Semantic search

This page or action requires JavaScript to work. Please enable JavaScript in your browser or use a browser where it is supported, so that functionality can be provided as requested. For further assistance, please have a look at the noscript help page.

Search Clear all entries

	Entered date	Site	Region	Reactor type	Event description	Topic
ENS 43611	31 August 2007 11:05:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	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 normal AC power supply and backup diesel generator were taken out of service for planned load center cleaning maintenance activities and the Technical Support Center (TSC) was declared non functional at 0703 Central Daylight Time on 8/31/2007. The maintenance activities are expected to last approximately 16 hours. Affected Emergency Response Organization members have been, instructed to report to designated backup facilities, per procedure EIP-ZZ-00240, in the event of an emergency. Though this does not affect state or local response capabilities, the SEMA Senior Radiological Emergency Program Planner and local personnel have been notified of this planned maintenance outage as a courtesy. The licensee has notified the NRC Resident Inspector. * * UPDATE ON 08/31/07 AT 1730 EDT BY STEVE KOCHERT TO MACKINNON * * * The normal AC power supply and backup diesel generator were restored to service and the TSC was declared functional at 1627 CDT on 8/31/2007. Affected Emergency Response Organization members have been instructed to resume normal use of the TSC in the event of a emergency. The licensee has notified the NRC Resident Inspector. R4DO (Troy Pruett) notified.
ENS 43622	7 September 2007 00:52:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	A relief valve (BG 8117) in the letdown system opened and released about 650 - 700 gallons of water from the reactor coolant system into the pressurizer relief tank. The rate of release from the letdown was 119 gpm. It was estimated that the pressurizer level lowered about 2-3%. The letdown system was isolated by closing the letdown orifice block isolation valve. Licensee is investigating the reason for the spurious lifting of the relief valve. Due to leakage from the reactor coolant system, the licensee entered EAL 4R. Plant is stable and operating at full power. The licensee notified the NRC Resident Inspector. * * UPDATE FROM THOMPSON TO ABRAMOVITZ AT 0120 EDT ON 09/07/07 * * * The licensee stated that the Unusual Event was exited at 0120 EDT. The licensee notified the NRC Resident Inspector. Notified R4DO (Pruett) and NRR EO (Evans) and IRD MOC (Cruz). * * UPDATE AT 1635 EDT ON 09/13/07 FROM JOHN WEEKLEY TO S. SANDIN * * * The licensee is retracting this report based on the following: This is a follow-up notification to inform the NRC that Callaway Plant is retracting an Unusual Event declaration reported on 09/07/2007 at 00:52 EDT. EAL 4R was entered and the declaration was made due to leakage from the reactor coolant system. The basis for EAL 4R indicates that the initiating condition for an Unusual Event would include failure of a relief valve to properly close following reduction of applicable pressure and NOT simply the actuation of the relief valve as designed. Based on troubleshooting efforts and upon review of the event, it has been determined that relief valve BG8117 functioned as designed to reduce pressure and therefore the declaration of the Unusual Event was not required. The relief valve did sense an over-pressurization and did perform its intended function. The relief valve reseated when the letdown line was isolated. Based on this, the Unusual Event declaration is retracted. The licensee informed the NRC Resident Inspector. Notified R4DO (Cain), EO (MJ Ross) and IRD (Blount).
ENS 44381	4 August 2008 11:07:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	The Callaway Plant Process Computer is being upgraded to a newer system. This implementation period is expected to start on August 4, 2008 and last approximately 14 days. During the implementation time for this upgrade, the Emergency Response Data System (ERDS) system will be out of service. Compensatory actions for emergency situations have been established. This event is reportable per 10 CFR50.72(b)(3)(xiii) since this constitutes a loss of ERDS for the duration of the evolution. The licensee has notified the NRC Resident Inspector.
ENS 44560	11 October 2008 02:47:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 0049 on 10/11/08 Letdown Relief valve BG8117 lifted prior to set point, resulting in Pressurizer water inventory being diverted the Pressurizer Relief Tank. Letdown was isolated within 13 minutes, isolating the leakage. Upon review of the level trends of the Pressurizer Relief Tank level changes, approximately 574 gallons were diverted from the Reactor Coolant system. This would result in an RCS leakage rate of 44 gpm of RCS Identified Leakage. At the time that the calculation of leakage rate was discovered, it was immediately recognized that this met the requirements for EAL 4R, 'RCS Identified Leakage greater than 25 gpm'. As a result of identification that the criteria of an EAL was exceeded, and no longer existed, a notification was made to the NRC Operation Center in accordance with 10 CFR50.72(a)(1)(i). Licensee has notified NRC Resident Inspector and will notify state and local agencies on the next business day.
ENS 44561	11 October 2008 10:07:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	During plant shutdown to begin a scheduled refueling outage, with the plant at 0% power in Mode 3, an actuation of the reactor trip system (RTS) occurred when a steam generator (S/G) Low-Low water level trip inadvertently occurred during recovery from a feedwater isolation actuation that had previously occurred in response to a steam generator high water level trip condition. At approximately 0500 hours, plant operators were closing the main steam isolation valves (MSIVs) for plant shutdown. Once the MSIVs were closed, the reactor coolant system (RCS) cooldown rate decreased significantly. The 'A' atmosphere steam dump valve (ASD) was then opened. Shortly after the ASD was opened, the MSIV was also opened. With both the MSIV and ASD open, however, the 'A' S/G water level swelled until the P-14 S/G Hi Level protective interlock setpoint was reached, resulting in a feedwater isolation (FWIS) actuation at 0505 hours. Subsequent to the FWIS actuation, plant operators took action to recover from the FWIS in accordance with off-normal operating procedure OTO-SA-00001, 'Engineered Safety Feature Actuation Verification and Restoration.' The motor-driven auxiliary feedwater pumps were started to restore S/G water level. However, S/G water level lowered rapidly in response to the cold auxiliary feedwater flow to the S/G. A S/G Low-Low water level trip signal was then reached on the 'A' S/G, thus resulting in a reactor trip system actuation at 0508 hours. All systems functioned normally in response to plant conditions. The NRC Senior Resident Inspector has been informed. * * UPDATE AT 0239 EDT ON 10/12/08 FROM FRED BIANCO TO VINCE KLCO * * * This report is an update to information reported under ENS notification 44561. The original notification reported a valid reactor trip system actuation as a 4-hour notification under 10CFR50.72(b)(2)(iv)(B). The correct reporting requirement is 10CFR50.72(b)(3)(iv)(A), an 8-hour notification, as the plant was in Mode 4 with the reactor subcritical at the time of the event. The (NRC) Resident Inspector will be notified. Notified R4DO (Powers).
ENS 44652	11 November 2008 22:30:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1846 the reactor was manually tripped due to 'B' Main Feed Pump (MFP) trip on low lube oil pressure. The plant was operating at 97 percent (power) when annunciation was received that 'B' MFP was experiencing low lube oil pressure. Subsequently the 'B' MFP tripped on low lube oil pressure. The operating crew manually tripped the reactor per procedure OTO-AE-00001. The Auxiliary Feedwater System automatically actuated. All control rods fully inserted during the event and all safety systems responded as designed. The unit is removing decay heat using steam dumps to the Main Condenser. No primary relief valves or Main Steam relief valves lifted during the event. (The licensee is) currently investigating low lube oil pressure on 'B' MFP. Aux Feed is supplying make up to the steam generators. The plant is in normal electrical shutdown line-ups. The licensee notified the NRC Resident Inspector.
ENS 44714	12 December 2008 01:12:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	The 'C' condensate pump tripped due to an electrical problem which caused a feedwater transient. The unit (automatically) tripped on high steam generator level at approximately 2301 CST. The unit is in mode 3 and stable. The reactor trip procedures are in progress at this time. All control rods fully inserted into the core during the reactor trip. Offsite power is available and powering safety loads. The steam generator atmospheric steam dumps lifted momentarily during the transient and reseated. There is no known primary to secondary leakage. Decay heat is being removed via steam dumps to the condenser with makeup provided by auxiliary feedwater to the steam generator. The standby diesel generators and safety systems are available. The licensee notified the NRC Resident Inspector.
ENS 44717	12 December 2008 14:36:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Valid Reactor Trip and Manual Initiation of Auxiliary Feedwater While in MODE 3 At 1042 on 12/12/2008, while in Mode 3, a valid reactor trip signal was generated during I&C maintenance activities on intermediate range nuclear instrument SENI0036. This resulted in a feedwater isolation signal. Reactor Operators manually started both motor driven auxiliary feedwater pumps to maintain steam generator levels. These pumps were started prior to receiving an Auxiliary Feedwater Actuation. Plant is stable in Mode 3. Normal feedwater supply has been restored. The cause of the reactor trip is understood. All systems functioned normally in response to plant conditions. The NRC Resident Inspector has been notified.
ENS 44719	14 December 2008 20:38:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Callaway Plant was at 98% power with two condensate pumps in service. At 1714 on 12-14-08, the reactor was manually tripped due to a motor ground fault on the 'B' condensate pump. The 'C' condensate pump was not available for service (See EN #44714). This left only one condensate pump available so the reactor was manually tripped. The plant is in mode 3 and stable. Reactor trip procedures have been implemented and exited and normal operating procedures are in progress at this time. All safety systems actuated as designed. All control rods inserted during the trip. Offsite power is available and powering safety loads. There is no primary to secondary leakage. Decay heat is being removed via steam dumps to the condenser with makeup provided by Auxiliary Feedwater to the steam generators. The standby diesel generators and safety systems are available. The NRC Senior Resident Inspector has been notified.
ENS 44863	19 February 2009 10:07:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	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 44864	19 February 2009 11:52:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	An Unusual Event was declared at 1021 CST due to toxic, corrosive, flammable gasses in amounts that have or could adversely affect normal plant operations. Licensee estimated that a plume of hydrogen gas 20 feet high was leaking in the Turbine Building at the North Generator Bearing. Licensee entered EAL HU3.1. There was no release above normal operating limits (0.1 Mr/hr at EAB). No offsite response required. Gas is being dissipated via emergency degassing of Main Generator. Presently, the Main Generator degas has been completed and no flammable environments remain. The Unusual Event will stay in effect until the area is accessible to personnel, as evaluated by chemistry. There was no fire or personnel injury related to this event. The Plant was already in Mode 3 due to an earlier event requiring a Technical Specification Action 3.3.2.Q shutdown. The licensee has notified the NRC Resident Inspector, and local, state and other government agencies. No media press release was anticipated. * * UPDATE FROM DAVID HURT TO JOHN KNOKE AT 1255 EST ON 02/19/09 * * * The hazard was eliminated by 1055 on 2/19/2008. The Unusual Event was closed out at 1115. The state and counties (Callaway, Gasconade, Montgomery, and Osage) were notified of the event closeout at 1126. A news release will be made by Ameren Corporate Communications. The licensee has notified the NRC Resident Inspector. Notified R4DO (Powers), DHS ( Cassandra McKentry) and FEMA (Mike Eaches).
ENS 45427	12 October 2009 12:00:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Loss of ventilation to an emergency response facility: Emergency Operations Facility (EOF). During performance of the EOF diesel generator operability test, the EOF ventilation system was placed in filtration mode. The air conditioning unit and air return fan did not run. Emergency Preparedness personnel evaluated the habitability of the EOF and determined that the filtration mode of the ventilation system was not functional. Because of the loss of the ventilation function for the EOF, the facility was not functional. The EOF is available for emergency response purposes unless the temperature could not be maintained or a release is in progress. The backup EOF is available for use if needed. Repair of the EOF's ventilation system is in progress. This is reported per 10CFR50.72(b)(3)(xiii). The licensee will notify the NRC Resident Inspector. * * UPDATE FROM STEVE SAMPLE TO DONALD NORWOOD AT 1620 10/12/09 * * * The EOF was restored to operable status at 1247 CDT. The licensee notified the NRC Resident Inspector. Notified R4DO (Campbell).
ENS 45571	15 December 2009 18:37:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	During a review of a High-Energy Line Break (HELB) calculation, valve FBV0146 on a 3" Auxiliary Steam line, FB-093-HBD-3", was found to be kept normally open. This is not consistent with HELB analysis, which assumes flow in line FB-093-HBD-3" is restricted by an orifice plate or isolated by FBV0146. This HELB analysis classified FB-093-HBD-3" as a moderate-energy line downstream of FBV0146 as a result of line isolation. No orifice plate was installed, and line FB-093-HBD-3" downstream of the FBV0146 is considered a high-energy line if FBV0146 is open. A room containing line FB-093-HBD-3" downstream from FBV0146 includes several components, the most critical of which are two RCS (Reactor Coolant System) pressure transmitters in one train which are used to provide indications during post-accident conditions. This configuration is therefore outside of current HELB analysis and potentially represents a condition that significantly degrades plant safety. Valve FBV0146 was closed at 1522. The NRC resident inspectors have been notified. * * RETRACTION FROM KEITH CRIBLEZ TO VINCE KLCO ON 1/21/2010 AT 1739 * * * On 12/15/2009, EN #45571 provided notification that valve FBV0146 on Auxiliary Steam line FB-093-HBD-3 was found to be kept normally open. This configuration was not consistent with High Energy Line Break (HELB) analysis which assumes flow beyond this valve to be restricted or isolated. An engineering evaluation was subsequently performed for the rooms containing this line downstream of FBV0146. This evaluation has determined that all safety-related components in the affected rooms would be able to perform their safety functions in the event of a line break. Pipe whip, jet impingement, compartment over pressurization, flooding, and internal missiles resulting from a postulated line break would not prevent any safety-related equipment from performing its design function. As supported by this evaluation, this condition does not meet the criteria for an unanalyzed condition that significantly degrades plant safety as stated in 10CFR 50.72(b)(3)(ii)(B). Therefore, the notification made on 12/15/2009 is hereby retracted. The (NRC) Resident Inspectors have been notified. Notified the R4DO (Werner).	Unanalyzed Condition
ENS 45715	20 February 2010 03:49:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 2145 CST on 2/19/2010, the Callaway Plant experienced a loss of switchyard bus 'A'. This resulted in a loss of off site power to 'B' train vital 4160 volt bus NB02. Technical specification LCO 3.8.1 was entered. The 'B' train emergency diesel generator started and the shutdown sequencer actuated for bus NB02. 'B' motor driven auxiliary feed water pump, 'B' centrifugal charging pump, and both 'A' and 'B' essential service water pumps started. The turbine driven auxiliary feed water pump actuated, and steam generator blowdown and sample isolation occurred. 'A' train offsite vital power and emergency diesel generator were available. The actuations that occurred were consistent with the loss of one vital AC train. All emergency systems responded as expected with the exception of steam generator blowdown valve BMHV0002 which was manually isolated when it failed to fully close. The loss of switchyard bus 'A' was due to a fault on the 'A' safeguards transformer. The faulted transformer has been isolated, and switchyard bus 'A' was reenergized at 0132 on 2/20/2010. The 'B' train vital 4160 volt bus NB02 was tied to offsite power at 0222 on 2/20/2010, and the 'B' emergency diesel generator was secured at 0233 on 2/20/2010. Technical specification LCO 3.8.1 was exited. Currently the plant is at 100% power. The licensee has notified the NRC Resident Inspector.
ENS 45747	5 March 2010 16:32:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Valve FBV0147, Boric Acid Batch Tank Auxiliary Steam Supply Isolation Valve, is credited with being closed in the Callaway FSAR. This eliminated the need to analyze lines FB-081-HBD and FB-082-HBD for high energy line breaks (HELB). However, FBV0147 was found to be kept normally open to allow steam service for the boric acid batching tank. This is contrary to the normal position assumed in the FSAR and HELB analyses. With valve FBV0147 open, the lines must considered high energy lines. The lines are in the auxiliary building and they traverse rooms containing several components including the flow transmitters for Residual Heat Removal (RHR) to train `A' accumulator injection supply header, RHR train `A' and 'B' SIS hot leg recirculation supply header, and several safety related auxiliary feedwater components. These instruments are used to provide indications during post-accident conditions. This configuration is therefore outside of current HELB analysis and potentially represents a condition that significantly degrades plant safety. The condition was identified to Operations at 0740. Valve FBV0147 was closed at 0810. At 1325 CST, the issue was determined to be reportable. The NRC Resident Inspector has been notified. * * RETRACTION AT 1557 EDT ON 5/3/10 FROM HURT TO HUFFMAN * * * On 03/05/2010, EN #45747 provided notification that valve FBV0147 was found to be kept normally open to allow steam service for the boric acid hatching tank. This configuration was not consistent with the normal position assumed in the FSAR and HELB analyses. An engineering evaluation was subsequently performed for the auxiliary steam inlet and outlet piping for the boric acid batching tank. This valuation identified four postulated break locations which have all been analyzed. The analyses determined that all safety-related components in the affected rooms would be able to perform their safety functions in the event of a line break. Pipe whip, jet impingement, compartment temperature and over pressurization, flooding, and internal missiles resulting from a postulated line break would not prevent any safety-related equipment from performing its design function. As supported by this evaluation, this condition does not meet the criteria for an unanalyzed condition that significantly degrades plant safety as stated in 10 CFR 50.72(b)(3)(ii)(B). Therefore, the notification made on 03/05/2010 is hereby retracted. The NRC Resident Inspector will be notified. R4DO (Farnholtz) notified.	Unanalyzed Condition Boric Acid
ENS 45837	13 April 2010 13:17:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On April 13, 2010 at 1200 CDT, Callaway Unit 1 declared an Unusual Event due to identified leakage of greater than 25 gallons per minute (EAL SU6.1). During the flushing of the 'A' Chemical and Volume Control System mixed bed demineralizer, a leak occurred from the vent valve exceeding 25 gallons per minute for approximately 5 minutes. The leak was isolated and the Unusual Event was terminated at 1223 CDT. No personnel contamination or outside release occurred. The licensee has notified the State and local authorities and the NRC Resident Inspector. * * UPDATE FROM WALTER GRUER TO DONG PARK AT 1614 EDT on 04/13/2010 * * * Callaway Plant declared an Unusual Event at 1200 CDT on 4/13/2010. The cause of the event was Emergency Action Level (EAL) SU6.1, identified leakage greater than 25 gallons per minute (gpm). When attempting to place the 'A' Chemical and Volume Control System (CVCS) mixed bed demineralizers in service, a drop in the Volume Control Tank (VCT) level was noted by the Reactor Operator (RO). Technical Specification (TS) 3.4.13 Condition A was entered at 1033 CDT upon identification of identified leakage of the Reactor Coolant System (RCS) greater than 10 gpm. TS 3.4.13 Condition A requires reduction of leakage to limits within 4 hours. The leakage was verified to be stopped at 1038 CDT, at which time TS 3.4.13.A was exited. The system was restored to a normal alignment. Upon review, it was determined that the VCT level dropped approximately 125 gallons in 5 minutes. EAL SU6.1 was declared at 1200 CDT and closed at 1223 CDT. The state and local counties (Callaway, Gasconade, Montgomery, and Osage) were notified of the event at 1210 CDT and of the event closeout at 1227 CDT. The NRC Resident Inspector was notified of the event. A news release will be made by Ameren Corporate Communications. Notified R4DO (Spitzberg), NRR EO (Nelson), and IRD (Marshall). * * RETRACTION ON 4/20/10 AT 1417 EDT FROM DAVID HURT TO R. ALEXANDER * * * The declaration of Unusual Event SU6.1, RCS leakage, on 4/13/10 is being retracted, because the declaration was inaccurate. The leak was an isolable intersystem leak of the CVCS, not RCS leakage, and the leak was stopped within the 15 minute time period allowed to determine EAL applicability. Therefore, the leakage did not meet the Initiating Condition for the EAL. The NRC Resident Inspectors have been notified. Notified R4DO (J. Whitten).
ENS 45989	8 June 2010 19:57:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At approximately 0430 CDT on June 8, 2010, during restoration following an addition of 10 gallons of hydrazine and a flush of 2 gallons of demineralized water to the Condensate Storage Tank (CST), a water-hydrazine mixture began to leak from check valve KHV0179. KHV0179 is a nitrogen supply check valve that can also be used for hydrazine addition. Chemistry technicians estimated that a water-hydrazine mixture on the order of 2 gallons leaked through KHV0179 before the line could be isolated. Samples taken from the atmosphere above the spill contained 0.25 ppm hydrazine. The fluid on the ground was measured to contain 15% hydrazine. The Department of Natural Resources (DNR) was notified of this event at approximately 1000 CDT on June 8, 2010. The Nuclear Regulatory Commission (NRC) Resident Inspectors will be notified.
ENS 46156	5 August 2010 15:39:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	The Technical Support Center (TSC) will be without power during performance of planned maintenance activities starting at approximately 1500 CDT on August 5, 2010. The maintenance activities, including electrical isolation and restoration, are expected to last approximately 12 hours. Contingency plans for emergency (response) situations have been established and the Emergency Response Organization members have been notified of their contingency actions. This event is reportable per 10CFR50.72(b)(3)(xiii) since this constitutes a loss of an emergency response facility for the duration of the maintenance activities. Region IV was notified of this planned outage. The licensee notified (State and local agencies and) the NRC Resident Inspector. * * UPDATE ON 8/6/10 AT 0407 FROM BONVILLIAN TO HUFFMAN * * * The Technical Support Center was restored to functional status at 0407 EDT. All systems verified operational. The licensee will notify State and local agencies and the NRC Resident Inspector. R4DO (Hagar) notified.
ENS 46581	1 February 2011 17:51:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1430 on 2-1-2011, due to worsening road conditions from heavy snowfall, a determination was made that there is a loss of plant access for some individuals and some impairment of evacuation routes. This meets the criteria for an immediate notification (8 Hour) per 10 CFR 50.72 (b)(3)(xiii). There is no impact on plant operation, all T/S (Technical Specification) required minimum staffing requirements are satisfied. The weather is predicted to be hazardous until the evening of 2/2/2011. The Missouri Department of Transportation reported they have a plow truck running from Callaway Plant to Jefferson City, MO. They also reported visibility is extremely poor due to blowing snow. The Missouri State Emergency Management Agency duty officer has been notified of the degraded Callaway ERO (Emergency Response Organization) response time and evacuation route issues. The NRC Resident Inspector was notified of this event by the licensee. Two shifts of personnel will be on site throughout this event. Diesel fuel, food, and water are above required minimums. * * UPDATE FROM DAVID BONVILLIAN TO JOHN KNOKE AT 1821 EST ON 02/02/11 * * * As of 1600 (CST) on 2/2/2011, road conditions have significantly improved. Primary evacuation routes have been reported to be passable. There is reasonable assurance of normal ERO response time. NRC Resident Inspector has been informed of the intent of this change and will be notified of this communication. Notified R4DO (Howell).
ENS 46597	7 February 2011 17:18:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On December 15, 2009, Callaway Plant reported a condition in which valve FBV0146, an isolation valve on an auxiliary steam line in the Auxiliary Building, was found to be kept normally open. With FBV0146 open, the auxiliary steam line downstream of FBV0146 must be considered a high energy line. This configuration was not consistent with the analysis of record for High Energy Line Break (HELB) events. Valve FBV0146 was closed upon discovery of the condition. This condition was reported under EN # 45571 as an unanalyzed condition that significantly degrades plant safety. EN #45571 was then retracted on January 21, 2010 when analysis showed that no safety-related components would be rendered inoperable in a postulated HELB event due to the condition. Based on this analysis, FBV0146 was reopened. Subsequent review of this condition now shows that, with FCV0146 open, a harsh environment from a postulated HELB downstream of FBV0146 could be transmitted to other areas of the Auxiliary Building. This would occur via a flow path through door gaps and an Auxiliary Building elevator shaft. This flow path had not been considered by the previous analysis. The areas that could be affected by a postulated line break contain safe shutdown equipment (such as equipment for the Component Cooling Water system) that is not assumed to experience harsh conditions. Because of the potential impact on this equipment, this condition is considered to have met the criteria for reporting under 10 CFR 50.72(b)(3)(ii)(B). FBV0146 is now closed. This review was performed as part of the ongoing evaluation of HELB Program deficiencies described in Callaway Plant License Event Report (LER) 2010-009-00. The NRC Resident Inspector has been notified. The auxiliary steam line in the Auxiliary Building feeds non-safety related components. * * UPDATE AT 1519 EDT ON 4/8/11 FROM KEITH DUNCAN TO S. SANDIN * * * The licensee is retracting this report based on the following: On 02/07/2011, EN #46597 documented that a harsh environment from a postulated High Energy Line Break (HELB) could be transmitted to areas of the Auxiliary Building not qualified for harsh environments. This break was postulated to occur on an Auxiliary Steam line downstream of valve FBV0146 when FBV0146 is open. This condition was initially reported as an unanalyzed condition that significantly degraded plant safety. When EN #46597 was reported, the analysis of the Auxiliary Steam line included postulated break locations at any intermediate fitting, welded attachment, or valve. Subsequent analysis shows that this section of Auxiliary Steam piping is able to withstand safe shutdown earthquake (SSE) loadings and rupture loadings. For piping of this qualification, line breaks are only assumed to occur at terminal ends and at the locations specified for ASME Class 2 and 3 piping. Breaks at intermediate fittings, welded attachments, and valves are not required to be assumed. Postulated breaks of this Auxiliary Steam line at the locations described above have been analyzed. This analysis demonstrates reasonable assurance that safety-related equipment would have performed their safety functions following a postulated break of this Auxiliary Steam line. Therefore, this condition is not an unanalyzed condition that significantly degrades plant safety and does not meet the reporting requirements of 10 CFR 50.72(b)(3)(ii)(B). Event notification #46597, made on 02/07/2011, is hereby retracted. The NRC Resident Inspectors have been notified. Notified R4DO (O'Keefe).	Safe Shutdown Unanalyzed Condition Safe Shutdown Earthquake
ENS 46693	24 March 2011 06:02:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	While performing an extent of condition review of high energy line break (HELB) analyses, a detailed review of the auxiliary steam system was being performed. During this review, sections of pipe that run through rooms 1206/1207 in the Auxiliary Building were identified that have design ratings indicating that they could possibly be classified as high energy lines. The pipes were verified to have not been considered in the current HELB analyses. This condition affects pressure transmitters ALPT0037, 38, & 39 which are not qualified for operation in a harsh environment. These pressure transmitters provide the Auxiliary Feedwater Pump (AFW) Suction Transfer signal on low suction pressure from the non safety Condensate Storage Tank to the Safety Related supply (Essential Service Water). Technical Specification (TS) 3.3.2-6.h bases state: "since these detectors are in an area not affected by HELBs or high radiation, they will not experience any adverse environmental conditions and the Trip Setpoint reflects only steady state instrument uncertainties." Based upon the above bases, with the identified aux steam lines in service, the pressure transmitter's operability could not be assured. This represented an unanalyzed condition and had the potential to affect equipment used for accident mitigation. TS 3.0.3 was entered at time 2354 (CST) on 3/23/2011. At 0009 (CST) on 3/24/2011, Aux Steam valves FBV0158, FBV0I48, FAV0002, and FAV0003 were isolated, removing the HELB concern (TS 3.0.3 was exited at this time). These are the active feed (isolation valves) to the lines passing through the Aux Building Rooms 1206/1207. The licensee notified the NRC Resident Inspector. * * RETRACTION AT 1525 ON 5/19/2011 FROM DAVID BONVILLIAM TO MARK ABRAMOVITZ * * * On March 23, 2011, event notification EN 46693 documented that a harsh environment from a postulated High Energy Line Break (HELB) could affect pressure transmitter ALPT0037, 38 and 39. These pressure transmitters provide the Auxiliary Feedwater Pump suction transfer signal on low suction pressure from the Condensate Storage Tank to the safety-related water supply (Essential Service Water). This break was postulated to occur on auxiliary steam lines in Auxiliary Building rooms 1206 And 1207. This condition was initially reported both as an unanalyzed condition that significantly degraded plant safety and as a condition that could have prevented fulfillment of a safety function. When EN 46693 was reported, it was assumed that breaks were required to be postulated at any intermediate fitting, welded attachment, or valve on the subject auxiliary steam lines. Subsequent analysis shows that these sections of auxiliary steam piping are able to withstand safe shutdown earthquake (SSE) loadings and rupture loadings. For piping of this qualification, breaks at all intermediate fittings, welded attachments, and valves do not need to be postulated. Instead, line breaks are only required to be assumed at the terminal ends of the lines and at the locations specified for ASME Class 2 and 3 piping. None of these postulated break locations are located inside rooms 1206 and 1207. Analysis has been performed on these auxiliary steam lines for the remaining break locations that are required to be postulated. This analysis demonstrates reasonable assurance that safety related equipment, including pressure transmitters ALPT0037, 38 and 39, would have performed their safety functions following a postulated break of these auxiliary steam lines. Therefore, this condition does not meet the reporting requirements for an unanalyzed condition that significantly degraded plant safety or a condition that could have prevented fulfillment of a safety function. Event notification 46693 is hereby retracted. The NRC Resident Inspectors have been notified. Notified the R4DO (Shannon).	Unanalyzed Condition Safe Shutdown Earthquake
ENS 46715	31 March 2011 20:50:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	In response to a condition identified in late 2010 concerning the control and removal of hazard barriers in the plant, a review of the basis and analysis for high energy line breaks (HELBs) and the barriers for protecting against such events has been underway at Callaway in accordance with the plant's corrective action program. While following up on a question from the NRC Resident Inspector, and as a result of an additional question from the Nuclear Oversight organization at Callaway, it was identified that non-safety piping located in the valve room associated with the Refueling Water Storage Tank (RWST) could potentially (make) all four RWST low water level pressure transmitters inoperable in the event of a malfunction of the non-safety piping concurrent with a design-basis loss-of-coolant accident (LOCA) and/or following a seismic event. The RWST water level transmitters (which are located in the RWST valve room) perform a safety-related function for the emergency core cooling system (ECCS) by automatically swapping suction sources for the ECCS during a LOCA from the RWST to the containment sumps when a low water level condition is reached in the RWST. These instrument channels are required to be OPERABLE in Modes 1, 2, 3 and 4 per Callaway Technical Specification 3.3.2, 'Engineered Safety Feature Actuation System (ESFAS) Instrumentation.' The subject non-safety piping delivers steam supplied by the Auxiliary Steam system to (and from) heaters surrounding the RWST for maintaining RWST contents above the minimum required temperature during winter conditions. The piping passes through the RWST valve room containing the noted RWST water level transmitters which were designed only for a mild environment. It has been identified, however, that the non-safety Auxiliary Steam piping constitutes a high energy line and that its failure could create harsh (hot and wet) conditions in the valve room to which the RWST water level instrumentation was not designed. Per the Callaway FSAR, where non-safety piping interfaces with safety-related piping or systems, the design must be such that failure of the non-safety piping does not adversely affect the safety function(s) of the interfacing safety-related piping or system (since non-safety piping may be assumed to malfunction in conjunction with a design-basis accident). In this case, and based on a conservative interpretation of the FSAR, if the non-safety piping in the RWST valve room is assumed to malfunction (i.e., break), a failure of the RWST instrumentation could occur, thereby preventing the ECCS suction swap over from occurring as required or assumed for LOCA mitigation. This condition required declaring all four RWST water level channels inoperable. In light of recognizing that the RWST water level instruments could be subject to a harsh environment when they were only designed for a mild environment, and could thus fail as a result, this condition represents an unanalyzed condition that significantly degrades plant safety. With regard to the impact on the required ECCS suction swap over function that requires the RWST water level channels to be operable, the inoperability of all four instrument channels is a condition that could have prevented the fulfillment of the safety function of structures or systems that are needed to shutdown the reactor and maintain it in a safe condition, remove residual heat, control the release of radioactive material, and mitigate the consequences of an accident. Upon declaring the RWST water level instrument channels inoperable, TS Limiting Condition for Operation (LCO) 3.0.3 was entered at time 1432 CDT on 3/31/2011. At 1634 CDT, the Auxiliary Steam system was isolated and depressurized. This removed the energy that could be released from a break in the non-safety piping, thereby restoring Operability for the RWST water level instruments. The NRC Senior Resident Inspector was notified. * * RETRACTION FROM ADAM SCHNITZ TO HOWIE CROUCH AT 1511 EDT ON 05/26/11 * * * On March 31, 2011, event notification EN 46715 documented that a harsh environment from a postulated High Energy Line Break (HELB) in the Refueling Water Storage Tank (RWST) valve room could affect RWST level transmitters. These level transmitters provide RWST water level indication in the main control room, which is identified as a safe shutdown function in the Callaway FSAR. They also provide low RWST water level signals for effecting automatic swap over of suction sources for the Emergency Core Cooling System in the event of a loss-of-coolant accident (LOCA). This break may be postulated to occur on non-safety related auxiliary steam lines that run through the RWST valve room and on to the RWST heaters. This condition was initially reported both as an unanalyzed condition that significantly degraded plant safety and as a condition that could have prevented fulfillment of a safety function. When EN 46715 was reported, it was assumed that breaks were required to be postulated at any intermediate fitting, welded attachment, or valve on the subject auxiliary steam lines. Subsequent analysis shows that the sections of auxiliary steam piping in the RWST valve room are able to withstand safe shutdown earthquake (SSE) loadings and rupture loadings. For piping of this qualification, breaks at all intermediate fittings, welded attachments, and valves do not need to be postulated. Instead, line breaks are only required to be assumed at the terminal ends of the lines and at the locations specified for ASME Class 2 and 3 piping. None of these postulated break locations are located inside the RWST valve room, and a postulated auxiliary steam line break outside of the room would not adversely affect the RWST level transmitters. Since none of the postulated break locations are located inside the RWST valve room, there exists reasonable assurance that the RWST level transmitters would have remained capable of performing their safe shutdown function following a postulated break of the subject auxiliary steam lines. Further, there is no adverse effect on the assumed response to a postulated design basis LOCA since a hazard (such as a break in an auxiliary steam line) is not assumed to occur concurrently with the LOCA. Therefore, this condition does not meet the reporting requirements for an unanalyzed condition that significantly degraded plant safety or a condition that could have prevented fulfillment of a safety function. Event notification 46715 is hereby retracted. The NRC Senior Resident Inspector has been notified. Notified R4DO (Haire).	Safe Shutdown Unanalyzed Condition Safe Shutdown Earthquake
ENS 46814	3 May 2011 17:55:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	The following is a non-emergency notification in accordance with 10CFR50.72(b)(2)(xi), Offsite Notification. At 1036, May 3, 2011, Callaway Plant notified the Missouri Department of Natural Resources (DNR) of an issue with the potable water supply system at the facility. This notification to the Missouri DNR was made in accordance with 10 CSR 60-4.055, 'Disinfection Requirements,' due to circumstances that adversely affect the quality of potable water. Specifically, loss of function of the potable water chlorine pumps resulted in residual chlorine in the potable water system falling below the levels specified by the regulation. DNR has not restricted drinking of Potable Water at Callaway Plant. Required compensatory actions have been initiated, including planned repairs of the potable water chlorination system. The NRC Resident Inspectors have been notified.
ENS 47084	21 July 2011 16:45:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On July 21, 2011 at 1100 (CDT) Callaway Plant staff determined that a design deficiency could adversely affect the 'B' Train of Essential Service Water (ESW) in the event of a Control Room fire. 'B' Train is the credited train for completion of a post-fire safe shutdown as a result of a Control Room evacuation. As a result of this deficiency, normally closed valve EFHV0060 could spuriously open during a postulated control room fire. EFHV0060 is located on the ESW return line from the 'B' Component Cooling Water (CCW) heat exchanger. If EFHV0060 spuriously opened as a result of this postulated fire, the flow balance in the 'B' Train of the ESW system would be affected. In this scenario, cooling water flow to other essential components could be reduced to below the minimum requirements. A fire watch has been imposed as a compensatory measure for this condition. Additionally, EFHV0060 has been closed and de-energized to preclude spurious opening in the event of a postulated control room fire. This condition is reported in accordance with 10 CFR 50.72 (b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. The NRC Resident Inspector has been notified.	Safe Shutdown Unanalyzed Condition Fire Watch
ENS 47275	18 September 2011 12:41:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	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). * * UPDATE FROM DAVID LANTZ TO JOHN KNOKE AT 1847 EDT ON 9/18/11 * * * 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).	Safe Shutdown
ENS 47291	25 September 2011 19:48:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1804 on Sunday, September 25, the Callaway Plant Technical Support Center (TSC) will undergo planned maintenance to replace the building's heating, ventilation, and air conditioning (HVAC) system. This maintenance is currently scheduled to last for approximately five days, at which time the TSC will be restored to service. During this period, the TSC's HVAC system will not be able to provide positive pressure to the TSC, thus rendering it non-functional. If an emergency is declared requiring TSC activation while the TSC is non-functional, TSC emergency response personnel will report to their backup locations in accordance with Callaway Plant emergency planning procedures. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii) due to the planned unavailability of an emergency response facility. The NRC Resident Inspector has been notified. * * UPDATE FROM TIM HOLLAND TO HOWIE CROUCH AT 2027 EDT ON 9/30/1 * * * At 1804 CDT on September 25, 2011, the Callaway Plant Technical Support Center (TSC) underwent planned maintenance to replace the building's heating, ventilation, and air conditioning (HVAC) system. While this maintenance was being performed, the TSC was unable to maintain positive pressure within the building, thus rendering it non-functional. This ENS update is to document that, at 1800 on September 30, 2011, the Callaway Plant TSC was returned to service following successful completion of planned maintenance on the building HVAC system. The NRC Senior Resident Inspector has been notified. Notified R4DO (Werner).
ENS 47315	3 October 2011 10:24:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 0850 (CDT) on Monday, October 03, the Callaway Plant Technical Support Center (TSC) is undergoing planned maintenance to repair MTSUB7001, Manual Transfer Switch between normal and emergency power. This maintenance is currently scheduled to last for 1 day, at which time the TSC will be restored to service. During this period, the TSC will be without either normal or emergency power, thus rendering it non-functional. If an emergency is declared requiring TSC activation while the TSC is non-functional, TSC emergency response personnel will report to their backup locations in accordance with Callaway Plant emergency planning procedures. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii) due to the planned unavailability of an emergency response facility. * * UPDATE AT 1907 EDT ON 10/03/11 FROM GERRY RAUCH TO JOE O'HARA * * * Callaway Plant Technical Support Center (TSC) normal power was restored at 1751 CDT. The TSC is functional and available as an emergency response facility. The NRC Resident Inspector has been notified. Notified R4DO (Whitten).
ENS 47426	9 November 2011 21:43:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On November 9, 2011 at 1715, Callaway Plant staff determined that a postulated design basis fire event in Fire Area C-1, (Control Building, elevation 1974, ESW Pipe Space, Room 3101) could result in failure of the High Density Polyethylene (HDPE) piping in the Essential Service Water (ESW) system. In 2008-2009 timeframe, Callaway Plant implemented a modification which replaced underground large bore carbon steel ESW piping with HDPE piping. Four short sections of this HDPE piping enter the Control Building and interface with steel piping in Room 3101. During the design of the modification, it was not recognized that a fire barrier should be installed to protect the HDPE piping from the consequences of a fire. As a result of the missing fire barrier, a postulated fire could cause a failure of one train of the large bore HDPE piping located within the fire area. The resultant pipe failure could lead to flooding in the fire area that could adversely affect both trains of ESW equipment required to achieve and maintain safe shutdown. An hourly fire watch has been imposed as a compensatory measure for this condition in accordance with the approved fire protection program. This condition is reported in accordance with 10 CFR 50.72 (b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. The NRC Resident Inspector has been notified.	Safe Shutdown Unanalyzed Condition Fire Barrier Fire Protection Program Hourly Fire Watch
ENS 47749	16 March 2012 14:29:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On March 11, 2012, a maintenance test of the Technical Support Center (TSC) diesel generator was performed. This diesel generator supplies backup A/C power to the TSC in the event of a loss of normal power. During this test, with the diesel generator supplying power to the TSC, two unexpected momentary losses of normal lighting to the TSC were observed. Following this event, the TSC diesel generator was declared non-functional. High-priority actions to troubleshoot and repair the TSC diesel generator were taken following this event. However, as of 1200 CDT on March 16, 2012, troubleshooting activities are still ongoing, and the cause of the event has not yet been identified. Normal power to the TSC has been available throughout this event, and the TSC is considered functional. However, due to the duration of the TSC diesel generator non-functionality, Callaway Plant is reporting this condition in accordance with 10 CFR 50.72(b)(3)(xiii) for a loss of emergency assessment capability. Please note that, in the event of a complete loss of power to the TSC concurrent with a plant emergency, the designated backup facilities will be used in accordance with the Callaway Plant emergency preparedness program procedures. The NRC Resident Inspector has been notified.
ENS 47783	28 March 2012 18:26:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1500 on March 28, 2012, Callaway Plant personnel discovered that the installation of a modification on the two 'B' train containment cooler units had inadvertently introduced a potential failure mechanism to the 'B' train containment coolers. Specifically, with the containment cooling fans initially in fast-speed operation, combined with certain initial plant conditions, thermal overload tripping of the coolers could occur. In such an event, during some postulated accidents, slow-speed restart of the containment coolers by the Load Shedding and Emergency Load Sequencing system could be prevented. As a result, the 'B' train containment coolers could be rendered unavailable for a portion of a postulated accident. Thus, the safety function of the 'B' train containment cooling fans cannot be assured when this degraded equipment condition is present and the containment cooling fans are run in fast-speed operation. This condition existed for the 'B' train containment cooling units since they were restored to service from maintenance at 0400 on March 15, 2012. Upon identification of this condition, the 'B' train containment cooling fans were switched from fast-speed to slow-speed operation and restored to operable status at 1515. This action precludes this degraded equipment condition from adversely affecting containment cooling fan function during an accident. Concurrent with this condition, the opposite train of containment coolers was removed from service for scheduled maintenance at 0505 on March 27, 2012. As a result, from 0505 on March 27, 2012 until 1515 on March 28, 2012, the safety function of the containment cooling system could not be assured for certain postulated accident conditions. The NRC Resident Inspector has been notified.
ENS 47885	1 May 2012 22:01:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1300 on May 1, 2012, as a result of fire water flushing operations, it was observed that the floor drains in the 'A' and 'B' ESF (Engineered Safety Features) 4160 VAC switchgear rooms were draining extremely slow. Engineering was consulted and it was identified that the floor drains in these rooms are credited with preventing any water accumulation in these rooms as a result of internal flooding due to a pipe break. It is expected that the floor drains in the 'A' ESF switchgear room can drain approximately 134 gallons per minute (gpm) and the floor drains in the 'B' ESF switchgear room can drain approximately 208 gpm. With the floor drains partially blocked, a break in the 'A' Essential Service Water pipe in the 'B' ESF Switchgear Room would result in flood levels in the 'B' ESF Switchgear Room to exceed the maximum levels calculated in the current flooding analysis. The higher flood level may result in the inoperability of 'B' train Electrical Switchgear. The 'A' train Essential Service Water supplied equipment would be adversely affected due to the reduced flow. Consequently the pipe break would result in both ESF trains being adversely affected. Compensatory measures have been taken to restore system operability. The NRC Resident Inspector has been notified. * * RETRACTION FROM KEITH DUNCAN TO JOHN KNOKE AT 1534 ON 05/31/12 * * * On May 1, 2012, Callaway Plant made an ENS notification in accordance with 10 CFR 50.72(b)(3)(ii)(B) to report the discovery of partially blocked floor drains in the safety-related 4160 V switchgear rooms. At the time of the initial notification, preliminary information indicated that the partially blocked floor drains could have caused a postulated flooding event to adversely affect independent trains of safety-related equipment inside these rooms. Upon further analysis, Callaway Plant staff determined that the pipe break assumed in the flooding calculation of these rooms was overly conservative. Specifically, based on seismic qualifications, the guillotine break of Essential Service Water piping that was originally assumed is not required to be postulated. Instead, a much smaller, through-wall crack of fire protection system piping is the most severe break that must be postulated in the safety-related 4160 V switchgear rooms. An analysis of a postulated flood hazard in these rooms was performed based on the correct water source. Even if considering a complete blockage of the floor drains in these rooms, this analysis demonstrates that a postulated fire protection system piping crack would not have adversely affected safety-related equipment. Based on the results of this analysis, the partially-blocked floor drain condition described in EN 47885 did not meet the criteria for reportability as an unanalyzed condition that significantly degrades plant safety. Event Notification 47885 is hereby retracted. The licensee has notified the NRC Resident Inspector. Notified the R4DO (Greg Pick)	Unanalyzed Condition Internal Flooding
ENS 47930	17 May 2012 12:11:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 0438 (CDT) on Thursday, May 17, the Callaway Plant Emergency Operations Facility (EOF) was declared non-functional when the building's return fan was found not running. Loss of the EOF return fan, results in an inability to maintain a positive pressure on the facility. Efforts are underway to return this fan to service. If an emergency is declared requiring EOF activation while the EOF is non-functional, EOF emergency response personnel will report to their backup locations in accordance with Callaway Plant emergency planning procedures. 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 Resident Inspector has been notified. * * UPDATE FROM BRANDON LONG TO JOHN SHOEMAKER ON 05/17/12 AT 1704 EDT * * * At 1330 (CDT) on 05/17/12, the Callaway Plant EOF was been returned to service. The licensee will notify the NRC Resident Inspector. Notified R4DO (Powers).
ENS 48112	17 July 2012 15:18:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1140 (EDT) on Tuesday, July 17, the Callaway Plant Technical Support Center (TSC) was declared non-functional due to a degraded charcoal filter in the building's filter absorber unit. At 1140 (EDT) on July 17, 2012, Callaway was notified of the test results for a charcoal test sample that was taken on July 5, 2012. The results did not meet surveillance procedure acceptance criteria. Efforts are underway to replace the charcoal in the unit. If an emergency were to be declared requiring activation of the TSC while it is non-functional, TSC emergency response personnel would report to their backup locations in accordance with Callaway Plant emergency planning procedures. This notification is being made in accordance with 10 CPR 50.72(b)(3)(xiii) due to the unavailability of an emergency response facility. The NRC Resident Inspector has been notified." The licensee indicated the TSC will be functional within 24 hours. * * UPDATE AT 1012 EDT ON 07/18/12 FROM TIM HOLLAND TO JOHN KNOKE * * * The TSC was restored to functional status at 2200 (CDT) on July 17, 2012. The licensee informed the NRC Resident Inspector. Notified R4DO (Walker).
ENS 48236	27 August 2012 18:36:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Notification was made to Missouri Department of Natural Resources and the EPA National Spill Response Center of a Neutralization Tank discharge piping leak on 8/27/12 at 1526 hrs. (CDT). Subsequent testing of the leaking fluid at 1430 hrs. revealed the pH of the leaking fluid was 13, which is a characteristic hazard waste. Reportable quantity is 100 lbs. The estimated total volume released was less than 100 gallons, but greater than 100 lbs. This spill was reported to offsite organizations. Therefore, this event is reportable to the NRC per 10CFR50.72(b)(2)(xi). Mitigating strategy is to neutralize the contents of the tank, and the leaking fluid is being absorbed by absorbent materials. The licensee has notified the NRC Resident Inspector.
ENS 48245	28 August 2012 18:51:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1500 CDT on Tuesday, August 28, the Callaway Plant Technical Support Center (TSC) was declared non-functional due to ventilation recirculation flow rate outside of normal limits. Efforts are underway to restore TSC ventilation recirculation flow rate to normal. If TSC activation is necessary during the period of TSC non-functionality, the Emergency Coordinator 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 Resident Inspector has been notified
ENS 48268	2 September 2012 14:45:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	In response to identification of a non-radiological leak from the Neutralization Tank at Callaway Plant today (9/2/2012), notification was made to the EPA National Spill Response Center at 1031 CDT and to the Missouri Department of Natural Resources at 1043 CDT. The leak was initially identified at 0926 CDT. From testing of a sample taken from the tank, the pH of the tank fluid was reported to be 1.9. Initially, the leak was to the ground and into a ditch that is part of a flow path that ultimately leads off site via a storm sewer. However, there is no indication of any of the leakage flowing beyond the site boundary via that pathway since action was promptly taken to divert the leakage to the sump area of the equalization tank (on site). The leakage will thus be collected there until it terminates. At 0926 CDT, the leakage rate was estimated to be approximately 20 gpm; at 1025 CDT the leakage was estimated to be approximately 50 gpm. The leak is at the bottom of the Neutralization Tank, and thus will terminate when the tank is emptied. At 1218 CDT, the fluid level in the Neutralization Tank was at 17%. The initial quantity of fluid in the tank (at the onset of the leak) was approximately 110000 gallons. This spill was reported to offsite organizations, as noted. This event is reportable to the NRC pursuant to 10CFR50.72(b)(2)(xi). The NRC Senior Resident Inspector has been notified of the event and this ENS notification. 17% tank fluid level corresponds to approximately 25000 gallons.
ENS 48442	25 October 2012 10:22:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On October 25, 2012, Callaway Plant will begin implementation of a modification to the plant computer system. The Emergency Response Data System (ERDS) and plant computer stations in the Technical Support Center (TSC) and Emergency Operations Facility (EOF) will be unavailable during the modification. Plant computer stations will remain available in the Control Room. The period of unavailability is anticipated to be approximately 12 hours on October 25, 2012, with an additional 8 hours for system testing on October 26, 2012. During the modification process, the TSC and EOF will remain functional and available for use. Plant procedures provide guidance for manual data collection and sending ERDS data to the NRC. This notification is being made in accordance with 10 CFR 50.72(b)(3)(xiii). The NRC Resident Inspector has been notified. * * * UPDATE FROM SHANNON GAYDOS TO PETE SNYDER AT 2123 ON 10/25/12 * * * Based on the current work progress on the plant computer system, the Emergency Response Data System (ERDS) and the plant computer stations in the Technical Support Center (TSC) and Emergency Operations Facility (EOF) will not be available until early evening on October 26, 2012. The NRC Resident Inspector will be notified. Notified R4DO (Hagar). * * * UPDATE FROM DAVID LANTZ TO DONG PARK AT 2033 EDT ON 10/26/12 * * * Modification has been completed on the plant computer system. The Emergency Response Data System (ERDS) and the plant computer stations in the Technical Support Center (TSC) and Emergency Operations Facility (EOF) have been restored to normal operation. The NRC Resident Inspector will be notified. Notified R4DO (Hagar).
ENS 48879	2 April 2013 20:30:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At 1707 CDT on 4/2/13 an arc flash occurred at the 'B' safeguards transformer (XMDV24) in the plant switchyard at Callaway. At the time of the flash, ground straps were being placed on the 'B' safeguards transformer which had been removed from service for maintenance. The event resulted in a loss of power to areas/buildings outside the power block. There was no impact to equipment and systems in the plant. Four workers were injured or affected by the flash. The extent of the electrical-related injuries has not been determined. However, based on reports from the scene, all of the workers were conscious and walked away from the scene. One person was transported by helicopter and two by ambulance to a local hospital. The fourth person experienced only a minor injury. The hazard has been isolated and investigation of the cause is in progress. Notifications of this event are planned to be made to OSHA and the Missouri Public Service Commission. The licensee notified the NRC Resident Inspector. * * UPDATE FROM ROB STOUGH TO VINCE KLCO AT 1955 EDT ON 4/4/2013 * * * Ameren Missouri issued a press release about the event described above at approximately 1507 CDT on April 4, 2013. The NRC Resident Inspector was notified. Notified the R4DO (Kellar).	Arc flash
ENS 49014	9 May 2013 07:18:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	During Callaway refueling outage 19 on 5/8/13 at approximately 1900 hour CDT, water was observed dripping from piping insulation in the overhead by RCS loop 4. Further investigation determined it was near Safety Injection (EP) vent valve EPV0109. A scaffold was built and insulation was removed to perform an inspection. At approximately 0509 hours CDT on 5/9/13, engineering inspected the piping and determined there was a crack in the socket weld where 3/4 inch vent valve EPV0109 is connected to the 'B' train injection piping to RCS loop 4 Cold Leg. The estimated leakage rate through the crack is 6 (six) drops per minute. The configuration of this vent valve is a 3/8 inch flow restrictor socket welded to the six inch piping and a 3/4 inch vent valve socket welded to the flow restrictor. The crack is in the socket weld between the ASME code class 1 flow restrictor socket and the ASME code class 2 vent piping. Callaway plant was in mode 6 with refueling pool level greater than 23 feet above the reactor vessel flange at the time of the discovery. The 'A' RHR train which discharges to RCS loops 1 and 3 Cold Legs is the currently operable RHR train. 'B' RHR train was declared inoperable when the weld crack was identified. Only one RHR train is required to be operable at the present plant Mode of applicability. Repair plans are being developed. Basis for Reportability: This condition constitutes abnormal degradation of a principle safety barrier due to unacceptable welding defects within the primary coolant system. There is a check valve between this leak and the reactor coolant system. Therefore, this is considered unisolable and pressure boundary leakage. The licensee notified the NRC Resident Inspector.	Pressure Boundary Leakage
ENS 49103	10 June 2013 17:06:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	This 60-day telephone notification is being made per the reporting requirements specified in 10CFR50.73(a)(2)(iv)(A) and 10CFR50.73(a)(1) to describe an invalid actuation signal affecting the emergency feedwater system. While the plant was in Mode 5 on 4/11/2013, during performance of a maintenance procedure for AMSAC system logic verification, an invalid MDAFAS occurred. (Note: AMSAC is ATWAS Mitigation System Actuation Circuitry and MDAFAS is Motor Driven Auxiliary Feedwater Actuation Signal). Both trains of the Motor Driven Auxiliary Feedwater Pumps (MDAFPs) started. While generation of the actuation signal is an expected result of the procedure, the actuation occurred several steps earlier in the procedure than expected. Additionally, the Control Room Operators were not expecting the MDAFPs to start. The pumps were manually stopped. The actuation was caused by procedural guidance not containing a sufficiently prescribed sequence of activities that should occur when simulating plant conditions leading to the intended actuation of the AMSAC system. The plant was not in a condition where feedwater was required. The Senior NRC Resident Inspector was notified.
ENS 49141	22 June 2013 13:04:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	This 60-day telephone notification is being made per the reporting requirements specified in 10CFR50.73(a)(2)(iv)(A) and 10CFR50.73(a)(1) to report an event involving an invalid actuation signal affecting the Auxiliary Feedwater (AFW) and Essential Service Water (ESW) systems. Initial conditions on 04/24/2013: refueling outage was in progress, there was no fuel in the reactor vessel (No MODE), a B safety-related train outage was in progress, and the A ESW train was in operation to support cooling of the A train safety-related equipment. Some separation group 2 bistables were in a tripped condition because instrument power bus NN02 was de-energized. At approximately 0400 (CDT) on 04/24/2013, Separation Group 4 DC bus NK04 experienced a ground condition. Plant personnel were using a plant procedure to search for the ground. When breaker NK5409 was opened, some unexpected Engineered Safety Features Actuation System (ESFAS) signals occurred. Opening the breaker removed power to the B ESFAS cabinet. With power removed to the B ESFAS cabinet, the circuit cards that generate cross-train trips failed to a tripped condition (thus generating cross-train trip signals) which resulted in some A train ESFAS actuations, in particular, auxiliary feedwater actuations for the A motor-driven and the turbine-driven AFW pumps. Additionally, an AFW Low Suction Pressure (LSP) circuit card tripped, and when combined with the bi-stable that was in a tripped state because bus NN02 was de-energized, the 2-out-of-3 logic was made up, resulting in an auxiliary feedwater LSP actuation. The LSP actuation resulted in the A Train ESW pump receiving a start signal, and the A motor-driven and the turbine-driven AFW pump suction supply valves receiving an actuation signal to transfer the suction supply from the normal source to the ESW system. Neither the motor-driven nor the turbine-driven auxiliary feedwater pumps started because they had been properly removed from service earlier in the outage. The A ESW pump was already running. No water was transferred from the ESW system to the AFW system since system tagging had been previously placed to isolate the two systems. The actuations were considered invalid because they were caused by opening breaker NK5409 which resulted in loss of power to the B ESFAS cabinet. The Senior Resident Inspector was notified.
ENS 49219	27 July 2013 01:14:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	On July 26, 2013, at 2349 CDT, the Callaway nuclear power plant declared an Unusual Event due to a fire not extinguished within 15 minutes of control room notification, EAL HU 2.1. The fire was located in the turbine building near the main generator. Concurrent with the fire, the reactor tripped due to a turbine trip. All control rods fully inserted and all reactor coolant pumps (RCPs) tripped. The fire has been extinguished and the licensee is in progress of restoring RCPs. The licensee notified the NRC Resident Inspector, State Emergency Management Agency and Local Authorities. Notified DHS SWO, FEMA, and DHS NICC. * * UPDATE ON 7/27/13 AT 0201 EDT FROM MARK COVEY TO BILL HUFFMAN * * * The licensee terminated the Unusual Event at 0101 CDT. Decay heat is being removed via aux feed water from the steam generators to the condenser. Visual inspection determined the location of the fire to be in the phase B generator bus duct. Notified R4DO (Allen), NRR EO (Monninger), IRD (Marshall), DHS SWO, FEMA, and DHS NICC. * * UPDATE ON 7/27/13 AT 0430 EDT FROM MARK COVEY TO DONG PARK * * * The licensee made notifications under 10CFR50.72(b)(2)(iv)(B) (RPS Actuation), 10CFR50.72(b)(2)(xi) (Offsite Notification) and 10CFR50.72(b)(3)(iv)(A) (ESF Actuation - AFW). The licensee will be making a press release and notifying the NRC Resident Inspector. Notified R4DO (Allen). * * UPDATE ON 7/27/13 AT 0826 EDT FROM MARK COVEY TO BILL HUFFMAN * * * Upon further review, the licensee believes that the initially reported EAL for the UE notification, HU 2.1, was not applicable. Although indications of a fire were present for greater than 15 minutes, the criteria at Callaway apply to a fire within 50 feet of safety related equipment. There was no safety related equipment within 50 feet of where the fire occurred. The proper EAL classification should have been HU 3.1 due to release of potentially toxic gas or asphyxiant or flammable gas that could impact plant operation. This EAL is applicable due to the heavy smoke release from burning electrical insulation and melted bus and ductwork which prevented access to the turbine building area where the fire took place. The licensee will notify the NRC Resident Inspector of this update. Notified R4DO (Allen).
ENS 49398	1 October 2013 01:05:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	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. * * UPDATE FROM RICHARD HUGHEY TO JOHN SHOEMAKER AT 0248 EDT ON 10/02/13 * * * 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 49422	9 October 2013 18:23:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	A review of industry operating experience regarding the impact of unfused Direct Current (DC) ammeter circuits in the control room has determined that the condition described below to be applicable to Callaway Nuclear Plant resulting in an unanalyzed condition with respect to 10 CFR 50 Appendix R analysis requirements. The original plant wiring design and associated analysis for the Class 1E Train B batteries and chargers (including the B Swing charger) 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 would 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 being reported in accordance with 10 CFR 50.72(b)(3)(ii)(B) as an unanalyzed condition that significantly degrades plant safety. Compensatory measures (fire watches) have been implemented for affected areas of the plant. The NRC Resident Inspector has been notified. Similar Events: EN #49411 and EN #49419	Hot Short Safe Shutdown Unanalyzed Condition
ENS 49857	26 February 2014 18:18:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Contrary to the requirements in 10 CFR 26.137(b), a DHHS (Department of Health and Human Services) certified laboratory returned results for a blind specimen that were inconsistent with what was expected. On 02/25/2014, dilute blind specimens from the same lot # were sent to the three contracted DHHS laboratories. Upon review by the Callaway MRO (Medical Review Officer) at approximately 07:30 (CST) on 2/26/2014, it was discovered that one of the laboratories (Toxicology) reported results of negative. That result was inconsistent with the certification received from the blind provider (ProTox) certifying the specimen as negative and dilute. Later in the day on 2/26/14, the remaining two labs (Quest and CRL) also returned results of negative instead of negative and dilute. 10 CFR 26.719(c)(3), reporting requirements requires that 'If a false negative error occurs on a quality assurance check of validity screening tests, as required in � 26.137(b), the licensee or other entity shall notify the NRC within 24 hours after discovery of the error.' While it initially appears that the blind specimen certification provided by ProTox may be in error, since all three DHHS labs obtained the same testing result, additional investigation is necessary. This report is being made conservatively until the cause can be determined. The licensee informed the NRC Resident Inspector.
ENS 50056	24 April 2014 14:08:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Contrary to the requirements in 10 CFR 26.137(b), a Department of Health and Human Services (DHHS) certified laboratory returned results for a blind specimen that was inconsistent with what was expected. On 04/22/2014, blind specimens from the same lot number were sent to the two contracted DHHS laboratories. On 04/23/2014, one of the labs reported unexpected results while the other laboratory reported the expected results. At approximately 1530 (CDT) on 04/23/2014, the lab report was reviewed by Fitness For Duty Management at Callaway Plant and the inaccurate result was identified. On 04/24/2014, the Medical Review Officer (MRO) contacted Clinical Reference Laboratory (CRL) to discuss the testing discrepancy and directed the lab to retest the specimen. The MRO requested that CRL initiate an investigation to determine the reason for the inaccurate result and provide a report of the results of that investigation within 20 days. 10 CFR 26.719(c)(3), 'Reporting Requirements,' requires that 'if a false negative error occurs on a quality assurance check of validity screening tests, as required in � 26.137(b), the licensee or other entity shall notify the NRC within 24 hours after discovery of the error.' The licensee has notified the NRC Resident Inspector.	Fitness for Duty
ENS 50333	31 July 2014 19:02:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Voluntary notification per the NEI Groundwater Protection Initiative. On July 31, 2014, Callaway Plant received results of a sample from a new ground water monitoring well. The sample was taken on July 25, 2014. The sample results indicated a tritium concentration of approximately 1.6 E6 picocuries/liter and a Co-60 concentration of approximately 12 picocuries/liter. The new monitoring well is located within the plant's property and is adjacent to a manhole where the plant's discharge piping joins with the cooling tower blowdown piping. Both the plant discharge piping and the cooling tower discharge piping are buried. Releases from the plant discharge line have been suspended. A backup sample taken on July 25, 2014, will be sent to a lab for analysis. Another sample will be taken on August 1, 2014. There is no effect on drinking water, and therefore, no dose to the general public or plant staff. The licensee will notify the Missouri State Department of Natural Resources and Callaway County officials. The licensee will notify the NRC Resident Inspector.
ENS 50465	17 September 2014 13:59:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	At approximately 0913 CDT, the Callaway Plant Control Room was notified that an oil tanker truck overturned on plant property. The location of the incident was inside the owner controlled area but outside of the protected area. The truck was making a delivery to the plant. The Callaway County Emergency Operation Center was contacted at approximately 0930 to request an ambulance for the driver. The driver of the truck was transported offsite for medical treatment. The drivers injuries are not life threatening. The incident has resulted in a slow leak of diesel fuel that is being contained onsite. Missouri Department of Natural Resources was notified of the spill. The Missouri Highway Patrol is onsite assisting with the incident and restoration efforts. Both NRC Resident Inspectors were notified.
ENS 50474	19 September 2014 16:35:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	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.	Hot Short Safe Shutdown Unanalyzed Condition
ENS 50625	19 November 2014 03:39:00	Callaway	NRC Region 4	Westinghouse PWR 4-Loop	Following shift turnover from days to nights on 11/18/2014, it was discovered that all (4) of the Safety Injection (SI) Accumulator Outlet Isolation Valve breakers were unlocked and closed. At the time of discovery, 3 of the safety injection accumulator valves were open and 1 was closed for testing. At that time the plant was in MODE 3 at normal operating pressure and temperature. The plant had been performing RCS pressure isolation valve testing prior to shift turnover. The condition was discovered during testing of valves associated with the 'C' safety injection accumulator. After discovery of the condition, Operations directed that the 'A', 'B', and 'D' SI Accumulator Outlet Isolation Valve breakers be opened and locked. This action was completed by approximately 1930 (CST) on 11/18/2014. The NRC Resident Inspector was notified. The plant entered T.S. 3.0.3 for approximately 30 minutes while restoring the 'A', 'B' and 'D' accumulators to operable (breakers opened and locked with their associated outlet valves open).	Unanalyzed Condition Time of Discovery

Semantic search

Query log

Navigation menu