ML12283A400

Email, Draft Request for Additional Information, License Amendment Request to Adopt National Fire Protection Agency (NFPA)-805 Performance-Based Standard for Fire Protection for LWR Electric Generating Plants

ML12283A400
Person / Time
Site:	Cooper
Issue date:	10/09/2012
From:	Lynnea Wilkins Plant Licensing Branch IV
To:	Mccutchen E Nebraska Public Power District (NPPD)
Wilkins L
References
TAC ME8551
Download: ML12283A400 (27)

Text

From: Wilkins, Lynnea To: McCutchen, Edward L.

Cc: Victor,, Wiilliam R.- Strategic Initiatives; Fields, Leslie

Subject:

DRAFT: RAIs for Cooper Nuclear Station Re: NFPA-805 LAR (ME8551)

Date: Tuesday, October 09, 2012 3:49:00 PM Attachments: ME8551 Draft RAIs for Cooper NFPA 805.docx Ed, By letter dated April 24, 2012, (ADAMs Accession No. ML121220216) Nebraska Public Power District, (NPPD) submitted a license amendment request (LAR) to transition the fire protection licensing basis at the Cooper Nuclear Station, from Title 10 of the Code of Federal Regulations (CFR), Section 50.48(b), to 10CFR50.48(c), National Fire Protection Association Standard NFPA 805 (NFPA 805).

The Nuclear Regulatory Commission NRC staff has reviewed the information provided by the NPPD and also conducted an audit from October 1 to October 5, 2012. The NRC staff has determined that additional information specified in the attached Request for Additional Information (RAI) is needed for the staff to complete its evaluation. In addition, please note that review efforts on this LAR are being continued and additional RAIs may be forthcoming.

Please contact me if a clarifying teleconference is needed for the attached RAIs.

Thanks Lynnea Lynnea Wilkins, Project Manager Fort Calhoun Station, Unit 1 Cooper Nuclear Station Plant Licensing Branch IV Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation US Nuclear Regulatory Commission Phone: 301-415-1377

DRAFT PRE-AUDIT QUESTIONS/PRESENTATION REQUESTS LICENSE AMENDMENT REQUEST TO ADOPT NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR LIGHT WATER REACTOR GENERATING PLANTS COOPER NUCLEAR STATION (TAC NO. ME8551)

Fire Protection Branch PRA Licensing Branch Health Physics and Human Performance Branch SSD RAI 01 License Amendment Request (LAR) Section 4.2.1.1 identifies that the nuclear safety capability assessment (NSCA) methodology review evaluated the existing post-fire safe shutdown analysis methodology against the guidance for transitioning to National Fire Protection Association Standard (NFPA) 805, Performance Based Standard for Fire Protection for Light Water Reactor Generating Plants, provided in NEI 00-01, Rev. 1, Guidance for Post-Fire Safe Shutdown Circuit Analysis, and the subsequent performance of a gap analysis to identify impacts from NEI 00-01, Rev. 1 to Rev. 2. Provide a summary of the technical issues from the gap analysis from NEI 00-01 Rev. 1 to Rev. 2. including the following:

a. NEI 00-01, Rev. 2, Section 3.2.1.2 describes that any post-fire operation of a manual rising-stem valve that has been exposed to fire conditions should be well justified. Identify instances where it is necessary to manually operate valves post-fire that are located in the fire area of concern and may have been exposed to the fire.

b. NEI 00-01, Rev. 2, Section 3.5.1, requires consideration of proper-polarity hot shorts in certain direct current (dc) control circuits for non-high-low pressure interface components. Identify whether proper-polarity dc shorts in non-high-low pressure interfacing components are considered.

SSD RAI 02 Section 4.2.1.2 describes actions necessary to achieve and maintain safe and stable conditions for the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />; however, no description is provided of the actions and resources required to maintain safe and stable conditions beyond the 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> coping period.

a. Describe the specific capabilities that will be required to meet the performance criteria beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

b. Describe any system or component capacity limitations and time-limited actions needed replenish systems, make repairs, or otherwise maintain safe and stable conditions, (e.g. nitrogen supply for automatic depressurization system safety relief valves (ADS SRVs), DC battery power, etc.).

c. Describe whether there are any actions to recover NSCA equipment to sustain safe and stable conditions. Describe the resource (staffing) requirements and timing of these actions.

d. Describe how the feasibility of the actions in b and c above are evaluated or addressed.

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e. Provide a more detailed discussion of the risk of failure of the actions necessary to sustain safe and stable conditions beyond 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />.

f. LAR Section 4.2.1.2 states, For the plant to be in a safe and stable condition, it may not be necessary to perform a transition to cold shutdown as currently required under 10 CFR 50, Appendix R. Therefore the unit may remain at or below the temperature defined by a hot shutdown plant operating state for the event. Confirm that the NSCA does not require the plant to achieve cold shutdown to be in a safe and stable condition or confirm that the NSCA has included cold shutdown equipment and procedures in the analysis. Define the term event in the context of the statement in Section 4.2.1.2 as it applies to achieving and maintaining safe and stable conditions.

SSD RAI 03 LAR Attachment D describes the methods to identify and resolve pinch-points identified from the non power operation (NPO) transition review. Provide a response to the following:

a. Provide a description of any actions being credited to minimize the impact of fire-induced spurious actuations on power operated valves (e.g., air operated valves (AOVs) and motor operated valves (MOVs)) during NPO either as pre-fire configuring or as required during the fire response recovery (e.g., pre-fire rack-out and isolation of air supplies).

b. Identify the locations where key safety functions (KSFs) are achieved solely by recovery actions (RAs) or for which instrumentation not already included in the at-power analysis is needed to support recovery actions required to maintain safe and stable conditions. Identify those recovery actions and instrumentation relied upon in NPO and describe how recovery action feasibility is evaluated. Include in the description whether these variables have been or will be factored into operator procedures supporting these actions.

SSD RAI 04 Attachment V of the LAR, provides discussion of an incipient detection system to be installed (Attachment S, Implementation Item S-2.4), based on insights from analyses for two panels (9-32 and 9-33) in the Auxiliary Relay Room (ARR) (part of fire area CB-D). This incipient detection system is to provide indication in the Control Room (CR) so that an operator/auxiliary operator can respond to the ARR confirm that the incipient detector for one of these panels has activated, and inform the CR. Describe the necessary immediate actions by the CR operators to these incipient detection alarms and how these actions mitigate the circuit failures of concern.

Also describe the longer term RAs remaining given confirmation of activation of detector.

SSD RAI 05 LAR Attachment G, describes the method used to transition operator manual actions (OMAs) as RAs. Provide additional discussion and details of the following RAs:

a. Fire Area CB-D - VFDR CBD-07: repair of the 125VDC and 250VDC train B battery charger cables,

b. Fire Areas CB-D and RBCF - VFDRs CBD-10 and RBCF-05: lifting leads to secure power to valves: RW-AOV-AO82, RW-AOV-AO94, 2

c. Fire Area CB-A - VFDR CBA address why is there no RA for the repair of the fuel oil transfer pump, which is an existing action under Appendix R and included in the Fire PRA (Attachment V SR: SY-A24).

SSD RAI 06 LAR Attachment S, Implementation Item S-3.6 describes confirmatory walk downs of the feasibility of RAs following completion of procedure changes to incorporate NFPA 805 actions.

Implementation Item S-3.6(2) addresses validation of execution times to physically perform the action. Describe the extent to which the actions will be validated (e.g., opening of cabinets to access components and verifying the components can be operated as described). Describe whether there are procedures that address the performance and acceptance criteria for the procedure validations being performed during these confirmatory walk downs.

SSD RAI 07 LAR Attachment F, Fire-Induced Multiple Spurious Operations Resolution, states (under Results of Step 2), The analysis was updated in January 2011 without reconvening the expert panel. Provide additional discussion of the January 2011 update of the multiple spurious operation (MSO) analysis and the process used for this update.

SSD RAI 08 LAR Attachment C describes a means of meeting ventilation cooling requirements for various components (e.g., VFDR CBD-05: EE-BAT-125-1B, EE-BAT-250-1B, EE-SWGR-125B, EE-SWGR-250B; VFDR CBA1-01: EE-SWGR-125B, EE-BAT-124B; VFDR CBB-01: EE-PNL-CDP1A, EE-MCC-LX) via open compartments. Describe whether these compartments require actions to open doors or other features. If these actions are required, describe whether feasibility has been reviewed and whether these actions should be included in LAR Attachment G as RAs. Describe if any other heating ventilation and air conditioning (HVAC) RAs are credited.

SSD RAI 09 Numerous RAs identified in Attachment G document the removing of fuses and operation of MOVs using the motor starter. Use of the motor starter from the motor control center (MCC) bypasses the protective functions of the torque and limit switches. Application of stall thrust to MOVs may cause structural damage to the valve (stem, yoke, stem nut, etc.). Describe the procedural guidance and training provided to the operators to assure that the valve will be positioned to the desired position and also how the process prevents damage to the valve/actuator due to overtorque/overthrust.

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FPE RAI 01 LAR Section 4.1.2.3 lists Chapter 3 elements for which approval is requested via 10 CFR 50.48(c)(2)(vii) but does not include Element 3.3.3. Chapter 3 Element 3.3.3 is included in Attachment A as Submit for NRC Approval, and also in Attachment L as Approval Request 2.

Confirm that NRC approval is requested for NFPA 805 Chapter 3, Element 3.3.3.

FPE RAI 02 LAR Attachment I identifies Yard as a Building /Structure in the Power Block. Identify the structures and more clearly define the needed pieces of equipment included in the Yard in a more detailed list.

FPE RAI 03 Table 4-3, (Fire Areas CB-D and RB-M), Attachment C, and Attachment S (Modifications S-2.5,

-2.6, and -2.7) identify existing and planned installations of radiant energy and flame impingement shields (e.g., Promat-H board) as features required for risk. For each of the existing or planned installations of radiant or flame impingement shields, provide additional information and a description regarding the design of the shields, the installation configuration, and the protection function that is credited in the NFPA 805 analyses. Include descriptions of the fire exposure assumed in determining the acceptability of the shields to meet the protection function. Describe the additional fire protection systems, if any, provided in these areas FPE RAI 04 LAR Attachment A, Section 3.2.3, states, Complies with Required Action. Attachment S, Table S3, Item S-3.1 states that performance based surveillance frequencies will be established as described in EPRI Technical Report 1006756, Fire Protection Surveillance Optimization and Maintenance Guide for Fire Protection Systems and Features. The use of performance-based methods to meet the requirements of NFPA 805, Chapter 3 requires NRC approval in accordance with 10 CFR 50.48(c)(2)(vii).

a. Describe how the guidance in EPRI Technical Report 106756 will be integrated into the NFPA 805 monitoring program.

b. Discuss your plans for complying with 10 CFR 50.48(c)(2)(vii) regarding the use of EPRI Technical Report 1006756.

FPE RAI 05 LAR Attachment A, Section 3.3.5.1 and Attachment L, Approval Request 3, requests NRC approval for minor amounts of wiring located above suspended ceilings that does not meet qualification criteria and is not installed in conduit. Provide the following additional information:

a. Describe the specific circuits associated with the unqualified wires or cables (e.g.,

type, voltage, communication, data, signal, etc.).

b. Describe whether the areas above the suspended ceilings are provided with fire detection or suppression.

c. Provide additional details describing the visual inspection for ignition sources above the suspended ceilings and indicate if the inspection was considered comprehensive.

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d. Describe whether or not the wires and cables that do not meet the qualification criteria of 3.3.5.1, meet IEEE-383, Standard for Type Test of Class 1E Electric Cables, Field Splices, and Connections for Nuclear Power Generating Stations, or other qualification standards. If so, indicate the other standards.

e. Provide additional discussion of minimal amount as used in the Acceptance Criteria Evaluation.

f. Describe the pathway for smoke above the suspended ceiling. If the area is a plenum, describe the exhaust path and whether it is part of a smoke purge system.

g. Provide discussion of the subject wiring installations relative to fire areas containing nuclear safety capability systems and equipment. Identify if any NSCA cables are routed in the areas above suspended ceilings where unqualified cables are located.

FPE RAI 06 LAR Attachment A, Section 3.6.1 and Attachment L, Approval Request 7, requests NRC approval of deviations from NFPA 14, Standard for the Installation of Standpipe and Hose Systems, regarding the design and installation of standpipes and hose systems. The Attachment L Acceptance Criteria Evaluation for NFPA 14, Section 322, states that the subject fire zones can be reached with a maximum of 50-feet of hose in addition to the 100 feet required by the standard. Confirm that the hydraulic calculations for the standpipe system demonstrates acceptable pressure and flow conditions at the nozzle with the head-loss associated with 150-feet of hose.

FPE RAI 07 LAR Attachment A, Element 3.5.6 Compliance Statement, states, Submit for NRC Approval, but this element is not cited in the Approval Request. Clarify that Attachment L, Approval Request 6 also applies to NFPA 805, Section 3.5.6.

FPE RAI 08 Attachment S, Table S-3, Implementation Item S-3.2 establishes enhanced transient and combustible controlled zones in high risk Fire Zones 8A (cable spreading room (CSR)), 9A (Relay Room), 2C above the (traversing incore probe (TIP) Room, 3C, and 3D in the areas around instrument racks 25-5 and 25-6. Describe the assumptions made for these enhanced transient and combustible controlled zones and the types of controls to be put in place relative to other combustible control zones.

Implementation Item S-3.25 identifies the designation of enhanced transient and hot work controlled fire zones. Define what enhanced transient and hot work controlled fire zones means, and specifically what controls will be put in place. Describe what it means to restrict hot work in the context of these enhanced zones.

FPE RAI 09 LAR Section 4.5.2.2 and Figure 4-7 summarizes the approach to evaluating defense-in-depth (DID) and safety margin in the resolution of variance from deterministic requirements (VFDRs).

Under the heading, Disposition of VFDR, the LAR indicates the results of the risk evaluation, DID, and safety margin are summarized in Attachment C. Attachment C does not include discussion or summary of DID and safety margin for the individual VFDRs or on a fire area 5

basis. Provide additional discussion of the methods and criteria for evaluating DID and safety margins and summarize the results as required by NFPA 805, Section 4.2.4.2.

FPE RAI 10 Attachment S, Item S-2.4, identifies a modification to install incipient detection in two panels in the ARR. Because of the various vendor types of incipient detection systems, provide a description of the incipient detection system that will be installed, including a discussion of the design, installation and testing criteria provided in frequently asked question (FAQ) 08-0046.

Describe the compensatory measures necessary in the period between post-transition and prior to completion of the modification, or during incipient detection outages, that will provide the necessary early detection and response as credited in the fire probabilistic risk assessment (FPRA).

FPE RAI 11 LAR Section 4.2.2 describes the process and criteria used to evaluate Existing Engineering Equivalency Evaluations (EEEEs) to determine that a fire protection system or feature is adequate for the hazard. None of the summaries of the EEEEs cited in LAR Table B-1 or described in LAR Table B-3 state that the basis of acceptability of remains valid. Provide an explicit statement that the credited EEEEs were determined to meet the NEI 04-02, Guidance for Implementing a Risk-Informed, Performance Based Fire Protection Program Under 10 CFR 50.48(c), criteria and that the basis of acceptability of previous EEEEs remains valid.

FPE RAI 12 There appears to be inconsistencies between LAR Attachment A (Table B-1) and Attachment S.

Examples include:

Table B-1, Sections 3.3.1.2 Control of Combustibles, 3.3.1.3.1 Control of Ignition Sources, 3.4.2 Fire Pre-Plans, are affected by implementation items listed in Attachment S, but do not reflect the compliance category complies with required action.

Attachment S implementation Items S-3.2 and S-3.25 are associated with enhanced combustible and hot work controls, and Item S-3.20 is associated with pre-fire planning, but are not identified in the associated sections of Table B-1 described above.

a. Clarify that these selected Table B-1 sections comply with required action as appropriate.

b. Perform an extent of condition review to identify all situations where implementation items are identified and ensure that the appropriate compliance strategy ("complies with required action") is reflected as required in the transition report (B-1 Table).

FPE RAI 13 LAR Attachment L, Approval Request 5, requests NRC approval of the bulk hydrogen storage configuration. NFPA 805, Section 3.3.7.2 applies to outdoor storage of high-pressure flammable gas containers. Cooper describes the bulk hydrogen storage as being in a separate structure. Describe how the configuration of the bulk storage of hydrogen gas is a deviation from the requirements of NFPA 805, Section 3.3.7.2.

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FPE RAI 14 With regard to LAR Attachment L, Approval Request 6, describe indications available to the CR operators in the event of electric fire pump failure to start while the diesel fire pump is locked out from starting. For example, describe if there is an alarm or indication of low fire water system pressure.

FPE RAI 15 Describe the post-transition NFPA 805 compliance basis for LAR Attachment A, Element 3.2.3, since the stated technical specification (TS) section cited in the compliance basis will be deleted during transition.

FPE RAI 16 Attachment L, Request 3 states that it is similar to the request made by Arkansas Nuclear One Unit 2. However, that request contains an error; that is:

Power and control cables at ANO are IEEE-383-1974 or equivalent. FAQ 06-0022 identified acceptable electrical cable construction tests. Plenum rated cable is tested to NFPA 262, Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces, and the FAQ concluded that the NFPA 262 test is equivalent to the IEEE-383-1974 test. Therefore, IEEE cable is inherently equivalent to plenum rated cable and acceptable to be routed above suspended ceilings. [emphasis added]

While FAQ 06-0022 documented the fact that NFPA 262 is a more stringent fire test than IEEE-383, the reverse is not true. Just because a cable passes the IEEE-383 flame test does not mean that it can pass NFPA 262.

Describe whether the assumption of equivalence between the IEEE-383-1974 and NFPA 262 tests is relied upon. If the assumption is relied upon, revise the request so that this is no longer the case.

FPE RAI 17 Provide the NRC citations that establish the previous approval for LAR Attachment A, Elements 3.4.1(a) and 3.6.4.

FPE RAI 18 Describe and justify why the dry well is not included in LAR Attachment C (B-3 Table) and Table 4-3. Alternatively, revise the tables to include this fire area.

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PRA RAI-01 Internal Events PRA F&Os Clarify the following dispositions to Internal events (IE) Probabilistic Risk Assessment (PRA)

Facts and Observations (F&Os) identified in Attachment U of the LAR that appear to have the potential to noticeably impact the fire PRA (FPRA) results and do not seem fully resolved:

a) F&O against HR-G7: Dependencies between multiple human actions in the same cutset appear not to be evaluated in all cases. Discuss in more detail the F&O examples.

Include discussion of the use of Human Error Probability (HEP) floors in the Human Reliability Analysis (HRA) dependency analysis.

b) F&O against HR-I3, DA-E3, IE-D3, IF-F3, and SC-C3: The requirement to document key assumptions and sources of uncertainty appears not to have been met for a number of PRA elements. Describe how key assumptions and sources of uncertainty were identified and documented for the PRA elements cited in these F&Os. Include in this description, identification of criteria used to judge the importance of assumptions and whether any sensitivity studies were performed as a result.

c) F&O against QU-E3: Discuss the F&O disposition and why the finding has no impact.

Specifically it is not clear whether a state-of-knowledge correlations (SOKC) of failure rates using plant specific data was performed. Clarify that for component failures based on the same plant specific data SOKC was taken into account.

d) F&O against AS-A2: Confirm that examination of thermo-hydraulic analysis demonstrates that event sequences modeled in the PRA reach a stable state.

e) F&O against SY-A4; It is not clear that since the individual plant evaluations (IPEs) that walkdowns and interviews with plant engineers and operators have been specifically performed to support the PRA. Describe the system walkdowns and interviews that have been performed to confirm that the PRA system analysis reflects the as-built, as-operated plant.

f) F&O against QU-D4. Describe the reasonableness review performed on the non-significant cut sets for the PRA results supporting the LAR.

g) F&O against QU-S5. Describe the limitations that were identified for the quantification process and how they are addressed in the PRA.

PRA RAI-02 Fire PRA F&Os Clarify the following dispositions to fire PRA F&Os and supporting requirement SR assessment identified in Attachment V of the LAR that appear to have the potential to noticeably impact the FPRA results and do not seem fully resolved:

a) F&O 4-1 against PP-B2: In response to this F&O a review of the justification of partitioning between fire zones was performed for screened fire zones. Describe the criteria used to determine whether a barrier is substantial enough to preclude fire spread to adjacent fire zones within the fire compartment. Clarify the difference, if any, between barriers defined for zones and those defined for fire compartments (i.e., the physical analysis units). Include in this clarification, a discussion of how elements of 8

partitioning were considered for fire zones. In particular, discuss how ducting, spatial separation and localized protection features were considered.

b) F&O 5-2 against CS-A7: The disposition to this F&O states that Kerite was treated as thermoset material with respect to flame spread and heat release rate (HRR) but treated as thermosplastic with respect to damaging heat flux. The FPRA peer review report provides the following reviewers elaboration on this F&O: FAQ 08-0053 was generated by CNS to justify consideration of Kerite cable as thermoset. Recent testing conducted by NRC tends to indicate that Kerite cable should be treated as thermosplastic.

However, a final determination has not been made as FAQ 08-0053 is still open. FAQ 08-0053 has now been finalized and a closure memo issued by the NRC (ADAMS Accession Number ML121440155). The closure memo recommends, based on experimental evidence from NUREG/CR-7102, Kerite Analysis in Thermal Environment of Fire (KATE-Fire); Test Results-Final Report, that a temperature of 477 °F (247 °C) be assumed as the minimum threshold of electrical failure for Kerite-FR cables. Discuss the following:

i. Describe the use of Kerite, identify locations it is credited in the PRA, and explain how Kerite cables are treated in the FPRA. Specifically clarify what damaging heat flux values (e.g., 205°C or 372°C) and what HRR values (see Section 7.4 of NUREG-7102) were used (e.g., 150 or 250 kW/m2) for the justification for these values.

ii. Provide the results of a sensitivity analysis showing the impact on the PRA results (total and delta core damage frequency (CDF)/ large early release frequency (LERF)) from evaluating Kerite-FR as thermoplastic material using the recommended temperature from the FAQ 08-0053 closure memo.

c) F&O 4-10 against PRM-B11: The FPRA peer review report presents the reviewers recommended resolution to this F&O: that instrument indication requirements be added directly the fault tree logic in an AND-gate with the corresponding operator actions. The disposition to this F&O explains that instruments (i.e., indication) required for diagnosis are addressed in the Human Reliability Analysis (HRA), and if the cables for those indications have not been traced the failure of the corresponding human error probability (HEP) is set to 1.0. Clarify how indications needed for diagnosis, and associated instrumentation, are identified and documented in the fire PRA, and explain how random failures of those instruments are addressed.

d) F&O 5-12 against FSS-F1: In response to this F&O an update to Calculation NEDC 09-090 (Exposed Structural Steel) was performed that addresses fire impact on the steel columns caused by oil cascading to a lower elevation. Describe the update to the calculation, assumptions made about the size of the oil spill, and the basis for those assumptions.

e) F&O 6-2 against FSS-E4: This F&O points out that the uncertainty and sensitivity report (Task 7.15 Uncertainty and Sensitivity Analysis) makes no mention of assumed cable routes, even though it states that cable routing could be the source of uncertainty.

Discuss the extent to which assumed cable routes are factors in the FPRA and if the cable routes assumed, describe the impact of these assumptions on risk estimates.

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f) F&O 6-15 against FSS-H5: The disposition to this F&O cites NEDC 08-041 (Main Control Room Abandonment) as addressing the fire spread between Main Control Board (MCB) panels and electrical panels in the MCR. Discuss the modeling of both MCB and electrical panels, including the following:

i. Where it is assumed that fire does not propagate between open back cabinets, confirm that there is no cable run between the exposing and exposed panels.

ii. Neither NEDC 08-041 nor NEDC 10-001 discuss the treatment of sensitive electronics. Explain the extent to which sensitive electronics are installed, both in the MCR and elsewhere in the plant, and how sensitive electronics were treated in the PRA. Clarify if the treatment of sensitive electronics is in accordance with NUREG/CR-6850 and discuss the sensitivity of the PRA results to the NUREG/CR-6850 treatment of sensitive electronics.

g) F&O 1-9 against HR-G1: This F&O indicates that there were a number of significant HFEs for which screening values were applied. Clarify what significant HFEs were assigned high failure probabilities and provide the bases for those values.

h) F&O 1-17 against QU-E3: This disposition for this F&O provides a detailed explanation of why quantitative uncertainty results are not provided as part of the fire PRA results and appears to present an informal estimate of the risk uncertainty that concludes with the following statement: a reasonable estimate of the uncertainty interval is minus 10 to plus 5 on the calculated mean value, where the mean is estimated to be on the order of a factor of 5 to10 lower than calculated. Attachment W of the LAR states that calculated values are estimated to be conservative by a factor of 5 to 10.. Thus better estimates of CDF and LEF are <~1E-5/yr and <~2E-6/yr. This statement in Attachment W seems to indicate that parametric data uncertainty was propagated and that the risk estimates in Attachment W are calculated mean based on propagation of parametric uncertainty referred to in the F&O disposition. Clarify how parametric uncertainty was propagated and how the risk values in LAR Attachment W was determined.

i) Assessment against SY-A24: This SR assessment comes from the fire PRA peer review SR Summary assessment table (i.e., Appendix B) against SY-A24. (Attachment V-2 of the LAR does not attribute an F&O to this SR assessment.). The disposition to the assessment of this SR acknowledges that the fire PRA includes repair of battery charters and diesel generator fuel oil transfer pumps which are supported by procedures, pre-staged equipment, and timing assessments. The requirement of SR SY-A24 is to DO NOT MODEL the repair of hardware faults, unless the probability of repair is justified through an adequate analysis or examination of data. Repairing equipment damaged by fire would appear to be difficult to proceduralize. Describe the basis for the determination of the HEPs for these repairs. As part of this description discuss the procedure for performing these repairs and how it addresses the variability and uncertainty presumably associated with fire damage. Discuss to what extent examination of data was performed to support determination of these HEPs.

j) Assessment against SY-A6: This SR assessment comes from the fire PRA peer review SR Summary assessment table (i.e., Appendix B) assessment SY-A6 (Attachment V-2 of the LAR does not attribute an F&O to this SR). This assessment points out that instrumentation may need to be added to system boundary definitions for the fire PRA.

The disposition to this SR noncompliance explains that new components were added to 10

system definitions for the fire PRA. Describe what components were added to the system boundary definitions, whether instruments were included, and the criteria for adding new components.

k) Assessment against PRM-B9: This SR assessment comes from the fire PRA peer review SR Summary assessment table (i.e., Appendix B) assessment PRM-B9 (Attachment V-2 of the LAR does not attribute an F&O to this SR). Significant changes were made to the internal events PRA models to produce the fire PRA models, but it is difficult to review and judge completeness of these models given this information resides in various reports not parallel to the internal events systems analysis. As a result it is difficult to determine that this SR and associated ones (e.g., SY-A2, SY-A3, SY-A4, SY-A6, SY-A12 and SY-A24) are met. Discuss the extent of PRA model changes made since the peer review and whether these changes constitute a PRA Upgrade as defined in the ASME/ANS PRA standard and clarified in Regulatory Guide 1.200.

l) F&O 4-5 against PRM-B9. If the failure mode Fails to Remain Open/Closed is not modeled in the IEPRA model, discuss how it is assured that this failure mode is considered for the FPRA model.

m) F&O 1-30 against FSS-E3. Provide more detailed justification describing why meeting Cat I, and not Cat II, is acceptable for this application.

n) F&O 4-22 against HRA-A4. The disposition appears to suggest that the focus of the interviews were on select dominant sequences rather than relevant actions identified in SR HRA-A1, HRA-A2, and HRA-A3. Clarify how the interviews satisfy the requirements of HRA-A4 with regard to the cited SRs.

o) F&O 2-15 against HR-G7. Discuss how the peer review observation was addressed that The current quantification method does not use higher HEP values in quantification and does not apply recovery file that includes HEP combination events.

p) F&O 7-8 against QU-D6. The disposition mentions that the CDF and LERF cutsets were not merged. Discuss how reasonableness reviews were performed for CDF and LERF custsets.

q) F&O 8-6 against LE-G3. It is not clear how the disposition addresses the peer review finding on documenting LERF contributions. Clarify how the contributions to LERF were documented.

r) F&O 7-8 against QU-D7. Discuss what was reviewed, what results were reviewed, and the conclusions from the review.

s) F&Os 7-8 and 8-2 against QU-F3. Explain how it is known if the significant basic events are reasonable.

PRA RAI-03 PRA Modeling of VEWFDS LAR Attachment V states (first paragraph of Section V.2) that the very early warning fire detection system (VEWFDS) was modeled using FAQ 08-0046, with the exception that rather than modeling the increased potential for suppressing the fire, the analysis only modeled the early detection and then applied human reliability analyses to model operator response to the 11

early detection. As indicated the guidance in FAQ 08-0046 is meant for determining increased probability of fire suppression, not to determine the probability of shutdown from the MCR before forced abandonment. Discussion on page V-3 indicates that two operator actions are credited. A probability of 0.01 is assigned to the failure of operators to confirm the situation locally and report back to the MCR. A probability of 0.01 is also assigned to the failure of MCR operators to respond using procedures for these panels. Attachment S (see Item S-2.4) states that crediting these actions allows for shutdown from the Control Room with minimal field actions and a lower CCDP (i.e., 0.0127) than if ASD is modeled (0.1). However, these operator actions are not the actions defined in the FAQ-08-0046 Event Tree.

Accordingly, it is not clear a probability of 0.01 is an appropriate probability for these operator failures. No HRA is presented or referred to. In light of the significant risk reduction from VEWFDS (in combination with these HEPs), provide the basis for these operator error probabilities. Include as part of this basis more description of the required operator actions and the basis for the HEPs. In addition, clarify if the two cabinets where the VEWFDS is being installed are sealed cabinets per NUREG/CR-6850 and FAQ 08-0042 and, if not, justify why the fire is not postulated to propagate to adjacent cabinets.

PRA RAI-04 Transient Fire Heat Release Rate Attachment V identifies that the Cable Spreading Room and Auxiliary Relay Room have been designated enhanced transient and hot work controlled fire zones, and therefore a reduction (beyond NUREG/CR-6850 recommendations) from 317 kW to 69 kW is made for transient fires analyzed in these areas. Provide further justification for the use of 69 kW transient fires in these fire zones. Specifically, the justification should address the specific attributes and considerations applicable to the location, plant administrative controls, the results of a review of records related to violations of the transient combustible controls, and any other key factors for this reduced fire size. If the HRR cannot be justified using the guidance criteria, discuss the impact on the analysis.

PRA RAI-05 Flame and Radiant Heat Shields Table 4-3 of the LAR identifies flame impingement shields and radiant energy shields as features of the Fire Protection program. Although, Table 4.3 indicates that these shields are credited as Required for Risk Significance, it is not clear whether they are credited as part of the fire modeling supporting the fire PRA. If they credited, define what is credited and provide justification of this credit. Include in the discussion identification of engineering evaluations used to support the assumptions made about the function of these shields.

PRA RAI-06 Non-suppression Probability The non-suppression probability (Pns) results reported in NEDC-08-041, Rev. 3 (i.e., Tables 11, 12, 13, 21, 22, and 23) used non-suppression probability values less than 0.001, contrary to NUREG/CR-6850 Attachment P. Provide the results of a sensitivity analysis (CDF, LERF, CDF, LERF) using non-suppression probabilities no lower than 1E-03.

PRA RAI-07 MCB Modeling Attachment A of NEDC-10-001 shows a single fire scenario for MCB 9-4. Attachment D of NEDC-09-085 indicates that this scenario results in MCR abandonment. Discuss the modeling of this panel and why there are no loss-of-control scenarios.

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PRA RAI-08 Fixed Fire Ignition Frequencies Attachment B of NEDC 08-032 identifies instances in which motors/pumps smaller than 5 hp are included in the count for Bins 21 and 26 (e.g., pages 44 and 45). There are also instances in which transformers rated less than 45 kVa are included in the count for Bin 23b (e.g., page 55).

Clarify whether these components, and any others so identified, have been assessed appropriately and, if not, provide an assessment of the impact on the PRA results (CDF, LERF, CDF, LERF) of not including these components in the ignition source weighting factors.

PRA RAI-09 Inclusion of Multiple Compartment Scenarios Attachment W, states that The total calculated CDF and LERF (post NFPA 805), including multi-compartment scenarios, are 5.2E-5/yr and 1.2E-5/yr respectively. However, Table W-2 shows the fire CDF and LERF to be 5.07E-5/yr and 1.05E-5/yr, respectively. This suggests that Table W-2 does not include the contribution from the multi-compartment scenarios. Reconcile this discrepancy. If the CDF and LERF, and the additional risk of Recovery Actions (RAs) shown in Table W-2 do not include the contribution of multi-compartment scenarios, then provide a recompilation of Table W-2 that includes risk from multi-compartment scenarios.

PRA RAI-10 Spread of Fire to Other Combustibles Please describe how your evaluation includes the possible increase in heat release rate caused by the spread of a fire from the ignition source to other combustibles. Please summarize how suppression is included in your evaluation PRA RAI-11 Transient Fire Modeling at Pinch Points Per Section 11.1.5.6 of NUREG/CR-6850, transient fires should at a minimum be placed in locations within the plant PAUs where critical targets are located, such as where CCDPs are highest for that PAU, i.e., at pinch points. Pinch points include locations of redundant trains or the vicinity of other potentially risk-relevant equipment, including the cabling associated with each. Transient fires should be placed at all appropriate locations in a PAU where they can threaten pinch points. Hot work should be assumed to occur in locations where hot work is a possibility, even if improbable (but not impossible), keeping in mind the same philosophy. With this context, provide the following:

a) Describe how transient and hot work fires are distributed within the PAUs at CNS. In particular, identify the criteria at CNS which determine where an ignition source is placed within the PAUs. Also, if there are areas within a PAU where no transient or hot work fires are located since those areas are considered inaccessible, describe the criteria used to define inaccessible. Note that an inaccessible area is not the same as a location where fire is simply unlikely, even if highly improbable.

b) Relative to the MCR, provide an assessment of the impact on the PRA results (CDF, LERF, CDF, LERF) of placing transients behind the open-back MCBs and back panels.

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PRA RAI-12 Defense in Depth and Safety Margins Describe the methodology that was used to evaluate defense-in-depth and that was used to evaluate safety margins. The description should include what was evaluated, how the evaluations were performed, and what, if any, actions or changes to the plant or procedures were taken to maintain the philosophy of defense-in-depth or sufficient safety margins.

PRA RAI-13 Fire Ignition Frequencies from Supplement 1 Section 10 of NUREG/CR-6850 Supplement 1 states that a sensitivity analysis should be performed when using the fire ignition frequencies in the Supplement as the base case instead of the fire ignition frequencies provided in Table 6-1 of NUREG/CR-6850. Provide the results of a sensitivity analysis of the impact of using the Table 6-1 frequencies instead of the Supplement frequencies on CDF, LERF, CDF, and LERF for all of those bins that are characterized by an alpha that is less than or equal to one. If the sensitivity analysis indicates that the change in risk acceptance guidelines would be exceeded using the values in Table 6-1, please justify not meeting the guidelines.

PRA RAI-14 Main Control Room Abandonment Please describe how CDF and LERF are estimated in main control room (MCR) abandonment scenarios. Please state if fires outside of the MCR cause MCR abandonment because of loss of control and/or loss of control room habitability. Please state if screening values for post MCR abandonment used [e.g., conditional core damage probability (CCDP) of failure to successfully switch control to the Primary Control Station and achieve safe shutdown of 0.1] or have detailed human error analyses been completed for this activity. Please justify any screening value used. The justification should provide the results of the human failure event (HFE) quantification process, such as that described in Section 5 of NUREG-1921, which would include the following, or an analogous method:

a) The results of the feasibility assessment of the operator action(s) associated with the HFEs, specifically addressing each of the criteria discussed in Section 4.3 of NUREG-1921.

b) The results of the process in Section 5.2.8 of NUREG-1921 for assigning scoping human error probabilities (HEPs) to actions associated with the use of alternate shutdown, specifically addressing the basis for the answers to each of the questions asked in the Figure 5-5 flowchart.

c) The results of a detailed HRA quantification, per Section 5.3 of NUREG-1921, if the screening CCDP is determined to not be bounding.

PRA RAI-15 Control Power Transformer Credit It was recently stated at the industry fire forum that the Phenomena Identification and Ranking Table Panel being conducted for the circuit failure tests from the DESIREE-FIRE and CAROL-FIRE tests may be eliminating the credit for Control Power Transformers (CPTs) (about a factor 2 reduction) currently allowed by Tables 10-1 and 10-3 of NUREG/CR-6850, Vol. 2, as being invalid when estimating circuit failure probabilities. Provide a sensitivity analysis that removes this CPT credit from the PRA and provide new results that show the impact of this potential 14

change on CDF, LERF, CDF, and LERF. If the sensitivity analysis indicates that the change in risk acceptance guidelines would be exceeded after eliminating CPT credit, please justify not meeting the guidelines.

PRA RAI-16 Calculation of VFDR CDF and LERF Attachment W of the LAR provides the CDF and LERF for the variances from the deterministic requirements (VFDRs) for each of the fire areas, but the LAR does not describe either generically or specifically how CDF and LERF were calculated. Describe the method(s) used to determine the changes in risk reported in the Tables in Appendix W. The description should include:

a) A summary of PRA model additions or modifications needed to determine the reported changes in risk. If any of these model additions used data or methods not included in the fire PRA Peer Review please describe the additions.

b) Identification of new operator actions (not including post MCR abandonment which are addressed elsewhere) that have been credited in the change in risk estimates. If such actions are credited, how is instrument failure addressed in the HRA.

c) Clarification of why and how the VDFR risk estimates provided in the Fire Risk Evaluations (FRE) reports are different from the CDF and LERF values provided in Attachment W of the LAR for each Fire Area.

d) Discuss how the FREs considered modifications and recovery actions in the determination of risk evaluations.

e) LAR Table W-2 reports a negative delta risk for Fire Area RB-FN. During the audit of the NFPA 805 LAR, held October 1 to 5, 2012, NPPD indicated that this reported delta risk was likely in error. Provide the revised delta risk (CDF and LERF) for Fire Area RB-FN and any other identified corrections to Table W-2. Discuss the reason for the error in the results and whether the source of the error has potentially broader implications. If there is determined to be broader implications, provide updated risk results where applicable.

PRA RAI-17 RG 1.200 Rev 2 Clarifications Clarify if the peer reviews for both the internal events and fire PRAs consider the clarifications and qualifications from Regulatory Guide (RG) 1.200, Revision 2, "An Approach for Determining the Technical Adequacy of Probabilistic Risk Assessment Results for Risk-Informed Activities,"

March 2009 (ADAMS Accession No. ML090410014) to the ASME/AMS PRA Standard. If not, provide a self-assessment of the PRA model for the RG 1.200 clarifications and qualifications and indicate how any identified gaps were dispositioned.

PRA RAI-18 Wrapped or Embedded Cables Identify if any variance from deterministic requirement (VFDRs) in the LAR involved performance-based evaluations of wrapped or embedded cables. If applicable, describe how wrapped or embedded cables were modeled in the Fire PRA including assumptions and insights on how the PRA modeling of these cables contributes to the VFDR delta-risk evaluations.

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PRA RAI-19 Implementation Item Impact on Risk Estimates Identify any plant modification (implementation item) in Attachment S of the LAR that have not been completed but which have been credited directly or indirectly in the change-in-risk estimates provided in Attachment W. When the affects of a plant modification has been included in the PRA before the modification has been completed, the models and values used in the PRA are necessarily estimates based on current plans. The as-built facility after the modification is completed may be different than the plans. Please add an implementation item that, upon completion of all PRA credited implementation items, verifies the validity of the reported change-in-risk. This item should include your plan of action should the as-built change-in-risk exceed the estimates reported in the LAR.

PRA RAI-20 Model Changes and Focused Scope Reviews Since Full Peer Review Identify any changes made to the IEPRA or FPRA since the last full-scope peer review of each of these PRA models that are consistent with the definition of a "PRA upgrade" in ASME/ANS-RA-Sa-2009, Standard for Level 1/Large Early Release Frequency for Nuclear Power Plant Applications, as endorsed by Regulatory Guide 1.200. Also, address the following:

a) If any changes are characterized as a PRA upgrade, indicate if a focused-scope peer review was performed for these changes consistent with the guidance in ASME/ANS-RA-Sa-2009, as endorsed by Regulatory Guide 1.200, and describe any findings from that focused-scope peer review and the resolution of these findings.

b) If a focused-scope peer review has not been performed for changes characterized as a PRA upgrade, describe what actions will be implemented to address this review deficiency.

PRA RAI-21 Fire Barriers A number of dampers are blocked open and non-rated fire barriers exist.

a) Please state if these have been considered in the FPRA and FREs. In performing Fire Risk Evaluations, state which assumptions are made for (1) non-rated fire barriers, (2) blocked open fire dampers.

b) Please state if all such dampers and fire barriers have been considered in the FPRA.

Specifically, discuss the following ones. Include a discussion on fire modeling and conclusions, as well as application of NUREG/CR-6850 guidance on multi-compartment analysis.

i. Both RPS Rooms are connected by ventilation without fire-rated dampers and non-rated barriers according to EE 09-040. Please describe how this is considered in the FPRA and FREs.

ii. FA RB-J has non-rated fire barriers for critical switchgear rooms. Please state how this is considered in the FPRA and FREs.

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PRA RAI-22 MSO Combinations The LAR p. F-4 states For cases where the pre-transition MSO combinations did not meet the deterministic compliance, the MSO combinations were added to the scope of the RI-PB change evaluations. Please elaborate on this. Discuss the risk significance of the MSOs identified, and the contributing reasons for the observed significance.

PRA RAI-23 SSC Modeling Describe any SSC boundaries, failure modes, or success criteria that have been changed from the IEPRA model for the FPRA model.

PRA RAI-24 Success Criteria Discuss if windmilling the RHR SW pumps from the SW booster pumps is a new success criteria. If so, provide the technical basis including this success criteria in the fire PRA.

PRA RAI-25 Drywell De-inertion Discuss the risk significance of potential drywell de-inertion pathways for this application, and insights which are important to its significance.

PRA RAI-26 Containment Bypass Discuss how containment bypass pathways have been considered and which ones are modeled in the FPRA.

PRA RAI-27 Hardened Vent Discuss how the hardened wetwell vent is credited in the FPRA and how the potential fire impact on vent cables has been considered for the FPRA. Also, discuss if fire areas with potential impact on hardened wetwell venting have been walked down.

PRA RAI-28 VFDR VFDR ISA-03 is not specified as a separation issue. Please state what type of issue VFDR ISA-03 is.

PRA RAI-29 Human Reliability Analysis a) According to the peer review report, for the HRA analysis many of the actions are based on timing from the internal events HRA (e.g., HR-G4, HR-G5). Please state if this applies to operator manual actions (OMAs). If so, discuss why the timing applies.

b) PCV-XHE-FO-AOV is a containment venting basic event. NEDC 09-083 does not contain an HRA worksheet for this basic event. Provide the worksheet or clarify. PC-XHE-FO-AOV is also an OMA in Fire Areas RB-J (3A), RB-K (3B), DGA (14A), DGB (14B), and DGA (14C). Discuss why this basic event is associated with these fire areas.

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c) PCV-XHE-FO-HPV is the basic event for when operators fail to operate the primary containment hard pipe vent system. Discuss what the operator actions are and how fire impact was considered for these actions.

d) Human Error Probabilities considered fire with minimal instrumentation as noted in NEDC 09-83. Discuss what is meant by minimal instrumentation and clarify if required instrumentation is verified to be available where it is credited in the FPRA sequences. If less than minimal instrumentation is available, discuss how HEPs are quantified.

e) Identify which RAs involve operator actions at the ASD panel while maintaining an operator presence in the MCR. Provide justification for their HEPs, and discuss their significance for the application.

f) The detailed HEP worksheets show that for the case of minimal instrumentation available, the HEPs are insensitive to the parameter TSW . For example, short times generally have HEPs of 0.15, while long times can be slightly greater. Describe why the HEP does not increase for shorter TSW times. Include a discussion on why the HEPs do not appear to vary between times when the fire impacts could be significant and when fire impacts would not be expected to be significant.

g) Discuss what time line is assumed for which the fire is assumed not to affect operator actions and discuss how this is worked into the fire HEPs.

h) Discuss any floors used in the HEP and dependency analyses.

PRA RAI 30 Risk Importance LAR Section 4.6 (Risk Monitoring) indicates that risk significance criteria such as specific Risk Achievement Worth (RAW) values will be used. Use of RAW values would require initiating and failure event related information. Since risk significance based on the fire PRA will be used in the Monitoring Program, confirm that this information can and will be developed using the fire PRA.

PRA RAI 31 Exclusion Analysis NEDC 09-089 explains that the Feedwater and Condensate System (F&C) was significantly enhanced for support the fire PRA and discusses an exclusionary analysis that was performed to credit the F&C in the fire PRA for certain fire scenarios. Discuss how this system and its supporting systems were modeled in the fire PRA, including how random failures of components added to the enhanced model were treated. Furthermore, discuss the results of the exclusionary analysis and how the results were used in the fire PRA. Specifically discuss additional circuit analysis performed to determine the location of both control and instrumentation & diagnostic cabling. In addition, discuss how fire induced impact to instrument air lines were modeled in the PRA, including how brazed instrument lines were modeled.

PRA RAI 32 Fire Area DW NEDC 09-085 reports risk results (CDF/LERF) for Fire Area DW/Fire Zone Drywell. However, LAR Table W-2 does not have an entry for this fire area. Explain this discrepancy. If the risk results for the drywell fire zone are not included in Table W-2, provide an updated table with the 18

risk results for this fire zone/area. Discuss whether there are any other missing fire zones/areas and, if so, provide the risk results for these areas.

PRA RAI 33 Torus Monitoring FRE For the FRE performed for VFDR RBDI-05, discuss the risk calculation. The variant case involves loss of all indication and operator actions at the ASD panel. The operator actions appear to apply only to scenarios when minimal instrumentation is available. If these actions are credited in the variant case, provide justification for their application. Also, if this scenario is a main control room abandonment scenario with control switched to the ASD panel, provide justification for their application since such scenarios have been modeled differently in the MCR abandonment risk analysis. Further a FRE will typically model the impact of a fire. For this scenario, it appears that the impact is not directly modeled. Explain how the impact is modeled for the variant case.

PRA RAI 34 Recovery Actions Explain which of the RAs in Attachment G of the LAR are included in the FPRA model. Include the basic event description and probability, and note if it is a dependent probability. In addition, clarify which RAs are new and which are previously approved.

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RR RAI 01 Provide information on the availability and use of spill control kits, temporary dikes, storm drain covers, retention ponds, settling ponds, etc. for containment of liquid effluents in areas where permanent engineering controls are not in place (e.g., tanks, sumps, concrete containment, etc.).

RR RAI 02 In areas where containment of gaseous and liquid effluents is not achieved and radiation monitoring is credited as a mitigating measure:

a. Describe the actions to be taken or methods to be used to minimize radioactive effluent (e.g., closing of doors, shutting off smoke educators).

b. For these areas, provide a qualitative or quantitative bounding analysis to ensure that the 10 CFR 20 annual dose limits for members of the public will be met.

RR RAI 03 Explain the potential discrepancy between statements in the LAR, Section 4.4, Radioactive Release Performance Criteria, that the methodology used was based on guidance in NFPA 805 Task Force FAQ 09-0056 (related to meeting limitations for instantaneous release of radioactive effluents in a licensees Technical Specifications) and the analyses and conclusions in calculation NEDC 10-062 and NEDC 11-148 which conclude that the offsite radioactive effluent releases will be limited to less than the annual dose limits of 10 CFR 20.

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Monitoring Program RAI 01 Describe the process that will be used to identify systems, structures, and components (SSCs) for inclusion in the NFPA 805 monitoring program. Include an explanation of how SSCs that are already within the scope of the Maintenance Rule program will be addressed with respect to the NFPA 805 monitoring program.

Monitoring Program RAI 02 Describe the process that will be used to assign availability, reliability, and performance goals to SSCs within the scope of the NFPA 805 monitoring program including the approach to be applied to SSCs for which availability, reliability, and performance goals are not readily quantified. Describe how SSCs that fail to meet assigned availability, reliability, or performance goals will be addressed.

Monitoring Program RAI 03 Describe how the NFPA 805 monitoring program addresses programmatic elements that fail to meet performance goals (examples include discrepancies in programmatic areas such as combustible controls programs).

Monitoring Program RAI 04 Describe how the NFPA 805 monitoring program addresses fundamental fire protection program elements.

Monitoring Program RAI 05 Describe how periodic assessments of the monitoring program will be performed taking into account, where practical, industry wide operating experience, including whether this process will include both internal and external assessments and the frequency at which these assessments will be performed.

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Programmatic RAI 01 Describe the specific documents that will comprise the post transition design basis document in accordance with NFPA 805 Section 2.7.1.2.

Programmatic RAI 02 Describe the changes that are anticipated to the configuration control program to incorporate the requirements of the NFPA 805 Section 2.7.2.

Programmatic RAI 03 Describe the changes that are anticipated to the fire protection program manual as a part of the NFPA 805 transition process, including associated training and identification of the recipients of any such training necessary to support the program changes.

Programmatic RAI 04 Describe where the requirements for periodic assessments (audits) of the fire protection program will reside in the NFPA 805 program documentation and how these requirements are anticipated to differ from the current requirements.

Programmatic RAI 05 Describe how the NFPA 805 plant change evaluation process will be implemented post-transition. Include identification of specific documents that need to be developed or changed to support the process, a description of how these documents will implement the process presented in Section 4.7.2 of the LAR, and a description of the training program that will support the change evaluation process to include who will be trained and how the training will be implemented (e.g., classroom, computer-based, reading program).

Programmatic RAI 06 Describe how the combustible loading program will be administered to ensure that fire PRA assumptions regarding combustible loading are met.

Programmatic RAI 07 Describe your commitment to conduct future NFPA 805 analyses in accordance with the requirements of NFPA 805 Section 2.7.3, Compliance with Quality Requirements.

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Fire Modeling RAI 01 Section 4.5.1.2, "Fire PRA" of the Transition Report states that fire modeling was performed as part of the Fire Probabilistic Risk Assessment (Fire PRA) development (NFPA 805 Section 4.2.4.2). Reference is made to Attachment J, "Fire Modeling V&V," for a discussion of the acceptability of the fire models that were used.

Regarding the acceptability of the PRA approach, methods, and data:

a. It appears that non-cable intervening combustibles were missed in some areas of the plant. An example is the combustible insulation of the heat exchangers in fire area RB-M. Explain how non-cable secondary combustibles were accounted for in the fire modeling analyses. In addition, describe the criteria that were used to determine when a secondary combustible could be ignored in the ZOI calculations. Identify where secondary combustibles were not and should have been considered, and assess the impact on the risk of including scenarios involving the intervening combustibles in the fire modeling analyses.

b. Explain why the effect of the size of the ventilation opening was not evaluated in the temperature sensitive equipment hot gas layer study, or revise the analysis to include the ventilation opening size.

c. In the structural steel analysis for beams in areas 13A and 20B the flame height exceeds the elevation of the beams. Explain why the gas temperature around the beams used in the analysis is lower than the flame temperature, or revise the analysis to reflect the flame temperature.

d. The fire resistance of the columns in area 13A is determined from an empirical method that is based on test data for ASTM E 119 exposure. In the pool fire scenario that is considered in the structural steel analysis, the lower part of the columns is exposed to a more severe hydrocarbon fire. Provide justification for using an empirical method that is based on ASTM E 119 test data, or revise the analysis to reflect the more severe hydrocarbon fire.

e. Explain how the licensee will ensure that the model assumptions in terms of transient combustibles in a fire area or zone will not be violated during and post-transition.

f. Specifically regarding the use of the algebraic models:

i. Explain how fire location corner and wall proximity effects are accounted for in the method of McCaffrey, Quintiere, and Harkleroad for calculating hot gas layer (HGL) temperature; and in Alperts method for calculating ceiling jet temperature.

ii. Describe in detail how the time to sprinkler actuation and the time to heat and smoke detector actuation was calculated. In particular, describe and justify any tuse of steady state models to time-varying conditions.

iii. Explain how the damage threshold for targets in a mixed convective/radiative environment was established. The response should also address the Fire PRA Finding and Observation (F&O) 3-9 under FSS-D1.

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iv. Explain how the elevation and dimensions of ignition source fires were determined. If the height and dimensions were not adjusted following ignition of secondary combustibles, justify why these aspects were not adjusted.

g. Since this is the first time that the staff has observed the use of CFAST in a multi-compartment analysis:

i. Provide the input files in electronic format (*.in and *.o) for all CFAST runs that were conducted in support of this multi-compartment analysis.

h. Specifically regarding the use of FDS in the Main Control Room (MCR) abandonment study:

i. Provide the input files in electronic format (*.fds) for all FDS runs that were conducted in support of the MCR abandonment time study.

ii. Provide justification for assuming an alarm set point of 8.2 %/m of smoke detector SD-1001 in the Cable Spreading Room (CSR).

iii. Provide justification for using a response time index (RTI) of 132 m1/2s1/2 for the fusible link of the dampers between the MCR and the CSR.

Fire Modeling RAI 02 Section 4.5.1.2, "Fire PRA" of the Transition Report states that fire modeling was performed as part of the Fire PRA development (NFPA 805, Section 4.2.4.2). Reference is made to Attachment J, "Fire Modeling V&V," for a discussion of the verification and validation (V&V) of the fire models that were used. Furthermore Section 4.7.3 "Compliance with Quality Requirements in Section 2.7.3 of NFPA 805" of the Transition Report states that "Calculational models and numerical methods used in support of compliance with10 CFR 50.48(c) were verified and validated as required by Section 2.7.3.2 of NFPA 805. "

Regarding the V& V of fire models:

a. Attachment J of the Transition Report states that the algebraic models implemented in the FDTs and FIVE, Rev. 1, were used to characterize flame radiation, flame height, plume temperature, ceiling jet temperature and HGL temperature. However, the FDTs and/or FIVE, Rev. 1 spreadsheets were not used to perform the calculations, but selected algebraic models from NUREG-1805 and FIVE, Rev. 1, were used in a new spreadsheet (or set of spreadsheets). Describe how this new (set of) spreadsheet(s) was verified, i.e., how was it ensured that the empirical equations and correlations were coded correctly and that the solutions are identical to those that would be obtained with the corresponding chapters in NUREG-1805 or FIVE, Rev. 1.

b. For V&V of the aforementioned algebraic models reference is made to NUREG1824, "Verification and Validation of Selected Fire Models for Nuclear Power Plant Applications." Provide technical details to demonstrate that the algebraic models have been applied within the validated range of input parameters, or to justify the application of the equations outside the validated range reported in NUREG-1824.

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c. Provide technical details to demonstrate that CFAST has been applied in the multi-compartment analysis for zones 7A and 8A and the sensitive equipment hot gas layer study within the validated range of input parameters, or to justify the application of the model outside the validated range reported in NUREG-1824.

d. Provide technical details to demonstrate that FDS has been applied in the MCR abandonment study and plume/hot gas layer study within the validated range of input parameters, or to justify the application of the model outside the validated range reported in NUREG-1824.

e. Provide the V&V basis for the method that models a smoke detector as a heat detector and uses a temperature increase of 10°C as the criterion for detector actuation. The response to this question should also address Fire PRA F&O 3-1 under FSS-D1.

f. Provide the V&V basis for the plume temperature equation (3.2.9) in the book by Zalosh on Industrial Fire Protection Engineering that is used in the structural steel analysis for fire zones 13A and 20B.

Fire Modeling RAI 03 Section 4.7.3, "Compliance with Quality Requirements in Section 2.7.3 of NFPA 805," of the Transition Report states that "Engineering methods and numerical models used in support of compliance with 10 CFR 50.48(c) were and are used with the same limitations and assumptions supported by the V&V for the methods as required by Section 2.7.3.3 of NFPA 805."

Regarding the limitations of use, Fire PRA F&O 3-12 under FSS-D1 states that there are no clear limits on the applicability of the ZOI parameters. Identify uses, if any, of the fire modeling tools outside the limits of applicability of the method and for those cases explain how the use of the fire modeling approach was justified.

Fire Modeling RAI 04 Section 4.5.1.2, "Fire PRA" of the Transition Report states that fire modeling was performed as part of the Fire PRA development (NFPA 805, Section 4.2.4.2). This requires that qualified fire modeling and PRA personnel work together. Furthermore, Section 4.7.3, "Compliance with Quality Requirements in Section 2.7.3 of NFPA 805," of the Transition Report states that "For personnel performing fire modeling or Fire PRA development and evaluation, NPPD will develop and maintain qualification requirements for individuals assigned various tasks. Position Specific Guides will be developed to identify and document required training and mentoring to ensure individuals are appropriately qualified per the requirements of NFPA 805 Section 2.7.3.4 to perform assigned work.

Regarding qualifications of users of engineering analyses and numerical models (i.e., fire modeling techniques):

a) Describe the process/procedures for qualifying engineers/personnel performing the fire analyses and modeling activities.

b) Explain how the necessary communication and exchange of information between fire modeling analysts and Fire PRA personnel was accomplished and any 25

direction/guidance provided by one group to the other was confirmed to be implemented correctly.

Fire Modeling RAI 05 Section 4.7.3, "Compliance with Quality Requirements in Section 2.7.3 of NFPA 805" of the Transition Report states that "Uncertainty analyses were performed as required by 2.7.3.5 of NFPA 805 and the results were considered in the context of the application. This is of particular interest in fire modeling and Fire PRA development used to support performance-based approach."

Regarding the uncertainty analysis for fire modeling:

a. Describe how the uncertainty associated with the fire model input parameters (compartment geometry, radiative fraction, thermophysical properties, etc.) was addressed for this application and accounted for in the analyses.

b. Describe how the model and completeness uncertainties were addressed for this application and accounted for in the analyses. NUREG-1934 provides guidance on quantifying model/completeness uncertainty.

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