NRC-2015-0001, Response to Request for Additional Information (Probabilistic Risk Assessment) License Amendment Request 271 Associated with NFPA 805

Response to Request for Additional Information (Probabilistic Risk Assessment) License Amendment Request 271 Associated with NFPA 805

ML15015A281
Person / Time
Site:	Point Beach
Issue date:	01/16/2015
From:	Mccartney E Point Beach
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
NRC-2015-0001
Download: ML15015A281 (20)

Text

January 16, 2015 NRC 2015-0001 10 CFR 50.90 U.S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555 Point Beach Nuclear Plant, Units 1 and 2 Dockets 50-266 and 50-301 Renewed License Nos. DPR-24 and DPR-27 Response to Request for Additional Information (Probabilistic Risk Assessment)

License Amendment Request 271 Associated with NFPA 805

References:

(1) NextEra Energy Point Beach, LLC, letter to NRC, dated June 26, 2013, "License Amendment Request 271, Transition to 10 CFR 50.48(c) -

NFPA 805, 'Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants,' 2001 Edition" (ML131820453)

(2) NRC e-mail to NextEra Energy Point Beach, LLC, dated September 9, 2013, "Point Beach Nuclear Plant, Units 1 and 2- Acceptance Review Regarding the NFPA 805 License Amendment Request- Opportunity to Supplement (TAG Nos. MF2372 and NF2373)" (ML13256A197)

(3) NextEra Energy Point Beach, LLC, letter to NRC, dated September 16, 2013, "License Amendment Request 271 Supplement 1 Transition to 10 CFR 50.48(c)- NFPA 805" (ML13259A273)

(4) NRC letter to NextEra Energy Point Beach, LLC, dated September 25, 2013, "Point Beach Nuclear Plant, Units 1 and 2 - Acceptance of Licensing Action re: License Amendment Request to Transition to NFPA 805, 'Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants' (TAG NOS. MF2372 and MF2373)" (ML13267A037)

(5) NRC e-mail to NextEra Energy Point Beach, LLC, dated November 19, 2014, "RE: Point Beach Nuclear Plant, Units 1 and 2- Follow-up Requests for Additional Information (AFPB) re: NFPA 805 License Amendment Request Review (TAG Nos. MF2372 and MF2373)" (ML14325A540)

Pursuant to 10 CFR 50.90, NextEra Energy Point Beach, LLC, (NextEra) requested to amend Renewed Facility Operating Licenses DPR-24 and DPR-27 for Point Beach Nuclear Plant (PBNP), Units 1 and 2 (Reference 1 and supplemented via Reference 3). The NRC accepted the license amendment request for review in response to Reference (2), as documented in Reference (4).

The NRC Staff has determined that additional information (Reference 5) is required to complete its evaluation. The Enclosure provides the NextEra response to the NRC Staff's request for additional information.

Document Control Desk Page 2 This letter contains no new Regulatory Commitments and no revisions to existing Regulatory Commitments.

If you have any questions regarding this letter, please contact Mike Millen at (920) 755-7845.

I declare under penalty of perjury that the foregoing is true and correct.

Executed on January 16, 2015.

Very truly yours, NextEra Energy Point Beach, LLC Eric McCartney Site Vice President Enclosure cc: Administrator, Region Ill, USNRC Project Manager, Point Beach Nuclear Plant, USNRC Resident Inspector, Point Beach Nuclear Plant, USNRC PSCW

ENCLOSURE NEXTERA ENERGY POINT BEACH, LLC POINT BEACH NUCLEAR PLANT, UNITS 1 AND 2 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION (PROBABILISTIC RISK ASSESSMENT) LICENSE AMENDMENT REQUEST 271 ASSOCIATED WITH NFPA 805 Pursuant to i 0 CFR 50.90, NextEra Energy Point Beach, LLC, (NextEra) requested to amend renewed Facility Operating Licenses DPR-24 and DPR-27 for Point Beach Nuclear Plant (PBNP), Units 1 and 2 (Reference 1 and supplemented via Reference 3). The NRC accepted the license amendment request for review in response to Reference (2), as documented in Reference (4).

The NRC Staff has determined that additional information (Reference 5) is required to complete its evaluation. This Enclosure provides the NextEra responses to the NRC Staff's requests for additional information.

PRA RAI 05.01 (Justification of Reduced Transient Heat Release Rates)

It is not clear that the response to PRA RAJ 05.b (ADAMS Accession No. ML 1421 OA645) provides adequate justification for the reduced heat release rates (HRRs) credited in the Fire PRA. The response explains that the "quantities of combustibles needed to perform activities would not typically exceed the reduced heat release rates modelled in the fire PRA': but that "l[i]n the event that combustibles are required to be brought into these areas, their presence will require a continuous fire watch." The NRC staff notes that for the two cited fire areas, the licensee's Fire PRA does not credit a continuous fire watch, but rather reduced HRRs, and that the controls described in the response do preclude the possibility of transient combustibles present in quantities that would exceed the reduced HRR used in the fire PRA. Accordingly, it is not clear whether the controls discussed in the RAI response are the current controls or the updated controls credited in the Fire PRA.

In light of these observations, please describe the updated controls that are credited in the Fire PRA for limiting transient combustibles, and justify that they provide an adequate basis for the reduced HRRs used in the Cable Spreading Room and Vital Switchgear Room.

The controlsto be imposed will be to restrict all transient combustibles in these fire zones with specific compensatory actions to be in place in timeframes during which transient combustibles must be in the fire zone to support a particular maintenance or testing activity. With these controls in place, the expected transient combustibles in the fire zones will be negligible, and 69 kW (FZ 305, Vital Switchgear Room) and 142 kW (FZ 318, Cable Spreading Room) heat release rates (HRR) are assumed to bound potential infringement of the new transient controls.

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The 69 kW and 142 kW HRRs are based on an evaluation of the potential infringement of the proposed administrative controls, where administrative procedures will implement a zero transient combustible control criteria, except for transient combustibles to support maintenance or testing with associated specific..compensatory actions . The expectation is that the implementation of a zero transient combustible limit with exceptions noted will significantly reduce the size of potential transient combustibles, which could be placed in the zone infringing on the applied HRR limits. This type of transient combustible control is a newly imposed criterion that will require a monitoring program to address future adherence to the requirements.

Should an infringement of these controls occur, the results of post-transition monitoring with respect to these controls will be the basis for implementation of appropriate corrective actions.

PRA RAI 10.01 (Main Control Room Abandonment Modeling)

The response to PRA RA/10 (ADAMS Accession No. ML14210A645) does not directly address the question in the RAJ about how estimation of CDF/CLERP for Main Control Room (MCR) abandonment due to foss of habitability (LOH) considers fire induced failures including spurious actuations. Regarding determination of non-abandonment scenario CCDPICLERP, the response states: "N[n]o split fractions are used to credit abandonment," and that "in some cases, this is conservative as there is some possibility that operators decide to abandon." It is not completely clear how these statements address the question of how fire impacts are considered in the estimation of CDF/LERF. The analysis appears to indicate that the human error probabilities (HEPs) used to calculate the CCDP for MCR abandonment do not include actions (e.g., manually trip reactor coolant pumps (RCPs), isolation of letdown flow, isolation of open main steam isolation valves (MS!Vs)) to mitigate fire-induced failures or actuations.

The response provided to PRA RAI 16 appears to indicate that a single CDF/LERF was used to model MCR abandonment due to LOH (i.e., one scenario with a CCDP of 0.56). This appears inconsistent with the response to PRA RAJ 10 which refers to more than one CDF for these scenarios (e.g., the phrase is used: "are multiplied together to determine the abandonment CDFfor each scenario'?. In general, due to the range of failures associated with remote shutdown operations, it is expected that a rangeof CCDPs is needed to characterize the likelihood of shutdown failure associated with MCR abandonment for either LOH or loss of control (LOG).

In light of these observations, please:

a) Explain how estimation of CDFs/CLERPs for MCR abandonment due to LOH addresses fire induced failures including spurious actuations, and why the estimation of CCDPICLERP does not appear to include operator actions to recover the impact of spuriOus actu8.ti0ns. Identify the. . .8i5tions crea7te*a7n the Fire PRATOflfllCR"""BbEifldoiifnenl ~~.- -..-*-*----~. ~-~. --

and justify that the operator actions credited include actions necessary for alternate shutdc;>wn.

b) Explain the statements made in response to PRA RAJ 10, "N[n]o split fractions are used to credit abandonment" and that "in some cases, this is conservative as there is some possibility that operators decide to abandon," and how these statements address the question of fire-induced impact on estimation of CDFs/CLERPs for MCR abandonment on LOH.

c) Justify the single abandonment CCDPs for the post transition and compliant plants for both LOH and LOG given that a range of CCDPs is possible.

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NextEra Response a) The development of the post-transition model CCDP/CLERP values for Main Control Room (MCR) abandonment for loss of habitability is based on a detailed Human Reliability Analysis (HRA) of AOP-10A, "Safe Shutdown- Local Control." AOP-10A is designed to accommodate both LOH and LOC for the worst-case Appendix R fire scenario in the MCR, Cable Spreading Room, or 4160V Vital Switchgear Room, with extensive damage that results in alternate shutdown outside of the main control room.

AOP-1 OA includes initial steps in the MCR to isolate and trip critical plant equipment related to safe shutdown. This includes, but is not limited to, the following actions performed in the MCR to prevent spurious operation and enable recovery of components that may have spuriously operated: de-energizing feeder breakers, tripping Reactor Coolant Pumps (RCPs), tripping main feed pumps, shutting Main Steam Isolation Valves (MSIVs), shutting PORV block valves. Additionally, later steps in the AOP-1 OA procedure and attachments prescribe operators to locally isolate or recover equipment that may or may not have been affected by fire-induced failures, which includes fire-induced spurious operations.

Based on AOP-1 OA and its attachments, actions credited in the detailed MCR Abandonment HRA are developed for the following:

• Failure of Unit 1 Control Operator to provide AFW decay heat removal to each unit per AOP-1 OA Attachment C by aligning Turbine Driven AFW pump to B Steam Generator.

~ Failure of Third Reactor Operator to provide AFW decay heat removal to each unit per AOP-1 OA Attachment B by gagging open Turbine Driven AFW pump recirculation valves to prevent pump damage.

e Failure of Unit 2 Control Operator to provide charging to each unit per Attachment D by aligning a charging pump to alternate shutdown power and by local valve alignment.

e Failure of DOS to align B-08 and B-09 to charging and SW pumps to each unit per AOP-1 OA Attachment A by aligning alternate power to charging and service water pumps.

• Failure of Third Reactor Operator to align Gas Turbine Generator G-05 to 13.8 kV Bus H-01 for both units per AOP-10A Attachment B by starting G-05 and supplying Bus H-Oi.

~~ Failure of an operator to place battery charger in service for both units per 0-

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03 when it is powered from bus B-81.

The HRA for each of the events in the list above includes additional conservative timing for performing steps 1-4 of EOP-0 (Unit 1/2 Safety Related, REACTOR TRIP OR SAFETY INJECTION), along with the steps of AOP-1 OA (MCR isolation, etc.) that precede the events/actions in the above list.

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For each MCR fire scenario, where loss of habitability forces abandonment of the MCR and where local safe shutdown is required, the same procedure (AOP-1 OA) is executed.

Because AOP-1 OA accommodates potential fire-induced equipment failures in the most severe fire scenario cases., it is justified for the post-transitionmodel to use the failure probability of the operator actions in AOP-1 OA as a bound for the variety of possible fire-induced failures for fire scenarios that lead to MCR abandonment due to LOH.

b) The purpose of the first statement ("N[n]o split fractions are used to credit (lbandonment") is to identifyJhat there is no split fraction used to partition ignition frequency between abandonment and non-abandonment cases. The full fire frequency is applied to both scenarios that lead to abandonment caused by LOH (utilizing AOP-1OA for alternate shutdown), and to non-abandonment scenarios where AOP-1 OA is not used. In abandonment cases caused by LOH, recoveries of fire-induced failures are captured in and are bounded by AOP-1 OA as per the discussion in the response to Part (a) of this RAI. Non-abandonment scenarios utilize actions outside of AOP-1 OA to mitigate potential fire-induced impacts. The fraction of scenarios leading to loss of habitabi~ity is not removed. Therefore, the non-abandonment fire frequencies are slightly larger than they would be, if a split-fraction for the abandonment cases was applied. As a result, the CDF/LERF values are conservative due to the higher fire frequencies.

The second statement ("In some cases, this is conservative as there is some possibility that operators decide to abandon") reflects that no credit is given for the operators' decision to execute AOP-1 OA outside of LOH for the post-transitibn model. For example, a fire scenario in the MCR has the potential to include a decis.ion to use AOP-1 OA should the loss of control be severe enough to warrant alternate shutdown. In all applicable fire areas and scenarios of the compliant model, critical actions required for alternate shutdown are considered for LOH and LOC as per the discussion in the response to Part (c) of this RAI. This treatment of LOH/LOC leads to conservative CDF/LERF results in the post-transition model, and may be non-conservative for the-CDF/LERF values for the compliant case, as per discussion in the response to Part (c),

to maintain conservatism in delta risk calculations between the post-transition and compliant models.

c) As stated in the responses to Parts (a) and (b) of this RAI, LOH is bounded in the post-transition plant model using AOP-iOA. This procedure was designed for a worst-case Appendix R fire and incorporates procedural steps to isolate and recover from fire-induced failures caused by fires in the MCR, Cable Spreading Room, or 4160V Vital Switchgear Room. Abandonment actions (AOP-10A) are not credited in the PRA for

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Applicable Emergency Operating Procedures (EOPs) and Abnormal Operating Procedures (AOPs) that do not invoke AOP-1 OA are utilized for those fires.

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As per Attachment W of the LAR, the compliant plant model uses Conditional Core Damage Probability (CCDP) and Conditional Large Early Release Probability (CLERP) values of 0.19 and 0.019, respectively, as upper limits for any fire scenario in the 4kV Vital Switchgear Room (Fire Area A24), Cable Spreading Room (Fire Area A30) and Control Room (Fire Area A31). Any CCDP/CLERP values for scenarios in Fire Areas A24, A30, and A31 determined to be below these upper limits are retained to avoid non-conservatism in delta risk calculations. The abandonment CCDP/CLERP values for the compliant model assume that operators are perfect in recognizing that a fire has become severe enough to warrant alternate shutdown and operators are perfect in executing the steps required for alternate shutdown. The values are thereby only formulated based on a summation of significant equipment failures related to alternate shutdown (gas turbine G-05 and turbine-driven AFW pumps 1(2)P-29). Essentially, this allows for the compliant case to take credit for both LOC and LOH with a conservative basis (i.e.,

consequences of severe fires in these compliant plant fire areas with high CCDP/CLERP values are overridden by alternate shutdown actions to mitigate risk and to provide an upper bound for compliant plant risk results).

PRA RAI 13.01 (Fire PRA Credit for Westinghouse RCP Seals)

There appears to be a possible mismatch between the RCP shutdown seals that will be installed and credit taken for these seals in the Fire PRA. The response to PRA RAJ 13 (ADAMS Accession No. ML14210A645) states that report PWROG-14001-P/NP, "PRA Model for the Generation Ill Westinghouse Shutdown Seal" was used as the basis for credit taken in the Fire PRA integrated analysis provided in response to PRA RAI 03. However, updated Table S-2 of the LAR, Item MOD-3 (The RCP Seal will be upgraded to Westinghouse Shutdown Seals), does not indicate which seals (e.g., Generation 2 or 3 Westinghouse Shutdown Seals) will be installed.

Therefore, please provide the following:

a) Explain which Westinghouse Shutdown Seals will be installed.

b) If the credit taken in the Fire PRA is not consistent with the report cited in the RAJ response, then identify the proper report on which the analysis relies.

NextEra Response a) Point Beach is installing the Westinghouse Electric Company (WEC) SHIELD Generation Ill Shutdown Seal (SDS) into the Reactor Coolant Pump (RCP) seals for

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two Unit 1 RCPs during the U 1R35 refueling outage in October 2014 and is planned for installation in the two Unit 2 RCPs during U2R34 scheduled in fall 20i 5.

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b) The report cited in the response to PRA RAI 03 -Integrated Analysis, Table PRA RAI 3.a-1, Item 13, was WEC Report PWROG-14001-P/NP, "PRA Model for the Generation Ill Westinghouse Shutdown Seal, PA-RMSC-0499R2." This report is applicable to the SDSs installed and planned to be installed in Point Beach Nuclear Plant, Units 1 and 2, respectively. The PRA model for the WEC SHIELD Generation Ill SDS was incorporated into the Fire PRA for the quantification results provided in the 120 Day RAI Response (Reference 6).

A markup to the updated LAR Table S-2 from the September 25, 2014 Letter NRC 2014-0056 (Attachment 5 of Enclosure 2) is included at the end of this enclosure.

PRA RAI 16.01 (Calculation of Change-in~Risk)

The approach and basis for calculation of the change-in-risk for "MCR abandonment non-habitability cases" (i.e., loss of control (LOG) cases) is not clear. This response and updated Section W.2. 1 of the LAR explain that MCR abandonment is credited in the compliant plant model for the MCR, Cable Spreading Room, and the 4kV Vital Switchgear Room, for both habitability and non-habitability scenarios. In contrast, the response indicates that in the post-transition plant model MCR abandonment is not credited for LOG scenarios. Accordingly, it appears that for these fire areas the compliant and post-transition plants for LOG scenarios are based on different models: MCR abandonment is modeled for the compliant plant and not modeled for the post-transition plant.

For the MCR abandonment scenarios, the response explains that in the compliant plant model operator actions are assumed to be successful and so the CCDP (0. 19) is based on the likelihood of random hardware failures associated with alternate shutdown. The response does not discuss contributors to CCDP for the post-transition plant model, but the NRC staff infers that the contributors are fire-induced and random failures of normal shutdown systems and actions. Of concern is that the difference in compliant plant and post-transition plant models can produce anomalous change-in-risk results. For example, it is possible that the post-transition plant CDFILERF could be less than the compliant plant CDFILERF which would result in a negative change-in-risk. Given a CCDP of 0. 19 for MCR abandonment, it appears likely that there are a number of fires in the cited abandonment fire areas that would result in a lower CCDP for the post-transition plant model. The staff notes that a conservative estimate of the compliant plant model CCDP can lead to non-conservative change-in-risk estimates. The response to PRA RAI 16.a appears to address, though it is not certain, the possibility of anomalous change-in-risk results.

In light of these observations, please provide the following:

-~-~~~~

a) Explain how calculation of the change-in-risk for LOG scenarios in which MCR abandonment is credited in the compliant but not the post-transition plant model avoids producing anomalous results such as a negative change-in-risk. Also, explain what the following phrase means: "An example of application would be if a specific fire scenario in an abandonment area had a CCDP of 0. 75 this CCDP would be replaced with the

0. 19 ceiling, because it is assumed the operators have perfect judgment to initiate abandonment, when it will reduce plant risk."

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b) Of the nine random failure contributors to the estimate of 0. 19 for CCDP of the compliant plant in MCR abandonment scenarios, discuss the dominant contributors and justify that an overly conservative complaint plant CCDP estimate does not lead to a non-conservative change-in-risk estimate.

NextEra Response a) The post-transition model does not credit Main Control Room (MCR) abandonment/alternate shutdown actions (AOP-1 OA, Safe Shutdown - Local Control) due to loss of control (LOC) for fires in the MCR, Cable Spreading Room, and 4kV Vital Switchgear Room. Fires that do not force abandonment due to loss of habitability (LOH) in the post-transition model utilizeAOPs and EOPs that do not invoke AOP-10A. This conservative approach results in CDF/LERF estimates relating to abandonment that are higher than the expected best estimate for the post-transition plant. The compliant plant has an upper limit for fire scenarios in the MCR, Cable Spreading Room, and 4kV Vital Switchgear Room based on abandonment CCDP/CLERP values of 0.19 and 0.019, respectively. These values are based on a summation of significant equipment failures related to alternate shutdown {gas turbine G-05 and turbine-driven AFW pumps 1(2)P-29).

The compliant model assumes the operators recognize the need for abandonment of the MCR caused by loss of control with perfect cognition. Therefore, if a fire scenario in the MCR, Cable Spreading Room, and 4kV Vital Switchgear Room is quantified and has CCDP a*nd CLERP values that exceed 0.19 and 0.019, respectively, the quantified CCDP/CLERP values are replaced with the ceiling values (i.e., for the cited example in this question: if an MCR fire scenario were to have a CCDP of 0.75 in the compliant model, it would be replaced with 0.19). This approach is more liberal for the LOC fire scenarios in fire areas where the abandonment procedure is applicable and results in slightly lower CDF/LERF values, as compared to best estimate results relating to the abandonment modeling.

Since the post-transition model incorporates an approach for LOC that yields potentially higher than expected best estimates for risk, and the compliant model incorporates an approach for LOC that yields potentially lower than expected best estimates for risk, the change-in-risk values are conservatively higher with respect to treatment of LOC and do not contribute to anomalous results such as a negative change-in-risk.

b) The following are the nine random failure contributors to the estimated 0.19 CCDP for

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• GAS TURBINE GENERATOR FAILS TO RUN AFTER THE FIRST HOUR

• GAS TURBINE G-05 FAILS TO RUN IN THE FIRST HOUR

• GAS TURBINE G-05 FAILS TO START

• GAS TURBINE G-05 UNDER TEST AND MAINTENANCE

• TOP 1(2)P29 FAILS TO RUN IN THE FIRST HOUR

• TOP 1(2)P29 FAILS TO RUN IN HOURS 2-24 411 TOP 1 (2)P29 TEST AND MAINTENANCE TOP 1(2)P29 FAILS TO START 411 1(2)P29 MIN FLOW RECIRC VALVE SPURIOUS ISOLATION Page 7 of 18

The most dominant contributors to the 0.19 CCDP are related to the failures of G-05.

The summation of the failure probabilities is approximately 0.17 for gas turbine generator failure modes listed above. The most dominant individual failure is the unavailability of G-05 due to testing and maintenance (0.099).

This approach for the compliant model assumes that operator actions for alternate shutdown are always successful, which includes, but is not limited to, alignment and start of the G-05 gas turbine. This approach only considers significant equipment failures without consideration of human failures to execute.

The 0.19/0.019 CCDP/CLERP values are only used in the compliant case for both an upper-bound (as discussed in the response to Part (a) in this RAI for potential LOC or the CCDP/CLERP values in an MCR LOH scenario. The post-transition model does not apply the AOP-1 OA credit for LOG scenarios. Additionally, the LOH CCDP/CLERP values are much higher in the post-transition model versus the compliant model. As per the change-in-risk calculation, constraining the total risk of the compliant model will

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inherently yield higher delta risk values for CDF and LERF. Therefore, this approach is con-servative and does not lead to a non-conservative change-in-risk estimate.

PRA RAI 25.01 (Changes in Modification Identified in AttachmentS)

The response does not describe the adjustments made to the Fire PRA to add or remove credit for modifications affected in the updated Table S-2 of the LAR as requested in the RAI.

Accordingly, it is not clear whether changes to modifications presented in the updated Table S-2, including the deletion of a number of modifications, are reflected in the integrated analysis provided in response to PRA RAJ 03. The response to SSA RAJ 05 indicates that modeling of overcurrent trip (OCT) logic was added to the Fire PRA in order to justify removing a number of modifications. The response to PRA RAJ 25 states that for four modifications (i.e., M00-17, M00-28, M00-29, and M00-30) "OCT analysis confirmed this modification was not necessary," and "A[a]cceptability confirmed by final quantification. Though not clear from the II response provided to PRA RAI 25, it appears that OCT logic was excluded from the original Fire PRA associated with the LAR submittal and later added so that the risk increase associated with deleting these modifications could be incorporated into the risk results.

Please describe the adjustments made to the Fire PRA to add or remove credit for modifications affected in the updated Table S-2 of the LAR used for performing the integrated analysis provided in response to PRA RAJ 03, and justify that the adjustments are sufficient to reflect the

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The following table includes the table for the i 20-day response to PRA RAI 25 with an additional column appended to address the impact on the Fire PRA for removing or adjusting the scope of -each individual modification. All of the modification changes and updates were simultaneously incorporated into the integrated analysis provided in response to PRA RAI 03.

As such, the risk results presented as part of PRA RAI 03 reflect the incorporation of changes to modifications as described in the original response to PRA RAI 25.

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PRA RAI 25 Table Changes Incorporated in the Fire PRA Reflecting Type of Change and the Change of Item Proposed Modification Modification Scope Justification EC Cable ZE23213CE in Fire Scope removed. Protection for this cable 279326 Area A01-B will be was removed from the Fire protected to preserve Acceptable risk results PRA for quantification. Risk VNBI. are achieved with the results presented in the existing plant design 120-day RAI responses and operation. Feasible reflect risk with this and reliable recovery modification removed.

actions, included in IMP-143 and Attachment G, are relied upon in lieu of the modification.

MOD-1 Bus duct between the B- Scope changed. The change to this MOD is 03 and B-04 busses will the specific use of cables be modified so that a Bus bars will be instead of modifying the bus HEAF is no longer a replaced with cables, ducts to prevent HEAF concern in Fire Areas which are not damage. This results in a A23N and A23S. susceptible to the HEAF new vulnerability of cable failure mode. This damage to these new change is addressed in cables. The fire modeling the Fire Model reports was updated for the for the affected areas. affected fire scenarios.

Risk results presented in the 120-day RAI responses reflects the updated fire modelinq.

MOD-4 Add additional power Clarification of An assumed routing inputs to B-08 and to B- description. scheme was incorporated in

09. Power to come from the Fire PRA to provide an tie line independent of The increased load alternate power source to switchyard. capacity is no longer 480V switchgear buses B-required and this mod 08/B-09 from 4.16 kV bus will only provide an 2A-06. Risk results

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RAI responses reflect the modification chanqes.

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MOD-7 The following cables will Clarification of The original proposed be re-routed and/or description. modification for MOD-7 protected from fire included the following:

damage in fire Scope reduced based compartment FC187GRP. on circuit analysis from "Protect the following The re-routes will be EPM Report R2337- cables in FZ-187:

reviewed to ensure 0010-01 RO, Evaluation ZK11429A and ZL 1!430A attachment C and W of Spurious Pressurizer ZP21429A and ZQ21430A" results are not PORV Operation Due to significantly impacted. Instrument Failures. Protections that were removed from the original ZK11429A Acceptability confirmed MOD-7 (compared to the ZP21429A by final quantification. revised MOD-7 submitted with the 120-day RAI response) were removed from the Fire PRA model.

Risk results presented in the 120-day RAI responses reflect risk with this modification updated.

MOD-8 The following PORV Scope removed. Protections for these cables I cables will be protected in were removed from the Fire FZ 511: Additional refinements PRA for quantification. Risk in circuit analysis from results presented in the ZK11429Q EPM Report R2337- 120-day RAI responses ZL 114317 0010-01 RO determined reflect risk with this ZN11449H that the cable protection modification removed.

ZL 114300 was not required.

Acceptability confirmed by final quantification.

MOD-9 The following PORV Scope removed. Protections for these cables cables will be protected in were removed from the Fire FZ 516: Additional refinements PRA for quantification. Risk in circuit analysis from results presented in the ZK11429Q EPM Report R2337- 120-day RAI responses ZL 114300 0010-01 RO determined reflect risk with this ZMil4317 that the cable protection modification removed.

ZN11449H was not required.

Acceptability confirmed by final quantification.

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MOD- The following cables will Scope reduced to a The original proposed 10 be re-routed and/or single channel of modification for MOD-1 0 protected from fire cabling. .* included the following:

damage in fire zone FZ-318. Additional refinements "Protect the following in circuit analysis from cables in FZ-318:

114298-C-D-H-M EPM Report R2337- 114298-C-0-H-M 0010-01 RO determined 114308-C-E-M-P that the cable protection 114313, 114318, 1i4319 was not required. 11431 8-1-J-M-N-T-U 114498-E-F 114498-E-F ZA1J1368, ZK11429A, Acceptability confirmed ZA 1J1368, ZK1l429A, ZN11449A by final quantification. ZL1/430A, 214298-C-D-H-M ZM11431A, ZN11449A 214298-C-0-H-M 214308-C-E-M-P 214498-E-F 214313, 214318, 214319, ZC2J1368, ZP21429A, 214318-/J-ZS21449A. M-N-T-U 214498-E-F ZC2J1368, ZP21429A, ZQ21430A, ZR21431A, ZS21449A" Protections that were removed from the original MOD-1 0 (compared to the revised MOD-1 0 submitted with the 120-day RAI response) were removed from the Fire PRA model.

Risk results presented in the 120-day RAI responses reflect risk with this modification updated.

MOD- Cables ZE2328CA and Scope removed. Protections for these cables 12 ZE2328C8 in FZ 304N were removed from the Fire will be protected to make Minimal risk reduction in PRA for quantification. Risk P38A available. the final quantification results presented in the resuHS.~ i 20-day-RAI.responses reflect risk with this modification removed.

Page 11 of i 8

MOD- Protect cables Scope removed. Protections for these cables 13 ZB1 B17BH, ZB1A84A1, were removed from the Fire and ZB i A84A2 in FZ Acceptable results are PRA for quantification. Risk 304S to restore power to achieved with existing results presented in the 18-04. plant design and 120-day RAI responses operation, and reflect risk with this additional transient modification removed.

combustible controls.

IMP-144 has been updated to include Fire Zone 304S ventilation area.

MOD- To address the potential Scope revised. The MSO for the main 14 fail open scenarios steam isolation valves associated with multiple Model and circuit (MSIVs) and the condenser spurious operation analysis has been steam dump valves were concerns, solenoid valves updated and is reflected added to the Fire PRA will be installed in the air in final quantification. model to evaluate the lines supplying the revision to MOD-i 4. MOD-Condenser Steam Dump 14 is incorporated into the Valves and steam inlet Fire PRA as per Appendix I valves to the MSRs each of "NFPA 805 Fire PRA on both units with a Quantification Notebook" manually activated switch (P209i -2900-02, Revision outside the Control 2)

Room. Cable routing and power supplies will not be Risk results presented in in the Cable Spreading the 120-day RAI responses Room or the Control reflect risk with this Room or dependent on -*H*

modification updated.

, *...

• c *

• equipment in either area.

MOD- Cables ZD2426MA, Scope removed. The Fire PRA model was 15 ZD2426MB, and enhanced to credit existing ZD2426MC, associated Acceptable results are plant design and operation.

with letdown valve achieved with existing 2RC-427 in Fire Area plant design and Protections for these cables AOi-B, will be protected operation, and reliance were removed from the Fire to prevent spurious on an action in the main PRA for quantification. Risk LOCA. control room to isolate

~-~~

results presented in the air to containment, as 120-day RAI-responses reflected in EPM report reflect risk with this R2168-9999-01. modification removed.

Page 12 of 18

MOD- Cable ZB1426MC for unit Scope removed. The Fire PRA model was 16 1 and ZD2426MC for unit enhanced to credit existing 2, associated with Acceptable results are plant design and operation.

letdown valve 1/2RC-427 achieved with existing in FZ 318, will be plant design and Protections for these cables protected. operation, and reliance were removed from the Fire on an action in the main PRA for quantification. Risk control room to isolate results presented in the air to containment, as 120-day RAI responses reflected in EPM report reflect risk with this R2168-9999-01. modification removed.

MOD- Protect the following Scope removed. Overcurrent trip (OCT) 17 cables in the fire areas failure modes and resulting noted to preserve DC OCT analysis confirmed secondary fire impacts were control power to the this modification was incorporated into the Fire required breakers: not necessary. PRA model. The removal Acceptability confirmed of OCT -related Cable ID: Fire Area by final quantification. modifications was also D3102A A15 incorporated in the risk D3102A A01-H results for the 120-day RAI 041 02A A01-G responses.

D4102A A02 D4102AA06 D4102A A24 ZAD1107AA30 ZAD11 07 A A23S ZFD0406A A30 ZFD0406A A68 ZFD0406A A23N ZFD0206A A23N ZFD0206A A30 ZFD1402A2 A68 ZFDi 402A 1 A30 ZFD1402A1/A2 A23N ZFD0208A A23N ZCD3109A1 A23S ZCD3109Ai A24 ZED0307 A A 15 ZEDOi08A A23S Page i 3 of i 8

MOD- Either Pump P38A or Scope removed. Protections for these cables 18 P38B is required to be were removed from the Fire restored; to restore pump Pump P38B cable not PRA for quantification. Risk P38A, cables WK114042A credited in AOi-B/46. results presented in the and ZK11460H in FZ 237, Acceptability confirmed 120-day RAI responses will be protected. by final quantification. reflect risk with this modification removed .

MOD- Reduce dependence on Scope clarification. Change in scope does not 23 instrument air for P-38 impact the Fire PRA AOVs by providing 24 modeling.

hour pneumatic supply.

MOD- Provide coordinated fuses Scope removed. Overcurrent trip (OCT) 28 to prevent cables that are failure modes and resulting remote to the switchgear OCT analysis confirmed secondary fire impacts were from preventing an over this modification was incorporated into the Fire current trip for the not necessary. PRA model. The removal following breaker circuits: Acceptability confirmed of OCT -related 1A52-02, 1A52-06, by final quantification. modifications was also 1A52-12, iA52-85 incorporated in the risk 2A52-22, 2A52-31, 2A52- results for the 120-day RAI 49 responses.

Page i4 of 18

MOD- Provide coordinated fuses Scope removed. Overcurrent trip (OCT) 29 and additional relays to failure modes and resulting prevent cables that are OCT analysis confirmed secondary fire impacts were remote to the switchgear this modification was incorporated into the Fire from preventing an over not necessary. PRA model. The removal current trip for the Acceptability confirmed of OCT -related following breaker circuits: by final quantification. modifications was also H52-22, H52-32, H52-16 incorporated in the risk 1A52-05, 1A52-07, results for the 120-day RAI 1A52-08, 1A52-09, responses.

1A52-10, 1A52-11, 1A52-13, 1A52-15, 1A52-58, 1A52-59, 1A52-84 2A52-19, 2A52-20, 2A52-21, 2A52-23, 2A52-25, 2A52-28, 2A52-30, 2A52-32, 2A52-33, 2A52-67, 2A52-73, 2A52-7 4,

... 2A52-75, 2A52-88, 2A52-89 MOD- Provide automatic backup Scope removed. Overcurrent trip (OCT) 30 DC power to the following failure modes and resulting buses independent of fire OCT analysis confirmed secondary fire impacts were area A24: this modification was incorporated into the Fire 1-A01, 1-A02, 2-A01, 2- not necessary. PRA model. The removal A02 Acceptability confirmed of OCT -related Note: Providing self- by final quantification. modifications was also energized over current incorporated in the risk trip devices on the results for the 120-day RAI individual breakers on responses.

these buses negates the requirement of backup DC power.

MOD- Protect cables Scope removed. Fire modeling and circuit 31 (ZCG0201 H, ZCG0201J, analysis were updated in ZCB020i T, and Refined fire modeling the Fire PRA model for the ZEG01 01 T) for breaker and circuit analysis 120-day RAI responses.

~2AS27ob-etwe-en~2A:..:03 - ~c-cmflrmmtthis

-~

~

and 2A-05 in FZ 31 8 from modification was not Protections for these cables damage due to a fire in necessary. were removed from the Fire cabinet DYOA. PRA for quantification. Risk results presented in the 120-day RAI responses reflect risk with this modification removed.

Page 15 of 18

MOD- Protect cable ZFi N 8 139A Scope removed. Fire modeling and circuit 32 for breaker 252391 analysis were updated in between 28-39 and D-09 Refined fire modeling the Fire PRA model for the in FZ 318 from damage and circuit analysis 120-day RAI responses.

due to a fire in bus 18-04. confirmed this modification was not Protection for this cable necessary. was removed from the Fire PRA for quantification. Risk results presented in the 120-day RAI responses reflect risk with this modification removed.

MOD- Protect cable Di 208A for Scope removed due to Fire modeling and circuit 33 breaker 2A5276 between refined fire model and analysis were updated in 2A-03 and 2A-05 in FZ circuit analysis. the Fire PRA model for the 318 from damage due to 120-day RAI responses.

a fire in cabinet D-26.

Protection for this cable was removed from the Fire PRA for quantification. Risk results presented in the 120-day RAI responses reflect risk with this modification removed.

EC Install low suction New modification. Charging pump low-suction 272841 pressure trip logic to at pressure trip logic was and least two charging pumps Modification added to included in the Fire PRAto 261021 per unit. provide additional risk prevent failure on loss of reduction. adequate suction failure for charging pumps 1 (2)-P2A, 8, and C). This includes incorporation of an operator action to manually open CV-1128 or CV-358 to provide a water source from

~

lilt: nt:IUt:IIII!:J vvc:uer Storage Tank (RWST) or Volume Control Tank

- , (VCT). This model logic and PRA results also include potential spurious actuations causing a low pressure trip.

Page 16 of 18

References (1) NextEra Energy Point Beach, LLC, letter to NRC, dated June 26, 2013, "License Amendment Request 271, Transition to 10 CFR 50.48(c)- NFPA 805, 'Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants,'

2001 Edition" (Mli 31820453)

(2) NRC e-mail to NextEra Energy Point Beach, LLC, dated September 9, 2013, "Request for Supplemental Information Regarding the Acceptability of the Proposed Amendment Request" (ML13256A197)

(3) NextEra Energy Point Beach, LLC, letter to NRC, dated September 16, 2013, "License Amendment Request 271 Supplement 1 Transition to 10 CFR 50.48(c)- NFPA 805" (ML13259A273)

(4) NRC letter to NextEra Energy Point Beach, LLC, dated September 25, 2013, "Point Beach Nuclear Plant, Units 1 and 2 - Acceptance of Licensing Action re: License Amendment Request to Transition to NFPA 805, 'Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants' (TAC NOS. MF2372 and MF2373)" (ML13267A037)

(5) NRC e-mail to NextEra Energy Point Beach, LLC, dated November 19, 2014, RE: Point Beach Nuclear Plant, Units 1 and 2- Follow-up Requests for Additional Information (AFPB) re: NFPA 805 License Amendment Request Review (TAC Nos. MF2372 and MF2373)" (ML14325A540)

(6) NextEra Energy Point Beach, LLC, letter to NRC, dated September 25, 2014, "Response (120 Day) to Request for Additional Information and Revision to 60 Day Response License Amendment Request 271 Associated with NFPA 805" (ML14282A446)

Page i 7 of i 8

NextEra PBNP Attachment S - Modifications and Implementation Items I Table S-2 Plant Modifications Committed i

Item Rank 1 Unit Problem Statement Proposed LAR Current Comp Risk I Modification FPRA FPRA Measure Characterization MOD-2 H 1,2 Provide a9ditional Cross tie y y y Risk is reduced by having the flexibility fqr supplying TDAFWP steam unaffected unit available to AFW to SGs. I swpplies and pump receive steam or add water to I discharge(s) to maintain Decay Heat allow opposite Unit Removal support.

Com12ensatory measures for NFPA 805: A1212ro12riate com12ensatory measures will be established as reguired until the modification is i

I im lemented.

MOD-3 H 1,2 When cooling flow is The RCP Seal will y y N Risk is reduced as change lost to the burrent be upgraded to provides a more controllable RCP seal there is a Westinghouse leak rate, if cooling flow is lost rapid tran~ition into a SHIELD to the RCP seal.

considerable loss of Generation Ill inventory 4s a Seal Shutdown Seal LOCA. I y y

~r~=~~ec~~~t~t ~~nt MOD-4 'H 1,2 Add additional N Risk is reduced by providing power inputs to B- alternate means of AC power.

credited b~sses there 08 and to B-09.

are multipl~ areas Power to come where buspes may not from a tie line be available for independent of the required skte and switch yard.

Stable Eq4ipment without extensive re12airs or $ctions.

to 9/25/14 Letter NRC 2014-0056 (Attachment 5 of Enclosure 2)

Page 18 of 18