EDT, Comanche Peak reported unanalyzed conditions involving Station Service Water System trains and a 480V Motor Control Center (MCC) per 10 CFR 50.72(b)(3)(ii)(B). The reported conditions involved sections of piping that were not adequately shielded for a Moderate Energy Line Break (MELB). In the event of a MELB crack along any portion of the unshielded piping, the MELB had a potential impact to the function of safety-related equipment in the Service Water Intake Structure and the Unit 2 Safeguards Building. On October 10, 2016 at 1708 CDT, as a result of ongoing extent of condition walkdowns, a section of fire protection pipe in the Unit 1 Safeguards Building was identified that was not adequately shielded for a MELB. In the event of a MELB crack along any portion of this unshielded pipe, the MELB had the potential to impact Unit 1 Train B Switchgear 1EA2, Unit 1 Train B 480V MCC 1EB4-2, and Unit 1 Train B Distribution Panel 1ED2-2. Only one of these power supplies at a time would be affected. 1EA2 provides 6.9KV electrical power to various Unit 1 Train B safety-related pumps, panels, sequencer, and transformers. 1EB4-2 provides 480V electrical power to various Unit 1 Train B safety-related pumps, valves, fans, panels, and transformers. 1ED2-2 provides 125VDC electrical power to EDG 1-02 channel 1 starting circuit. The affected fire protection pipe was isolated shortly after it was discovered to not be adequately shielded for a MELB. Since Unit 1 Train A Switchgear 1EA1, Unit 1 Train A 480V MCC 1EB3-2, and Unit 1 Train A Distribution Panel 1ED1-2 have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, if the MELB were to have occurred during these times and affected the opposite train, then both trains of Unit 1 6.9KV power (1EA2 and 1EA1), both trains of Unit 1 480V power (1EB4-2 and 1EB3-2), and both trains of Unit 1 125VDC power (1ED2-2 and 1ED1-2) along with the safety-related equipment they supply could potentially have been inoperable and this represents an unanalyzed condition per 10 CFR 50.72(b)(3)(ii)(B). At the time of discovery, none of the affected Train A equipment was inoperable. Therefore, this condition is not reportable as a loss of safety function per 10 CFR 50.72(b)(3)(v). The NRC Resident Inspector was informed. Notified R4DO (Werner).

  • * * UPDATE FROM HUNTER SCHILL TO DONALD NORWOOD AT 1457 EST ON 11/7/2016 * * *

This is an update to Event Number 52239. On November 17, 2016 at 0730 CST, during ongoing extent of condition walkdowns in the Boric Acid Transfer Pump Area of the Auxiliary Building, two pressurized fire protection pipe segments were identified that did not contain Moderate Energy Line Break (MELB) shielding. In the event of a MELB crack along the unshielded portion of these pipes, the MELB had the potential to impact Unit 1 Train B 480V Motor Control Center (MCC) 1 EB4-1. This MCC provides 480V electrical power to various Unit 1 Train B safety-related pumps, valves, fans, battery chargers, and transformers. At 0743 CST, Technical Specification 3.8.9 Condition A was entered for one AC electrical power distribution subsystem inoperable. At 1021 CST, MCC 1 EB4-1 was declared Operable after MELB shielding was installed on the affected fire protection lines. Since Unit 1 Train A 480V MCC 1 EB3-1 and the associated Unit 1 Train A safety-related pumps, valves, fans, battery chargers, and transformers have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, given the MELB condition, 1 EB4-1, 1 EB3-1 and both trains of the Unit 1 safety-related pumps, valves, fans, battery chargers, and transformers they supply could have been inoperable and this represents an unanalyzed condition. At the time of discovery, 1 EB3-1 and the associated Unit 1 Train A safety-related pumps, valves, fans, battery chargers, and transformers were operable. Therefore, this condition is not reportable as a loss of safety function per 10 CFR 50.72(b)(3)(v). The NRC Resident Inspector was informed. Notified R4DO (Azua).

  • * * UPDATE ON 12/05/2016 AT 1730 EST FROM HUNTER SCHILL TO STEVEN VITTO * * *

This is an update to Event Number 52239. On December 5, 2016 during ongoing extent of condition walk downs in the Auxiliary Building, pressurized fire protection pipe segments (a flange and a pipe elbow) were identified which did not contain Moderate Energy Line Break (MELB) shielding. In the event of a MELB crack along the un-shielded portion of the pipes, a MELB had the potential to impact Unit 2 Train B 480V Motor Control Center (MCC) 2EB4-1. This MCC provides 480V electrical power to various Unit 2 Train B safety-related pumps, valves, fans, battery chargers, and transformers. At approximately 1355 CST Technical Specification 3.8.9 Condition A was entered for one AC electrical power distribution subsystem inoperable. At 1459 CST, MCC 2EB4-1 was declared Operable after MELB shielding was installed on the affected fire protection line locations. Since Unit 2 Train A 480V MCC 2EB3-1 and the associated Unit 2 Train A safety-related pumps, valves, fans, battery chargers, and transformers have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, given the MELB condition, 2EB4-1 , 2EB3-1 and both trains of the Unit 2 safety-related pumps, valves, fans, battery chargers, and transformers they supply could have been inoperable and this represents an un-analyzed condition. At the time of discovery, 2EB3-1 and the associated Unit 2 Train A safety-related pumps, valves, fans, battery chargers, and transformers were operable. Therefore, this condition is not reportable as a loss of safety function per 10CFR 50.72(b)(3)(v). The NRC Resident Inspector was informed. Notified R4DO (Gaddy).

  • * * UPDATE ON 12/22/2016 AT 1649 EST FROM HUNTER SCHILL TO DONG PARK * * *

This is an update to Event Number 52239. On December 22, 2016 at approximately 1046 (CST) during ongoing extent of condition walk downs in the common Auxiliary Building (AB) corridor room (X-179), several normally pressurized Waste Processing (WP) pipe segments and one Vent & Drain (VD) segment which are greater than 1" nominal pipe diameter, did not contain MELB shielding. In the event of a MELB crack along the unshielded portion of these pipes, a MELB could have had the potential to impact Unit 1, Train B 480V Motor Control Center (MCC) 1EB4-1. This MCC provides 480V electrical power to various Unit 1 Train B safety-related pumps, valves, fans, battery chargers, and transformers. Prior to the field walkdown, the subject WP and VD line segments were either isolated and depressurized (WP lines) and/or the AB sump discharges realigned (VD) such that the subject lines would pose no threat to the MCC 1EB4-1 if confirmed that shielding is required. As such, the identified condition does not adversely affect operability of 1EB4-1 and entry into a Technical Specification action statement was not required. Field activities continue to install MELB shielding in the affected locations. Since Unit 1 Train A 480V MCC 1EB3-1 and the associated Unit 1 Train A safety-related pumps, valves, fans, battery chargers, and transformers have been periodically declared inoperable at various times in the last three years for surveillance testing or maintenance, given the MELB condition, 1EB4-1, 1EB3-1 and both trains of the Unit 1 safety-related pumps, valves, fans, battery chargers, and transformers they supply could have been inoperable and this represents an unanalyzed condition. At the time of discovery, 1EB3-1 and the associated Unit 1 Train A safety-related pumps, valves, fans, battery chargers, and transformers were operable. Therefore, this condition is not reportable as a loss of safety function per 10CFR 50.72(b)(3)(v). The NRC Resident Inspector was informed. Notified R4DO (Hay).

ENS 522171 September 2016 18:39:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

During a review of ongoing analyses related to postulated tornado missiles, a question was raised about the sentinel valve on the turbine driven auxiliary feedwater pump (TDAFW). The sentinel valve is designed as a warning system on steam equipment to warn personnel of increased back pressure. The valve is not an ASME component and its operation is not required to support TDAFW operation. The draft analysis predicts the TDAFW exhaust stack could be partially crimped by a tornado missile and the resultant back pressure on the turbine would increase to approximately 40 psi. This is higher than the set point for the sentinel valve (nominally 27 and 29 psi for Units 1 and 2, respectively). Therefore, in a design basis tornado with a design basis tornado missile striking the TDAFW exhaust stack, and in a condition where the TDAFW is demanded to run, the sentinel valve is expected to lift and allow steam to flow into the room. Vendor correspondence indicates that at approximately 40 psi the sentinel valve will conservatively pass 600 lbm/hr. Thus, it is conservatively considered operation of the TDAFW under such conditions would create an adverse steam environment which would be beyond that which the TDAFW pump has been analyzed to operate. Actions planned to alleviate the above condition would eliminate the potential for adverse environmental conditions. The steam supplies to the TDAFW have been isolated to affect repairs, which are expected to be limited to removal of the sentinel valve from each Unit and installation of a plug. Said activities are expected to be completed within the Allowed Out-of-Service Time (AOT) of the TDAFW of seventy-two hours per Technical Specification 3.7.5. NRC Resident Inspector has been informed.

  • * * RETRACTION ON 10/27/2016 AT 1353 EDT FROM DANNY BRADFORD TO BETHANY CECERE * * *

On 09/01/2016 Comanche Peak reported an ENS Report (no. 52217) related to unanalyzed conditions related to the sentinel valve on the turbine driven auxiliary feedwater pump (TDAFW) during postulated tornado-based scenarios and non-tornado based scenarios. The technical concern was the potential for the sentinel valve to release steam into the TDAFW room and result in adverse environmental conditions within the room and potentially external to the TDAFW room for both tornado-based and non-tornado based scenarios. Subsequent investigations by Engineering have determined the sentinel valve would not be demanded to open during tornado based scenarios and would not result in adverse environmental conditions internal or external to the TDAFW room in any design bases scenario. The licensee has notified the NRC Resident Inspector. Notified the R4DO (Farnholtz).

ENS 5195524 May 2016 17:48:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

CPNPP (Comanche Peak Nuclear Power Plant) experienced an unplanned loss of the seismic monitoring instrument on May 24, 2016 at 1022 (CDT). The unplanned loss of the seismic monitor resulted in a loss of assessment capability for the HA1.1 (seismic event greater than operating basis earthquake) Alert emergency classification. The seismic monitor was restored to service on May 24, 2016 at 1043. This loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR 50.72(b)(3)(xiii). The NRC Resident Inspector has been notified.

  • * * UPDATE ON 6/2/16 AT 1630 EDT FROM ANTHONY PATE TO DONG PARK * * *

On May 24, 2016 at 1748 (EDT), Comanche Peak reported an unplanned loss of emergency assessment capability per 10 CFR 50.72(b)(3)(xiii) (EN# 51955). Specifically, Comanche Peak reported an unplanned loss of the seismic monitoring instrument. The unplanned loss of the seismic monitor would have resulted in a loss of assessment capability for the HA 1.1 (seismic event greater than operating basis earthquake) Alert emergency classification. The seismic monitor was restored to service on May 24, 2016 at 1043 (CDT). The engineering review determined that the alarms displayed on the seismic monitoring screen provides Operations awareness of the system status. Signals were still being received from the sensor and if there was an OBE (Operating Basis Earthquake) during the time the alarms were in, it would have displayed on the monitoring screen and on the Main Control Board by providing an OBE Exceedance alarm, maintaining emergency assessment capability. Therefore, Comanche Peak requests that the May 24, 2016, 10 CFR 50.72(b)(3)(xiii) reportable event for Units 1 & 2 be retracted. The licensee will notify the NRC Resident Inspector. Notified R4DO (Deese).

ENS 5187119 April 2016 19:54:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopWhile performing a monthly check source on radiation monitor 1-RE-2328 (Main Steamline 1-04 Radiation Detector), the monitor was determined to be non-functional. With this radiation monitor non-functional, all of the emergency action levels for a steam generator tube rupture in steam generator 1-04 could neither be evaluated nor monitored. This unplanned condition is reportable as a major loss of assessment capability per 10 CFR 50.72(b)(3)(xiii). Comanche Peak Nuclear Power Plant (CPNPP) has assurance of steam generator integrity and fuel cladding integrity and there is a negligible safety significance to the current condition from a public health and safety perspective. Additionally, compensatory measures are in place to assure adequate monitoring capability is available to implement the CPNPP emergency plan in the unlikely event of challenges to the steam generator or fuel cladding. Until this radiation monitor can be restored, Operations has implemented compensatory measures to monitor main steamline 1-04 N16 Radiation Monitor for early signs of a steam generator tube leak/rupture, pre-brief radiation protection technicians on taking local readings with a geiger-mueller tube on main steam line 1-04 and reporting the reading to the Control Room. Corrective actions are being pursued to restore 1-RE-2328 to functional status. The NRC Resident Inspector has been notified.
ENS 5175123 February 2016 20:45:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

At CPNPP (Comanche Peak Nuclear Power Plant), eyewash stations are located just outside of the Class 1E battery rooms. The battery room doors are normally open and if a MELB (Moderate Energy Line Break) occurred on the demineralized water line connected to the eyewash station, the water could potentially spray onto the Class 1E safety related batteries. If this occurred, an electrical short could potentially cause a loss of both the batteries and the associated battery chargers. This condition has been conservatively determined to be reportable per 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition. Currently, the demineralized water lines on the battery room eyewash stations for both Units 1 and 2 have been isolated, therefore, all safety related equipment is currently operable. Comanche Peak Engineering is performing a past operability review of this condition. The NRC Resident Inspector has been notified.

  • * * RETRACTION AT 1821 EST ON 02/27/2016 FROM DANNY BRADFORD TO JEFF HERRERA * * *

On February 23, 2016 at 2045 (EST), Comanche Peak reported an unanalyzed condition per 10 CFR 50.72(b)(3)(ii)(B). Specifically, the reported condition involved eyewash stations that are located just outside of the Class 1E battery rooms. The battery room doors are normally open and if a Moderate Energy Line Break (MELB) occurred on the demineralized water line connected to the eyewash station, the water could potentially spray onto the Class 1E safety related batteries. If this occurred, an electrical short could have potentially caused a loss of both the batteries and the associated battery chargers. This condition was conservatively determined to be reportable per 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition. The demineralized water lines on the battery room eyewash stations for both Units 1 and 2 were isolated, and Comanche Peak Engineering initiated a past operability evaluation of this condition. The past operability evaluation has been completed and shows that there are no operability concerns regarding a MELB impact on the Class 1E batteries, DC bus or Class 1E battery chargers. Therefore, Comanche Peak requests that the February 23, 2016, 10 CFR 50.72(b)(3)(ii)(B) reportable event for Units 1 & 2 be retracted. The NRC Resident Inspector has been notified. Notified the R4DO (Whitten).

ENS 517179 February 2016 09:54:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

Planned maintenance of the Plant Computer System (PCS) will cause a loss of emergency assessment capability. Beginning February 9, 2016, PCS data will not be available to the following Comanche Peak Nuclear Power Plant (CPNPP) facilities due to planned PCS software modifications: -Emergency Operations Facility (EOF) -Backup EOF -Operations Support Center The Emergency Response Data System (ERDS) will also be unavailable. The planned maintenance of the PCS is being reported as a loss of assessment capability in accordance with 10 CFR 50.72(b)(3)(xiii) because the duration is expected to be more than 72 hours and the data to the Backup EOF is also affected. CPNPP has compensatory measures in place to ensure timely emergency classification, protective action recommendation and emergency notification, as needed. The PCS modification is expected to be complete by February 18, 2016. A follow-up ENS (Emergency Notification System) communication will be made when the EOF assessment capability is restored. The Licensee has notified the NRC Resident Inspector.

  • * * UPDATE FROM RAUL MARTINEZ TO STEVEN VITTO ON 02/18/2016 AT 1541 EST * * *

The planned maintenance of the Comanche Peak Plant Computer System (PCS) that began on February 9, 2016 is complete. Assessment capability in the following facilities was restored effective 1300 (CST) February 18, 2016: -Emergency Operations Facility (EOF) -Backup EOF -Operations Support Center The Emergency Response Data System availability has also been restored. The Licensee has notified the NRC Resident Inspector. Notified the R4DO(Werner).

ENS 516397 January 2016 14:16:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0759 CST on 01/07/2016, a partial loss of the 25kV Plant Support Power Distribution System caused an unplanned loss of both primary and backup meteorological towers at Comanche Peak Nuclear Power Plant. Loss of both meteorological towers constitutes a major loss of emergency assessment capabilities in regard to meteorological conditions. During the power loss, the National Weather Service was available to compensate for the on-site data loss. The 25kV system and both meteorological towers were restored at 0923 CST on 01/07/2016. The 25kV Plant Support Power Distribution System feeds non-safety related equipment and does not affect plant operation, with the exception already described. The fault occurred due to an aged stress cone and faulty lightning arrestor. The fault was isolated and power was restored. The licensee notified the NRC Resident Inspector.
ENS 514443 October 2015 12:02:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

During the scheduled Unit 2 down power to start 2RF15, Steam Generator 3 Feed Control Valve failed to control in Automatic or Manual resulting in excessive feedwater flow. Control Room Operators manually tripped the reactor and aligned Auxiliary Feedwater. No automatic RPS or ESF actuations occurred. Plant conditions are stable. All control rods fully inserted on the trip and no safety or relief valves lifted. The plant is supplying water to the steam generators with auxiliary feedwater and removing decay heat through the main condenser. The unit is in its normal shutdown electrical lineup. There was no effect on unit-1. The licensee informed the NRC Resident Inspector.

  • * * UPDATE AT 1848 EDT ON 10/05/15 FROM JOHN RASMUSSEN TO JEFF HERRERA * * *

The licensee added 10 CFR 50.72(b)(3)(iv)(A) to the 10 CFR codes reporting section. No other text was modified. Notified the R4DO (Taylor).

ENS 509657 April 2015 18:50:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopLuminant Generation Company LLC (Luminant Power) has completed a review of seismic monitor performance at the Comanche Peak Nuclear Power Plant (CPNPP) over the last three years. The CPNPP emergency preparedness plan requires seismic monitoring instruments to diagnose an earthquake for emergency action levels (EAL) HA1.1 (seismic event greater than OBE (operating basis earthquake) and HU1.1 (identified seismic event that is less than the OBE). The seismic monitor performance review identified one unplanned instance of monitor unavailability and three instances when planned monitor outage durations exceeded 24 hours. Any loss of seismic monitoring capability results in a major loss of assessment capability for the Alert (HA1.1) and a degraded assessment capability for the Unusual Event (HU1.1) emergency classification. The seismic monitor is currently functional, however it was determined to be non-functional on the following dates: Unplanned out-of-service: 12/4/2013 through 12/1 0/2013 Planned out-of-service lasting greater than 24 hours: 5/16/2012 through 5/24/2012 3/20/2013 through 3/27/2013 9/29/2014 through 10/1/2014 The loss of assessment capability is reportable to the NRC within 8 hours of discovery in accordance with 10 CFR50.72(b)(3)(xiii). This report is required per 10 CFR50.72(a)(1)(ii) as an event that occurred within 3 years of the date of discovery. The seismic monitor issues and the missed reporting of the loss of assessment capability have been documented in the CPNPP corrective action program. This review was prompted by the licensee's evaluation of industry's operating experience. A similar report was received from Limerick Generating Station - EN # 50951. The licensee informed the NRC Resident Inspector.
ENS 509555 April 2015 13:55:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0852 CDT on 04/05/2015, a partial loss of the 25kV Plant Support Power Distribution System caused a loss of both the Primary and Backup Meteorological Towers at Comanche Peak Nuclear Power Plant. Loss of both Meteorological Towers constitutes a major loss of emergency assessment capabilities in regard to meteorological conditions. The 25kV Plant Support Power Distribution System feeds certain non-safety related equipment and does not affect plant operation. An investigation into the cause of the loss of power is in progress. The licensee informed the NRC Resident Inspector.
ENS 5083519 February 2015 20:18:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopDuring Main Steam Safety Valve testing conducted prior to refueling outages, normally closed watertight doors are opened in support of the testing. If a postulated one square foot non-mechanistic crack were to occur within the Break Exclusion Area during the test, safety related equipment located just outside of these doors could be adversely affected. With these watertight doors open, compliance with the Comanche Peak licensing basis may not be assured. This condition has been conservatively determined to be reportable as an unanalyzed condition per 10 CFR 50.72(b)(3)(ii)(B). Currently, the watertight doors on both Units 1 and 2 are closed, therefore, all safety related equipment is currently operable. Comanche Peak Engineering is performing a review of the original Comanche Peak licensing basis regarding the non-mechanistic crack event to determine what equipment impacts are required to be assessed. The NRC Resident Inspector has been notified.
ENS 5077328 January 2015 11:38:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

The Comanche Peak Primary Emergency Operations Facility (EOF) will be unavailable during planned maintenance on the EOF ventilation system. On January 28, 2015, CPNPP (Comanche Peak Nuclear Power Plant) began planned work to improve the reliability of the EOF ventilation system. The EOF will be unavailable for approximately three weeks. During the time the primary EOF is unavailable, the affected ERO members will respond to the Backup EOF in Granbury, Texas for any declared emergency event. Therefore, it is expected that appropriate assessment of plant conditions, notifications, and communications could still be made, if required, during the time the primary EOF is unavailable. The extended unavailability of the primary EOF is being reported in accordance with 10CFR50.72(b)(3)(xiii), which is any event that results in a major loss of emergency assessment capability, offsite response capability, or offsite communications capability. The NRC Resident (Inspector) has been notified. A follow-up ENS communication will be made when the primary EOF availability is restored.

  • * * UPDATE ON 03/11/2015 AT 1811 EDT FROM BRIAN MITCHELL TO JEFF HERRERA * * *

The availability of the Comanche Peak Primary Emergency Operations Facility (EOF) has been restored following planned maintenance on the EOF ventilation system. On January 28, 2015, CPNPP (Comanche Peak Nuclear Power Plant) began planned work to improve the reliability of the EOF ventilation system. The unavailability of the primary EOF was reported in accordance with 10 CFR 50.72(b)(3)(xiii). This report serves as a follow-up to Event Number 50773. The licensee notified the NRC Resident Inspector. The R4DO (Okeefe) was notified.

ENS 507153 January 2015 14:14:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0538 (CST) on 01/03/2015, a partial loss of the 25KV Power Distribution System caused a loss of both the Primary and Backup Meteorological Towers at the Comanche Peak Nuclear Power Plant. This resulted in a major loss of emergency assessment capabilities in regard to meteorological conditions. The 25KV Plant Support Power Loop feeds certain non-safety-related support equipment and did not result in an impact to plant/unit operation. Meter and Relay technicians are performing ongoing investigation of the cause of the breaker trip. A similar incident occurred 01/02/2015 at 0314 (CST). Reference (NRC) EN# 50713. The licensee will notify the NRC Resident Inspector.
ENS 507132 January 2015 11:43:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0314 (CST) on 01/02/2015, a partial loss of the 25KV Power Distribution Systems caused a loss of both the Primary and Backup Meteorological Towers at the Comanche Peak Nuclear Power Plant. This resulted in a major loss of emergency assessment capabilities in regard to meteorological conditions. The 25 KV Plant Support Power Loop feeds certain non-safety-related equipment and does not affect plant operation. An investigation by Meter and Relay Technicians revealed no abnormal conditions/damaged equipment. The supply breaker was re-closed at 0915 on 01/02/2015. Power was restored to both Meteorological Towers and proper operation was verified. The licensee notified the NRC Resident Inspector.
ENS 5056223 October 2014 16:42:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopThe following information is provided as a 60 day telephone notification to the NRC in accordance with 10 CFR 50.73(a)(1) reported under 10 CFR 50.73(a)(2)(iv)(A) for an invalid actuation of the Unit 1, Train 'A' Emergency Diesel Generator on September 12, 2014, at 1342 CDT. Per NUREG-1022, R.3, page 33, the following information should be provided for an invalid actuation reported under 10 CFR 50.73(a)(1): (a) the specific train(s) and system(s) that were actuated, (b) whether each train actuation was complete or partial, (c) whether or not the system started and functioned successfully. (a) The specific train(s) and system(s) that actuated were: Unit 1, Train 'A' Emergency Diesel Generator. (b) Whether each train actuation was complete or partial: The actuation of the Unit 1, Train 'A' Emergency Diesel Generator was a complete actuation. (c) Whether or not the system started and functioned successfully: The Unit 1, Train 'A' Emergency Diesel Generator started and functioned successfully. The NRC Senior Resident Inspector has been notified.
ENS 503507 August 2014 17:26:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0925 (CDT) on 08/07/14, a Condition Report was initiated identifying that one of the two air conditioning condenser coil fans for the CPNPP (Comanche Peak Nuclear Power Plant) Emergency Operations Facility (EOF) air conditioner was damaged. With low outside air temperatures, the air conditioner can adequately maintain habitability of the EOF with one of the two air conditioning fans not working. However, outside air temperatures at CPNPP are forecast to reach 100 degrees F later today, and it is believed that the air conditioner will likely trip due to the increased load. With the air conditioner out of service and outside air temperatures near 100 degrees F, the EOF may no longer have the capability for protracted operation under emergency conditions. Compensatory measures are currently in place to staff and activate the Alternate EOF in the event of a declared emergency. Repair of the damaged air conditioning condenser coil fan is scheduled to be completed by the end of the day on 08/08/14. The NRC Resident Inspector has been informed.
ENS 5021219 June 2014 15:19:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopThis report describes an invalid actuation of the Unit 2, Train A (2-01) Emergency Diesel Generator (EDG) that occurred on April 22, 2014. This report is being made in accordance with 10CFR50.73(a)(2)(iv)(A). 10CFR50.73(a)(1) states, in part, 'In the case of an invalid actuation reported under 10CFR50.73(a)(2)(iv), other than actuation of the Reactor Protection System (RPS) when the reactor is critical, the licensee may, at its option, provide a telephone notification to the NRC Operations Center within 60 days after discovery of the event instead of submitting a written LER.' On April 22, 2014, Comanche Peak Nuclear Power Plant Unit 2 was in Mode 5 during the 14th refueling outage. At approximately 0830 CDT, while performing a lockout test on EDG 2-01, the Reactor Operator made a place keeping error that resulted in EDG 2-01 starting and rolling up to approximately 300 RPM. The start signal should have been blocked as part of the test. However, a step was skipped due to a place keeping error and this resulted in an inadvertent start of EDG 2-01 during the performance of a subsequent step. The specific train and system that actuated was the Unit 2, Train A, Emergency Diesel Generator. During the inadvertent EDG start the system started and functioned correctly, and the EDG only reached 300 RPM before it was shut down. The licensee has notified the NRC Resident Inspector.
ENS 5019011 June 2014 23:17:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

Release of Halon into the Unit 2 Cable Spreading Room. No indication of fire in the area. HU3.1 (Toxic, corrosive, asphyxiant or flammable gases in amounts that have or could adversely affect normal plant operations) was declared at 2154 CDT due to Halon release and Oxygen levels below safe habitability conditions (19% oxygen). Ability still exists to maintain safe operations and safely shut down the reactor. No adverse plant response or control board alarms indicated. No smoke or fire in the room and access is provided with SCBA. Escalation criteria would be if not able to maintain safe operations or safely shut down the reactor. Exit criteria would be when normal oxygen levels are restored to Unit 2 Cable Spreading Room. Local NRC resident notified at 2223 CDT. Unit 2 is stable at 100% power. Unit 1 was not affected and remains stable at 100% power. The licensee notified the State of Texas, the local counties, and the NRC Resident Inspector. Notified DHS, FEMA, and NICC. FEMA NWC and Nuclear SSA were notified via email.

  • * * UPDATE FROM SCOTT HARVEY TO CHARLES TEAL AT 1642 EDT ON 6/12/14 * * *

At 0330 CDT the Unusual Event was terminated. The licensee notified the NRC Resident Inspector. Notified R4DO (Werner), NRR (Uhle), IRD (Grant), DHS, FEMA, and NICC. FEMA NWC and Nuclear SSA were notified via email.

ENS 5004318 April 2014 14:35:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopWhile implementing a multiple spurious operations (MSO's) modification during a refueling outage, it was identified that a fire safe shutdown cable routing location may have been in question. On 04/18/2014 at 1252 CDT, it was determined that this cable was routed through a cable tray that was not designed to have a fire safe shutdown barrier. This created an unanalyzed condition that significantly degrades plant safety, consistent with NUREG 1022, Rev. 3 guidance. This cable is associated with a Motor Operated Valve (MOV) used to isolate the containment sump from the Residual Heat Removal (RHR) pump suction during normal system operations. Compensatory measures in this area were already in effect for the resolution of MSO's scenarios. The compensatory measures assure the Systems, Structures, and Components (SSC's) associated with this cable remain operable. The licensee has notified the NRC Resident Inspector.
ENS 4974318 January 2014 12:18:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0840 (CST), Comanche Peak NPP (CPNPP) Unit 1 turbine tripped causing a reactor trip. All rods inserted. No evolutions were in progress at time of trip. The cause of the trip is under investigation. A Generator Negative Sequence Current High Alarm was received immediately prior to turbine trip. Both Motor Driven Auxiliary Feed Water Pumps and the Turbine Driven Auxiliary Feed Water Pump started in response to Steam Generator Lo-Lo Levels. Currently, Unit 1 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IPO-007A and the Emergency Response Guideline Procedure Network has been exited. Decay heat is being rejected to the Main Condenser via Steam Dump Valves (Turbine Bypass Valves). Normal plant response was observed and all systems actuated as expected. No radiological release is in progress. There was no impact to CPNPP Unit 2, and off-site power remains available. The licensee has notified the NRC Resident Inspector.
ENS 496064 December 2013 15:14:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

At 1343 CST on 12/04/2013, Comanche Peak Nuclear Power Plant experienced a loss of safeguards electrical power when 345KV transformer XST2 lost power from offsite while 138KV transformer XST1 was out of service for maintenance. Non-Safeguards electrical power remained energized. Both Units remain at power in Mode 1. Both units Emergency Diesel Generators automatically started and all safeguards busses were re-energized from the Emergency Diesel Generators. All ESF systems functioned as expected and the Turbine Driven Auxiliary Feedwater Pump automatically started as designed. Operators reduced reactor power to maintain reactor power less than 100 percent rated thermal power. At 1350 CST, the licensee declared an Unusual Event due to losing both startup transformers. The cause of the loss of the second start up transformer was a cut cable. No one was injured during this event. The licensee informed State and Local Government Agencies and the NRC Resident Inspector. Notified other Federal Agencies (DHS SWO, FEMA Ops, DHS NICC, and Nuclear SSA via email).

  • * * UPDATE AT 1718 EST ON 12/4/2013 FROM MATT KARL TO STEPHEN SANDIN * * *

Correction to initial event report description; actual loss of electrical power time was 1341 CST. Include 8-HR Non-Emergency report for Specified System Actuation for automatic start of Auxiliary Feedwater and Emergency Diesel Generators. Notified the R4DO (Vasquez).

  • * * UPDATE FROM DAVE BUTLER TO JOHN SHOEMAKER AT 1840 EST ON 12/05/13 * * *

Comanche Peak terminated from the Unusual Event at 1717 CST on 12/05/13. Offsite power has been restored to both safeguard busses on both units via the transformer XST2. Work continues on transformer XST1. Comanche Peak Units 1 and 2 continue to operate at 100% power. The licensee has notified the NRC Resident Inspector. Notified R4DO (Vasquez), NRR EO (Bahadur), IRD MOC (Gott), and DHS SWO, FEMA Ops, DHS NICC, and Nuclear SSA via email.

ENS 494972 November 2013 01:44:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 2147 CDT on 11/1/2013, Unit 2 Reactor tripped during Solid State Protection System Slave Relay Testing. This test utilizes a blocking circuit to verify the operability of the slave relay which trips the Main Turbine and both Main Feedwater pump turbines, on a Hi-Hi Steam Generator level or Safety Injection. No valve actuation is expected to occur. While positioning the Slave Relay switch in a testing lineup, the relay actutated. The Unit 2 Turbine tripped as well as both Main Feedwater Pumps. The Turbine Trip actuated the Reactor Trip since power was above 50%. The trip of both Main Feedwater Pumps started both Motor Driven Auxiliary Feedwater Pumps. The Steam Generator Lo Lo Levels started the Turbine Driven Auxiliary Feed Water Pump. All systems responded as expected. Currently, Unit 2 is being maintained in Hot Standby (Mode 3) in accordance with Integrated Plant Operating Procedure IPO-007B and the Emergency Response Guideline Procedure Network has been exited. Decay Heat is being rejected to the Main Condenser via Steam Dump Valves (Turbine Bypass Valves). The licensee has notified the NRC Resident Inspector.
ENS 494198 October 2013 15:42:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopA review of industry operating experience regarding the impact of unfused Direct Current (DC) ammeter circuits in the control room has determined the described condition to be applicable to Comanche Peak Nuclear Power Plant resulting in a potentially unanalyzed condition with respect to 10CFR50 Appendix R analysis requirements. The original plant wiring design and associated analysis for the Class 1 E batteries control room ampere indications do not include overcurrent protection features to limit the fault current. In the postulated event, a fire in the control room could cause one of the ammeter wires to hot short to the ground plane. Simultaneously, the fire causes another DC wire from the opposite polarity on the same battery to also hot short to the ground plane. This could cause a ground loop through the unprotected ammeter wiring. This event could result in excessive current flow (heating) in the ammeter wiring to the point of causing a secondary fire in the raceway system. The secondary fire could adversely affect safe shutdown equipment and potentially cause the loss of the ability to conduct a safe shutdown as required by 10CFR50 Appendix R. This condition is reportable in accordance with 10CFR50.72(b)(3)(ii)(B) as an unanalyzed condition. Compensatory measures (fire watches) have been implemented for affected areas of the plant. The licensee has notified the NRC Resident Inspector. See related Event #49411.
ENS 4895322 April 2013 14:58:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

The Comanche Peak Nuclear Power Plant Emergency Operations Facility (EOF) is not available due to the loss of HVAC and filtering capabilities resulting from a failed Emergency Operations Facility (EOF) ventilation fan. The condition was discovered at 0900 CDT on 4/22/13. Repair parts are expected by the morning of 4/23/13 and the EOF is projected to be available by the end of the day on 4/23/13. Compensatory measures are in place to staff and activate the Alternate EOF in the event of a declared emergency. The NRC Resident Inspector has been informed.

  • * * UPDATE FROM MIKE STAKES TO HOWIE CROUCH AT 1426 EDT ON 4/23/13 * * *

The Emergency Operations Facility vent fan was returned to service at 1400 EDT on 4/23/13. The licensee has notified the NRC Resident Inspector. Notified R4DO (Whitten).

ENS 4851417 November 2012 12:30:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 1023 CDT Comanche Peak Unit 2 automatically tripped due to steam generator low level. The trip was uncomplicated. All control and shutdown rods fully inserted. Neither emergency diesel generator started. All safety systems functioned as designed. Both motor driven and the turbine driven AFW pumps started as required to restore steam generator level as a result of the trip. The turbine driven AFW pump was returned to auto-start status. The turbine driven AFW pump has been placed in pull-out as per procedure after verifying normal motor driven AFW pump operation. Currently Unit 2 is in Mode 3, (no-load Tave 557 - degrees Fahrenheit) with temperature being maintained with the AFW and steam dumps to the main condenser. Recovery actions will be planned. All electrical busses are powered from offsite power and grid conditions are stable. The initiating event appears to be a sheared instrument air tubing line that feeds the common heater drain pump discharge valve which will fail close resulting in loss of all heater drain flow. The licensee has notified the NRC Resident Inspector.
ENS 484752 November 2012 03:30:00Comanche PeakNRC Region 4Westinghouse PWR 4-LoopAt 0142 CDT, Comanche Peak Nuclear Power Plant Unit 1 was manually tripped due to high temperature indications on the 1-04 reactor coolant pump motor radial bearing concurrent with a high / low oil reservoir level alarm. The trip was uncomplicated; all control rods and shutdown rods fully inserted; neither emergency diesel generator started; all safety systems functioned as designed. Both motor driven and the turbine driven auxiliary feed water pumps started as required to restore steam generator levels as a result of the trip. The turbine driven AFW pump was stopped per procedure and returned to auto-start status. Currently, Unit 1 is in Mode 3, no load Tave of 557 degrees F, with temperature being maintained with AFW and steam dumps to the main condenser. All electrical busses are powered from offsite and grid conditions are stable. The licensee has notified the NRC Resident Inspector.
ENS 4846331 October 2012 14:09:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

On October 31, 2012 at 0615 hours CDT, Unit 1 Train 'B' Safety Injection/Blackout Sequencer faulted resulting in a start of the Turbine Driven Auxiliary Feed Water (TDAFW) Pump and Train 'B' Emergency Diesel Generator (EDG). Reactor power was reduced to 97% rated thermal power (RTP) by an immediate load reduction of 50 MWe due to the resulting cooler Auxiliary Feed Water being injected into the Steam Generators; reactor power did not exceed 100% RTP. Train 'A' equipment was not affected by the event. The TDAFW Pump was secured at 0628 hours by closing the Train 'B' steam supply valve from the main control board and the steam supply valve was declared operable at 0916 hours when the hand switch was returned to 'Auto' and the control switch lineup surveillance was completed. The Train 'B' EDG was loaded to 100% capacity in accordance with the operating procedure and secured at 1032 hours. The EDG is available but remains inoperable until the Sequencer is declared operable. Efforts continue to restore the Sequencer at this time. A faulted 15 Volt power supply was identified and further investigation/calibration will determine if other conditions contributed to the fault. A final surveillance test will determine Sequencer operability. The most limiting Shutdown Technical Specification action statement is 24 hours in accordance with Safety Injection Sequencer TS 3.8.1 F. Current projections for Sequencer operability, and thus Train 'B' EDG operability, are 1800 hours. This action appears to be an invalid actuation. However, this will be confirmed after a cause analysis and an update to this event will be provided at that time. The licensee has notified the NRC Resident Inspector.

  • * * UPDATE FROM ROBERT CLARK TO VINCE KLCO ON 12/20/12 AT 1130 EST * * *

This is an update to Event Notification #48463. This event was initially reported on October 31, 2012 as a valid actuation per 50.72(b)(3)(iv)(A). However, further evaluation of this event has confirmed that the cause was isolated to a failed 15VDC power supply and the ESF bus voltage sensed by the Blackout Sequencer did not dip. Therefore, a valid blackout condition did not occur and the starts of the Unit 1 Turbine Driven Auxiliary Feed Water Pump (TDAFWP) and the Unit 1 Train B Emergency Diesel Generator (EDG) were both determined to be invalid. For the EDG start, the associated electrical bus was never de-energized and the EDG output breaker did not close. Therefore, the EDG start is not reportable per 10CFR50.73(a)(2)(iv)(A) since it was an invalid actuation and the safety function (i.e. provide power to the safety related electrical bus) had already been completed at the time of the EDG actuation. For the TDAFWP start, the AFW system safety function had not already been completed. Therefore, the TDAFWP start is reportable as an invalid actuation per 10CFR50.73(a)(2)(iv)(A) with the option to provide a telephone notification within 60 days instead of an LER per 10CFR50.73(a)(1). The following required information is being submitted per NUREG-1022, Rev. 2 for the TDAFWP start: (a) The specific train(s) and system(s) that were actuated - Unit 1 Turbine Driven Auxiliary Feed Water Pump. (b) Whether each train actuation was complete or partial - The train actuation was complete. (c) Whether or not the system started and functioned successfully - The system started and functioned successfully. The NRC Resident Inspector has been informed. Notified R4DO (Spitzberg).

ENS 4835227 September 2012 14:08:00Comanche PeakNRC Region 4Westinghouse PWR 4-Loop

On September 27, 2012, Comanche Peak Nuclear Power Plant began a cyber security related modification to the Unit 1 and 2 Plant Computer Systems (PCS) and associated network infrastructure. The entire PCS for each unit will be out of service for approximately 6 hours. During that time, the PCS satellite display systems (SDSs) in the TSC and EOF will be inoperable. After approximately 8 hours, the PCS will be restored to service along with the SDSs in the TSC. The SDSs in the EOF will remain out of service until the modification and related site acceptance testing is complete, currently scheduled for October 5, 2012. During this period. the remote display of Radiation Monitoring System (RMS) information in the EOF and OSC will be unavailable. The loss of EOF SDS terminals will be compensated by use of an alternate plant parameter display system, and loss of EOF/OSC RMS remote display will be compensated by means of the status board recorder telephone loop. Therefore, it is expected that appropriate assessment of plant conditions. notifications, dose projections, and communications could still be made, if required, during the time that the SDSs and RMS remote displays are inoperable. The extended loss of the EOF SDSs and EOF/OSC remote RMS data is being reported in accordance with 10.CFR.50.72(b)(3)(xiii). which is any event that results in a major loss of emergency assessment capability, offsite response capability, or off site communications capability. The NRC Resident Inspector has been notified. A follow-up ENS communication will be made when the EOF SDSs and EOF/OSC remote RMS remote displays are fully restored to service.

  • * * UPDATE FROM RAUL MARTINEZ TO JOHN SHOEMAKER AT 0224 EDT ON 10/06/12 * * *

Maintenance has been completed on the Unit 1 and Unit 2 Plant Computer System. The system has been tested and returned to service. The licensee will notify the NRC Resident Inspector. Notified R4DO (Powers).