View source for 1CAN011601, Response to Round 3 Request for Additional Information, Adoption of National Fire Protection Association Standard NFPA-805

{{Adams
| number = ML16015A421
| issue date = 01/15/2016
| title = Response to Round 3 Request for Additional Information, Adoption of National Fire Protection Association Standard NFPA-805
| author name = Browning J
| author affiliation = Entergy Operations, Inc
| addressee name = 
| addressee affiliation = NRC/Document Control Desk, NRC/NRR
| docket = 05000313
| license number = DPR-051
| contact person = 
| case reference number = 1CAN011601
| document type = Letter type:, Response to Request for Additional Information (RAI)
| page count = 14
| project = 
| stage = Request
}}

=Text=
{{#Wiki_filter:s Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Jeremy G. Browning Vice President - Operations Arkansas Nuclear One 1CAN011601 January 15, 2016 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

==SUBJECT:==
Response to Round 3 Request for Additional Information Adoption of National Fire Protection Association Standard NFPA-805 Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51

==Dear Sir or Madam:==

By email dated January 12, 2016 (Reference 12), the NRC requested additional information associated with the Entergy Operations, Inc. (Entergy) request to amend the Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specifications (TS) and licensing bases to comply with the requirements in 10 CFR 50.48(a), 10 CFR 50.48(c), and the guidance in Regulatory Guide (RG) 1.205, Risk-Informed Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants. The amendment request followed Nuclear Energy Institute (NEI) 04-02, Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program under 10 CFR 50.48(c). This submittal described the methodology used to demonstrate compliance with, and transition to, National Fire Protection Association (NFPA) 805, and included regulatory evaluations, probabilistic risk assessment (PRA), change evaluations, proposed modifications for non-compliances, and supporting attachments.
The request for additional information (RAI) is associated with a previous RAI (Safe Shutdown Analysis (SSA) 11.01, Entergy response provided in Reference 10) regarding an inhibit circuit (i.e., a shorting switch) intended to be used to address the circuit failure modes identified in Information Notice (IN) 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ML031200481), for several valves at ANO-1. In a conference call held with members of the NRC staff at 1300 CST on January 6, 2016, Entergy verbally committed to include a failure probability for the subject circuits in the ANO Fire PRA model similar to that performed by the Browns Ferry nuclear facility and accepted in NRC Safety Evaluation Report dated October 28, 2015 (ML15212A796). The Entergy response to the RAI is included in Attachment 1 to this letter.
The information, as detailed in this letter, with respect to the original Entergy request (Reference 1) has been reviewed and Entergy has determined that the information does not invalidate the no significant hazards consideration included in the Reference 1 letter.

1CAN011601 Page 2 of 3 In accordance with 10 CFR 50.91(b)(1), a copy of this application is being provided to the designated Arkansas state official.
One new commitment is included in Attachment 2 to this letter.
If you have any questions or require additional information, please contact Stephenie Pyle at 479-858-4704.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on January 15, 2016.
Sincerely, ORIGINAL SIGNED BY TERRY A. EVANS FOR JEREMY G. BROWNING JGB/dbb

==Attachment:==
: 1. Response to Round 3 Request for Additional Information - ANO-1 Transition to NFPA-805
: 2. List of Regulatory Commitments cc:     Mr. Marc L. Dapas Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Ms. Andrea E. George MS O-8B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. Bernard R. Bevill Arkansas Department of Health Radiation Control Section 4815 West Markham Street Slot #30 Little Rock, AR 72205

1CAN011601 Page 3 of 3

==REFERENCES:==
: 1. Entergy letter dated January 29, 2014, License Amendment Request to Adopt NFPA-805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition) (1CAN011401) (ML14029A438)
: 2. NRC letter dated May 5, 2015, Arkansas Nuclear One, Unit 1 - Request for Additional Information Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805 (TAC No. MF3419) (1CNA051501) (ML15091A431)
: 3. Entergy letter dated May 19, 2015, Response to Request for Additional Information -
Adoption of National Fire Protection Association Standard NFPA-805 (1CAN051501)
(ML15139A196)
: 4. Entergy letter dated June 16, 2015, 60-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN061501) (ML15167A503)
: 5. Entergy letter dated July 21, 2015, 90-Day Response to Request for Additional Information
    - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN071501)
(ML15203A205)
: 6. Entergy letter dated August 12, 2015, 120-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN081501) (ML15224A729)
: 7. NRC email dated September 8, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA091501)
(ML15251A220)
: 8. Entergy letter dated September 22, 2015, Round 2 Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN091501) (ML15265A113)
: 9. NRC email dated October 6, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Part 2 Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419)
(1CNA101501) (ML15280A114)
: 10. Entergy letter dated November 4, 2015, Second Set of Round 2 Responses to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111501) (ML15308A452)
: 11. Entergy letter dated November 17, 2015, Clarification of Response to Round 2 Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111502) (ML15321A076)
: 12. NRC email dated January 12, 2016, Arkansas Nuclear One, Unit 1 - 3rd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA011601)

Attachment 1 to 1CAN011601 Response to Round 3 Request for Additional Information ANO-1 Transition to NFPA-805 to 1CAN011601 Page 1 of 8 RESPONSE TO ROUND 3 REQUEST FOR ADDITIONAL INFORMATION ANO-1 Transition to NFPA-805 By email dated January 12, 2016 (Reference 12), the NRC requested additional information associated with the Entergy Operations, Inc. (Entergy) request to amend the Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specifications (TS) and licensing bases to comply with the requirements in 10 CFR 50.48(a), 10 CFR 50.48(c), and the guidance in Regulatory Guide (RG) 1.205, Risk-Informed Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants. The amendment request followed Nuclear Energy Institute (NEI) 04-02, Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program under 10 CFR 50.48(c). This submittal described the methodology used to demonstrate compliance with, and transition to, National Fire Protection Association (NFPA) 805, and included regulatory evaluations, probabilistic risk assessment (PRA), change evaluations, proposed modifications for non-compliances, and supporting attachments.
In a conference call held with members of the NRC staff at 1300 CST on January 6, 2016, Entergy verbally committed to include a failure probability for the subject circuits in the ANO Fire PRA model similar to that performed by the Browns Ferry nuclear facility and accepted in NRC Safety Evaluation Report dated October 28, 2015 (ML15212A796). The Round 3 RAI is included below for convenience, followed by the Entergy response. The response includes a new commitment as stated in Attachment 2 of this letter.
SSA RAI 11.01 Response Clarification In its letter dated November 4, 2015, the licensee submitted a response to Safe Shutdown Analysis (SSA) request for additional information (RAI) 11.01. Specifically, the licensee provided an extensive qualitative explanation concluding that installation of an inhibit circuit (i.e.,
a shorting switch) addresses the circuit failure modes identified in Information Notice (IN) 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ADAMS Accession No. ML031200481), for several valves at ANO-1. Based on the licensees response to SSA RAI 11.01, it appears that these shorting switches are credited with precluding spurious actuations of the IN 92-18 valves, and so fire-induced damage on DC control circuits located in the vicinity of cables having fusing greater than 10 amps of the inhibit circuits is not modeled in the Fire PRA.
The NRC staff cannot conclude that spurious actuations can be precluded without additional information. As an alternative to concluding that spurious actuation is precluded, spurious actuation need not be modelled if the risk is insignificant for both transition and post-transition risk evaluations (i.e., less than the self-approval risk guidelines); however, the NRC staff cannot reach this conclusion with the limited risk information provided by the licensee. Please provide a sensitivity study demonstrating that the risk impact of failing the protected valves is insignificant, or that the risk of the excluded scenarios in which a fire causes a spurious actuation and the inhibit switch fails is insignificant with regard to the plant change evaluations.
to 1CAN011601 Page 2 of 8

===Response===
Entergy determined during the original assessment of various fire-related station risks associated with the transition of the ANO-1 licensing basis to NFPA 805 that certain motor and air operated valves (MOVs and AOVs, respectively) could fail in an undesired state, resulting in station risk elevated sufficiently to warrant modification of the associated circuits. Subsequently, an inhibit circuit was designed and committed to in support of lowering overall station risk following transition to NFPA 805. As stated in the above RAI, Entergy has previously provided extensive qualitative discussion regarding the implementation of the subject inhibit circuits. The qualitative discussion was intended to indicate that failure of the inhibit circuit to meet its objective was not credible. However, the above RAI requires a risk-informed assessment to provide a quantitative justification in order to reinforce the previously submitted and related qualitative information.
In a conference call held with members of the NRC staff at 1300 CST on January 6, 2016, Entergy verbally committed to include a failure probability for the subject circuits in the ANO Fire PRA model, similar to that performed by the Browns Ferry nuclear facility and accepted in NRC Safety Evaluation Report (SER) dated October 28, 2015 (ML15212A796). Such modeling would be in lieu of the sensitivity study suggested by the RAI. In a letter dated March 14, 2014 (ML1479A159), the Browns Ferry nuclear facility provided the NRC information supporting the use of a 1E-03 failure probability assumption associated with the subject inhibit circuits. The NRC accepted the Browns Ferry application of the 1E-03 inhibit circuit failure probability in the aforementioned SER. The following discussion provides similar ANO-1 specific information supporting application of a failure probabilities in relation to the subject circuits.
While the subject control circuits for MOVs and AOVs may be affected by fire, the inhibit circuit (or shorting switch), associated conductors, and actuated device are required to undergo multiple failures to defeat this configuration (open circuit and hot short in limited locations). The inhibit circuit bonds the line-side of the actuation device of concern to the circuit return path (neutral or negative) and is assumed to maintain electrical continuity, preventing application of a sufficient voltage that can cause spurious operation via the shorting switch, thus allowing the intended function of the shorting switch to remain effective. Fire exposure in AC circuits is not postulated to cause open circuits as the primary failure mode. Typically, insulation is fully consumed before the copper conductor melts and potential target and source conductors would already be grounded, or the associated fuse/breaker would have cleared. Consequently, no credible hot shorts from either intracable or intercable interactions to other conductors also connected to the line-side of the actuation device are assumed to energize the actuation device because the source conductor is immediately shorted to the circuit return path.
The control circuits that utilize the shorting switch concept have cables routed in raceways for control voltage circuits that are nominally 120 VAC, 125 VDC, or less. This protects target cables from higher energy AC circuits, although the cables will still be exposed to DC cables that have been shown in some tested instances to aggressively arc when fused at greater than 10 amps (reference NUREG/CR-7100, "Direct Current Electrical Shorting in Response to Exposure Fire). A postulated failure mode where aggressive electrical arcing from a source DC circuit causes collateral damage to the target cable resulting in an open circuit of the shorting switch conductors and failure of the shorting switch function is considered. Any hot short that could cause spurious actuation of the subject MOV or AOV would need to occur subsequent to this postulated failure that melts open the inhibit circuit conductor. ANO-1 raceways can contain cables for DC circuits; therefore, a probability of 1E-03 is proposed to model the likelihood that a to 1CAN011601 Page 3 of 8 cable containing shorting switch conductors is located next to a DC circuit cable capable of generating an arc that causes collateral damage and potential open circuit of the shorting switch conductors. Although there is uncertainty associated with this probability, it bounds the likelihood that the cable containing shorting switch conductors is located next to a cable capable of generating the arc, that the arc would be generated when the cable is affected by a fire and results in an open circuit of the shorting conductors, and that after the open circuit occurs, a fire-induced short causes a spurious operation.
All of the shorting switches for both the MOV and the AOV control circuits will be in the Main Control Room panels located in Fire Area G. For a fire inside the Main Control Room panel where the shorting switch is located, the shorting switch will be assumed damaged before the fire induced hot short occurs on the modified circuit. Spurious hot short probabilities listed in NUREG/CR-7150, Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE), will be credited for the modified circuits where the shorting switch is physically damaged by the fire inside the panel in lieu of the 1E-03 circuit failure probability (these probabilities will typically be higher than the 1E-03). As noted previously, insulation on the shorting switch conductor would have to be fully consumed before the copper conductor melts, or the terminal strips, shorting switch, or other devices in the shorting conduction path would have to be consumed/destroyed prior to potential target and source conductors shorting together.
The aggregate risk results of this modeling will be included in the final PRA results to be included in response to PRA RAI 03. This commitment is captured in Attachment 2 of this letter.
In Entergy letter dated November 4, 2015 (Reference 10), a complete list of items associated with the final response to PRA RAI 03 was included in response to PRA RAI 03.b.01. Because a new commitment is being added via this letter, the previous submitted list is copied below, with this new item added for completeness.
Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                                 respect to the self-support of the LAR (to be incorporated into the Description                                                                approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
Same approach as that Spatial separation is not credited. The zone of PRA RAI 01.a                                                                used for the final influence is allowed to cross non-barrier regarding spatial                                                           integrated analysis boundaries. No change to the Fire PRA (FPRA) separation                                                                  provided in support of model is required.
the LAR.
to 1CAN011601 Page 4 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                            respect to the self-support of the LAR (to be incorporated into the Description                                                            approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
There are no active fire protection systems supporting the Multi-Compartment Analysis (MCA) fire barriers that require an actuation Same approach as that system (i.e., barrier features which credit PRA RAI 01.b                                                            used for the final systems that require signals from cables or a regarding fire                                                          integrated analysis detection system) as part of any physical barriers                                                                provided in support of analysis unit (PAU) boundary at ANO-1 (e.g.,
the LAR.
water curtains). The MCA is being revised to sum the generic barrier failure probabilities for each type of barrier present between PAUs.
The panel factor approach was eliminated prior to submitting the LAR. Severe and non-severe Same approach as that PRA RAI 01.c        panel fires have been defined based on the zone used for the final regarding fire      of influence up to and excluding the nearest integrated analysis propagation from    target. The methodology used is based on data provided in support of electrical cabinets provided in NUREG/CR-6850, Appendices E the LAR.
and H, and the methodology defined in the Generic Fire Modeling Treatments (GMFT).
Circuit failure likelihood values used will be PRA RAI 01.e        consistent with the values specified in regarding circuit   NUREG/CR-7150.
failure likelihood  The guidance from NUREG/CR-7150 regarding           Same approach as that analysis /          other cable configurations recommends the use     used for the final PRA RAI 01.e.d      of the aggregate spurious operation conditional     integrated analysis regarding           probabilities for in-panel wiring and trunk cables. provided in support of spurious            For instrument circuits, no spurious operation      the LAR.
operation in other  conditional probability will be credited. The cable               guidance on other cable configurations will be configurations      incorporated into the ANO-1 FPRA in support of the integrated risk assessment PRA RAI 03.
PRA RAI 01.g        The FPRA will incorporate the update to the         Same approach as that regarding           Human Reliability Analysis (HRA) methodology        used for the final modeling new fire   that is consistent with developing detailed human   integrated analysis Human Error         error probabilities (HEPs) as outlined in           provided in support of Events              NUREG-1921.                                         the LAR.
PRA RAI 01.h        A SOKC was applied to ignition frequencies,         Same approach as that regarding state of  circuit failure probabilities, non-suppression      used for the final knowledge           probabilities, and HRA basic events. The SOKC       integrated analysis correlation         will be addressed in the final FPRA                 provided in support of (SOKC)              documentation.                                      the LAR.
to 1CAN011601 Page 5 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                            respect to the self-support of the LAR (to be incorporated into the Description                                                           approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
PRA RAI 02.a                                                           Same approach as that regarding impact  The FPRA model will be revised to address the        used for the final of                phenomenological issues as identified in             integrated analysis phenomenological response to PRA RAI 02.a.                             provided in support of conditions                                                             the LAR.
Spurious operation of the ADVs and ERV, which        Same approach as that PRA RAI 02.b could impact Pressure-Induced Steam Generator        used for the final regarding Tube Rupture (SGTR) and Thermal-Induced              integrated analysis completion of SGTR, will be incorporated in the Integrated         provided in support of LERF analysis Analysis performed in response to PRA RAI 03.        the LAR.
Not applicable to the development of the PRA RAI 02.d                                                           post transition self-The internal events model is not altered by the regarding                                                              approval model, since response to this RAI (see RAI response for counting                                                               this RAI did not impact basis). Therefore, the resolution of this RAI does operational                                                            the integrated analysis not impact the PRA quantification.
demands                                                                and the aggregated results provided in support of the LAR.
Not applicable to the development of the post transition self-The internal events model is not altered by the PRA RAI 02.e                                                           approval model, since response to this RAI (see RAI response for regarding                                                              this RAI did not impact basis). Therefore, the resolution of this RAI does counting failures                                                      the integrated analysis not impact the PRA quantification.
and the aggregated results provided in support of the LAR.
PRA RAI 04                                                             Same approach as that regarding reduced Reduced heat release rate values are used in         used for the final transient heat    distinct areas with restricted transient controls in integrated analysis release rates     the new fire protection program.                     provided in support of (HRRs)                                                                 the LAR.
PRA RAI 05        The impact of the results of walkdowns of            Same approach as that regarding         sensitive electronics will be incorporated into the  used for the final treatment of      final FPRA quantification as necessary,              integrated analysis sensitive         consistent with the methodology outlined in          provided in support of electronics       FAQ 13-0004.                                         the LAR.
to 1CAN011601 Page 6 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                            respect to the self-support of the LAR (to be incorporated into the Description                                                           approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
A review of the well-sealed panels that house circuits below 440 V is in progress. The well-PRA RAI 07                                                             Same approach as that sealed panels represent a small percentage of regarding                                                              used for the final the total Bin 15 count and will be removed from propagation of fire                                                    integrated analysis the Bin 15 frequency allocation. Additionally, the from > 440 V                                                           provided in support of FPRA will be revised to include fire propagation electrical cabinets                                                    the LAR.
from sealed > 440 V panels, consistent with the guidance in FAQ 14-0009.
PRA RAI 08 Same approach as that regarding use of    Transient Frequency Adjustment Factor of 0.1 is used for the final the transient       being removed from the analysis and replaced integrated analysis frequency           with a frequency adjustment that is consistent provided in support of adjustment          with FAQ 12-0064.
the LAR.
factors Same approach as that PRA RAI 09          Fire propagation in the main Control Room used for the final regarding fire      (MCR) is being addressed consistent with the integrated analysis propagation in the  guidance of NUREG/CR-6850 Chapter 11 and provided in support of MCR                 Appendix S.
the LAR.
The FPRA method for control room abandonment evaluation of the variant and Same approach as that PRA RAI 11          compliant cases is addressed in the RAI used for the final regarding           response. No changes to this methodology are integrated analysis crediting MCR       expected to be required, however, the values provided in support of abandonment         provided in the RAI response may change once the LAR.
revisions are incorporated and the final results are quantified.
Same approach as that PRA RAI 12 The updated quantification will assume the heat    used for the final regarding multiple release rates associated with multi-bundle         integrated analysis versus single configuration for all MCR panels.                  provided in support of cables the LAR.
PRA RAI 14          See PRA RAI 15.                                    See PRA RAI 15.
to 1CAN011601 Page 7 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                              respect to the self-support of the LAR (to be incorporated into the Description                                                              approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
PRA RAI 15 Not applicable to the
[corrected RAI      The response to this RAI will calculate the total development of the number for this     risk increase associated with the unresolved post transition self-subject, original   variances from deterministic requirements approval model, since list incorrectly    (VFDRs) (i.e., VFDRs that are not associated this RAI did not impact identified RAI as   with a plant modification and discuss the impact the integrated analysis PRA RAI 14]         of important modeling assumptions contributing and the aggregated regarding large     to the risk significant scenarios for fire areas in results provided in reduction credit    the compliant plant model).
support of the LAR.
for modifications FM RAI 01.k Same approach as that regarding The abandonment frequency will be updated as           used for the final evaluation of necessary to reflect the response provided for         integrated analysis MCR Fire Modeling (FM) RAI 01.k.                           provided in support of abandonment the LAR.
times a)    Each joint HEP value used in the FPRA below 1.0E-05 will include its own justification that demonstrates the inapplicability of the NUREG-1792 lower         Same approach as that PRA RAI 18.01 -            value guideline.                                used for the final Minimum Joint                                                              integrated analysis HEP floor value      b)    An estimate of the number of these joint        provided in support of HEPs below 1.0E-05 and at least two             the LAR.
different examples of the justification will be provided with the final PRA RAI 03 response.
Inhibit circuits of valves associated with IN 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ML031200481) discussed in Same approach as that SSA RAI 11.01       response to SSA RAI 11.01 in Entergy letter used for the final Clarification -     dated November 4, 2015, will be modeled with a integrated analysis Inhibit Circuit     failure probabilities as discussed in the RAI provided in support of Failure Probability response of Entergy letter dated January 15, the LAR.
2016. The aggregate risk results of the modeling will be included in the final PRA results in response to PRA RAI 03.
to 1CAN011601 Page 8 of 8

==REFERENCES:==
: 1. Entergy letter dated January 29, 2014, License Amendment Request to Adopt NFPA-805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition) (1CAN011401) (ML14029A438)
: 2. NRC letter dated May 5, 2015, Arkansas Nuclear One, Unit 1 - Request for Additional Information Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805 (TAC No. MF3419) (1CNA051501) (ML15091A431)
: 3. Entergy letter dated May 19, 2015, Response to Request for Additional Information -
Adoption of National Fire Protection Association Standard NFPA-805 (1CAN051501)
(ML15139A196)
: 4. Entergy letter dated June 16, 2015, 60-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN061501) (ML15167A503)
: 5. Entergy letter dated July 21, 2015, 90-Day Response to Request for Additional Information
     - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN071501)
(ML15203A205)
: 6. Entergy letter dated August 12, 2015, 120-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN081501) (ML15224A729)
: 7. NRC email dated September 8, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA091501)
(ML15251A220)
: 8. Entergy letter dated September 22, 2015, Round 2 Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN091501) (ML15265A113)
: 9. NRC email dated October 6, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Part 2 Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419)
(1CNA101501) (ML15280A114)
: 10. Entergy letter dated November 4, 2015, Second Set of Round 2 Responses to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111501) (ML15308A452)
: 11. Entergy letter dated November 17, 2015, Clarification of Response to Round 2 Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111502) (ML15321A076)
: 12. NRC email dated January 12, 2016, Arkansas Nuclear One, Unit 1 - 3rd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA011601)

Attachment 2 to 1CAN011601 List of Regulatory Commitments to 1CAN011601 Page 1 of 1 LIST OF REGULATORY COMMITMENTS The following table identifies those actions committed to by Entergy in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.
TYPE (Check one)               SCHEDULED COMMITMENT                                                      COMPLETION ONE-TIME     CONTINUING              DATE ACTION     COMPLIANCE Entergy will model the Arkansas Nuclear One, Unit 1, inhibit circuits of valves associated with Information Notice (IN) 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ML031200481) discussed in response to NRC request for additional information                                        Concurrent with (RAI) 11.01 in Entergy letter dated                                         final response to November 4, 2015,* with failure                                                 PRA RAI 03.
probabilities as discussed in the RAI response included in Entergy letter dated January 15, 2016. The aggregate risk results of the modeling will be included in the final probabilistic risk assessment (PRA) results in response to PRA RAI 03.
* Entergy letter dated November 4, 2015, Second Set of Round 2 Responses to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111501) (ML15308A452)

s Entergy Operations, Inc.
1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Jeremy G. Browning Vice President - Operations Arkansas Nuclear One 1CAN011601 January 15, 2016 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

==SUBJECT:==
Response to Round 3 Request for Additional Information Adoption of National Fire Protection Association Standard NFPA-805 Arkansas Nuclear One, Unit 1 Docket No. 50-313 License No. DPR-51

==Dear Sir or Madam:==

By email dated January 12, 2016 (Reference 12), the NRC requested additional information associated with the Entergy Operations, Inc. (Entergy) request to amend the Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specifications (TS) and licensing bases to comply with the requirements in 10 CFR 50.48(a), 10 CFR 50.48(c), and the guidance in Regulatory Guide (RG) 1.205, Risk-Informed Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants. The amendment request followed Nuclear Energy Institute (NEI) 04-02, Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program under 10 CFR 50.48(c). This submittal described the methodology used to demonstrate compliance with, and transition to, National Fire Protection Association (NFPA) 805, and included regulatory evaluations, probabilistic risk assessment (PRA), change evaluations, proposed modifications for non-compliances, and supporting attachments.
The request for additional information (RAI) is associated with a previous RAI (Safe Shutdown Analysis (SSA) 11.01, Entergy response provided in Reference 10) regarding an inhibit circuit (i.e., a shorting switch) intended to be used to address the circuit failure modes identified in Information Notice (IN) 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ML031200481), for several valves at ANO-1. In a conference call held with members of the NRC staff at 1300 CST on January 6, 2016, Entergy verbally committed to include a failure probability for the subject circuits in the ANO Fire PRA model similar to that performed by the Browns Ferry nuclear facility and accepted in NRC Safety Evaluation Report dated October 28, 2015 (ML15212A796). The Entergy response to the RAI is included in Attachment 1 to this letter.
The information, as detailed in this letter, with respect to the original Entergy request (Reference 1) has been reviewed and Entergy has determined that the information does not invalidate the no significant hazards consideration included in the Reference 1 letter.

1CAN011601 Page 2 of 3 In accordance with 10 CFR 50.91(b)(1), a copy of this application is being provided to the designated Arkansas state official.
One new commitment is included in Attachment 2 to this letter.
If you have any questions or require additional information, please contact Stephenie Pyle at 479-858-4704.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on January 15, 2016.
Sincerely, ORIGINAL SIGNED BY TERRY A. EVANS FOR JEREMY G. BROWNING JGB/dbb

==Attachment:==
: 1. Response to Round 3 Request for Additional Information - ANO-1 Transition to NFPA-805
: 2. List of Regulatory Commitments cc:     Mr. Marc L. Dapas Regional Administrator U. S. Nuclear Regulatory Commission Region IV 1600 East Lamar Boulevard Arlington, TX 76011-4511 NRC Senior Resident Inspector Arkansas Nuclear One P. O. Box 310 London, AR 72847 U. S. Nuclear Regulatory Commission Attn: Ms. Andrea E. George MS O-8B1 One White Flint North 11555 Rockville Pike Rockville, MD 20852 Mr. Bernard R. Bevill Arkansas Department of Health Radiation Control Section 4815 West Markham Street Slot #30 Little Rock, AR 72205

1CAN011601 Page 3 of 3

==REFERENCES:==
: 1. Entergy letter dated January 29, 2014, License Amendment Request to Adopt NFPA-805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition) (1CAN011401) (ML14029A438)
: 2. NRC letter dated May 5, 2015, Arkansas Nuclear One, Unit 1 - Request for Additional Information Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805 (TAC No. MF3419) (1CNA051501) (ML15091A431)
: 3. Entergy letter dated May 19, 2015, Response to Request for Additional Information -
Adoption of National Fire Protection Association Standard NFPA-805 (1CAN051501)
(ML15139A196)
: 4. Entergy letter dated June 16, 2015, 60-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN061501) (ML15167A503)
: 5. Entergy letter dated July 21, 2015, 90-Day Response to Request for Additional Information
    - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN071501)
(ML15203A205)
: 6. Entergy letter dated August 12, 2015, 120-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN081501) (ML15224A729)
: 7. NRC email dated September 8, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA091501)
(ML15251A220)
: 8. Entergy letter dated September 22, 2015, Round 2 Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN091501) (ML15265A113)
: 9. NRC email dated October 6, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Part 2 Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419)
(1CNA101501) (ML15280A114)
: 10. Entergy letter dated November 4, 2015, Second Set of Round 2 Responses to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111501) (ML15308A452)
: 11. Entergy letter dated November 17, 2015, Clarification of Response to Round 2 Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111502) (ML15321A076)
: 12. NRC email dated January 12, 2016, Arkansas Nuclear One, Unit 1 - 3rd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA011601)

Attachment 1 to 1CAN011601 Response to Round 3 Request for Additional Information ANO-1 Transition to NFPA-805 to 1CAN011601 Page 1 of 8 RESPONSE TO ROUND 3 REQUEST FOR ADDITIONAL INFORMATION ANO-1 Transition to NFPA-805 By email dated January 12, 2016 (Reference 12), the NRC requested additional information associated with the Entergy Operations, Inc. (Entergy) request to amend the Arkansas Nuclear One, Unit 1 (ANO-1) Technical Specifications (TS) and licensing bases to comply with the requirements in 10 CFR 50.48(a), 10 CFR 50.48(c), and the guidance in Regulatory Guide (RG) 1.205, Risk-Informed Performance-Based Fire Protection for Existing Light-Water Nuclear Power Plants. The amendment request followed Nuclear Energy Institute (NEI) 04-02, Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program under 10 CFR 50.48(c). This submittal described the methodology used to demonstrate compliance with, and transition to, National Fire Protection Association (NFPA) 805, and included regulatory evaluations, probabilistic risk assessment (PRA), change evaluations, proposed modifications for non-compliances, and supporting attachments.
In a conference call held with members of the NRC staff at 1300 CST on January 6, 2016, Entergy verbally committed to include a failure probability for the subject circuits in the ANO Fire PRA model similar to that performed by the Browns Ferry nuclear facility and accepted in NRC Safety Evaluation Report dated October 28, 2015 (ML15212A796). The Round 3 RAI is included below for convenience, followed by the Entergy response. The response includes a new commitment as stated in Attachment 2 of this letter.
SSA RAI 11.01 Response Clarification In its letter dated November 4, 2015, the licensee submitted a response to Safe Shutdown Analysis (SSA) request for additional information (RAI) 11.01. Specifically, the licensee provided an extensive qualitative explanation concluding that installation of an inhibit circuit (i.e.,
a shorting switch) addresses the circuit failure modes identified in Information Notice (IN) 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ADAMS Accession No. ML031200481), for several valves at ANO-1. Based on the licensees response to SSA RAI 11.01, it appears that these shorting switches are credited with precluding spurious actuations of the IN 92-18 valves, and so fire-induced damage on DC control circuits located in the vicinity of cables having fusing greater than 10 amps of the inhibit circuits is not modeled in the Fire PRA.
The NRC staff cannot conclude that spurious actuations can be precluded without additional information. As an alternative to concluding that spurious actuation is precluded, spurious actuation need not be modelled if the risk is insignificant for both transition and post-transition risk evaluations (i.e., less than the self-approval risk guidelines); however, the NRC staff cannot reach this conclusion with the limited risk information provided by the licensee. Please provide a sensitivity study demonstrating that the risk impact of failing the protected valves is insignificant, or that the risk of the excluded scenarios in which a fire causes a spurious actuation and the inhibit switch fails is insignificant with regard to the plant change evaluations.
to 1CAN011601 Page 2 of 8

===Response===
Entergy determined during the original assessment of various fire-related station risks associated with the transition of the ANO-1 licensing basis to NFPA 805 that certain motor and air operated valves (MOVs and AOVs, respectively) could fail in an undesired state, resulting in station risk elevated sufficiently to warrant modification of the associated circuits. Subsequently, an inhibit circuit was designed and committed to in support of lowering overall station risk following transition to NFPA 805. As stated in the above RAI, Entergy has previously provided extensive qualitative discussion regarding the implementation of the subject inhibit circuits. The qualitative discussion was intended to indicate that failure of the inhibit circuit to meet its objective was not credible. However, the above RAI requires a risk-informed assessment to provide a quantitative justification in order to reinforce the previously submitted and related qualitative information.
In a conference call held with members of the NRC staff at 1300 CST on January 6, 2016, Entergy verbally committed to include a failure probability for the subject circuits in the ANO Fire PRA model, similar to that performed by the Browns Ferry nuclear facility and accepted in NRC Safety Evaluation Report (SER) dated October 28, 2015 (ML15212A796). Such modeling would be in lieu of the sensitivity study suggested by the RAI. In a letter dated March 14, 2014 (ML1479A159), the Browns Ferry nuclear facility provided the NRC information supporting the use of a 1E-03 failure probability assumption associated with the subject inhibit circuits. The NRC accepted the Browns Ferry application of the 1E-03 inhibit circuit failure probability in the aforementioned SER. The following discussion provides similar ANO-1 specific information supporting application of a failure probabilities in relation to the subject circuits.
While the subject control circuits for MOVs and AOVs may be affected by fire, the inhibit circuit (or shorting switch), associated conductors, and actuated device are required to undergo multiple failures to defeat this configuration (open circuit and hot short in limited locations). The inhibit circuit bonds the line-side of the actuation device of concern to the circuit return path (neutral or negative) and is assumed to maintain electrical continuity, preventing application of a sufficient voltage that can cause spurious operation via the shorting switch, thus allowing the intended function of the shorting switch to remain effective. Fire exposure in AC circuits is not postulated to cause open circuits as the primary failure mode. Typically, insulation is fully consumed before the copper conductor melts and potential target and source conductors would already be grounded, or the associated fuse/breaker would have cleared. Consequently, no credible hot shorts from either intracable or intercable interactions to other conductors also connected to the line-side of the actuation device are assumed to energize the actuation device because the source conductor is immediately shorted to the circuit return path.
The control circuits that utilize the shorting switch concept have cables routed in raceways for control voltage circuits that are nominally 120 VAC, 125 VDC, or less. This protects target cables from higher energy AC circuits, although the cables will still be exposed to DC cables that have been shown in some tested instances to aggressively arc when fused at greater than 10 amps (reference NUREG/CR-7100, "Direct Current Electrical Shorting in Response to Exposure Fire). A postulated failure mode where aggressive electrical arcing from a source DC circuit causes collateral damage to the target cable resulting in an open circuit of the shorting switch conductors and failure of the shorting switch function is considered. Any hot short that could cause spurious actuation of the subject MOV or AOV would need to occur subsequent to this postulated failure that melts open the inhibit circuit conductor. ANO-1 raceways can contain cables for DC circuits; therefore, a probability of 1E-03 is proposed to model the likelihood that a to 1CAN011601 Page 3 of 8 cable containing shorting switch conductors is located next to a DC circuit cable capable of generating an arc that causes collateral damage and potential open circuit of the shorting switch conductors. Although there is uncertainty associated with this probability, it bounds the likelihood that the cable containing shorting switch conductors is located next to a cable capable of generating the arc, that the arc would be generated when the cable is affected by a fire and results in an open circuit of the shorting conductors, and that after the open circuit occurs, a fire-induced short causes a spurious operation.
All of the shorting switches for both the MOV and the AOV control circuits will be in the Main Control Room panels located in Fire Area G. For a fire inside the Main Control Room panel where the shorting switch is located, the shorting switch will be assumed damaged before the fire induced hot short occurs on the modified circuit. Spurious hot short probabilities listed in NUREG/CR-7150, Joint Assessment of Cable Damage and Quantification of Effects from Fire (JACQUE-FIRE), will be credited for the modified circuits where the shorting switch is physically damaged by the fire inside the panel in lieu of the 1E-03 circuit failure probability (these probabilities will typically be higher than the 1E-03). As noted previously, insulation on the shorting switch conductor would have to be fully consumed before the copper conductor melts, or the terminal strips, shorting switch, or other devices in the shorting conduction path would have to be consumed/destroyed prior to potential target and source conductors shorting together.
The aggregate risk results of this modeling will be included in the final PRA results to be included in response to PRA RAI 03. This commitment is captured in Attachment 2 of this letter.
In Entergy letter dated November 4, 2015 (Reference 10), a complete list of items associated with the final response to PRA RAI 03 was included in response to PRA RAI 03.b.01. Because a new commitment is being added via this letter, the previous submitted list is copied below, with this new item added for completeness.
Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                                 respect to the self-support of the LAR (to be incorporated into the Description                                                                approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
Same approach as that Spatial separation is not credited. The zone of PRA RAI 01.a                                                                used for the final influence is allowed to cross non-barrier regarding spatial                                                           integrated analysis boundaries. No change to the Fire PRA (FPRA) separation                                                                  provided in support of model is required.
the LAR.
to 1CAN011601 Page 4 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                            respect to the self-support of the LAR (to be incorporated into the Description                                                            approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
There are no active fire protection systems supporting the Multi-Compartment Analysis (MCA) fire barriers that require an actuation Same approach as that system (i.e., barrier features which credit PRA RAI 01.b                                                            used for the final systems that require signals from cables or a regarding fire                                                          integrated analysis detection system) as part of any physical barriers                                                                provided in support of analysis unit (PAU) boundary at ANO-1 (e.g.,
the LAR.
water curtains). The MCA is being revised to sum the generic barrier failure probabilities for each type of barrier present between PAUs.
The panel factor approach was eliminated prior to submitting the LAR. Severe and non-severe Same approach as that PRA RAI 01.c        panel fires have been defined based on the zone used for the final regarding fire      of influence up to and excluding the nearest integrated analysis propagation from    target. The methodology used is based on data provided in support of electrical cabinets provided in NUREG/CR-6850, Appendices E the LAR.
and H, and the methodology defined in the Generic Fire Modeling Treatments (GMFT).
Circuit failure likelihood values used will be PRA RAI 01.e        consistent with the values specified in regarding circuit   NUREG/CR-7150.
failure likelihood  The guidance from NUREG/CR-7150 regarding           Same approach as that analysis /          other cable configurations recommends the use     used for the final PRA RAI 01.e.d      of the aggregate spurious operation conditional     integrated analysis regarding           probabilities for in-panel wiring and trunk cables. provided in support of spurious            For instrument circuits, no spurious operation      the LAR.
operation in other  conditional probability will be credited. The cable               guidance on other cable configurations will be configurations      incorporated into the ANO-1 FPRA in support of the integrated risk assessment PRA RAI 03.
PRA RAI 01.g        The FPRA will incorporate the update to the         Same approach as that regarding           Human Reliability Analysis (HRA) methodology        used for the final modeling new fire   that is consistent with developing detailed human   integrated analysis Human Error         error probabilities (HEPs) as outlined in           provided in support of Events              NUREG-1921.                                         the LAR.
PRA RAI 01.h        A SOKC was applied to ignition frequencies,         Same approach as that regarding state of  circuit failure probabilities, non-suppression      used for the final knowledge           probabilities, and HRA basic events. The SOKC       integrated analysis correlation         will be addressed in the final FPRA                 provided in support of (SOKC)              documentation.                                      the LAR.
to 1CAN011601 Page 5 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                            respect to the self-support of the LAR (to be incorporated into the Description                                                           approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
PRA RAI 02.a                                                           Same approach as that regarding impact  The FPRA model will be revised to address the        used for the final of                phenomenological issues as identified in             integrated analysis phenomenological response to PRA RAI 02.a.                             provided in support of conditions                                                             the LAR.
Spurious operation of the ADVs and ERV, which        Same approach as that PRA RAI 02.b could impact Pressure-Induced Steam Generator        used for the final regarding Tube Rupture (SGTR) and Thermal-Induced              integrated analysis completion of SGTR, will be incorporated in the Integrated         provided in support of LERF analysis Analysis performed in response to PRA RAI 03.        the LAR.
Not applicable to the development of the PRA RAI 02.d                                                           post transition self-The internal events model is not altered by the regarding                                                              approval model, since response to this RAI (see RAI response for counting                                                               this RAI did not impact basis). Therefore, the resolution of this RAI does operational                                                            the integrated analysis not impact the PRA quantification.
demands                                                                and the aggregated results provided in support of the LAR.
Not applicable to the development of the post transition self-The internal events model is not altered by the PRA RAI 02.e                                                           approval model, since response to this RAI (see RAI response for regarding                                                              this RAI did not impact basis). Therefore, the resolution of this RAI does counting failures                                                      the integrated analysis not impact the PRA quantification.
and the aggregated results provided in support of the LAR.
PRA RAI 04                                                             Same approach as that regarding reduced Reduced heat release rate values are used in         used for the final transient heat    distinct areas with restricted transient controls in integrated analysis release rates     the new fire protection program.                     provided in support of (HRRs)                                                                 the LAR.
PRA RAI 05        The impact of the results of walkdowns of            Same approach as that regarding         sensitive electronics will be incorporated into the  used for the final treatment of      final FPRA quantification as necessary,              integrated analysis sensitive         consistent with the methodology outlined in          provided in support of electronics       FAQ 13-0004.                                         the LAR.
to 1CAN011601 Page 6 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                            respect to the self-support of the LAR (to be incorporated into the Description                                                           approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
A review of the well-sealed panels that house circuits below 440 V is in progress. The well-PRA RAI 07                                                             Same approach as that sealed panels represent a small percentage of regarding                                                              used for the final the total Bin 15 count and will be removed from propagation of fire                                                    integrated analysis the Bin 15 frequency allocation. Additionally, the from > 440 V                                                           provided in support of FPRA will be revised to include fire propagation electrical cabinets                                                    the LAR.
from sealed > 440 V panels, consistent with the guidance in FAQ 14-0009.
PRA RAI 08 Same approach as that regarding use of    Transient Frequency Adjustment Factor of 0.1 is used for the final the transient       being removed from the analysis and replaced integrated analysis frequency           with a frequency adjustment that is consistent provided in support of adjustment          with FAQ 12-0064.
the LAR.
factors Same approach as that PRA RAI 09          Fire propagation in the main Control Room used for the final regarding fire      (MCR) is being addressed consistent with the integrated analysis propagation in the  guidance of NUREG/CR-6850 Chapter 11 and provided in support of MCR                 Appendix S.
the LAR.
The FPRA method for control room abandonment evaluation of the variant and Same approach as that PRA RAI 11          compliant cases is addressed in the RAI used for the final regarding           response. No changes to this methodology are integrated analysis crediting MCR       expected to be required, however, the values provided in support of abandonment         provided in the RAI response may change once the LAR.
revisions are incorporated and the final results are quantified.
Same approach as that PRA RAI 12 The updated quantification will assume the heat    used for the final regarding multiple release rates associated with multi-bundle         integrated analysis versus single configuration for all MCR panels.                  provided in support of cables the LAR.
PRA RAI 14          See PRA RAI 15.                                    See PRA RAI 15.
to 1CAN011601 Page 7 of 8 Disposition with respect to the final integrated Disposition with analysis and the aggregated results provided in RAI No. /                                                              respect to the self-support of the LAR (to be incorporated into the Description                                                              approval model for final PRA RAI 03 response which includes the post-transition changes final Fire PRA quantification results)
PRA RAI 15 Not applicable to the
[corrected RAI      The response to this RAI will calculate the total development of the number for this     risk increase associated with the unresolved post transition self-subject, original   variances from deterministic requirements approval model, since list incorrectly    (VFDRs) (i.e., VFDRs that are not associated this RAI did not impact identified RAI as   with a plant modification and discuss the impact the integrated analysis PRA RAI 14]         of important modeling assumptions contributing and the aggregated regarding large     to the risk significant scenarios for fire areas in results provided in reduction credit    the compliant plant model).
support of the LAR.
for modifications FM RAI 01.k Same approach as that regarding The abandonment frequency will be updated as           used for the final evaluation of necessary to reflect the response provided for         integrated analysis MCR Fire Modeling (FM) RAI 01.k.                           provided in support of abandonment the LAR.
times a)    Each joint HEP value used in the FPRA below 1.0E-05 will include its own justification that demonstrates the inapplicability of the NUREG-1792 lower         Same approach as that PRA RAI 18.01 -            value guideline.                                used for the final Minimum Joint                                                              integrated analysis HEP floor value      b)    An estimate of the number of these joint        provided in support of HEPs below 1.0E-05 and at least two             the LAR.
different examples of the justification will be provided with the final PRA RAI 03 response.
Inhibit circuits of valves associated with IN 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ML031200481) discussed in Same approach as that SSA RAI 11.01       response to SSA RAI 11.01 in Entergy letter used for the final Clarification -     dated November 4, 2015, will be modeled with a integrated analysis Inhibit Circuit     failure probabilities as discussed in the RAI provided in support of Failure Probability response of Entergy letter dated January 15, the LAR.
2016. The aggregate risk results of the modeling will be included in the final PRA results in response to PRA RAI 03.
to 1CAN011601 Page 8 of 8

==REFERENCES:==
: 1. Entergy letter dated January 29, 2014, License Amendment Request to Adopt NFPA-805 Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants (2001 Edition) (1CAN011401) (ML14029A438)
: 2. NRC letter dated May 5, 2015, Arkansas Nuclear One, Unit 1 - Request for Additional Information Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805 (TAC No. MF3419) (1CNA051501) (ML15091A431)
: 3. Entergy letter dated May 19, 2015, Response to Request for Additional Information -
Adoption of National Fire Protection Association Standard NFPA-805 (1CAN051501)
(ML15139A196)
: 4. Entergy letter dated June 16, 2015, 60-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN061501) (ML15167A503)
: 5. Entergy letter dated July 21, 2015, 90-Day Response to Request for Additional Information
     - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN071501)
(ML15203A205)
: 6. Entergy letter dated August 12, 2015, 120-Day Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN081501) (ML15224A729)
: 7. NRC email dated September 8, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA091501)
(ML15251A220)
: 8. Entergy letter dated September 22, 2015, Round 2 Response to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN091501) (ML15265A113)
: 9. NRC email dated October 6, 2015, Arkansas Nuclear One, Unit 1 - 2nd Round Part 2 Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419)
(1CNA101501) (ML15280A114)
: 10. Entergy letter dated November 4, 2015, Second Set of Round 2 Responses to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111501) (ML15308A452)
: 11. Entergy letter dated November 17, 2015, Clarification of Response to Round 2 Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111502) (ML15321A076)
: 12. NRC email dated January 12, 2016, Arkansas Nuclear One, Unit 1 - 3rd Round Request for Additional Information - ANO-1 NFPA 805 LAR (TAC No. MF3419) (1CNA011601)

Attachment 2 to 1CAN011601 List of Regulatory Commitments to 1CAN011601 Page 1 of 1 LIST OF REGULATORY COMMITMENTS The following table identifies those actions committed to by Entergy in this document. Any other statements in this submittal are provided for information purposes and are not considered to be regulatory commitments.
TYPE (Check one)               SCHEDULED COMMITMENT                                                      COMPLETION ONE-TIME     CONTINUING              DATE ACTION     COMPLIANCE Entergy will model the Arkansas Nuclear One, Unit 1, inhibit circuits of valves associated with Information Notice (IN) 92-18, Potential for Loss of Remote Capability during a Control Room Fire (ML031200481) discussed in response to NRC request for additional information                                        Concurrent with (RAI) 11.01 in Entergy letter dated                                         final response to November 4, 2015,* with failure                                                 PRA RAI 03.
probabilities as discussed in the RAI response included in Entergy letter dated January 15, 2016. The aggregate risk results of the modeling will be included in the final probabilistic risk assessment (PRA) results in response to PRA RAI 03.
* Entergy letter dated November 4, 2015, Second Set of Round 2 Responses to Request for Additional Information - Adoption of National Fire Protection Association Standard NFPA-805 (1CAN111501) (ML15308A452)}}