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| Entered date | Event description | |
|---|---|---|
| ENS 51649 | 12 January 2016 18:37:00 | On January 12, 2016, during performance of an EOF (Emergency Off-Site Facility) Diesel Operability Test, the EOF Air Conditioning unit and EOF Air Return fan did not run as expected. Per plant procedure, the operators placed the system in filtration mode and then back in normal mode. Again, both units did not run as expected. The EOF was declared non-functional due to the failure of the air conditioning unit and fan. The EOF is available for emergency response purposes unless the temperature can not be maintained or a release is in progress. The backup EOF is available for use if needed. The licensee notified the NRC Resident Inspector.
The Emergency Off-Site Facility (EOF) was restored to functional status at 1223 CST on 01/13/2016. The licensee notified the NRC Resident Inspector. Notified R4DO (Kellar) |
| ENS 50474 | 19 September 2014 16:35:00 | From review of Event Notification 50468 made by Wolf Creek Nuclear Operating Company on 9/18/2014, which in turn was based on review of INPO Event Report 14-33, 'Direct Current Circuits Challenge Appendix R Fire Analysis,' it was determined that portions of the control circuits for the main turbine-generator direct-current (DC) Emergency Lube Oil Pump and the Emergency DC Seal Oil Pump at Callaway Plant are not properly fused to prevent overload and possible secondary fires. The review found that a fire at the motor starter cabinet in the turbine building could cause specific 'smart' hot shorts that could cause overheating of the control cable and result in secondary fires outside the turbine building, including the Control Building, thereby potentially affecting safe shutdown capability for the plant. Based on this information, it has been determined that this condition is unanalyzed, and on a conservative basis, is reportable per 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. As compensatory measures, hourly fire watches are in place in the affected areas of the Turbine Building and Control Building. These compensatory measures, in addition to automatic fire detection and suppression capability in these fire areas, ensure protection of the potentially affected equipment. The NRC Resident Inspector has been notified. The licensee continues to evaluate other control circuits to identify if this condition exists elsewhere. |
| ENS 49398 | 1 October 2013 01:05:00 | At 2257 CDT on September 30, 2013 the Callaway Plant Emergency Off-Site Facility (EOF) was declared nonfunctional due to air in-leakage outside acceptance criteria while ventilation is in filtration mode. Efforts are underway to restore the air in-leakage within acceptance criteria at the EOF. If EOF activation is necessary during the period of EOF non-functionality, the Recovery Manager will evaluate the suitability of the facility for the specific conditions of the event. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii) due to the unavailability of an emergency response facility. The NRC Senior Resident Inspector has been notified.
Repairs were made to the EOF ventilation system and all required post-maintenance testing has been completed satisfactorily. The EOF has been restored to a functional status. The licensee will notify the NRC Resident Inspector. Notified R4DO (Gepford). |
| ENS 47275 | 18 September 2011 12:41:00 | An Alert was declared at Callaway Nuclear Plant at 1056 (CDT) due to EAL HA3.1. Access to an Auxiliary Building area which is prohibited due to release of toxic gas which jeopardizes operation of systems required to maintain safe operations or safely shutdown the reactor. EAL HU3.1 (Unusual Event) is also applicable at the same time. The cause of the toxic gas release was a Freon gas leak from the 'A' Control Room air conditioner unit. The licensee has notified the NRC Resident Inspector and state and local government. Also notified USDA (Pitt) and HHS (Emerson).
At 1737 CDT, Callaway Nuclear Plant exited from the Alert for EAL HA3.1, and exited from the Unusual Event for EAL HU3.1. The plant continues to operate at 100% power in Mode 1. There was no radiological release due to this event. Additionally, a press release will be performed after the event closeout. The licensee has notified the NRC Resident Inspector and state and local government. Notifications were also given to R4DO (Pick), NRR EO (Giitter), IRD-MOC (Morris), HQ PAO (Hayden), DHS (Gates), FEMA (Via), DOE (Foote), USDA (Sanders) and HHS (Hoskins). |
| ENS 44863 | 19 February 2009 10:07:00 | The plant was operating in MODE 1 at 100% power. At 0228 on 2/19/09, a power supply to cabinet SA036D, Channel 1 of the Engineered Safety Features Actuation System (ESFAS) failed. As a result of the failure, both trains of control room ventilation isolation signal (CRVIS), containment purge isolation signal (CPIS), and fuel building isolation signal (FBIS) inadvertently actuated. The cause of the failure of SA036D is under investigation. Technical Specification (TS) Action 3.3.2.Q was entered which requires the plant to be in MODE 3 in 6 hours and MODE 4 in 12 hours. Load reduction began at 0530. MODE 2 was entered at 0750. MODE 3 was entered at 0817. All systems functioned properly. The NRC Resident Inspector has been notified. The licensee is replacing the entire power supply and will investigate the cause. |
| ENS 42548 | 3 May 2006 13:55:00 | This report is being made pursuant to 10CFR50.72(b)(3)(xiii), 8-hour Non-Emergency Report due to the loss of off-site response capability. As of 0700 Central Daylight Savings Time on 5/03/2006 the TSC was declared non-functional due to the discovery of non-conservative surveillance acceptance criteria for the TSC ventilation system flow balance. The acceptance criteria allow for a higher percentage of pressurization flow from filtered outside air and lower recirculation flow than is supported by the radiological consequences analysis for the TSC. This condition is complicated by the fact that the radiological consequences analysis has not been updated to incorporate changes to plant operation and radiological source term derived from the current license basis Loss of Coolant Accident analysis. Preliminary evaluations using current plant configuration, current TSC ventilation flow balance values, and current calculation methodology indicate that post-accident dose to TSC personnel is approximately 31.7 Rem to the thyroid, exceeding the acceptance criterion of 30 Rem. Activities to revise applicable surveillance acceptance criteria and restore TSC functionality by re-balancing TSC ventilation flows to establish acceptable dose consequences have been initiated and are expected to be complete by 2000 on 5/3/2006. Affected Emergency Response Organization members have been instructed on compensatory measures in place until the TSC is fully functional. Callaway Plant is currently operating in Mode 1 at 100% power. Normal plant operation is unaffected by the partial loss of TSC function. The licensee has notified the NRC Resident Inspector. * * * UPDATE FROM F. BIERMANN TO P. SNYDER AT 2036 ON 5/3/06 * * * TSC ventilation flow balancing activities to restore TSC functionality have been completed. The TSC was declared functional and restored to service at 1930 CDT on 5/3/06. The licensee will inform the NRC Resident Inspector. Notified R4DO (Bywater). |
| ENS 42497 | 13 April 2006 14:25:00 | This report is being made pursuant to 10CFR50.72(b)(3)(xiii), 8-hour Non-Emergency Report due to the loss of emergency assessment capability. The TSC filter absorber unit (FUB7001) and the TSC were declared non-function at 0738 Central Daylight Savings Time on 4/13/2006 for charcoal replacement activities. Charcoal replacement activities have an estimated completion time of 2000 on 4/13/2006. Affected Emergency Response Organization members have been instructed in the event of an emergency to report to designated backup facilities. Callaway Plant is currently operating in Mode 1 at 100% power. Normal plant operation is unaffected by the loss of ventilation filtration. The licensee has notified the NRC Resident Inspector.
Maintenance and post maintenance testing activities for charcoal replacement in the TSC filter absorber unit have been completed. The TSC filter absorber unit and the TSC were declared functional and restored to service at 1738 CDST on 4/13/06 Notified R4DO (T. Pruett) |
| ENS 41326 | 12 January 2005 21:48:00 | At 1330 on January 12, 2005, station personnel identified an error in connection of pilot lines to the manual-pneumatic actuator on halon bottles required for fire suppression. The vendor was contacted to confirm the configuration. The vendor indicated that the halon bottles would not properly discharge if the pilot lines were not properly connected. The system engineer inspected the halon systems. It was determined that five of six fire areas protected by halon systems were affected. Fire watches were implemented for the affected fire areas. Affected areas: A-27, Load Center/MG set Room, main - correct, reserve - 1 valve correct/1 valve incorrect A-17, South Electrical Penetration Room, main - correct, reserve - incorrect A-18, North Electrical Penetration Room, Main - correct, reserve - correct C-9, ESF Switchgear room 1*, main - incorrect, reserve - incorrect C-10, ESF Switchgear room 2*, main - incorrect, reserve - incorrect C-27, Control room cable trenches/chases**, bottle 1 - correct, bottle 2 - incorrect The main bank is sufficient to suppress a fire in a fire area.
The design and licensing basis for the fire protection system does not require consideration of a fire in more than one fire area at a time. No degraded fire barriers between the above fire areas were identified which would have allowed a fire to affect more than one of the fire areas at a time. Repairs were immediately initiated to correct the condition. As of 2010 CST, the repairs have been completed for the affected fire areas and restored to operable status. The licensee notified the NRC Resident Inspector.
Investigation - Informational tests conducted by the Vendor (Chemetron) and witnessed by Wolf Creek, Callaway, and NRC personnel on January 26, 2005 determined that the Halon systems would have properly actuated in the as-found incorrect configuration (port 'A' and 'B' connections reversed). The only identified difference in the actuation sequence between the tests conducted in the incorrect configuration versus the correct configuration is a delay of less than 2 seconds from the time the solenoid received the discharge signal until the first cylinder actuated. There is no regulatory or National Fire Protection Association standard or guideline that places a time requirement on this interval. This very slight time delay would have had no effect on the designed function of the Halon suppression system to extinguish a fire. Additional details are provided in the Chemetron report, 'Report on Actuation Arrangements for Halon Extinguishing System Units,' (Correspondence ULNRC 05-121) that includes the test procedure and results. Halon system function is to establish sufficient halon concentration for sufficient time to suppress a fire. This capability was not lost with the delay in actuation. Regulatory Evaluation - Guidance for reporting to the criterion of 10 CFR 50.73(a)(2)(ii) is provided in section 3.2.4 of NUREG 1022 rev 2, 'Event Reporting Guidelines 10 CFR50.72 and 50.73.' This guidance states that an LER is required for a seriously degraded principal safety barrier or an unanalyzed condition that significantly degrades plant safety. Operating License Condition 2.C(5)(c) states the following: The Operating Corporation shall maintain in effect all provisions of the approved fire protection program as described in the SNUPPS Final Safety Analysis Report for the facility through Revision 15, the Callaway site addendum through Revision 8, and as approved in the SER through Supplement 4, subject to provisions d below. Conclusion: - Based upon the information provided, the Halon suppression system would have operated to extinguish a fire. This condition is not considered reportable to the requirements of 10 CFR 50.72(b)(3)(ii)(B), 10 CFR 50.73(a)(2)(ii), nor is it a violation of the Operating License Condition 2.C(5)(c). Consistent with this conclusion, ENS notification number 41326 for this event is to be retracted. The licensee notified the NRC Resident Inspector. |
| ENS 40507 | 5 February 2004 18:32:00 | At 1701 (CST) on 02/05/2004, a report was made to the Missouri Public Service Commission (MPSC) to notify the MPSC of a forced outage at the Callaway Nuclear Plant. This notification is reportable under 4CSR240 20.080(3)(B) because the outage is expected to last longer than 72 hours. At 0439, 02/03/04, Callaway Plant experienced a reactor trip while operating transmission breakers located in the plant switchyard. It was determined on 02/05/2004 that the outage was expected to last longer than 72 hours. The Licensee will inform the NRC Resident Inspector of the MPSC notification. |
| ENS 40373 | 3 December 2003 17:24:00 | While reviewing operator emergency response times contained in Callaway Plant's Final Safety Analysis Report (FSAR), it was determined that emergency procedure E-0 did not contain specific guidance for actions to be taken when one train of Control Room Emergency Ventilation System (CREVS) failed to properly operate. In FSAR Chapter 15A, the limiting single failure analyzed for the CREVS is the failure of a filtration fan within one train of CREVS. In this accident analysis scenario, a Control Room Filtration Unit fan fails and the train must be secured to prevent inadequately filtered Control Building air from being introduced into the Control Room. If the train is not isolated within 30 minutes, postulated dose to Control Room staff could potentially exceed GDC 19 limits. While procedure E-0 addressed identifying faulted CREVS equipment and an attempted restoration of the faulted equipment, it did not contain sufficient guidance to ensure the Control Room staff would isolate the faulted train of CREVS if the equipment restoration attempt failed. A revision to procedure E-0 has been issued to correct this procedural deficiency. The licensee has notified the NRC Resident Inspector.
This notification is being retracted. Further evaluations concluded that a local area radiation monitor would have alerted the Control Room staff to a developing adverse condition in sufficient time for operators to have identified and isolated the faulted CREVS train prior to exceeding regulatory dose limits. This event does not represent an unanalyzed condition reportable per 10CFR50.72(b)(3)(ii)(B)." The NRC Resident Inspector was notified of this retraction by the licensee. Notified R4 DO (A. Gody) |