SBK-L-13158, First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation
| ML13247A177 | |
| Person / Time | |
|---|---|
| Site: | Seabrook  |
| Issue date: | 08/28/2013 |
| From: | Vehec T NextEra Energy Seabrook |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| EA-12-051, SBK-L-13158 | |
| Download: ML13247A177 (26) | |
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NEXTera ENERGY August 28, 2013 SBK-L-13158 Docket No. 50-443 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Seabrook Station NextEra Energy Seabrook, LLC's First Six-Month Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA- 12-051)
References:
- 1. NRC Order Number EA- 12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, dated March 12, 2012
- 2. NRC Interim Staff Guidance JLD-ISG-2012-01, Compliance with Order EA- 12-051, Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, Revision 0, dated August 29, 2012
- 3. NEI 12-02, Industry Guidance for Compliance with NRC Order EA- 12-05 1, "To Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," Revision 1, dated August 2012
- 4. NextEra Energy Seabrook, LLC Initial Status Report in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, (Order Number EA- 12-051), dated October 26, 2012
- 5. NextEra Energy Seabrook, LLC Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation, (Order Number EA- 12-051), dated February 26, 2013
- 6. NRC E-mail, John Lamb to NextEra Energy Seabrook, Mike Ossing, Draft RAI Regarding the Seabrook Overall Integrated Plan for Reliable SFP Instrumentation, dated July 18, 2013 (ML13217A166)
On March 12, 2012, the Nuclear Regulatory Commission (NRC) issued an order (Reference 1) to NextEra Energy Seabrook, LLC (NextEra Energy Seabrook). Reference 1 was immediately effective and directs NextEra Energy Seabrook to install reliable spent fuel pool level instrumentation. Specific requirements are outlined in Attachment 2 of Reference 1. 06
U.S. Nuclear Regulatory Commission SBK-L-13158/Page 2 Reference 1 required submission of an initial status report 60 days following issuance of the final interim staff guidance (Reference 2) and an overall integrated plan pursuant to Section IV, Condition C. Reference 2 endorses industry guidance document NEI 12-02, Revision 1 (Reference 3) with clarifications and exceptions identified in Reference 2. Reference 4 provided the NextEra Energy Seabrook initial status report regarding mitigation strategies. Reference 5 provided the NextEra Energy Seabrook overall integrated plan. In Reference 6, the NRC requested additional information to enable the continued technical review of the NextEra Energy Seabrook, LLC (NextEra) Overall Integrated Plan (OIP).
Reference I requires submission of a status report at six-month intervals following submittal of the overall integrated plan. Reference 3 provides direction regarding the content of the status reports. The purpose of this letter is to provide the first six-month status report pursuant to Section IV, Condition C.2, of Reference 1, that delineates progress made in implementing the requirements of Reference 1. The attached report provides an update of milestone accomplishments since the last status report, including any changes to the compliance method, schedule, or need for relief and the basis, if any. It also provides responses to the Reference 6 request for additional information.
This letter contains no new regulatory commitments. If you have any questions regarding this report, please contact Mr. Michael Ossing, Licensing Manager, at (603) 773-7512.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on 9/Z8 ,2013.
SincerŽl/
ThomaTVehec Plant General Manager NextEra Energy Seabrook, LLC cc: NRC Region I Administrator J.G. Lamb, NRC Project Manager, Project Directorate 1-2 NRC Senior Resident Inspector Director, Office of Nuclear Reactor Regulation Ms. Jessica A. Kratchmann, NRR/JLD/PMB, NRC Mr. Eric E. Bowman, NRR/DPRIPGCB
U.S. Nuclear Regulatory Commission SBK-L-13158/Page 3 Director Homeland Security and Emergency Management New Hampshire Department of Safety Division of Homeland Security and Emergency Management Bureau of Emergency Management 33 Hazen Drive Concord, NH 03305 Mr. John Giarrusso, Jr., Nuclear Preparedness Manager The Commonwealth of Massachusetts Emergency Management Agency 400 Worcester Road Framingham, MA 01702-5399
ATTACHMENT Enclosure 1 NEXTERA ENERGY SEABROOK, LLC SEABROOK NUCLEAR PLANT FIRST SIX MONTH STATUS REPORT FOR THE IMPLEMENTATION OF ORDER EA-12-051, ORDER MODIFYING LICENSES WITH REGARD TO RELIABLE SPENT FUEL POOL INSTRUMENTATION I
1.0 INTRODUCTION
By letter dated February 26, 2013 (Agency wide Documents Access and Management System (ADAMS) Accession No. ML13063A439), NextEra Energy Seabrook, LLC (NextEra, the licensee) submitted an Overall Integrated Plan (OIP) for the Seabrook Nuclear Plant in response to the March 12, 2012, U.S. Nuclear Regulatory Commission (NRC) Order modifying licenses with regard to requirements for Reliable Spent Fuel Pool (SFP) Instrumentation (Order Number EA- 12-05 1; ADAMS Accession No. ML12056A044). This attachment provides an update of milestone accomplishments since submittal of the Overall Integrated Plan, including any changes to the compliance method, schedule or need for relief/relaxation and the basis.
2.0 MILESTONE ACCOMPLISHMENTS
" Commence Engineering and Design - This milestone is in progress. Seabrook has selected SFP level instrumentation that will be used to meet the criteria delineated in the Overall Integrated Plan.
" Submit First 6 month update - Complete 3.0 MILESTONE SCHEDULE STA TUS There currently are no changes to the Milestone Schedule provided in the Overall Integrated Plan (Reference 2). Any changes to the following target dates will be reflected in the six month updates:
The current milestones are:
" Submit Second 6 Month Update IQ 2014 (February)
- Submit Third 6 Month Update 3Q 2014 (August)
- Complete Engineering and Design 4Q 2014 (December)
- Submit Fourth 6 Month Update IQ 2015 (February)
- Complete Procurement of SFP Instruments IQ 2015 (March)
- Complete Installation/ Instruments Operational 3Q 2015 (August)
" Submit Fifth 6 Month Update 3Q 2015 (August)
- Second Refueling Outage 3Q 2015 (October)
- Training Complete 3Q 2015 (October)
Required implementation date: 3Q 2015 (Refueling Outage 17) 4.0 CHANGES TO COMPLIANCE METHOD There currently are no changes to the compliance method documented in the Overall Integrated Plan (Reference 2). Consistent with the requirements of Order EA- 12-051 and the Order guidance documents, the six month reports will delineate any proposed changes to compliance methods.
5.0 NEED FOR RELIEF!RELAXATION AND BASIS Seabrook is not requesting relief from the requirements of Order EA-12-051 or guidance document JLD-ISG-2012-03 (Reference 4) at this time.
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6.0 REQUESTS FOR ADDITIONAL INFORMATION The NRC staff determined that additional information was required to enable the continued technical review of the NextEra Energy Seabrook, LLC (NextEra) Overall Integrated Plan (OIP).
Table 1 provides a summary of the status of responses to the Request for Additional Information (RAIs) that was received from the NRC staff on July 18, 2013 (Reference 1). The response to the open RAIs in the table requires design information that is not available at this time. As details are developed responses to these RAIs will be provided to the NRC as part of future six month updates.
Table 1 Open RAIs Status RAI-3 a, b, c - Mounting In progress RAI-4 a, b, c - Qualification In progress RAI-7 a, b - Accuracy In progress RAI-8 a, b, c, d - Testing In progress RAI-10 a, b - Program Features In progress RAI-11. a, b, c - Testing and Calibration In progress RAI-]: Levels of RequiredMonitoring The OIP states, in part, that; Level I is the level adequate to supportoperation of the normalfuel pool cooling system - Based on preliminarycalculation,the low level limitfor reliableSFP coolingsystem operation correspondsto an elevation of approximately22ft., 6 in. This level is based on a preliminary calculationthat assumes mitigatingeffects by the installedsuction straineron vortexing. The actualeffect of the straineron this level will be determinedduringthe engineeringand design phase of the project.
Forthe purposes of this submittal the minimum level that will be adequate to support normal fuel pool cooling system operation,as indicatedon either the primary or backup instrument channel,is assumedto correspondto a plant elevation of 22ft., 6 in.
Level 2 is adequate to provide substantialradiationshieldingfora person standing on the spent fuel pool operatingdeck - Indicatedlevel on either the primaryor backup instrument channelof greaterthan an elevation of 10ft., 9.5 in will provide substantialradiationshieldingfora personstanding on the SFP operatingdeck. This elevation is approximately 13 feet above the top of the spentfuel positionedin the pool (NominalElev. (-)I ft.. 5-3/4 in.). With 13feet of water above the highestfuel elementposition, the calculateddose rate at the surface of the SFP is less than 2.5 mrem/hr (Reference 10, Section 12.3.2.1. c). This monitoringlevel ensures there is adequate water level to provide substantialradiationshieldingfor personnelto respondto Beyond-Design-BasisExternal Events includingthe initiationof SFP makeup strategies that would require access to the Fuel StorageBuilding (FSB).
Level 3 is wherefuel remainscovered - Indicatedlevel on either the primary or backup instrument channelof greaterthan Elevation (-)1 foot. This is the nominal water level 3
approximately 6 in. above the top ofthe fuel racks. This monitoring level will assure the maximum range of level information is available to the plant Operatorsand emergency responsepersonnel.
This level is also assumedto be the minimum level that assures that adequate water level remains above the top of the storedfuel seated in the SFP (nominal elevation of (-)2ft., 2.5 in.).
Pleaseprovide the following:
a) For level 1, specify how the identified elevation represents the HIGHER of the two points describedin the NEI 12-02 guidancefor this level.
b) A clearly labeledsketch depicting the elevation view of the proposedtypical mounting arrangementfor the portionsof instrumentchannelconsistingofpermanent measurementchannel equipment (e.g., fixed level sensors and/orstilling wells, and mounting brackets). Indicate on this sketch the datum values representingLevel 1, Level 2, and Level 3 as well as the top of the fuel racks.
Indicate on this sketch the portion of the level sensor measurementrange that is sensitive to measurementof thefuel pool level, with respect to the Level 1, Level 2, and Level 3 datum points.
NextEra Response RAI-I.a For Level 1, the two points described in the NEI 12-02 guidance are; the level at which reliable suction loss occurs due to uncovering of the coolant inlet pipe, weir or vacuum breaker (depending on the design), or the level at which the water height, assuming saturated conditions, above the centerline of the cooling pump suction provides the required net positive suction head specified by the pump manufacturer or engineering analysis.
To determine the higher of the two levels the following was taken into consideration:
(1) The level at which reliable suction loss occurs due to uncovering the coolant inlet pipe or any weirs or vacuum breakers associated with suction loss. This level was established based on nominal suction strainer inlet elevation and conservative estimate for the onset of vortexing.
The actual effect of the strainer on this level has been formally determined by calculation C-S-1-24606, "Spent Fuel Pool Level for Reliable Pump Suction," (Reference 7). The elevation for reliable pump suction is plant elevation 23 ft., 4 inches.
(2) The level at which the normal spent fuel pool cooling pumps lose required NPSH assuming saturated conditions in the pool. Reference 7 demonstrates that the point of zero NPSH margin is 22 ft., 4 inches of plant elevation. With the spent fuel pool at 212 degrees F, saturated conditions, the NPSHA is approximately 11.2 ft. The NPSHR for the pump is 10 ft.
at 212 degrees F. This results in a ratio of NPSHA/NPSHR value of approximately 1.12.
Therefore, the NPSHA is greater than the NPSHR at saturated conditions.
The higher of the above points is the level where the inlet strainer will lose suction (Item (1) above).
Therefore, Level 1 has been revised to elevation 23 ft., 4 inches for both the primary and backup instrumentation.
The SFP level instrument upper range will be at least 12 inches above Level I to account for upper instrument sensitivity band and instrument loop uncertainty. From a practical perspective, the upper range capability will extend even higher (e.g. above normal operating level).
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Level 3 has also been revised to provide margin for instrument sensitivity band and uncertainty. For the purposes of this submittal an indicated level on either the primary or backup instrument channel of greater than plant elevation (-) 0 ft., 6 in will be assumed to assure that the fuel remains covered. The actual effect of the instrument sensitivity band and accuracy on this level will be determined during the engineering and design phase of the project.
NextEra Response RAI-1.b Enclosure 2 contains an elevation view of the proposed arrangement for the portions of the instrument channel consisting of permanent measurement channel equipment. In addition, the datum values for the Levels 1, 2 and 3 are depicted as well as the assumed sensitivity and accuracy of the equipment.
RAI-2: INSTRUMENTA TIONDESIGNFEA TURES Arrangement The OIP states, in part,that; The Spent Fuel PoolLevel (SFP)Instrumentationfor each channel will consist of a level sensing probe suspended in the SFP, a signal conditioningprocessormodule, level indicatorand a backup battery system. Redundant Train A and Train B cables will be routedfrom the Fuel Storage Building (FSB) through the Containment Enclosure Ventilation Area (CEVA) and into the PrimaryAuxiliary Building (PAB) to connect eachprobe to a signal conditioningprocessormodule. The signalprocessor module is a panel-mounted instrumentthat has a display screen showing a numericalreadout of SFP level as a continuous indication (i.e., remote Indication). The signal conditioningprocessormodule for each channel will be mounted in a separatestainlesssteel enclosure locatedin the PAB so that the instruments will not be subject to the radiation,high temperatureand high humidity conditions that could resultfrom postulatedloss of water inventory in the SFP. The primary operatorindicationand backup battery systems will be provided in the TrainA and Train B EssentialSwitchgearRooms (Elev.
21 ft., 6 in.) located in the ControlBuilding.
Please modify the sketch in FigureI or provide a marked-up plantdrawing of the plan view of the SFP area,depicting the SFP inside dimensions, the plannedlocations/placementof the primary and back-up SFP level sensors, and the proposedroutingof the cables that will extend from the sensors toward the location of the local electronicscabinets and read-out/displaydevices in the main control room or alternateaccessible location.
NextEra Response RAI-2 Enclosure 3 contains a plan view of the proposed arrangement for the portions of the instrument channel consisting of permanent measurement channel equipment. As requested the enclosure depicts the inside dimensions of the SFP, planned placement of the primary and backup level sensors in the SFP and the proposed routing of cables that will connect the sensors to the level transmitters. The location of the signal conditioning processor module (level Transmitter) for each channel has been revised from the Primary Auxiliary Building to the Containment Enclosure Building. The planned location of the UPS/ remote display in the Train A and Train B Essential switchgear Rooms is also provided.
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RAI-3: Mountinje The 0IP states, in part,that; Equipment mounting will be Seismic CategoryI in accordancewith guidelines of Regulatory Guide 1.29. Installed equipment will be seismically qualifiedto withstandthe maximum seismic ground motion consideredin the design of the plantarea in which it will be installed.
Where the collapse of components would adversely affect the performanceof the SFPlevel instrumentation,the components will be supportedto withstand seismic loadingor isolatedfrom the systems or components by Seismic Category I boundaryrestraints.
Pleaseprovide the following:
a) The design criteriathat will be used to estimate the total loadingon the mounting device((s),
includingstatic weight loads and dynamic loads. Describethe methodology that will be used to estimate the total loading, inclusive of design basis maximum seismic loads and the hydrodynamic loads that couldresultfrom pool sloshingor other effects that could accompanysuch seismicforces.
b) A descriptionof the manner in which the level sensor (andstilling well, if appropriate)will be attachedto the refuelingfloor and/or other supportstructuresfor each plannedpoint of attachment of the probe assembly. Indicate in a schematic the portionsof the level sensor that will serve as points of attachmentfor mechanical/mountingor electricalconnections.
c) A descriptionof the manner by which the mechanicalconnections will attach the level instrument to permanent SFP structuresso as to support the level sensor assembly.
NextEra Response RAI-3.a, b, c The answer to this request requires design information that is not available at this time. Information that is available will be provided in future 6-month update reports.
RAI-4: Oualification The QIP states, in part,that; Components of the instrumentchannels will be qualfiedfor shock and vibration using one or more of the following methods...
The effects ofpostulatedseismic events on installedinstrument channel components (with the exception of batterychargersandreplaceablebatteries) will be verified to ensure that the equipment design and installationis robust.
Applicable components of the instrumentchannels will be qualified by the manufacturer(or otherwise tested)for seisimic effects at response levels commensuratewith the equipment mounting 6
location.Instrument channel qualificationwill be basedon the guidanceprovided in Sections 7, 8, 9, and 10 of IEEE Standard344-2004, IEEERecommended Practicefor Seismic Qualification of Class 1E Equipmentfor Nuclear Power GeneratingStations, or a substantiallysimilar industrial standard.
In addition,any of the below may also be used to provide additionalassurance that the equipment willperform as designedduringandfollowing a seismic event:
- Review of operatinghistoryfor component used in environments with significant vibration, such as for portablehand-helddevices or devices used in transportationapplications.The effects of low frequency, high acceleration will be included in the qualificationas discussed above. Vibration qualificationwill be inclusive of methods that demonstratethe effects of seismic motion impartedto the components at the locationof installation;
- Demonstrationthat devices are substantiallysimilarin design to equipment that has been previously testedfor seismic effects in accordancewith the plant design basis at the location where the instrumentis to be installed(g- levels andfrequencyranges).
In addition,pool mounted equipment will be qualifiedforsubmergence,providingprotectionfrom wave and seismic relateddisturbancesduringand after a seismic event.
Pleaseprovide the following:
a) A description of the specific method or combination of methods you intend to apply to demonstratethe reliabilityof the permanently installedequipment under Beyond- Design-Basis (BDB) ambient temperature,humidity, shock, vibration, and radiationconditions.
b) A descriptionof the testing and/or analyses that will be conducted to provide assurancethat the equipment will perform reliably under the worst-case credible design basis loadingat the location where the equipment will be mounted. Include a discussion of this seismic reliabilitydemonstration as it applies to a) the level sensormounted in the SFP area, andb) any control boxes, electronics,or read-outand re- transmittingdevices that will be employed to convey the level informationfrom the level sensor to the plant operatorsor emergency responders.
c) A descriptionof the specific method or combinationof methods that will be used to conifirm the reliabilityof the permanently installedequipment such thatfollowing a seismic event the instrumentwill maintain its requiredaccuracy.
NextEra Response RAI-4.a, b, C The answer to this request requires design information that is not available at this time. Information that is available will be provided in future 6-month update reports.
RAI-S: Independence The OIP states, in part,that, The backup instrumentchannel will be redundantto, and independentof the primaryinstrument channel.Independence will be obtainedthrough separationof the sensors, indication, backup 7
batterypower supplies, associatedcablingand channelpowerfeeds. Power sources to each channel will be from a different Class 1E plant bus (TrainA and Train B).
Pleaseprovide the following:
a) A descriptionof how the two channels of the proposedlevel measurementsystem in eachpool meet this requirementso that the potentialfor a common cause event to adversely affect both channels is minimized to the extent practicable.
b) Furtherinformation describingthe design and installationof each level measurementsystem, consistingof level sensor electronics,cabling,and readoutdevices. Please address how independence of these components of the primary and back-up channels is achieved through the applicationof independentpower sources,physical and spatialseparation,independence of signals sent to the location(s)of the readoutdevices, and the independenceof the displays.
NextEra Response RAI-5.a The permanently installed primary and backup instrument channels are redundant and will be installed independent of each other with respect to physical separation and electrical power sources. The physical and electrical separation will minimize the potential for a common cause event to adversely affect both channels. Each channel will consist of a level sensor, Level Transmitter and Uninterruptible Power Supply (UPS) with remote level display.
The level sensors will be located on the North and South sides of the SFP physically separated to the extent practical by a distance greater than the shortest length of a pool side. The length of the shortest side of the SFP is approximately 27 Ft feet. The horizontal separation will minimize the potential for a common cause event in the area of the SFP to adversely affect both channels.
The level transmitters, one per channel, will also be mounted in separate locations within the Containment Enclosure Ventilation Area (CEVA) using independent seismically qualified supports (see Enclosure 3). A vendor supplied cable will be independently run from each SFP sensor to the appropriate level transmitter. The vendor cables will be routed in dedicated rigid steel conduits that will be installed from each SFP sensor locations to the west wall of the SFP building, head south to the existing cable tray block outs, exit through the block outs to the transmitters located in CEVA. Each conduit will be installed on its own separate independent series of seismically qualified supports (i.e.
"A" train and "B" train supports) maintaining physical separation between the primary and backup channel routings. The spatial separation of the transmitters and associated conduits will minimize the potential for a common cause event in the SFP area to adversely affect both channels.
The primary and backup channel UPS/ Remote Indication Enclosures, which include the remote displays, will be located in the "A" and "B" train Essential Switchgear Rooms, one channel in each room. The Essential Switchgear Rooms are separated by physical barriers that assure train separation that preserves the independence of redundant Class 1E plant electrical systems to prevent the occurrence of a common failure mode. From the transmitter locations in CEVA, new plant cables will be installed in the existing seismically qualified "A" and "B" train tray systems to the remote indication enclosures (UPS/ Remote Indicator) located in the "A" and "B" train Essential Switchgear Rooms.
Rigid steel conduit will also be installed in each switchgear room from the enclosure to the tray system.
All conduit and trays for the routing of the cabling will be seismically qualified and capable of carrying safety related Class 1E circuits.
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The primary level channel will be powered from the 120VAC distribution panel for MCC 615 (Train "B"). MCC 615 is located in the train "B" Essential Switchgear Room. The backup level channel will be powered from the 120VAC distribution panel for MCC 515 (Train "A"). MCC 515 is located in the train "A" Essential Switchgear Room. These panels are physically separated from each other and will be normally powered from independent emergency diesel backed power supplies which serve to minimize the potential for a common cause event to affect both channels. In the event that the primary or backup power source from these panels is unavailable the channel UPS will automatically swap from 120VAC power to the battery backup power supply.
NextEra Response RAI-5.b Two completely redundant, independent and permanently installed SFP level measurement channels, both from the same supplier are being provided. Each channel utilizes guided wave radar (GWR) technology which uses the principle of time domain reflectometry to detect SFP water level.
Each level measurement channel will consist of a stainless steel sensor cable probe suspended in the SFP from a bracket attached to the operating deck at the side of the pool, a level transmitter located in an adjacent area (CEVA) and an Uninterruptible Power Supply (UPS) with remote level display.
Physical and spatial separation will be included in the design as described in the NextEra response to RAI-5.a above.
Each level measurement channel will be powered by an independent Emergency Diesel backed power source. The primary level channel will be powered from thel20VAC distribution panel for MCC 615 (Train "B"). The backup level channel will be powered from 120VAC distribution panel for MCC 515 (Train "A").
The primary level channel signals between the level probe, transmitter and level processor cabinet are entirely independent and separated from the backup level channel as described in the NextEra response to RAI-5.a above.
RAI-6: Power Supplies The OIP states, in part,that The primary and backup instrumentchannels will be poweredfrom redundantdedicatedbatteries and local battery chargers.The battery chargerswill normally be supplied 120 VACpowerfrom redundant Class 1E distributionpanels (Train A and Train B) that are sequencedandpowered by the Emergency Diesel Generatorsor the SupplementalEmergency PowerSystem (SEPS)on loss of off-site power (LOOP)events. If the normal Class 1Epower supply to a channel is not available, the dedicatedbattery supply will automaticallypower the instrumentchannel.A minimum battery life of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> will be providedfor each channel.
The design will include the capabilityto isolate the normal Class JEpower supply to each channel by opening the feeder breaker within the Class JE distributionpanel. The Class JE distributionpanels that will be usedfor this applicationare locatedin the Essential Train A and Train B SwitchgearRooms.
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The minimum battery life of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> will be sufficient to assure that the SFP level instrumentationwill provide reliablelevel indication until off-site resourcescan be deployed by the mitigatingstrategiesresultingfrom Order EA-12-049. As part of the mitigatingstrategiesfor OrderEA-12-049 (Reference 2), it is assumed that one channel of the SFP level instrumentation will be repowered by the SEPS approximately 10 minutes into the event if the emergency diesel generatorsare not available. Off-site resources (personnel,equipment, etc.) will begin to arriving at the station approximatelyhour 6 into the event andfill staffing is expected within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.
Requestedportableequipment that will be connected to repower the redundantvital plant bus, including the powerfeed to the redundantSFP level monitoring instrumentchannel,is assumedto arriveat the sitefrom the RegionalResponse Center (RRC) approximately 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> into the event.
Long term coping strategieswill include repoweringof the redundantSFP level monitoring instrument channeland SFP coolingequipment approximately36 hours into the event.
Pleaseprovide the following:
a) A description of the electricalAC power sources and capacitiesfor the primaryand backup channels.
b) If the level measurementchannels are to be powered through a battery system (either directly or through an UninterruptiblePowerSupply (UPS)), please provide the design criteriathat will be appliedto size the batteryin a manner that ensures,with margin, that the channel will be availableto run reliablyand continuouslyfollowing the onset of the BDB event for the minimum durationneeded, consistent with the plant mitigation strategiesfor BDB external events (OrderEA-12-049).
NextEra Response RAI-6.a As previously described, the primary level channel will be powered from the I20VAC distribution panel for MCC 615 (Train "B"). MCC 615 is located in the Train "B" Essential Switchgear Room and is normally powered from Unit Substation 61. The backup level channel will be powered from 120VAC distribution panel for MCC 515 (Train "A"). MCC 515 is located in the Train "A" Essential Switchgear Room and is normally powered from Unit Substation 51. The "A" and "B" Train Essential Switchgear Rooms are physically separated from each other by seismically qualified fire rated wall(s).
On a loss of offsite power MCC 615 and MCC 515 are powered from separate independent Emergency Diesel Generators. In the event that the primary or backup power source from these panels is unavailable the respective channel UPS will automatically swap from 120VAC to the battery backup power supply.
NextEra Response RAI-6.b Battery sizing will be in accordance with IEEE 485-2010. The design criteria for each channel will assume continuous level measurement system operation for at least 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> following a loss of the normal AC power source. Calculation of system power consumption will be based on the specified values listed in component manufacturer specifications. Margin will be added to the battery sizing calculations, following the guidelines of IEEE 485-2010, Section 6.2.2. The specified 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> battery mission time will provide ample margin to allow the implementation of Phase II FLEX actions as described in section IX of the Overall Integrated Plan. The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> battery life will be tested and 10
verified during the Factory Acceptance Test or Site Acceptance Test prior to final acceptance of the system..
RAI-7: Accuracy The QIP states, in part.that The instrumentchannels will be designedsuch that they will maintain their design accuracyfollowing a power interruptionor change in power source without recalibration.
Channel accuracy will considerSFP conditions, e.g., saturatedwater, steam environment, or concentratedboratedwater.
Additionally,instrumentchannel accuracywill be sufficient to allow trainedpersonnelto determine when the actuallevel exceeds the key spentfuel pool water levels (Levels 1. 2 and 3) without conflicting or ambiguous indication. The accuracy will be within the resolution requirementsof Figure 1 of NEI12-02.
Pleaseprovide the following:
a) An estimate of the expected instrumentchannelaccuracyperformance (e.g., in % of span) under both a) normalSFP level conditions (approximatelyLevel I or higher) and b) at the BDB conditions (i.e., radiation,temperature,humidity,post-seismic andpost- shock conditions) that would be present if the SFP level were at the Level 2 and Level 3 datum points.
I b) A descriptionof the methodology that will be usedfor determining the maximum allowed deviationfrom the instrumentchanneldesign accuracythat will be employed undernormal operating conditions as an acceptancecriterionfor a calibrationprocedureto flag to operators andto techniciansthat the channel requiresadjustment to within the normalcondition design accuracy.
NextEra Response RAI-7.a. b The answer to this request requires design information that is not available at this time. Information that is available will be provided in future 6-month update reports.
RAI-8: .Testinz The oIP states, in part,that; Instrument channel design will providefor routine testing and calibrationconsistentwith Order EA-12-051 and the guidance in NEI 12-02. Instrumentchannel testing and calibrationwill be performed using existingplant work controlprocesses. Detailsfor testing and calibrationwill be determinedduringthe engineeringand designphase of the project.
Pleaseprovide the following:
a) A descriptionof the capabilityandprovisions the proposedlevel sensing equipment will have to enableperiodic testing and calibration,including how this capability enables the equipment to be tested in-situ.
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b) A descriptionof how such testingand calibrationwill enable the conduct of regularchannel checks of each independentchannel againstthe other,and againstany otherpernmanently-installed SFP level instrumentation.
c) A descriptionof how calibrationtests andfunctional checks will be performed and the frequency at which they will be conducted Discuss how these surveillances will be incorporatedinto the plant surveillanceprogram.
d) A descriptionof whatpreventative maintenancetasks are requiredto be performedduring normal operation,and the plannedmaximum surveillance intervalthat is necessary to ensure that the channels arefully conditionedto accuratelyand reliablyperform theirfunctions when needed NextEra Response RAI 8.a. b, c, d The answer to this request requires design information that is not available at this time. Information that is available will be provided in future 6-month update reports.
RAI-9: Display The OIP states, in part,that The locationforprimary and backup SFP level indication will be accessible during and following an event. The Operatorindication (Primaryand Backup indication) will be provided in the Train A and Train B EssentialSwitchgearRooms (Elev. 21 ft., 6 in.) which are located in the Seismic CategoryI Control Building. The Train A and Train B EssentialSwitchgearRooms are in close proximity to the main ControlRoom and Emergency PlanningTechnical Support Center locatedon elevation 75ft of the ControlBuilding. The location of the primary and backup indication is:
0 Promptly accessible to the appropriateplant staffgiving appropriateconsideration to various draindown scenarios, 0 Outside of the FSB, e.g., an appropriatedistancefrom the radiologicalsources resultingfrom an event impacting the SFP,
" Inside a seismic category I structureprovidingprotectionagainstadverse weather and
" outside of any high radiationareasduringnormal operation.
Pleaseprovide the following:
a) Since the backup display location is not in the main controlroom, provide a descriptionof the display location that addressesprimaryand alternateaccess route evaluation,continuous habitability at display location(s), continualresource availabilityfor personnelresponsibleto promptly read displays, andprovisionsfor verbal communicationswith decision makersfor the various SFP drain down scenarios and external events.
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b) The reasonsjustifyingwhy the locationsselected will enable the ihformationfrom these instruments to be considered "promptlyaccessible ". Include considerationof various drain-down scenarios.
NextEra Response RAI 9.a Local and remote Spent Fuel Pool (SFP) wide range level instrument displays will be provided for each level measurement channel (Primary and backup). The displays will be located in areas outside of the area surrounding the SFP floor.
A local display will be located on the front of the primary and backup level transmitters located in the CEVA (Ref. Enclosure 3). The CEVA is adjacent to the Spent Fuel Building (SFP) and has multiple access routes through the Seismic Category I Primary Auxiliary Building (PAB) which is normally accessed through the Radiation Protection Checkpoint. Alternate routes into the PAB and CEVA are provided through doors P418 and EM414 (- Elev. 25 ft.). These doors provide access from the exterior of the PAB and are normally locked. Door EM 414 provides access into the Main Steam Feedwater Pipe Chase and/ or RCA Tunnel. Door P418 provides access to the 25 ft. elevation of the PAB.
Normal access into the CEVA is provided through door P415 which is located on the southeast corner of the 25 ft elevation of the PAB. An alternate access route into CEVA is provided from the West Main Steam and Feedwater Pipe Chase stairwell through door EM409 (Elev. 21 ft., 6 in.). The level transmitters and associated displays will be physically protected from the environmental and radiological conditions that could result from a beyond design basis (BDB) event by a reinforced concrete wall that separate the CEVA from the SFB.
Remote Spent Fuel Pool (SFP) wide range level instrument displays will also be located in the Train "A" and Train "B" Essential Switchgear Rooms (Elev. 21 ft., 6 in.) contained in the Seismic Category I Control Building (Ref. Enclosure 3, one remote indicator per Train). The Train A and Train B Essential Switchgear Rooms are in close proximity to the main Control Room and Emergency Planning Technical Support Center which are located on Elevation 75 ft of the Control Building. The remote level displays will be physically protected from the environmental and radiological conditions that could result from a beyond design basis (BDB) event by a reinforced concrete wall that separate the Essential Switchgear Rooms from the PAB and SFB. This area will be accessible and continuously habitable following a beyond design basis event.
Multiple routes are available to access the Essential Switchgear Rooms from the Control Building. The normal route from the Main Control Room is provided by door C300. This door provides access into the Turbine Building where stair cases TBST1, TBST2, TBST3 and TBST4 provide alternate routes to the 21 ft., 6 in. elevation and door C102. Door C102 provides access from the Turbine Building into the Train "A" Essential Switchgear Room. From the Train "A" Essential Switchgear Room, doors C 106 or C109 provide access into the Train "B" Essential Switchgear Room.
An alternate access path into the Train "B" Essential Switchgear Rooms is provided from the Main Control Room via an enclosed Seismic Category I stairwell (Stairwell CBST2). Door C312 provides access from the Main control room into the 75 ft elevation of the stairwell. Door CI 18 provides direct access from the 21 ft, 6 in elevation of the stairwell into the Train "B" Essential Switchgear room.
From the Train "B" Essential Switchgear room, doors C 106 or C 109 provide direct access into the 13
Train "A" Essential Switchgear room. Stairwell CBST2 can also be accessed from outside of the control building via door Cl 19 (Elev. 21 ft., 6 in.).
The minimum shift complement following a beyond design basis event will initially consist of the staffing positions noted below Shift Manager Unit Supervisor Work Control Supervisor Two Control Room Operators Five Nuclear Systems Operators Firefighter Chemistry Technician Health Physics Technician Primary and secondary responders from the Offsite Emergency Response Organization would augment this staff within 60 minutes of a declared Alert level (or higher) emergency condition if it is safe to access the plant. If it is unsafe to access the plant, the primary and secondary responders from the offsite Emergency Response Organization will report to the Alternate Technical Support Center/
Operation Support Center located at the Emergency Operations Facility in Portsmouth, New Hampshire. Staff from the Alternate Technical Support Center/ Operation Support Center will be dispatched to the plant when safe access routes are established.
Hand held radios, satellite phones, person to person contact or the plant PBX phone system are communication systems that will be available for transmitting information to and from the Control Room.
NextEra Response RAI-9.b The information from the SFP level instrument is promptly accessible for various drain-down scenarios and external events based on the reasons specified in RAI 9a above.
RAI-10: PROGRAM FEATURES Procedures The OIP states, in part,that Procedureswill be developed using guidelinesand vendor instructionsto addressthe maintenance, operation,and abnormalresponse issues associatedwith the new SFP instrumentation.
Procedureswill addressa strategy to ensure SFP water level addition is initiatedat an appropriatetime consistent with implementation of NE 12-06, Diverse and Flexible Coping Strategies (FLEX) ImplementationGuide and EA-12-049, Issuance of Orderto Modify Licenses with Regardto Requirementsfor Mitigation Strategiesfor Beyond-Design-BasisExternalEvents.
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Pleaseprovide the following:
a) A list of the operating(both normaland abnormalresponse)procedures,calibration/test procedures,maintenanceprocedures,and inspectionprocedures that will be developedfor use of the SFP instrumentationin a manner that addressesthe order requirements.
b) A briefdescriptionof the specific technical objectives to be achieved within eachprocedure. If your plan incorporatesthe use ofportable spentfuel level monitoring components,please include a descriptionof the objectives to be achieved with regardto the storage location andprovisionsfor installationof the portable components when needed.
NextEra Response RAI-10.a, b The answer to this request requires design information that is not available at this time. Information that is available will be provided in future 6-month update reports.
RAM-11: Testinz, and Calibration The QIP sates, in part,that Processeswill be establishedand maintainedforscheduling and implementing necessary testing and calibrationof the primary and backup spentfuel pool level instrumentchannels to maintain the instrumentchannels at the design accuracy. Testing and calibrationof the instrumentation will be consistentwith vendor recommendationsand any other documented basis. Calibrationwill be specific to the mounted instrumentsand indicators.
Pleaseprovide the following:
a) Furtherinformation describing the maintenance and testingprogram the licensee will establish and implement to ensure that regulartesting and calibrationis performed and verified by inspection and audit to demonstrateconformance with design and system readinessrequirements. Include a description of yourplansfor ensuringthat necessary channel checks, functional tests, periodic calibration,and maintenance will be conductedfor the level measurement system and its supporting equipment.
b) A description of how the guidance in NEI 12-02 Section 4.3 regardingcompensatory actionsfor one or both non-functioning channels will be addressed.
c) A description of the compensatory actions to be taken in the event that one of the instrument channels cannot be restoredto functionalstatus within 90 days.
NextEra Response RAI-11.a~b~c The answer to this request requires design information that is not available at this time. Information that is available will be provided in future 6-month update reports.
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References
- 1. NRC Electronic Mail to NextEra Energy Seabrook, LLC, "Draft Requests for Additional Information Regarding the Seabrook Overall Integrated Plan for Reliable SFP Instrumentation, dated July 18, 2013 (ADAMS Accession No. ML13217A166).
- 2. NextEra Energy Seabrook, LLC's Overall Integrated Plan in Response to March 12, 2012 Commission Order to Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation (Order Number EA- 12-051), dated February 26, 2013 (ADAMS Accession No. ML13063A439)
- 3. NextEra Energy Seabrook, LLC's Overall Integrated Plan in Response to March 12, 2012 Commission Order Modifying Licenses with Regard to Requirements for Mitigation Strategies for Beyond-Design-Basis External Events (Order Number EA-12-049), dated February 22, 2013 (ADAMS Accession No. ML13063A438)
- 4. NRC JLD-ISG-2012-03, Compliance with Order EA-12-051, Reliable Spent Fuel Pool Instrumentation, Revision 0, August 29, 2012.
- 5. NEI 12-02, Industry Guidance for Compliance with NRC Order EA-12-05 1, "To Modify Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," Revision 1, August 2012.
- 6. NEI 12-06, Diverse and Flexible Coping Strategies (FLEX) Implementation Guide, Revision 0, August 2012.
- 7. Seabrook Calculation C-S-1-24606, "Spent Fuel Pool Level for Reliable Pump Suction,"
Revision 00.
- 8. NRC Order EA-12-05 1, "Order Modifying Licenses with Regard to Reliable Spent Fuel Pool Instrumentation," dated March 12, 2012 (ADAMS Accession No ML12056A044).
- 9. Seabrook Drawings:
Drawing No. Title Revision 310733 Fuel Storage Building EL. 25'-0" 001 310724 Fuel Storage Building Exposed Conduit Plan 017 Elevation 25'-0" 102200 F.S.B. Stainless STL.- Spent Fuel Pool Liner SH.I 012 Area 040 FB 1-NHY-805059 Fuel Storage Building Plan Elevation 21"-6" & 012 25"-0" General Arrangement 1-NHY-310431 Control Building Elev. 21'-6" Electrical General 030 arrangement I-NHY-805062 Primary auxiliary Building Plans At Elev. 25"-0" 020 General Arrangement 101619 Containment Enclosure Ventilation Area Concrete 011 Plans At EL. 21'-6" & 53'-0" 16
ENCLOSURE 2 NEXTERA ENERGY SEABROOK, LLC SEABROOK NUCLEAR PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING OVERALL INTEGRATED PLAN IN RESPONSE TO ORDER EA-12-051, "RELIABLE SPENT FUEL POOL INSTRUMENTATION" SPENT FUEL POOL LEVELS ELEVATION VIEW Enclosure 2, Page 1 of 2
2 ENCLOSURE 2 Of SEABROOK SPENT FUEL POOL LEVELS ELEVATION VIEW
-10TO LEVEL TRANSMITTER 2
OPERATING FLOOR EL. 25'-0"
-- - INSTRUMENT NORMAL WATER LEVEL EL. 23'-4" TO 23'-9" SENSITIVITY BAND 6" RELIABLE SUCTION LEVEL EL. 23'-4"'- --- LEVEL
.----- 1 LOSS OF NPSH © 212' F EL. 22'-4" 4- TOP OF STRAINER -EL. 21'-8"
'- TECHNICAL -SPECIFICATION LIMIT EL. 21'-142" SUCTION STRAINER
.4 LEVEL FOR SUBSTANTIAL RADIATION SHIELDING EL. 10'-9'/2" - II ---.---.-. LEVEL 2 Poge S.OFUM.P .EL. _9'-.2"L 0212° F 2, NPSH- 11.2Ft 4, LEVEL WHERE FUEL REMAINS COVERED EL. (-)0-6" Do I -..-.f.-.-.-..-.-.. LEVEL 3 INSTRUMENT TOP OF FUEL RACK EL. (-) 1'-5Y4" E- SENSITIVITY BAND 6"
- NNTtE4vHL~1~M~~df~UIN A =Ea II NOMINAL 0 --
~.oo 0 0 00 9 0 ARE IL II 0
0:09
~00 0.
00
-BOTTOM OF SFP EL. (-) 15-11 '/2" ~p -A SCALE 0 ~o~o 0 0 0 00- 0 0 00 0 0' 0 ELEVATIONS TO NOTES=
ALL NOTES:
- 1. NOT
- 1. ARE NOMINAL
- 2. ALL ELEVATIONS
ENCLOSURE 3 NEXTERA ENERGY SEABROOK, LLC SEABROOK NUCLEAR PLANT RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING OVERALL INTEGRATED PLAN IN RESPONSE TO ORDER EA-12-051, "RELIABLE SPENT FUEL POOL INSTRUMENTATION" PLAN VIEWS OF INSTRUMENT CHANNEL ARRANGEMENT Enclosure 3, Page 1 of 5
ENCLOSURE 3 SFP CONTAINMENT ESSENTIAL BUILDING ENCLOSURE SWITCHGEAR ROOM BUILDING UPS/REMOTE INDICATOR SENSOR PROBE POOL SIMPLIFIED SFP LEVEL MONITORING CHANNEL SKETCH Enclosure 3, Page 2 of 5 JIM S SIMPLIFIED SFP.dgn 8/12/2013 2:07:10 PM________________________________________________
ENCLOSURE 3 Nq To Train B (Primary) Level Transmitter Train A (Backup) Level Sensor Probe Train A Dedicated Conduit & Supports Train B Dedicated Conduit & Supports To Train A (Backup) Level Transmitter To Train B (Primary) Level Transmitter Part of Drawing 1-NHY-310733, Rev. 1 Enclosure 3, Page 3 of 5
L ENCLOSURE 3 mL~A LL. zB-dý4 0