Semantic search
| Start date | Title | Description | Topic | |
|---|---|---|---|---|
| ENS 47905 | 8 May 2012 04:57:00 | Pressure Boundary Leakage | On May 7, 2012, at 2357 CDT, with the plant in MODE 3 at normal operating temperature and pressure, leakage from a transmitter manifold test valve diaphragm seal was determined to be pressure boundary leakage per TS 3.4.13. The manifold test valve is associated with pressurizer pressure transmitter PT-430. It has been determined that the most likely cause of the leakage is a cracked manifold diaphragm and that this is classified as part of the Reactor Coolant System Pressure Boundary per 10 CFR 50.2. This condition is being reported under 10 CFR 50.72(b)(3)(ii)(A) because the defect is associated with the Reactor Coolant Pressure Boundary. Isolation and repair of the leakage is being pursued. The licensee has notified the NRC Resident Inspector. The licensee closed the root isolation valves for the pressure transmitter to allow repair of the diaphragm, however there is still leakage past these valve. This leakage is quantified as a few drops per minute.
On May 8, 2012, EN #47905 provided notification of leakage from a pressurizer manifold valve that was potentially pressure boundary leakage. Since the leak could not quickly be determined to be otherwise, it was conservatively reported as pressure boundary leakage. Subsequent investigation and evaluation determined that the identified leakage originated from the mechanical components of the valve and not the pressure boundary. The leak has been isolated and the affected manifold valve is being repaired. Therefore, the leakage did not constitute pressure boundary leakage and this condition did not meet the reportability criteria identified in 10CFR50.72. As a result, the notification made on May 8, 2012 is hereby retracted. The NRC Resident Inspector has been notified. Notified R3DO (Giessner). | Pressure Boundary Leakage |
| ENS 47755 | 19 March 2012 21:12:00 | Potential for Aerial Lift to Impact Service Water Piping During Seismic Event | At 1612 on 3/19/12 it was identified that an aerial lift was located in the Auxiliary Building stored in a seismic storage area near Train A and Train B safety related service water piping to Control Room Air Conditioning (CRAC) Alternate Cooling System. This resulted in both trains of Service Water being INOPERABLE per TS 3.7.8 and both trains of CRAC Alternate Cooling system per TS 3.7.11. At this time, there is no conclusive information that would support the OPERABILITY of the Service Water System during a seismic event therefore this event is being conservatively reported under 50.72(b)(3)(ii)(B), 'The nuclear plant being in an unanalyzed condition that significantly degrades plant safety.' and 50.72(b)(3)(v)(A) and (D) 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structure systems that are needed for: (A) shutdown the reactor and maintain it in a safe shutdown condition, (D) mitigate the consequences of an accident.' The aerial lift was removed and the plant is no longer in the condition noted above. The NRC Resident Inspector has been informed.
On March 19, 2012, EN #47755 provided notification that both service water trains were potentially inoperable based on the potential for an improperly stored aerial lift to tip onto the adjacent service water piping during a seismic event. The notification was conservatively made due to the lack of conclusive information regarding any potential interaction between the aerial lift and the service water piping during a seismic event. Subsequent investigation and analysis determined that physical characteristics of the aerial lift are such that it would not have adversely interacted with the service water piping. Therefore, both service water trains remained operable and this condition did not meet the reportability criteria identified in 10CFR50.72. As a result, the notification made on 3/19/2012 (EN #47755) is hereby retracted. The NRC Resident Inspector has been notified. Notified R3DO (Stone). | Safe Shutdown Unanalyzed Condition Time of Discovery |
| ENS 47476 | 24 November 2011 09:15:00 | Emergency 4160 Volt Ac Busses Declared Inoperable | On Thursday, November 24, 2011, at 0315 CST, with the reactor at 100% steady state thermal power, Kewaunee Power Station declared both emergency 4160 Volt AC busses inoperable due to voltages being high outside of the procedurally directed voltage band. As a result, in accordance with Technical Specification 3.8.9, Distribution Sources - Operating, Kewaunee entered Technical Specification LCO 3.0.3 to, within 1 hour, initiate shutdown of the unit. At 0410 (CST), per management direction, the load tap changers for the supply transformers were adjusted to reduce the emergency bus voltages to within their procedural operating band. At this time, both emergency busses were declared Operable and LCO 3.0.3 was exited. Minimum required accident voltages were met at all times. The NRC Resident Inspector has been notified.
On November 24, 2011, EN # 47476 provided notification that both emergency 4160 Volt AC busses were inoperable based on voltages being high outside of a procedurally directed voltage band. Subsequent investigation and analysis determined that unnecessary conservatisms were used in the development of the voltage values used in procedure, OSP-MISC-002, Electrical Power System Weekly Surveillance Test. Review of the actual voltages present during the event determined that the voltages did not exceed the required values to support bus operability. Therefore, the busses remained operable and this condition did not meet the reportability criteria identified in 10 CFR 50.72. As a result, the notification made on 11/24/2011 is hereby retracted. The licensee informed the NRC Resident Inspector. | |
| ENS 46562 | 21 January 2011 21:39:00 | Steam Exclusion Door Declared Inoperable | On 1/21/2011 at 1539 CST, the NRC Resident Inspector informed the Control Room that the lower Cane bolt was disengaged on Steam Exclusion Door 3, between Emergency Diesel Generator Room B and the Cardox Room. While the Cane bolt was not engaged, the barrier was Non-Functional and, in accordance with TRM 3.0.9, all equipment supported by that steam exclusion barrier was immediately declared inoperable. This included both Emergency Diesel Generators A & 8, safety-related 4160 V Busses 5 & 6, Service Water Trains A & B, and safety-related 480 V Busses 51, 52, 61. & 62. In addition, with Service Water inoperable, the following equipment was also inoperable in accordance with TRM 3.3.1: Component Cooling Trains A & B, Safety Injection Trains A & B, Residual Heat Removal Trains A & B, Containment Spray and Cooling Trains A & B, Auxiliary Feedwater Pumps A & B, and the Turbine Driven Auxiliary Feedwater Pump. With all three AFW pumps inoperable. TS 3 A.b.2 was entered to immediately initiate action to restore one AFW Train to operable status and suspend all LCOs requiring mode changes until one AFW Train is restored to operable status. Steam Exclusion Door 3 was properly secured at 1545 CST on 1/21/2011, and LCO 3.0.c and TS 3 A.b.2 were exited at that time. All equipment affected by the steam exclusion barrier is operable. This is reportable under 10 CFR 50.72 (b)(3)(v)(B), 'Any event or condition that at the time of discovery could have prevented the fulfillment of a safety function,' and under 10 CFR 50.72(b)(3)(ii)(B) 'any event or condition that results in the nuclear plant being in an unanalyzed condition that significantly degrades plant safety.' The licensee notified the NRC Resident Inspector.
Retraction of EN #46562 Non-Functional Steam Exclusion Door. On January 21, 2011, EN #46562 provided notification that both trains of ESF equipment (e.g., SI, RHR, ICS, etc ) were inoperable following discovery that the lower cane bolt was disengaged on steam exclusion Door 3, between emergency diesel generator Room B and an adjacent equipment room in the turbine building. With the lower cane bolt disengaged, the steam exclusion barrier was considered non-functional. A subsequent engineering evaluation determined that the Door 3 lower cane bolt was not required for Door 3 to fulfill its function as a steam exclusion barrier. The previously reported condition would not have resulted in an environment that would have adversely impacted the equipment protected by Door 3. Therefore, the door remained functional and the supported ESF equipment remained operable. Consequently, this condition did not meet the reportability criteria in 10CFR50.72. As a result, the notification made on January 21, 2011, in EN #46562 is hereby retracted. The NRC Senior Resident Inspector has been notified. Notified R3DO(Cameron). | Unanalyzed Condition Time of Discovery |
| ENS 44938 | 26 March 2009 17:26:00 | Non-Functional Steam Exclusion Barrier | This event was additionally reported under 10 CFR 50.72(b)(3)(v)(D), 'Mitigate the Consequences of an Accident.' On 03/26/2009 at 1226 CDT, an engineering analysis determined that a steam exclusion door would not provide adequate steam exclusion protection. A metal plate, that had been installed over the door's glass window, would fail under the steam overpressure postulated during a high energy line break. The metal plate was replaced with one of a stronger design. Permanent repairs were completed on the door at 1549 on 03/26/2009. While the original plate was installed, the barrier was non-functional. In accordance with TRM 3.0.9, Section A.1 all equipment supported by that steam exclusion barrier was immediately declared inoperable. This zone includes both trains of ECCS and support equipment (i.e., SI, RHR, ICS, CCW, etc.). TS 3.0.c was entered and exited during the time the door issue was identified and repaired. All 3 trains of Auxiliary Feedwater were declared inoperable due to AFW low suction pressure trip channels were declared inoperable per TS 3.4.b.5. Power was reduced to less than 1673 MWt per TS 3.4.b.3. All mode changes were suspended per TS 3.4.b.2. Therefore, this is reportable under 10 CFR 50.72 (b)(3)(v), 'Any event or condition that at the time of discovery could have prevented the fulfillment of a safety function,' and under 10 CFR 50.72(b)(3)(ii)(B) 'any event or condition that results in the nuclear plant being in an unanalyzed condition that significantly degrades plant safety.' Containment Fan Coil Unit A was not operational during this event. The licensee notified the NRC Resident Inspector. * * * RETRACTION FROM JACK GADZALA TO PETE SNYDER ON 9/9/09 AT 1718 * * * On March 26, 2009 EN # 44938 provided notification that both trains of ESF equipment (e.g. SI, RHR, ICS, CCW, etc.) were inoperable based on an engineering analysis, which determined that a steam exclusion door in the auxiliary building would not provide adequate steam exclusion protection. Subsequent physical pressure testing of equivalent doors and engineering evaluation of the test results determined that the door remained capable of fulfilling its steam exclusion function. A series of pressure tests demonstrated that the door (including a metal plate that had been installed over the door's glass window) would withstand the steam overpressure postulated during a high energy line break. Therefore, the door remained functional and the supported ESF equipment in the auxiliary building remain operable. Consequently, this condition did not meet the reportability criteria in 10 CFR 50.72. As a result, the notification made on 3/26/09 is hereby retracted. This condition was also reported in Licensee Event Report (LER) 2009-005-00 on May 21, 2009." The licensee is planning on retracting this LER. | Unanalyzed Condition Time of Discovery |
| ENS 44832 | 5 February 2009 21:39:00 | Steam Exclusion Door Gap | At 1539 on 02/05/2009 it was identified that a Steam Exclusion door seal was not flush with the door. The door seal gap was noted during a Fire Zone Inspection. It was determined that the door exceeded the allowed limit. This could have allowed steam from the Turbine Drive Auxiliary Feed Pump room into the emergency safeguards bus area. This could have resulted in both trains of ESF Equipment failing to perform their required functions. Upon discovery Specification 3.0.c was entered at 1539. Work was completed on the door to return it to functional status at 1601, and Technical Specification 3.0.c was exited at that time. The NRC Resident inspector has been notified.
Retraction of EN 44832, both trains of Engineered Safeguards Features (ESF) equipment inoperable due to a degraded steam exclusion boundary door. EN 44832 provided notification that both trains of ESF equipment were inoperable due to degradation of a steam exclusion boundary door in the turbine driven auxiliary feedwater pump room on February 5, 2009. Subsequent engineering evaluation determined that the degraded door remained capable of fulfilling its steam exclusion function during the period when it was degraded. A degraded door seal had resulted in a slight gap to exist between the door and the sill. This gap could have allowed steam from the turbine driven auxiliary feedwater pump room into the emergency safeguards bus area. However, the force that would be exerted on the door by steam overpressure postulated under accident conditions, would compress the door seal sufficiently to reduce the gap such that the total allowed leak path criteria would not be exceeded. Therefore, the door remained functional and the supported ESF equipment in the emergency safeguards bus area remained operable. Consequently, this condition did not meet the reportabllity criteria in 10 CFR 50.72. As a result, the notification made on 02/05/2009 (EN 44832) is hereby retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (Peterson). | |
| ENS 44718 | 13 December 2008 20:20:00 | Steam Exclusion Boundary Door Latch Failure | At 1420 on 12/13/08 a plant electrician identified that a steam exclusion door would not close when he was transiting through the door. This door would not have closed and maintained the Steam Exclusion Boundary and could have led to steam through out the Auxiliary Building which could have resulted in both Trains of ESF Equipment failing to perform their required functions, i.e., SI, RHR, CC etc. A Unit Supervisor who was in the Auxiliary Building at the time immediately went up to the door and found the latch was broke and the broken piece was removed which then enabled the door to close and latch. At 1425 on 12/13/08 the Steam Exclusion Boundary was restored to functional and both Trains of ESF Equipment restored to operable. The licensee informed the NRC Resident Inspector.
01/22/2009 - Retraction of EN 44718, both trains of Engineered Safeguards Features (ESF) equipment inoperable due to a degraded steam exclusion boundary door. EN 44718 provided notification that both trains of ESF equipment (e.g. SI, RHR, CCW, etc.) were inoperable due to degradation of a steam exclusion boundary door in the auxiliary building on December 13, 2008. Subsequent engineering evaluation determined that the degraded door remained capable of fulfilling its steam exclusion function during the brief (five minute) period when it was degraded. A degraded latch mechanism prevented the door from latching closed. However, the door was closed against its door jam, which resulted in a sufficiently small gap such that total allowed leak path criteria were not exceeded. Additionally, the door swing was in the direction of postulated steam flow, such that the door would have been held in the closed position by any steam overpressure postulated under accident conditions. Therefore, the door remained functional and the supported ESF equipment in the auxiliary building remained operable. Consequently, this condition did not meet the reportabllity Criteria in 10 CFR 50.72. As a result, the notification made on 12/13/2008 (EN 44718) is hereby retracted. The licensee will notify the NRC Resident Inspector. Notified the R3DO (O'Brien). | |
| ENS 44182 | 30 April 2008 21:00:00 | Two Emergency Diesel Generators Inoperable | Two emergency diesel generators found inoperable while two trains of residual heat removal are required to be Operable for core cooling. On 4/30 at 1600 it was discovered that the level in Emergency Diesel Generator Fuel Oil Storage tanks were not trending together. The two underground fuel oil tanks have a capacity of 35,000 gallons each (useable volume of 34,674 gallons). The tanks are connected with a siphon line between the tanks to ensure a passive means of transfer so one emergency diesel can use both tanks. The siphon line does not appear to be transferring fuel oil. KPS is in a refueling outage and in REFUELING SHUTDOWN mode with the vessel drained to 6" below the flange for reactor vessel reassembly. Both trains of RHR are required to be OPERABLE per TS 3.1.a.2.B. Technical Specification 3.7.c states that when its normal or emergency power source is inoperable, a system, train or component may be considered OPERABLE for the purpose of satisfying the requirements of its applicable LCO provided: 1. Its corresponding normal and emergency power source is OPERABLE; and 2. Its redundant system, train, or component is OPERABLE. Kewaunee Power Station (KPS) Technical Specifications Section 3.7.a.7 states that the reactor shall not be made critical unless both diesel generators are operable. The two underground storage tanks combine to supply at least 35000 gallons of fuel oil for either diesel generator and the day tanks for each diesel generator contain at least 1,000 gallons of fuel oil. The current volume is 29,700 gallons in Tank A and 21,500 gallons in Tank B. Based on two trains found inoperable, this is reportable under: 10 CFR 50.72(b)(3)(ii) (8-Hr) 10 CFR 50.72(b)(3)(v)(B) (8-hr) Per TS 3.1.a.2.B the condition must be fixed immediately. Troubleshooting/investigation is in progress to determine repairs. Cause is being investigated. Condition was found during engineering review of logs taken during operator rounds. The licensee notified the NRC Resident Inspector.
EN 44182 provided notification that the emergency diesel generator (EDG) fuel oil tanks were not capable of supplying the combined volume of fuel oil (35,000 gallons) from two storage tanks to either EDG as required by Technical Specification (TS) 3.7.a.7 for EDG operability. That notification was based on a conservative determination that a siphon line, which connects the two fuel oil storage tanks, was nonfunctioning. TS 3.7.a.7 requires both EDGs to be operable when the reactor is critical. Although the reactor was in refueling shutdown mode at the time of this event (i.e., not critical, and therefore not in the mode of applicability for TS 3.7.a.7), the EDGs provide a support function (emergency power) for the Residual Heat Removal (RHR) system; two trains of which were required to be operable for core cooling per TS 3.1.a.2.B. A subsequent review confirmed that the capability to transfer fuel from either storage tank to either EDG existed independent of the siphon line. The siphon line is not needed for transferring fuel oil from either tank to either EDG. There are alternate means available to transfer fuel oil to the EDGs; sufficient time is available to implement these alternate means of fuel oil transfer within the time available. Additional fuel oil supply margin existed due to the mode of operation at the time (refueling shutdown). The 35,000 gallon TS requirement is based on the expected fuel consumption of one EDG operating for seven days at continuous rated load, thus ensuring adequate time to restore off-site power or to replenish fuel. The amount of fuel in the storage tanks was sufficient for the EDGs to be capable of performing their support function for RHR in the refueling shutdown mode. As such, both RHR trains remained operable and TS 3.1 a.2.B was satisfied. Consequently, this condition did not meet the reportability criteria in 10 CFR 50.72. As a result, the notification made on 4/30/2008 (EN 44182) is hereby retracted. The licensee notified the NRC Resident Inspector. Notified the R3DO (Peterson). | |
| ENS 43689 | 3 October 2007 20:30:00 | Potential Unavailability of Two Way Radio System to Support Safe Shutdown | In response to Self-Assessment Report SA014668 and preparation for the 2008 Triennial Fire Protection Inspection, a Fire Protection Improvement Plan implementation is in progress. Preliminary analysis of the major equipment, power supplies and cables associated with the two-way radio communication system (DCR-3341) indicates the potential for the plant two-way radio system to be adversely impacted and potentially unavailable to support post-fire safe shutdown operator actions and/or fire brigade fire fighting activities for a fire location in: - Fire Zone AX-35 (Control Room and AC Equipment Room) - Fire Zone TU-22 (Turbine Room) at the mezzanine elevation just outside Battery Room 1B - Fire Zone TU-98 (Battery Room 1B) This review has identified discrepancies regarding the credited means of communication required for use by Operators in response to an Appendix R fire. The safe shutdown procedures E-O-06 and E-O-07, and the Manual Action Feasibility Study (Fire Protection Engineering Evaluation FPEE-003) only credit the plant two-way radio system. However, upper tier program documents (e.g., Fire Protection Program Plan, Appendix R Design Description) do not consistently contain the same requirements. For example, the Fire Plan, Rev 7, Section 12.9 requires both the 5-channel Gai-Tronics system between key shutdown locations AND the multi-channel portable radio communications equipped with repeaters and provided for use by the plant fire brigade shall be operable at all times. The Appendix R Design Description. Rev. 5 is silent on safe shutdown communications. It is not clear at this time whether the 5-channel Gai-Tronics should also be credited in the safe shutdown procedures. If so, then the cables supporting operation of the Gai-Tronics would need to be identified and located by fire zone to determine their availability in lieu of two-way radio communications for a fire in any of the three fire zones identified above. Until this is verified, the Appendix R timeline for achieving sate shutdown may not be able to be met. Therefore, this is reportable under 10 CFR 50.72 (b)(3)(V)(A), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to: (A) shutdown the reactor and maintain it in a safe shutdown condition, (B) remove residual heat, (C) control the release of radioactive material, OR (D) mitigate the consequences of an accident. The licensee will notify the NRC Resident Inspector.
EN# 43689 provided notification that the Appendix R timeline for achieving safe shutdown may not be achievable due to potential loss of the credited two-way radio communication system due to fire and consequent need for face-to-face communications between the Operators. This position was adopted pending verification of the availability of the Gai-Tronics paging system. A subsequent engineering analysis of the major equipment, power supplies and cables associated with the Fire Protection/Appendix R two-way radio communication system, the Gai-Tronics plant paging system and the dedicated Emergency Gai-Tronics System, determined that adequate communications would have been available during a fire in the subject fire zones. Operators are familiar with and skilled in the use of the Gai-Tronics system as part of their job function. Interviews with on-shift Operators confirmed that operations would use the two-way radios; and if they failed, would then use the nearest Gai-Tronics handset station and then Emergency Gai-Tronics at specific locations for an Appendix R Dedicated Shutdown scenario. Where Operator manual actions are in close proximity to the Dedicated Shutdown panel, face-to-face communications would be achievable and timely. Consequently, the assumption of only face-to-face communications described in the Event Report would not have been necessary for all safe shutdown actions. Use of redundant communications systems (Gai-Tronics and Emergency Gai-Tronics) would have been available for fires in the subject fire zones such that the Appendix R safe shutdown time requirements would not have been significantly impacted. The loss of the two-way radio system for the identified fire zones would not have prevented the fulfillment of the safety function of systems that are needed to shut down the reactor and maintain it in a safe shutdown condition. As such, this condition is not reportable under 10CFR50.72(b)(3)(v)(A) as previously stated. Consequently, the notification made on 10/03/2007 (EN 43689) is hereby retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (Lipa). | Safe Shutdown Time of Discovery Operator Manual Action Fire Protection Program |
| ENS 43633 | 11 September 2007 19:39:00 | Auxiliary Building Special Ventilation and Shield Building Ventilation Systems Inoperable | At 1439 the Control Room received a Condition Report that identified an unanalyzed condition associated with the Auxiliary Building Special Ventilation and Shield Building Ventilation Systems which resulted in declaring this equipment inoperable. The issue was recirculation flow from Auxiliary Building Special Ventilation back to the Auxiliary Building added additional area heat gain resulting in exceeding the design capacity for the area fan coil units. Technical Specification LCO was entered per TS 3.6.c requiring a reactor shutdown within 12 hours. At 1654 Engineering provided information that if the control switch for Auxiliary Building Special Ventilation Train A was maintained in the off position, the area heat load was within the capacity of area fan coil units. This was completed and both trains of Shield Building Ventilation and Auxiliary Building Special Ventilation Train B was returned to operable. Technical Specification requirements to shutdown were exited. The plant remains in a 7 day Action Statement per TS 3.6.c with Auxiliary Building Special Ventilation Train A inoperable. This event is reportable under 10CFR50.72(b)(3)(v)(C), 'Any event or condition that at the time of discovery could have prevented the fulfillment of the safety function of structures or systems that are needed to control the release of radioactive material.' The licensee notified the NRC Resident Inspector.
On September 11, 2007 Kewaunee Power Station reported an unanalyzed condition associated with the Auxiliary Building Special Ventilation and Shield Building Ventilation Systems, which resulted in declaring the equipment inoperable. The issue involved recirculation flow from the Auxiliary Building Special Ventilation System back into the Auxiliary Building causing additional area heat gain resulting in exceeding the design capacity for the area fan coil units. A subsequent engineering review concluded that required equipment in the Auxiliary Building Fan Floor area would have remained functional during a design basis accident provided service water temperature does not exceed 78.14 degrees Fahrenheit. A review of service water temperatures over the past three years did not identify any occurrences exceeding this value. Therefore, the safety function of the systems would have been met. Based on the analysis performed, Event Notification EN# 43633 is hereby retracted. The Auxiliary Building Special Ventilation and Shield Building Ventilation Systems remain in a non-conforming condition because the maximum service water design temperature is 80 degrees Fahrenheit. Service water temperature is being administratively limited to 71 degrees Fahrenheit pending final corrective action. The licensee has notified the Point Beach NRC Senior Resident Inspector. Notified R3DO (Madera). | Unanalyzed Condition Time of Discovery |
| ENS 43324 | 29 April 2007 20:26:00 | Technical Specification Shutdown Due to Both Emergency Diesels Declared Inoperable | At 1453, (the licensee) declared D/G (Emergency Diesel Generator) - A inoperable due to outside air temperature exceeding 78.2 degrees Fahrenheit and entered Technical Specification 3.7.b.2 (which has a) 7-day LCO. At 1526, outside air temperature increased to greater than 81.4 degrees Fahrenheit and D/G - B was declared inoperable. With both D/Gs declared inoperable, Technical Specification 3.0.c , Standard Shutdown Sequence was entered. No other safety related components are inoperable at this time. Plant shutdown was initiated at 1624 on 4/29/07. Based on recent findings by the licensee, the EDGs may not be capable of generating the minimum electrical power output needed to support a safety bus when outside air temperature exceeds certain limits (Operability Determination 151 dated April 26, 2007) The licensee is in the process of making ventilation modifications that will correct this condition. The licensee expects that the temperatures will drop below the EDG inoperability limits before the plant actually shuts down. The licensee notified the NRC Resident Inspector.
EN 43324 provided notification of initiation of a unit shutdown due to both emergency diesel generators (EDGs) being declared inoperable due to outside air temperature exceeding allowable limits. Unit shutdown had been initiated per Technical Specification (TS) 3.0.c, Standard Shutdown Sequence, due to TS 3.7 not being met. A subsequent engineering evaluation allowed for increasing the allowable limit for outside ambient air temperature at which the EDGs are operable. The highest outside ambient air temperature recorded on 04/29/2007 (83.5 F) did not exceed the new allowable limit. Therefore, based on the new evaluation, both EDGs remained operable. TS 3.7 remained met and no TS shutdown was required. Consequently, this condition did not meet any reportability criteria in 10 CFR 50.72. As a result, the notification made on 4/29/07 (EN 43324) is hereby retracted." NRC R3DO (Patrick Louden) notified. The NRC Resident Inspector was notified of this retraction by the licensee. | |
| ENS 42534 | 28 April 2006 00:29:00 | Two Trains of Shield Building Ventilation Inoperable | At 19:29 on 04/27/2006 the Kewaunee Power Station declared two trains of Shield Building Ventilation (SBV) inoperable. Train B SBV was declared inoperable on 4/25/2006 at 17:25 when SW Train B was declared out of service for a leak that developed on the branch header to Diesel Generator B and TS 3.3.e.2 was entered. On 4/27/2006 at 19:29 QA typing discrepancies in RR-119 were discovered. QA-2 components were used in a QA-1 system, which could potentially cause a failure of some safety related equipment powered from this relay rack. As a result, all safety related equipment powered from RR-119 were declared inoperable and the appropriate technical specifications entered. SBV Train A Damper Control is powered from RR-119 and was declared inoperable at 19:29 on 4/27/2006 resulting in two trains of SBV being inoperable and TS 3.6.c.1 entered. The QA-2 components that may have an adverse affect on QA-1 safety related components in RR-119 have been removed and both trains of SBV were declared operable at 00:29 on 4/28/2006. The licensee notified the NRC Resident Inspector.
This event was reported on April 27, 2006 (Event Number 42534) for two trains of shield building ventilation (SBV) being declared inoperable. Train B SBV was declared inoperable due to loss of the service water spray system for the SBV charcoal filters and Train A SBV was declared inoperable due to relay rack RR-119 Quality Assurance typing discrepancies (relay rack provides power for SBV Damper Control). Subsequent review of analysis determined that the SBV spray system is not required for post-LOCA operation to control the release of radioactive material. Therefore, Train B of SBV was not required to be declared inoperable when Train B service water was declared out of service. With only one Train of SBV being inoperable, this event is not reportable and is being retracted. The licensee notified the NRC Resident Inspector. Notified R3DO (P. Louden). | |
| ENS 42152 | 17 November 2005 22:51:00 | Both Trains of Shield Building Ventilation Declared Inoperable Due to Missing Clamps | At 1651 on 11/17/2005 both trains of Shield Building Ventilation were declared out-of-service because it was identified that Shield Building penetrations 31 and 36NW flexible boot seals were not clamped per the design drawing. Since there is no documentation to show that Shield Building Ventilation would be able to perform its function during a design basis event with no clamps installed, Shield Building Vent was declared inoperable. Clamps have been installed and the penetrations were returned to the design configuration. At 1810 CST Shield Building Ventilation was declared Operable. The licensee notified the NRC Resident Inspector.
The licensee has performed an engineering review and determined that the boot seals would have been capable of performing their design basis function without the clamps installed. Consequently, this event is no longer considered reportable and is being retracted. The NRC Resident Inspector has been notified by the licensee. R3DO (O'Brien) has also been notified. | |
| ENS 41752 | 7 June 2005 16:25:00 | Unanalyzed Potential Impact on Emergency Diesel Generator Operability | At 1125 on 6/7/2005 it was determined that the Emergency Diesel Generators A and B were out of service due to the possibility of Tornado Missiles potentially collapsing the D/G Fuel Oil Tank Vents. The Emergency Diesel Generators are required as a support system for RHR Decay Heat Removal and RHR was also declared inoperable at the same time. Technical Specification requirements for RHR Decay Heat Removal are, if less than the required number of heat sinks are operable, then corrective action shall be taken immediately to restore the minimum number to operable status. Actions are being taken to restore full operability of the Emergency Diesel Generators A and B. Currently RHR is operating and providing decay heat removal and Emergency Diesel Generators are available as a support system for RHR. Event Report # 41528 had similar issues associated with the Emergency Diesel Generators exhaust ducts and their ability to withstand tornado forces. The licensee notified the NRC Resident Inspector. * * * RETRACTION FROM G. RISTE TO P. SNYDER ON 7/26/05 AT 1541 * * * Event Notice #41752 was initiated on 6/7/2005 to report an unanalyzed condition with the Emergency Diesel Generators A and B. The initial analysis for tornado missile strike probability results for the Emergency Diesel Generator fuel oil tank vent lines indicated they could be damaged by a tornado missile to the point they would potentially adversely affect Diesel operability. Additional analysis was performed and it was determined that the original fuel tank oil vent line configuration was acceptable. The licensee notified the NRC Resident Inspector. Notified R3DO (Mark Ring). | Unanalyzed Condition Tornado Generated Missile |
| ENS 40091 | 20 August 2003 15:45:00 | Unauthorized Access | Actual individual had been granted unescorted access to a vital area. Compensatory measures immediately taken upon discovery. NRC Senior Resident Inspector was notified of the event notification by the licensee.
Based on subsequent review, the licensee has determined that there was no security violation. This event has been retracted. For additional information, contact the Headquarters Operation Officer. R3DO (R. Gardner) & IAT (A. Davis) notified. NRC Resident Inspector was notified of this event by the licensee. |