ML15230A032

Calvert Cliffs Nuclear Power Plant, Units 1 and 2 - Request for Additional Information Regarding the National Association Standard 805 License Amendment Request Fire Protection

ML15230A032
Person / Time
Site:	Calvert Cliffs
Issue date:	08/13/2015
From:	Gellrich G H Exelon Generation Co
To:	Document Control Desk, Office of Nuclear Reactor Regulation
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ML15230A027	List: ML15230A032
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Download: ML15230A032 (25)

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SECURITY-RELATED INFORMATION -WITHHOLD UNDER 10 CFR 2.390George GellrichSite Vice PresidentExe~on GenerationCalvert Cliffs Nuclear Power Plant1650 Calvert Cliffs ParkwayLusby, MD 20657410 495 5200 Office717 497 3463 Mobilewww.exeloncorp.comgeorge.gellrich~exeloncorp.com10 CFR 50.90August 13, 2015U. S. Nuclear Regulatory CommissionATTN: Document Control DeskWashington, DC 20555Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2Renewed Facility Operating License Nos. DPR-53 and DPR-69NRC Docket Nos. 50-317 and 50-318

Subject:

Request for Additional Information Regarding the NationalAssociation Standard 805 License Amendment ReauestFire Protection

References:

1. Letter from G. H. Gellinch (CCNPP) to Document Control Desk (NRC), datedSeptember 24, 2013, License Amendment Request re: Transition to 10 CFR50.48(c) -NFPA 805 Performance Based Standard for Fire Protection2. Letter from A. N. Chereskin (NRR) to G. H. GelrInch (Exelon), dated July 15,2015, Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2 -Request forAdditional Information Regarding the National Fire Protection AssociationStandard 805 License Amendment Request (TAC Nos. MF2993 andMF2994)In Reference 1, Calvert Cliffs Nuclear Power Plant, LLC submitted a license amendmentrequest to transition to 10 CFR 50.48(c) -NFPA 805 Performance Based Standard for FireProtection. In Reference 2 the Nuclear Regulatory Commission staff requested additionalinformation regarding this amendment request. Attachment (1) and the Enclosure provide theresponse to the request for additional information. Enclosure 1 contains markups of the originallicense amendment package pages and supersedes the previously provided pages.The Attachment S page in Enclosure 1 contains security-related information and is requested tobe withheld from public disclosure under 10 CFR 2.390.This additional information does not change the No Significant Hazards Determination providedin Reference 1. No regulatory commitments are contained in this letter.Should you have questions regarding this matter, please contact Mr. Larry D. Smith at (410)495-5219.~uC~Upon removal of Attachment S pages in Enclosure 1, this submittal is not restricted Document Control DeskAugust 13, 2015Page 2I declare under penalty of perjury that the foregoing is true and correct. Executed on August 13,2015.Respectfully,George H. GellrichSite Vice PresidentGHG/PSF/bjm

Attachment:

(1)Request for Additional Information Regarding the National Fire ProtectionAssociation Standard 8905 License Amendment Request

Enclosure:

1 Contains markups of the original license amendmentpackage pages and supersedes the previously providedpagescc: NRC Project Manager, Calvert CliffsNRC Regional Administrator, Region INRC Resident Inspector, Calvert CliffsS. Gray, MD-DNR ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THENATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805LICENSE AMENDMENT REQUESTCalvert Cliffs Nuclear Power PlantAugust 13, 2015 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTBy letter dated September 24, 2013 Calvert Cliffs Nuclear Power Plant, LLC, submitted alicense amendment request (LAR) for Calvert Cliffs Nuclear Power Plant, Unit Nos. 1 and 2(CCNPP), to transition its fire protection licensing basis from Title 10 of the Code of FederalRegulations (10 CFR) Section 50.48(b) to 10 CFR 50.48(c), National Fire Protection AssociationStandard (NFPA) 805, "Performance-Based Standard for Fire Protection for Light WaterReactor Electric Generating Plants," "2001 Edition. The licensee submitted request for additionalinformation (RAI) responses. Based on its review of the RA/ responses, the U.S. NuclearRegulatory Commission (NRC) staff requests the following additional information to complete itssafety evaluation of the LAR:Probabilistic Risk Assessment (PRA) RAI 06.01:The response to Probabilistic Risk Assessment (PRA) RAI 06 (by letter dated April 13, 2015)appears to indicate that transient combustibles with heat release rates (HRRs) greater than thatassumed by the Fire PRA (FPRA) may be present and left unattended in Plant Area Units(PA Us) 311, 317, 407, and 430. The administrative controls currently discussed in the responseestablish expectations that appear to reduce the frequency that transient combustibles may bepresent but not necessarily the HRR of the combustibles. For example, if large amounts oftransient combustibles are brought into a switchgear room, then it would be subjected to theassociated administrative controls that seem to only reduce the frequency of large fires byreducing the time the combustibles will be present (e.g., "remove from the work area at the endof the shift'). Similarly, if "minor amounts" of transient combustibles ("minor amounts" is notdefined in the RAI response and is interpreted to be "only the amount needed to support thework," which could still be greater than the 142 kW HRR assumed in the PRA) are brought intoa switch gear room, then it would be subjected to a less stringent set of administrative controlsthat also seem to only reduce the frequency of large fires by reducing the time the combustibleswill be present (e.g., "the materials are to be removed from the work location at the completionof the work activity').Based on the above discussion, clarify how the administrative controls currently in place forPAUs 311, 317, 407, and 430 can be used, in conjunction with specific attributes andconsiderations applicable to these locations, to support a justification for selection of ascreening HRR that is lower than the 317 kW.CCNPP Response to NRC RAI 06.01 :Exelon will upgrade the existing transient combustible controls in the Switchgear Rooms andPAUs 311, 317, 407, and 430, by designating these rooms as transient combustible exclusionzones. At CCNPP, a transient combustible exclusion zone is an area in the plant in whichtransient combustible material is prohibited except when constantly attended, contained in metalcontainers with closed metal lids/openings or has a transient control permit. Minor amounts oftransient combustibles are not excluded from this requirement.Constantly attended transient combustible materials may be present in the room in the eventthat work activities are required. Plant procedures require that only the amount of combustiblesneeded to support the work be introduced into the area. Work activities are infrequent in theSwitchgear Rooms during power operations and combustible materials associated with theseactivities are typically limited to test equipment and small tubes of grease. Plant proceduresrequire that transient combustible materials not be staged or stored within 3 feet of heat sourcesor live electrical components unless unavoidable and, therefore, work activities in theSwitchgear Rooms are performed away from the fixed ignition sources. In addition, access to ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTthe Switchgear Rooms is limited; only plant personnel with vital area clearance can accessthese areas.The Switchgear Rooms are designated as high risk areas. Plant procedures requireconsideration of the potential impact of plant activities in these locations to ensure the FPRAassumptions, (e.g., changes to existing fire sources or addition of fire sources) remain valid.Therefore, a transient control permit will not be allowed for the Switchgear Rooms for transientcombustible materials that exceed the 142 kW transient fires postulated for the area.In summary, the combustible controls proposed for these rooms are strict and activities in theSwitchgear Rooms are monitored due to the high risk designation. In addition, access to theSwitchgear Rooms is limited and work activities are infrequent. Based on these controls, andthe history of transient combustible materials in these rooms as described in the response toPRA RAI 06, the selection of a reduced HRR in the Switchgear Rooms is justified.Implementation Items IMP-22 has been created to ensure applicable site procedures areupdated identifying PAUs 311, 317, 407, and 430 as transient combustible exclusion zones.PRA RAI 13.01:The response to PRA RAI 13 (by letter dated April 13, 2015) indicates that the main controlboard (MCB) analysis will be updated as part of the response to PRA RAI 03 to address theNRC staff's observation regarding the presence of both qualified and unqualified wiring in theMCB. However, the response does not state how the MCB analysis will be updated. Describe(or reference a description of) the MCB analysis and clarify how the revised treatment ofqualification is consistent with, or bounds, the MCB wiring configuration.CCNPP Response to NRC PRA RAI 13.01:The MOB analysis is being revised based on the conservative assumption that all cabling isunqualified cable using the associated NUREG/CR-6850 heat release rate of 1002 kWapplicable to open panels with unqualified cables (NUREG/CR-6850, Table E-6). The revisedMCB analysis will be included with the revised CCNPP FPRA quantification that will besubmitted in response to RAI PRA-03.PRA RAI 15:In the response to PRA RAI 15 (by letter dated April 13, 2015), the licensee clarified that MainControl Room (MCR) abandonment for loss of function was included in the PRA following firesin the cable spreading room. The licensee stated that loss of function is defined as the"....immediate or impending loss of vital auxiliaries, degraded steam generator level indicationand/or degraded flow control instruments [that] will lead to MCR abandonment." The licenseeclarified that loss of the whole Cable Spreading Room (CSR) meets these conditions and, forlesser fires, the appropriate fault tree logic is applied. The response further stated that the"..abandonment cases assume a complete relocation of the primary control station (PCS) tothe Auxiliary Safe Shutdown Panel (ASSDP)..." In the response to PRA RAI 18.a (by letterdated February 9, 2015), the licensee stated that Variance from Deterministic Requirements(VFDRs) were removed from the CCNPP FPRA compliant plant model by setting the VFDRrelated basic events to false "in all areas." However, in the latter response to PRA RAI 18.b (byletter dated April 13, 2015), the licensee clarified that instead of setting the VFDR related basicevents to false for scenarios that lead to MCR abandonment, Human Error Probability (HEPs)2 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTassociated with actions occurring away from the primary control station (PCS) actions wereeither adjusted to reflect an equivalent action at the PCS or assumed to be successful in thecompliant plant model Therefore, the effects of individual fires in the CSR are evaluated and, ifloss of control occurs, the PRA models the shutdown of the plant from the ASSDP.Furthermore, VFDRs are included as in all areas in the plant.Confirm that the effects of individual fires in the CSR are evaluated and different scenariosdeveloped based on the population of Structures, Systems, and Components (SSCs) failed fordifferent fires (i.e., not all fires lead to the use of the Auxiliary Safe Shutdown Panel, for both thepost-transition and compliant plant models).CCNPP Response to NRC PRA RAI 15:Based on impact, CSR fixed initiators are analyzed for fire impact using accepted fire modelingmethodologies, often resulting in multiple damage states. If an initiator progresses to wholeroom damage, the relevant portion of the initiator ignition frequency is added to a single severefire (whole room burn) scenario.Consistent with the approach described in PRA RAI 15 (April 13, 2015), CSR scenarios that donot result in a loss of the whole compartment are generally quantified assuming noabandonment. The results are then reviewed to identify scenarios with high CCDPs. Thosescenarios are marked for abandonment and requantified.This process is repeated as modeling refinements are incorporated. At this time only a smallpercentage of over 200 fixed or transient scenarios that do not result in a loss of the wholecompartment are marked for abandonment. Thus, distinct scenarios are developed for eachfixed or transient ignition and not all CSR fires lead to use of the Auxiliary Safe Shutdown Panel.The same variant plant scenarios are used for the compliant plant risk evaluation. A similarprocess to that described above is applied to determining if abandonment is required in thecompliant plant. In general, abandonment is not required in the compliant plant. An exceptionto this is during a severe fire (whole room burn) scenario which is marked for abandonment.As elsewhere, all VFDRs are corrected in the compliant plant.Fire Protection Engqineeringq (FPE) RAI 11:In its letter dated April 13, 2015, the licensee identified a plant condition that was not incompliance with NFPA 805 Section 3.3.1.2(1). In accordance with 10 CFR 50.48(c) (2) (vii), thelicensee submitted new Approval Request 7 as part of the amended pages to the LAR,Attachment L, to request NRC approval of a performance-based method to comply with NFPA805 Section 3.3.1.2(1). This section requires that wood used within the power block be listed aspressure-impregnated or coated with a listed fire-retardant application.The licensee requested the ability to store and use wood in designated fenced-in storage areasin Room 1101 (12' North Storage Area) and Room 1109 (Warehouse) in Fire AreaTB/NSB/A CA.3 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTAdditionally, it states in 10 CFR 50.48(c) (2) (vii) , in part, that performance-based methods thatare used to evaluate fire protection program (FPP) elements and minimum design requirementsof NFPA 805 Chapter 3, must meet certain criteria. It must be determined that the method:(A) Satisfies the performance goals, performance objectives, and performance criteriaspecified in NEPA 805 related to nuclear safety and radiological release;(B) Maintains safety margins; and(C) Maintains fire protection defense-in-depth (fire prevention, fire detection, firesuppression, mitigation, and post-fire safe shutdown capability).The NRlC staff requests the following information to evaluate the approval request:a. The approval request states that the storage areas contain various types and quantitiesof combustible storage, including but not limited to rack storage, and that limits on thequantities of storage are administratively established by the fire protection engineerthrough the use of the Combustible Loading Analysis Database.i. Characterize the type, quantities, and use of wood and other combustible storage inRooms 1101 and 1109, and include the relative contribution to combustible loadingof the non-treated wood compared to other combustible materials in these rooms.ii. Describe the specific limits and associated administrative controls on the amount ofnon-treated wood that can be stored in each of the fence-in storage areas in Rooms1101 and 1109 (in-situ or transient).b. The approval request states that the likelihood of a fire in Rooms 1101 and 1109, isexpected to be minimal due to the limited number of fixed ignition sources in the roomsand procedural controls on hot work and transient combustible materials. Describe thetypes of fixed ignition sources in, or near, the fenced-in storage areas, and the exposurefire hazards that could propagate to the fenced-in storage and potentially ignite thestored materials.c. The approval request states that in the event of a fire in the storage areas, wet pipeautomatic suppression is provided in the areas above the storage which has beenreviewed for compliance with NFPA 13. Summarize the technical basis for concludingthat the sprinkler design is acceptable for the hazard associated with 12-foot rackstorage of wood and other combustibles that substantiates the statement that theloading will not challenge that wet pipe sprinkler system, assuming the storage areascontain the maximum allowed quantity of non-treated wood and other combustibles.d. Discuss the bases for not needing the installation of an automatic smoke detectionsystem to provide early warning of a fire in the fenced-in storage areas, assuming thestorage areas contain the maximum allowed quantity of non-treated wood and othercombustibles. Describe the additional fire protection available in the area of the storagerooms that supports defense-in-depth (e.g., hose stations and extinguishers).e. Element 1 (Echelon 1) of defense-in-depth, as described in NFPA 805, Section 1.2, isassociated with fire prevention, which includes controlling the elements of fuels (i.e.,combustibles) and ignition that are necessary for fire to occur. In Approval Request 7,the discussion of Element 1 of defense-in-depth only addresses ignition sources.Provide additional discussion of how the storage and use of untreated wood in Rooms1101 and 1109 meets or has compensated for Element 1 of defense-in-depth relative tocontrol of combustibles.4 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTCCNPP Response to NRC FPE RAI 11:a.i. The storage in Rooms 1101 and 1109 consists of solid metal shelving (less than 12 feethigh), metal single row open storage single and double row racks with less than 12 feet ofstorage located on the racks, and materials stored on the floor. The metal open storageracks are separated from each other by a minimum distance of 8 feet. The areas containordinary combustibles and can be classified as Ordinary Hazard (Group 2) occupancieswith Type II Storage, as defined by NFPA 13, 1971 edition (code of record). The areas arenot used as storage areas for wood; instead, wood is incidental to the storage areas. Thewood in the areas consists of pallets, cable reels, shipment containers, and small handtools. The storage in the areas consists of plant supplies including both metal and plastictools, equipment, and supplies.The code of record does not contain detailed commodity classifications; therefore, thecurrent (2013) edition of NFPA 13 was used to classify the commodities in the area for thepurposes of this approval request. The commodities stored on the single and double rowopen storage racks and solid metal shelving can be primarily classified as Class I throughClass IV commodities. There are minor amounts (10 or fewer distributed, non-adjacentpallets, as allowed by NFPA 13, 2013 edition) of higher hazard commodities (i.e., Group Aplastics). Stacks of idle wood pallets are not stored in the area. It is estimated thatuntreated wood does not exceed 20% of total fire loading of the storage. The total fire loadof Room 1101 is approximately 2.2 Billion BTUs, resulting in a fire severity of approximately2 hours. The total fire load of Room 1109 is approximately 1.3 Billion BTUs, resulting in afire severity of approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.a.ii. Administrative controls in these areas include procedural controls on transient combustiblesand proceduralized inspections of the area. The Combustible Loading Analysis Database(CLAD) tracks the quantities of combustibles that are present in the areas. Theproceduralized inspections of the area will ensure that the storage in the requested areas(including the wood in these areas) does not exceed the design capabilities of the sprinklersystem protecting Rooms 1101 and 1109. The technical basis for concluding that storageconfigurations will not exceed the design capability of the sprinkler system is discussed insubpart (c), below. Implementation Item IMP-21 has been created to ensure thatproceduralized inspections of the area will verify that the storage configurations will notexceed the design capability of the sprinkler system protecting Rooms 1101 and 1109 andthat non-treated wood will not exceed 20% of the total fire loading of the storage.b. Fixed ignition sources in, or near, the fenced-in storage areas consist of small wall-mountedtransformers, forklift battery chargers, small wall-mounted panels, junction boxes, andelectrical cables. The ignition sources are located such that there is no continuous path offixed intervening combustibles present that could be expected to facilitate fire propagationfrom a fixed ignition source to potentially ignite the stored materials. Administrative controlsensure that adequate clearance, free of combustible material, is maintained aroundenergized electrical equipment. Additionally, existing processes ensure that administrativecontrols are being followed in these areas. This provides reasonable assurance thattransient combustibles will not provide a pathway for potential fire spread from a fixedignition source to the stored materials.c. Section 3.9.1 of NFPA 805 requires that automatic or manual water-based fire suppressionsystems required to meet the performance or deterministic requirements of Chapter 4 shall5 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTbe installed in accordance with NFPA 13. National Fire Protection Association 13,"Installation of Sprinkler Systems," 1971 edition, is the code of record to which the sprinklersystem protecting Room 1101 and Room 1109 was designed. The system was designedas an Ordinary Hazard pipe schedule system with a coverage area of 100 square feet persprinkler. The water supply is required to provide a flow of 1500 gpm with a minimumresidual pressure of 15 psi at the ceiling. The system, including the water supplyrequirements, were reviewed for compliance with NFPA 13, 1971 edition, as part of theNFPA 805 transition project and determined to comply with all the primary functionalrequirements of the standard. Per NFPA 13, 1971 edition, this configuration is sufficient toprotect miscellaneous storage up to 12 feet, as discussed below. Storage is required to belimited to 12 feet because if storage exceeded this height, additional high-piled storagerequirements would be invoked per Section 4045 of NFPA 13, 1971 edition. Detailsregarding compliance with NFPA 13, 1971 edition are discussed in the followingparagraphs:Section 1321 of NFPA 13, 1971 edition, lists "general warehouses and storage areas" as anexample of ordinary hazard occupancies. Section 2126 further classifies the warehousefacility as "Ordinary Hazard (Group 2). This group is defined as the group of the OrdinaryHazard class that has properties "where combustibility of contents and ceiling heights aregenerally less favorable than those listed in Group No. 1, but there are only minor amountsof flammable liquids and essentially no obstructions." An example given in NEPA 13, 1971edition, is "storage buildings (having low factors of combustibility and obstruction)." Thisclassification is consistent with the storage configurations in Room 1101 and 1109 atCCNPP.Section 3 of Appendix A to NEPA 13, 1971 edition, defines ordinary combustibles as"commodities, packaging, or storage aids which have heats of combustion (British thermalunits per pound) similar to wood, cloth or paper and which produce fires that may normallybe extinguished by the quenching and cooling effect of water." The storage in Rooms 1101and 1109 is primarily ordinary combustibles.In order for a system to perform as designed, the maximum allowable system area is limitedby NFPA 13. Section 12 of Appendix A to NFPA 13, 1971 edition, defines Type II Storageas storage in which "combustible commodities or noncombustible commodities involvingcombustible packaging or storage aids stored not over 15 feet high in solid piles or not over12 feet high in piles that contain horizontal channels." This section further states that,"minor quantities of commodities of hazard greater than ordinary combustibles may beincluded without affecting this general classification." Storage in Rooms 1101 and 1109meets the definition of Type II Storage. Section 3022 of NFPA 13, 1971 edition, limits themaximum system area to 52,000 square feet for Ordinary Hazard and Type II Storage. Thesystem at CCNPP covers a floor area of approximately 28,000 square feet; therefore, it iswell within the allowable size limitations.As the code of record does not contain detailed commodity classification requirements orguidelines and due to the increased prevalence of plastic in modern products compared to1971, the area/density requirements for the storage configuration were reviewed againstthe current (2013) edition of NFPA 13. It was determined that the existing storageconfiguration resembles Class IV commodities and the sprinkler protection requirementsare similar to those met by the installed sprinkler system. The current sprinkler system is6 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTadequate for the hazards present as long as the following bases for acceptability aremaintained:i. The height of storage (measured from floor to top of commodity) does not exceed12 feet.ii. Commodities stored on racks and shelves can be classified as Class I, Class II,Class Ill, or Class IV commodities as defined in Section 5.6 of NFPA 13, 2013 edition.*Exception: minor quantities of more severe commodities (e.g., Group A plastics)will be allowed as permitted by Section 5.3.1.2.3 of NFPA 13, 2013 edition (limitedto 10 distributed and non-adjacent pallets).iii. Current rack spacing is maintained (i.e., minimum of 8 foot spacing between storageracks).iv. There are no stacks of idle wood pallets present (Section 12.12.1.2 of NFPA 13, 2013edition).Proceduralized inspections of the area will ensure that the aforementioned bases for theacceptability of storage in Rooms 1101 and 1109 are maintained (refer to ImplementationItem IMP 21). Should the sprinkler system be upgraded in the future, the bases foracceptability, listed above '(storage height, acceptable commodities, rack spacing), may berevised consistent with the hazards/storage configurations allowed by NFPA 13 in the codeof record in force at the time the upgraded system is designed/installed.Additionally, the proceduralized inspections of the area will ensure that the followingconditions are maintained:* Non-treated wood does not exceed 20% of the total fire loading of the areas.* Adequate clearance, free of combustible material, is maintained around energizedelectrical equipment.* There are neither fixed ignition sources in, or near, the fenced-in storage areas, norexposure fire hazards that could propagate to the fenced-in storage and potentiallyignite the stored materials.Based on the administrative controls and storage practices in the subject storage areas, thesprinkler design is acceptable for the associated hazard and reasonable assurance isprovided that a fire in the areas will not challenge the wet pipe sprinkler system.Additionally, the fire brigade will respond to a fire in this area and supplement the systemwith manual hose streams.d. An automatic smoke detection system is not necessary in these areas because theautomatic wet-pipe suppression system is equipped with a flow switch that alarms in thecontinually-manned Control Room. Control Room operators will dispatch the onsite firebrigade to commence manual firefighting operations. Additional fire protection in the areasincludes fixed hose stations and portable fire extinguishers. These additional fire protectionfeatures support defense-in-depth (Echelon 2). Additionally, although a full room burn ofeither Room 1101 or Room 1109 is not expected, a deterministic analysis for each of theserooms was completed and demonstrated that for a fire in Room 1101 or 1109 damaging allNSCA targets, the plant would be able to achieve a safe and stable condition with a NSCAsuccess path free of fire damage, without recovery actions.7 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTe. The discussion of Echelon 1 of defense-in-depth in Approval Request 7 has been revised todiscuss how controls on combustibles in the areas contribute to the overall fire protectiondefense-in-depth.FPE RAt 12:In its letter dated April 13, 2015, the licensee identified a plant condition that was not incompliance with NFPA 805, Section 3.3.5.2. In accordance with 10 CFR 50.48(c) (2) (vii) , thelicensee submitted new Approval Request 8 as part of the amended pages to LAR Attachment Lto request NRC approval of a performance-based method to comply with NFPA 805,Section 3.3.5.2. This section requires that only metal trays and metal conduits be used forelectrical raceways, and that thin wall electrical metallic tubing (EMT) not be used for power,instrumentation, or control cables.The licensee stated that CCNPP currently uses non-metallic raceways (conduit) in concrete-embedded and underground applications; and that EMT is used to route cables in variouslocations throughout the plant. The licensee also requested permission to use a performance-based approach to evaluate and self-approve the use of non-metallic conduits that are neitherconcrete-embedded nor underground.It states in 10 CFR 50.48(c) (2) (vii), in part, that performance-based methods that are used toevaluate FPP elements and minimum design requirements of NFPA 805, Chapter 3, must meetcertain criteria. It must be determined that the method:(A) Satisfies the performance goals, performance objectives, and performance criteriaspecified in NFPA 805 related to nuclear safety and radiological release;(B) Maintains safety margins; and(C) Maintains fire protection defense-in-depth (fire prevention, fire detection, firesuppression, mitigation, and post-fire safe shutdown capability).The NRC staff requests the foliowing information to evaluate the approval request:a. For use of non-metallic raceways (conduits):i. The approval request states that the use of non-metallic conduit is required byCCNPP drawings/specifications for concrete-embedded and undergroundinstallations where metal raceways do not meet design requirements. The approvalrequest further states that new applications of non-metallic conduit are approvedand evaluated in accordance with design procedures which include a review of fireprotection design requirements. Describe the acceptance criteria that is included inthe current design procedures that allow the installation of non-metallic conduit atCCNPP, and clarify whether the current design procedure includes (or will include)criteria that involve: satisfying the nuclear safety and radiological releaseperformance goals, performance objectives and performance criteria; maintainingsafety margins; and maintaining fire protection defense-in-depth. Also, identify theimplementation item to revise the procedure(s), if needed.ii. The licensee stated during a June 4, 2015, public meeting that Approval Request 8will be revised and resubmitted to remove the use of non-metallic raceways(conduit) in applications that are neither embedded in concrete nor buriedunderground. Confirm that this is correct.8 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTb. For use of electrical metallic tubing (EMT):i. Provide a technical justification which does not rely on an unendorsed edition ofNFPA 805 (i.e., the 2015 edition) or any other unendorsed NFPA code (e.g., NFPA70).ii. Confirm that the EMT is not installed in any location subject to physical damage,and describe the criteria by which it will be used to ensure that future EMTinstallations will not be in locations subject to physical damage.iii. Provide additional detail regarding the extent of installation of EMT at CCNPP(e.g., a few specific fire areas or throughout the plant). Confirm whether EMT isused for any power, control, or instrument cables associated with Nuclear SafetyCapability Assessment components.iv. The licensee stated that EMT is non-combustible and will not contribute to the fireload, and stated that neither non-EMT nor EMT metallic conduits are credited in theNFPA 805 analyses to prevent or delay damage due to the fire. Confirm that firedamage and circuit failure assumptions for circuits in non-EMT metallic conduit andEMT conduit are the same, or describe the differences.CCNPP Response to NRC FPE RAI 12:a.i. The following general design criteria are used when installing non-metallic conduits:1. Conduit runs placed in concrete encasement are Polystyrene Type I conduit.2. Conduit runs placed in structural concrete slabs are concrete encased are PolystyreneType I1.3. Conduits are inspected and checked, before concrete pours, to assure continuity andposition.4. Duct banks are encased with a minimum envelope thickness of 4 inches.5. Duct banks under roadways are reinforced and installed a minimum of 24 inches belowfinished grade.6. Underground conduit slope a minimum of 1/16 inch per foot toward cable pits orbetween cable pits.7. Conduit elbows projecting above the floor or below the ceiling are standard rigid steel.8. Dead-ended duct banks (for the purpose of being extended later) have their duct tiersstaggers and adjusted so that each tier extends 18 inches farther out than the tierabove it. Conduits are plugged with plastic plugs, dux-seal, or equal.9. Minimum duct bank conduit sizes are 2 inches. Minimum slab or wall embed conduitsize are 1 inch in wall or 2 inches in slabs (except as noted by design).Procedure LS-AA-1 28-101 provides criteria that include:1. Satisfying the nuclear safety and radiological release performance goals, performanceobjectives and performance criteria;2. Maintaining safety margins; and3. Maintaining fire protection defense-in-depth.a.ii. Approval request #8 has been revised to remove the use of non-metallic raceways (conduit)in applications that are neither embedded in concrete nor buried underground.9 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTb.i. Electrical metallic tubing (EMT) is made from steel and is therefore impact resistant (tough)due to high yield and tensile strengths. Electrical metallic tubing provides a method ofrouting and supporting cables. Electrical metallic tubing completely encases the enclosedcable and therefore provides protection against damage. Electrical metallic tubing is non-combustible.Electrical metallic tubing in use at CCNPP has the following properties (other larger tradesizes may be used):Trade Size Internal WallDiameter Diameter Minimum Thickness(inches) (inches) Tolerance (inches Weight (Ibs/ft) (inchesOutside nominal) nominal)3/4 0.922 +/-0.005 0.824 0.435 0.0491 1.163 +/-0.005 1.049 0.64 0.0571 1/2 1.74 +/-0.005 1.61 1.1 0.0652 2.197 +/-0.005 2.067 1.4 0.065b.ii. Electrical metallic tubing is not installed in locations subject to severe physical damage.Routine load handling where forklift operations are in close proximity to NSCA cables is thetype of location where severe physical damage could occur. General areas throughout theplant are not subject to severe physical damage since routine load handling with forklifts arenot allowed.b.iii. Electrical metallic tubing (as well as rigid metal conduit) is used in all fire areas of the plantat CCNPP and is used to route NSCA cables for power, control, and instrumentationcircuits. Electrical metallic tubing has been a basic conduit type since original construction.Its presence has not adversely affected nuclear safety performance criteria, radiologicalrelease performance criteria, safety margin, or defense-in-depth.b.iv. The fire damage and circuit failure assumptions for non-EMT and EMT conduits are thesame as other raceway types. Electrical metallic tubing is metallic and will provide anelectrical ground path for circuit failures (e.g., an energized conduit could spuriouslyenergize an NSCA circuit); therefore, no credit is given for EMT to prevent or delay firedamage and circuit failures.Safe Shutdown Analysis (SSA) RAI 11.01:Safe Shutdown Analysis (SSA) RAI 11 requested in formation on how the Marinite boards werecredited in NFPA 805, Chapter 4. In its response to SSA RAI 11l.a (by letter dated April 13,2015), the licensee stated that the Marinite boards will no longer be credited to provide 20 footseparation in Unit 1 and Unit 2 containments; and that the Marinite boards are credited in theFire PRA as a "fire break" to prevent fire spread across the east and west portions of Unit 1 and2 containments. The licensee stated that a minimum of 25 feet of each cable tray (thattraverses between containment east to west) is covered (top and bottom) with 1/2-inchMarinite XL and the Marinite boards are banded to the trays with 3/8-inch stainless steelbanding, minimum of 12 gauge steeL.10 ATTACHMENT (1)REQUEST FOR ADDITIONAL INFORMATION REGARDING THE NATIONAL FIRE PROTECTIONASSOCIATION STANDARD 805 LICENSE AMENDMENT REQUESTIt states in NFPA 805, Section 4.1 that once a determination has been made that a fireprotection system or feature is required to achieve the performance criteria of Section 1.5, itsdesign and qualification shall meet the applicable requirement of Chapter 3. Based ondiscussions with the licensee during a public meeting on June 4, 2015, the NRC staffunderstands that the Marinite boards have been installed and are being credited in a similarmanner to metal cable tray top and bottom covers. Describe the Marinite board performanceassumptions, as credited in the performance-based analysis for the Marinite board.CCNPP Response to NRC SSA RAt 11.01 :The Marinite boards have been installed and are being credited in a similar manner to metalcable tray top and bottom covers. The Marinite boards are not credited to prevent fire damageto the cables routed in the cable trays.The Marinite boards are credited in the FPRA to prevent fire spread and propagation, and toallow the covered sections of the cable trays to be excluded as a secondary combustible. Thiscredit is consistent with the cable tray barrier test findings reported in NUREG/CR-6850,Appendix Q, and the testing results reported in NUREG-0381.11 ENCLOSURE 1Contains markups of the original license amendment package pagesand supersedes the previously provided pagesCalvert Cliffs Nuclear Power PlantAugust 13, 2015 Constellation Energy Nuclear Group Attachment L- NFPA 805 Chap. 3 Requirements for ApprovalApproval Request 7NFPA 805 Section 3.3.1.2(1) states:'W/ood used within the power block shall be listed pressure-impregnated or coated with a listedfire-retardant application.Exception: Cribbing timbers 6 in. by 6 in. (15.2 cm by 15.2 cm) or larger shall not be required tobe fire-retardant treated."The areas at CON PP listed below contain some quantity of wood that is not in compliance withNFPA 805, Section 3.3.1.2(1). CCNPP requests NRC approval for the ability to store/use woodin the designated portions of the subject rooms as an acceptable variance from therequirements of NFPA 805 Chapter 3. The request is applicable to the designated fenced-instorage areas described below:* Fire Area TB/NSB/ACA, Room 1101 (12' North Storage Area)o Fenced-in storage area between column DD/1 02.4 and GG/1 05.5(approximately 5,500 ft2).* Fire Area TB/N SB/ACA. Room 1109 (Warehouse)o Fenced-in storage area between column DD/207.5 and GG/208.5(approximately 1,900 ft2).o Fenced-in storage area west of the freight elevator to column AA/207.5(approximately 1,300 ft2).Basis for Request:firo ar.a TB/NSB/^C^ w.hich encompasses the 12' and4 27/31' e~levation of t.. he Nort'h SeR',iceBuilding all eleation of t...,he, Turbine., Building.,,- The storag ar....as. conai variou typos,, ..a-ndI of storage, includi,4ng butI not I~,limited to racknL sto'lrage'J~" heig;htdoes,-,not 12'),.hlimits,, on,.Ih f- quantities,, o,"f combutbe inm ta h,.. ,hese stor.age hara The storage in Rooms 1101 and 1109 consists of solid metal shelving (less than 12 feet high),metal single and double row open storage racks with less than 12 feet of storage located on the [Y ]racks, and materials stored on the floor. The metal open storage racks are separated from each IAother by a minimum distance of 8 feet. The areas contain ordinary combustibles and can beclassified as Ordinary Hazard (Group 2) occupancies with Type II Storage, as defined by NFPA LJ13, 1971 edition (code of record). The areas are not used as storage areas for wood; instead,wood is incidental to the storage areas. The wood in the areas consists of pallets, cable reels,shipment containers, and small hand tools. The storage in the areas consists of plant suppliesincluding both metal and plastic tools, equipment, and supplies.The code of record does not contain detailed commodity classifications; therefore, the current(2013) edition of NFPA 13 was used to classify the commodities in the area for the purposes ofthis approval request. The commodities stored on the single and double row open storage racksand solid metal shelving can be primarily classified as Class I through Class IV commodities.There are minor amounts (10 or fewer distributed, non-adjacent pallets, as allowed by NFPA 13,2013 edition) of higher hazard commodities (i.e., Group A plastics). Stacks of idle wood palletsCCNPP Page L-26CCNPPPage L-26 Constellation Energy Nuclear Group Attachment L- NFPA 805 Chap. 3 Requirements for Approvalare not stored in the area. It is estimated that untreated wood does not exceed 20% of total fireloading of the storage. The total fire load of Room 1101 is approximately 2.2 Billion BTUs,resulting in a fire severity of approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />. The total fire load of Room 1109 isapproximately 1.3 Billion BTUs, resulting in a fire severity of approximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br />.Administrative controls in these areas include procedural controls on transient combustibles andproceduralized inspections of the area. The Combustible Loading Analysis Database (CLAD)tracks the quantities of combustibles that are present in the areas. The proceduralizedinspections of the area will ensure that the storage in the requested areas (including the wood inthese areas) do no exceed the design capabilities of the sprinkler system protecting Rooms1101 and 1109.Implementation Item IMP-21 has been created to ensure that the proceduralized inspections ofthe area will verify that the storage configurations will not exceed the design capability of thesprinkler system protecting Rooms 1101 and 1109 and that non-treated wood will not exceed20% of the total fire loading of the storage. This includes verification of the following:* The height of storage (measured from floor to top of commodity) does not exceed 12feet.* Commodities stored on racks and shelves can be classified as Class I, Class II, Class IllI FPor Class IV commodities as defined in Section 5.6 of NFPA 13, 2013 edition.RAo Exception: minor quantities of more severe commodities (e.g., Group A plastics)will be allowed as permitted by Section 5.3.1.2.3 of NFPA 13, 2013 edition(limited to 10 distributed and non-adjacent pallets).* Current rack spacing is maintained (i.e., minimum of 8 foot spacing between storageracks).* There are no stacks of idle wood pallets present (Section 12.12.1.2 of NFPA 13, 2013edition).* Non-treated wood does not exceed 20% of the total fire loading of the areas.* Adequate clearance, free of combustible material, is maintained around energizedelectrical equipment.* There are neither fixed ignition sources in, or near, the fenced-in storage areas, norexposure fire hazards, that could propagate to the fenced-in storage and potentiallyignite the stored materials.The likelihood of a fire in these areas is expected to be minimal due to the limited number offixed ignition sources in the rooms. Fixed ignition sources in, or near, the fenced-in storageareas consist of small wall-mounted transformers, forklift battery chargers, small wall-mountedpanels, junction boxes, and electrical cables. The ignition sources are located such that there isno continuous path of fixed intervening combustibles present that could be expected to facilitatefire propagation from a fixed ignition source to potentially ignite the stored materials.Administrative controls ensure that adequate clearance, free of combustible material, ismaintained around energized electrical equipment. Additionally, existing processes ensure thatadministrative controls are being followed in these areas. This provides reasonable assurance [FPE]that transient combustibles will not provide a pathway for potential fire spread from a fixedIR Iignition source to the stored materials. -ai-hThe likelihood of a transient fire is minimized due lito procedural controls on hot work and transient combustible material at CCNPP. LIn the event of a fire in the storage areas, wet pipe suppression is provided in the areas abovethe storage which has been reviewed for compliance with NEPA 13, "Standard for theInstallation of Sprinkler Systems". The technical justification for compliance with NFPA 13, 1971edition is as follows:ICCNPP Page L-27CCNPPPage L-27 Constellation Energy Nuclear Group Attachment L- NFPA 805 Chap. 3 Requirements for ApprovalSection 3.9.1 of NFPA 805 requires that automatic or manual water-based fire suppressionsystems required to meet the performance or deterministic requirements of Chapter 4 shallbe installed in accordance with NFPA 13. NFPA 13, "Installation of Sprinkler Systems," 1971edition, is the code of record to which the sprinkler system protecting Room 1101 and Room1109 was designed. The system was designed as an Ordinary Hazard pipe schedulesystem with a coverage area of 100 square feet per sprinkler. The water supply is requiredto provide a flow of 1500 gpm with a minimum residual pressure of 15 psi at the ceiling. Thesystem, including the water supply requirements, were reviewed for compliance with NFPA13, 1971 edition, as part of the NFPA 805 transition project and determined to comply withall the primary functional requirements of the standard. Per NFPA 13, 1971 edition, thisconfiguration is sufficient to protect miscellaneous storage up to 12 feet, as discussedbelow. Storage is required to be limited to 12 feet because if storage exceeded this height,additional high-piled storage requirements would be invoked per Section 4045 of NFPA 13,1971 edition. Details regarding compliance with NFPA 13, 1971 edition are discussed in thefollowing paragraphs.Section 1321 of NFPA 13, 1971 edition, lists "general warehouses and storage areas" as anexample of ordinary hazard occupancies. Section 2126 further classifies the warehousefacility as "Ordinary Hazard (Group 2). This group is defined as the group of the OrdinaryHazard class that has properties "where combustibility of contents and ceiling heights aregenerally less favorable than those listed in Group No. 1, but there are only minor amountsof flammable liquids and essentially no obstructions." An example given in NFPA 13, 1971edition, is "storage buildings (having low factors of combustibility and obstruction)." Thisclassification is consistent with the storage configurations in Room 1101 and 1109 atCCNPP.rFP--Section 3 of Appendix A to NFPA 13, 1971 edition, defines ordinary combustibles as"commodities, packaging, or storage aids which have heats of combustion (British thermal RAunits per pound) similar to wood, cloth or paper and which produce fires that may normallybe extinguished by the quenching and cooling effect of water." The storage in Rooms 1101and 1109 is primarily ordinary combustibles.In order for a system to perform as designed, the maximum allowable system area is limitedby NFPA 13. Section 12 of Appendix A to NFPA 13, 1971 edition, defines Type II Storage asstorage in which "combustible commodities or noncombustible commodities involvingcombustible packaging or storage aids stored not over 15 feet high in solid piles or not over12 feet high in piles that contain horizontal channels." This section further states that "minorquantities of commodities of hazard greater than ordinary combustibles may be includedwithout affecting this general classification." Storage in Rooms 1101 and 1109 meets thedefinition of Type II Storage. Section 3022 of NFPA 13, 1971 edition, limits the maximumsystem area to 52,000 square feet for Ordinary Hazard and Type II Storage. The system atCCNPP covers a floor area of approximately 28,000 square feet; therefore, it is well withinthe allowable size limitations.As the code of record does not contain detailed commodity classification requirements orguidelines and due to the increased prevalence of plastic in modern products compared to1971, the area/density requirements for the storage configuration were reviewed against thecurrent (2013) edition of NFPA 13. It was determined that the existing storage configurationresembles Class IV commodities and the sprinkler protection requirements are similar to thosemet by the installed sprinkler system. The current sprinkler system is adequate for the hazardspresent as long as the following bases for acceptability are maintained:SThe height of storage (measured from floor to top of commodity) does not exceed 12CCNPP Page L-28CCNPPPage L-28 Constellation Energy Nuclear Group Attachment L- NFPA 805 Chap. 3 Requirements for Approvalfeet.*Commodities stored on racks and shelves can be classified as Class I, Class II, ClassIll, or Class IV commodities as defined in Section 5.6 of NFPA 13, 2013 edition.o Exception: minor quantities of more severe commodities (e.g., Group Aplastics) will be allowed as permitted by Section 5.3.1.2.3 of NFPA 13, 2013edition (limited to 10 distributed and non-adjacent pallets).*Current rack spacing is maintained (i.e., minimum of 8 foot spacing between storageracks.* There are no stacks of idle wood pallets present.Should the sprinkler system be upgraded in the future, the bases for acceptability, listedabove above (storage height, acceptable commodities, rack spacing), may be revised IFPEI{consistent with the hazards/storage configurations allowed by NFPA 13 in the code of record IAin force at the time the upgraded system is designed/installed.LIjA separate automatic smoke detection system is not necessary in these areas because theautomatic wet-pipe suppression system is expected to control the fire and is equipped with.A, t-ation-of-a water flow switch that results in a fire alarm signal being transmitted to thecontinually-manned Control Room. Control Room operators will dispatch CCNPP's onsite firebrigade to extinguish the fire. Additional fire protection in the area includes fixed hose stationsand portable fire extinguishers. These additional fire protection features support defense-in-depth.There are cable trays located near the ceiling of each room, approximately 24 feet above thefloor and 13 feet above the maximum height of storage. There is also a series of cable risers atcolumn FF/1 02.4 in Room 1101. Although a full room burn of either Room 1101 or Room 1109is not expected, a deterministic analysis for each of these rooms was completed. Room 1109does not contain any Nuclear Safety Capability Assessment (NSCA) targets. The deterministicanalysis of Room 1101 concluded the following:* Backup Control Room/Cable Spreading Room Ventilation and Cooling System isimpacted; however, CR/CSR HVAC remains available from redundant systems.* Offsite power is impacted; however, power remains available to credited 4kV buses fromEDGs.* Non-safety buses are impacted; however, power remains available to credited 4kVbuses.* Steam isolations downstream of the MSIVs are impacted for both units; however, theMSIVs remain available for both units to provide SG isolation.Based on the above discussion, the deterministic analysis demonstrated that for a fire in Room1101 or 1109 damaging all NSCA targets, the plant would be able to achieve a safe and stablecondition with a NSCA success path free of fire damage. Due to the presence of automaticFPsuppression, manual suppression by-&id the CCNPP onsite fire brigade, and the large roomRAvolume that precludes compartment flashover, the fire is not expected to spread to adjacent 1rooms. Fire Area TB/NSB/ACA is separated from adiacent fire areas by fire barriers.Administrative procedures prohibit wood within all other portions of power block structures atCCNPP.CCNPP Page L-29CCNPPPage L-29 Constellation Energy Nuclear Group Attachment L- NFPA 805 Chap. 3 Requirements for ApprovalAcceptance Criteria Evaluation:Nuclear Safety and Radiological Release Performance Criteria:Although the storage of wood in the subject fenced-in areas of Room 1101 and 1109 does notcomply with section 3.3.1.2(1) of NFPA 805, it will not result in a fire that will compromise thenuclear safety performance criteria of NFPA 805. Deterministic analysis has demonstrated for afire in Room 1101 or 1109 that the plant would be able to achieve a safe and stable conditionwith a Nuclear Safety Capability Assessment (NSCA) success path free of fire damage.The storage of wood in the subject fenced-in portion of Room 1101 and 1109 has no impact onthe radiological release performance criteria. The radiological release performance criteria aresatisfied based on the determination of limiting radioactive release (Attachment E), which is notaffected by the storage of wood within the subject areas.Safety Margin and Defense-in-Depth:The storage of wood to a height less than 12 feet in the subject fenced-in portions of Room1101 and 1109 is within the design capabilities of the NFPA 13 wet pipe sprinkler system and afire will not impact nuclear safety or radioactive release performance criteria; therefore, thesafety margin inherent in the analysis for the fire event has been preserved.The three echelons of defense-in-depth are:(1) To prevent fires from starting (combustible/hot work controls)(2) Rapidly detect, control and extinguish fires that do occur, thereby limiting damage (firedetection systems, automatic fire suppression, manual fire suppression, pre-f ire plans)(3) Provide adequate level of fire protection for systems and structures so that a fire will notprevent essential safety functions from being performed (fire barriers, fire rated cable,success path remains free of fire damage, recovery actions)Per NFPA 805 Section 1.2, defense-in-depth is achieved when an adequate balance of each ofthese elements are provided.Echelon 1 is met by the presence of hot work controls-aPi4, the limited number of fixed ignitionsources in or near the fenced-in areas, and administrative controls that ensure that the typesand quantities of storage in the subject areas do not exceed the design capabilities of theinstalled suppression system. Echelon 2 is met by the installed automatic wet pipe sprinklerFPsystem and the CCNPP on-site fire brigade. Echelon 3 is met through the fire barriersRAseparating Fire Area TB/NSB/ACA from adjacent fire areas as well as a success path remaining 1free of fire damage even if all cables located within each room are failed due to fire. Since abalance of the elemef, ts-echelons is provided, defense-in-depth is achieved.Conclusion:NRC approval is requested for the ability to store/use limited Quantities of wood in thedesignated portions of Room 1101 and 1109, contrary to the requirements of Section 3.3.1.2(1)of NFPA 805, 2001 Edition. Based on the analysis above, the level of risk encountered bymaintaining this current practice is acceptable, and the approach is considered acceptablebecause it:(A) Satisfies the performance goals, performance objectives, and performance criteriaspecified in NFPA 805 related to nuclear safety and radiological release;CCNPP Page L-30CCNPPPage L-30 Constellation Energy Nuclear Group Attachment L- NFPA 805 Chap. 3 Requirements for Approval(B) Maintains safety margins; and(C) Maintains fire protection defense-in-depth (fire prevention, fire detection, firesuppression, mitigation, and post-fire nuclear safety capability).CCNPP Page L-31CCNPPPage L-31 Constellation Energy Nuclear Group Attachment L -NFPA 805 Chap. 3 Requirements for ApprovalApproval Request 8NFPA 805 (2001) Section 3.3.5.2 states:"Only metal tray and metal conduits shall be used for electrical raceways. Thinwall metallic tubing shall not be used for power, instrumentation, or controlcables. Flexible metallic conduits shall only be used in short lengths to connectcomponents."This approval request is applicable to the following elements of Section 3.3.5.2:1. Non-metallic Raceways (Conduit): This section requires that only metal tray and metalconduits shall be used for electrical raceways. CCNPP currently uses non-metallicraceways (conduit) in concrete-embedded and underground applications.2. Thin Wall Metallic Tubing (EMT): This section requires that thin-wall metallic tubing, orelectrical metallic tubing (EMT), shall not be used for power, instrumentation, or controlcables. CCNPP currently uses exposed EMT to route cables in various locationsthroughout the plant.Basis for Request:Non-metallic Raceways (Conduit):The use of non-metallic conduit is required by CCNPP drawing/specificationsFP(61 406SEC1 05.3SH0001) for concrete-embedded and underground installations.-whe~re-enetaI FArac......a..ys doc not,,moot design ,oquirem.nt...... .. These design applications are required where: 1* corrosive conditions exist (water, chemicals, etc.) and metal conduits are subject tofailure; and* non-metallic conduit is not relied upon for groundingNon-metallic conduits are required to be suitable for their intended use. New applications ofnon-metallic conduit are approved and evaluated in accordance with design procedures whichinclude a review of fire protection program design requirements.Non-metallic conduit designs rely on the concrete in which they are embedded and/or theground in which they are buried to prevent:* the failure of credited internal circuits due to an external fire; or* the failure of credited external circuits due to an internal fireNon-metallic conduits are not credited to be fire resistance in the NFPA-805 analysis. Non-metallic conduits are combustible; however, due to the installed locations (underground,concrete-embedded) the combustible material associated with these conduits will not contributeto fire loading. Furthormore, currentoditionof NFPAO 805 (2015 o nly p.ro-hibht non.. metall ic F.,u .-. .. ~ nnvrt. r./nnil.,. n II n a ~ in ,.v n ...,r ,,,., II, 11.n n r. n. nnnnrnl n nrv.. llnr=rjCCNPP requests permission to use the following pe~ormance based approach to evaluate andco!f approve the use of non metallic conduits that are neither concrete embedded norUR4Gf§GU~d~The conditions for approval are:1. Environmental conditions preclude the use of metal!ic conduit (e.g., corrosivee4enn~eRts)~CCNPP Page L-32t/-'d12 Constellation Energy Nuclear Group Attachment L -NFPA 805 Chap. 3 Requirements for ApprovalP, "I'L.. ... ..I nr~ I 1Ff' (11 rinri rTInI:-1IIIf~ EO[1f1I III IF f-i~.':-iII 1:111-1(1 1 J~ :1 iii a: IIIIIfliJ I If:, 1)11 ]If-1UIIL]r I t-]1 1(IIf II H-[ ~-1Fdefined in Generic Letter 82 21, "the fire protection engineers (or engineering consultant)should have the qualifications for membership in the Society of Fire ProtectionEngineers at the grade of member."Artcle358 pr)otection 70sem Natind fleaturei, ande admNistrti, conEdtrons;a,"hueEMT sha. Saifibte permitdfoohermaosed gals, conealed wobj" ectioe, nd33.. pofmNFPA80was evisdcrcnisterinpcife winh NFPA 805t related tohuea saftene reandrdingtic allreletase;ctubi.gMaintainceNP fReprorteton drfensel inr depiinth (Fire preenio, fir1 Edetetion. firATice 358.10(A) ofi NFproAl 70,uNatioa ElcrcCdi(E)s04Edtosaes:TeueoSeto 5EMT. in then2015bedtion)ltae.FPEIRAI12FPERAI12The NEC permits the use of EMT in ap~pda~a§o~N4Ga~GRS-~,horo it is not subject tosevere*EMT has been installed at CCNPP since its original construction, in accordance withplant specifications/drawings, which allow for the use of EMT.*EMT has been installed at CCNPP under design and fire protection program proceduressuch that technical requirements are properly met for the intended use.Acceptance Criteria Evaluation:Nuclear Safety and Radioactive Release Performance Criteria:Non-metallic Raceways (Conduit)The use of non-metallic conduit does net adversely affect nuclear safety since the materials inwhich the conduits are run (concrete and earth) effectively render the non-metallic conduit non-combustible. New installations of non-metallic conduit are evaluated in accordance with designand fire protection program procedures.CCNPPPage L-33 Constellation Energy Nuclear Group Attachment L -NFPA 805 Chap. 3 Requirements for ApprovalThe use of non-metallic conduit in concrete-embedded and underground locations has noimpact on the radioactive release performance criteria. The radioactive release review wasperformed based on the potential location of radiological concerns and is not dependent on thetype of conduit material. The use of non-metallic conduit in concrete-embedded andunderground locations does not add additional radiological materials or challenge the integrity ofplant boundaries.Thin Wall Metallic TubinqThe use of EMT in the plant does not have an adverse effect on nuclear safety. EMT isnoncombustible and will not contribute to fire load. Neither non-EMT nor EMT metallic conduitsare credited in NFPA 805 analyses to prevent or delay damage due to fire. Therefore, the use ofEMT does not impact the nuclear safety performance criteria.The use of EMT has no impact on the radioactive release performance criteria. The radioactiverelease review was performed based on the potential location of radiological concerns and isnot dependent on the construction of metallic conduits. The use of EMT does not add additionalradiological materials or challenge the integrity of plant boundaries.Safety Margin and Defense-in-Depth:Non-Metallic Raceways (Conduits)The use of non-metallic conduit will not adversely impact the ability to meet the NFPA 805nuclear safety or radioactive release performance criteria. While non-metallic conduit iscombustible, it is embedded or buried in non-combustible materials. The use of these materialshas been defined by the limitations of the analytical methods used in the development of theFire PRA. Therefore, the inherent safety margin and conservatisms in these methods remainunchanged. The three echelons of defense-in-depth are:1) to prevent fires from starting (combustible/hot work controls),2) to rapidly detect, control, and extinguish fires that do occur, thereby limiting damage(fire detection systems, automatic fire suppression, manual fire suppression, pre-f ireplans), and3) to provide an adequate level of fire protection for systems and structures so that afire will not prevent essential safety functions from being performed (fire barriers, f ire-rated cable, success path remains free of fire damage, recovery actions).Per NFPA 805 (2001 )Section 1.2, defense-in-depth is achieved when an adequate balance ofeach of these elements is provided.Echelon 1: Non-metallic conduit is installed in concrete-embedded and underground locations.A fire occurring in one of the cables will not spread to impact adjacent fire areas due tocombustible non-metallic conduit because the conduits are embedded in, or buried under, non-combustible materials.Echelon 2: Areas adjacent to those containing non-metallic conduit are protected by manual firesuppression functions, such as portable extinguishers and hose reel stations that are availablefor manual firefighting activities by the site fire brigade, to assure that if a fire was to occur thatdamage from the fire would be limited.Echelon 3: The use of non-metallic conduit does not result in compromising automatic firesuppression functions, manual fire suppression functions, or the ability to maintain a successpath free of fire damage.CCNPP Page L-34CCNPPPage L-34 Constellation Energy Nuclear Group Attachment L -NFPA 805 Chap. 3 Requirements for ApprovalTherefore, the use of non-metallic conduit in concrete-embedded or underground installationsdoes not affect the balance of echelons, 1, 2, or 3 and fire protection defense-in-depth ismaintained.Thin Wall Metallic tubingThe use of EMT will not adversely impact the ability to meet the NFPA 805 nuclear safety orradioactive release performance criteria. EMT is noncombustible due to its metallic constructionand its use is allowed by the NEC. Therefore, the safety margin inherent in the analysis for thefire event has been preserved.The three echelons of defense-in-depth are:1) to prevent fires from starting (combustible/hot work controls),2) to rapidly detect, control, and extinguish fires that do occur, thereby limiting damage(fire detection systems, automatic fire suppression, manual fire suppression, pre-f ireplans), and3) to provide an adequate level of fire protection for systems and structures so that afire will not prevent essential safety functions from being performed (fire barriers, fire-rated cable, success path remains free of fire damage, recovery actions).Per NFPA 805 (2001) Section 1.2, defense-in-depth is achieved when an adequate balance ofeach of these elements is provided.Echelon 1: Administrative hot work controls and transient combustible controls are present inthe areas where EMT is routed. The use of EMT is permitted by the NEC when installed inareas not subject to severe physical damage. The use of EMT will not result in additional cablesbeing considered ignition sources.Echelon 2: Areas where EMT is used are protected by manual fire suppression functions, suchas portable extinguishers and hose reel stations that are available for manual firefightingactivities by the site fire brigade, to assure that if a fire was to occur that damage from the firewould be limited.Echelon 3: The use of EMT does not result in compromising automatic fire suppressionfunctions, manual fire suppression function, or the ability to maintain a success path free of firedamage.Therefore, the use of EMT does not affect the balance of echelons, 1, 2, or 3 and fire protectiondefense-in-depth is maintained.Conclusion:NRC approval is requested for the use of non-metallic conduit in concrete-embedded orunderground installations; and for the use of thin-walled metallic conduit (EMT) in existing and FPEfuture applcations. Tho al ,,.o include tho ,.t to.. us h porformance-based RAIapproac..h doscri.. horo4 ,..in to e.aluat the, use ...of non-metallic conduits that are neither 1concret nor.. underground. 4The performance. methods used for this analysisprovide an equivalent level of fire protection to NFPA 805 (2001) Section 3.3.5.2 and:* Satisfy the performance goals, performance objectives, and performance criteriaspecified in NFPA 805 related to nuclear safety and radioactive release;* Maintain safety margins; and* Maintain fire protection defense-in-depth (fire prevention, fire detection, firesuppression, mitigation, and post-fire safe shutdown capability).CCNPPPage L-35