1CAN091501, Round 2 Response to Request for Additional Information, Adoption of National Fire Protection Association Standard NFPA-805

Round 2 Response to Request for Additional Information, Adoption of National Fire Protection Association Standard NFPA-805

ML15265A113
Person / Time
Site:	Arkansas Nuclear
Issue date:	09/22/2015
From:	Jeremy G. Browning Entergy Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
References
1CAN091501
Download: ML15265A113 (14)

Text

s Entergy Operations, Inc.

1448 S.R. 333 Russellville, AR 72802 Tel 479-858-3110 Jeremy G. Browning Vice President - Operations Arkansas Nuclear One 1CAN091501 September 22, 2015 U.S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555

SUBJECT:

Round 2 Response to 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 September 8, 2015 (Reference 7), 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 subject 2nd Round Request for Additional Information responses are included in the attachment to this letter.

Changes or additional information, as detailed in this letter, with respect to the original Entergy request (Reference 1) have been reviewed and Entergy has determined that the changes do not invalidate the no significant hazards consideration included in the Reference 1 letter.

In accordance with 10 CFR 50.91(b)(1), a copy of this application is being provided to the designated Arkansas state official.

No new commitments have been identified in this letter.

1CAN091501 Page 2 of 3 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 September 22, 2015.

Sincerely, ORIGINAL SIGNED BY JEREMY G. BROWNING JGB/dbb

Attachment:

Round 2 Responses to Request for Additional Information - ANO-1 Transition to NFPA-805

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)

1CAN091501 Page 3 of 3 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

Attachment to 1CAN091501 Round 2 Responses to Request for Additional Information ANO-1 Transition to NFPA-805

Attachment to 1CAN091501 Page 1 of 10 ROUND 2 45-DAY RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION ANO-1 Transition to NFPA-805 By letter dated January 29, 2014 (ML14029A438), as supplemented by letters dated May 19, 2015 (ML15139A196), June 16, 2015 (ML15167A503), July 21, 2015 (ML15203A205), and August 12, 2015 (ML15224A729), Entergy Operations, Inc. (Entergy), submitted a license amendment request to transition the Arkansas Nuclear One, Unit 1 (ANO-1), fire protection program to one based on the National Fire Protection Association Standard 805 (NFPA 805),

"Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition, as incorporated into Title 10 of the Code of Federal Regulations (10 CFR)

Section 50.48(c).

In the course of its review, the NRC staff determined that additional information is required in order to complete its evaluation. A clarification call was held on September 2, 2015, where it was agreed that a response to the Requests for Additional Information (RAIs) would be provided by October 5, 2015. The following includes the subject requests for information and the relevant Entergy response to each question.

Fire Modeling (FM) RAI 05.01 Section 4.5.1.2, Fire PRA, of the License Amendment Request (LAR) states that fire modeling was performed as part of the Fire PRA development (NFPA 805 Section 4.2.4.2).

Section 2.7.3.4 of NFPA 805 states, in part, that the personnel who use and apply engineering analysis and numerical models (e.g., fire modeling techniques) shall be competent in that field and experienced in the application of these methods.

In its response to the second bullet of FM RAI 05 in a letter dated June 16, 2015 (Agencywide Document Access and Management System (ADAMS) Accession No. ML15167A503), the licensee explained that Entergys process for evaluating bids and proposals and for selection of suppliers ensures that individuals contracted to perform fire modeling tasks have the appropriate background and meet the necessary qualification requirements. However, the licensee did not address the process for qualifying Entergy personnel involved in fire modeling activities.

Describe how the qualifications of Entergy personnel involved in fire modeling activities met or will meet the requirements of NFPA 805 section 2.7.3.4 during the development of the application, before transition, during the transition period, and after transition.

Response

Work performed during the development of the LAR application and the subsequent NRC review has been completed by contracted individuals that have the appropriate background and meet the necessary qualification requirements. In addition, any fire modeling activities that may be needed during the transition period will be completed by contracted individuals as described above.

Attachment to 1CAN091501 Page 2 of 10 Entergy has developed a qualification card (Perform Fire Modeling - NFPA-805 Sites, FTK-ESPP-G00145) to be used after the transition (i.e., when the requirements of the Transition License condition are satisfied) to NFPA 805. The requirements of NFPA 805, Section 2.7.3.4, are met by requiring prerequisites including engineering calculation qualifications, eligibility requirements for Society of Fire Protection Engineers Professional Member status met, and fire modeling training course attendance (e.g., Electric Power Research Institute (EPRI) Fire Modeling Workshop, Jensen Hughes, Nexus, Engineering Planning and Management, Inc.

(EPM) Fire Modeling Database training) or equivalent as determined by an Entergy Fire Protection Engineer. Knowledge requirements include discussing which fire models should be used for different applications, the limitations of fire models, and the key differences among fire models, in particular those verified and validated in NUREG-1824. Contracted personnel with the appropriate background and meeting the necessary qualification requirements will continue to be utilized at ANO until sufficient Entergy personnel meet the designated FTK-ESPP-G00145 qualification requirements.

Fire Protection Engineering (FPE) RAI 04.01 In its response to FPE RAI 04 in a letter dated June 16, 2015 (ADAMS Accession No. ML15167A503), the licensee stated that code compliance evaluations were performed for Sections 3.4.1(b), 3.4.1(c), 3.4.1(d), 3.4.1(e), 3.9.2 and 3.9.3 of NFPA 805 and that the compliance statement will change from Complies to Complies with use of EEEEs. The licensee also stated that it will add the calculation reference to the Compliance Basis Section.

NFPA 805, Sections 3.4.1(b), (c), (d), and (e) address specific requirements for the industrial fire brigade members and do not specify an NFPA code as a means to satisfy the requirements.

In response to FPE RAI 04, the licensee stated that CALC-ANOC-FP-08-00005 is the calculation that demonstrates compliance for these subparts. Based on a review of the ANO Unit 1 LAR, CALC-ANOC-FP-08-00005 compares the ANO fire protection program to the 2000 Edition of NFPA 600. While NFPA 600 contains many requirements for the formation, management, and utilization of an industrial fire brigade, there is not a one-for-one correlation between the NFPA 805 requirements contained in 3.4.1 (b), (c), (d) or (e) and NFPA 600.

In addition, the licensee provided information to supplement its compliance basis for NFPA 805 Section 3.4.1 (c) in its response to FPE RAI 02, which was submitted in a letter dated May 19, 2015 (ADAMS Accession No. ML15139A196).

Clarify whether the NFPA code evaluation will replace or supplement the compliance statements in the "Compliance Basis" section of LAR Attachment A and the response to FPE RAI 02. If so, describe how the NFPA code evaluation addresses the specific requirements contained in NFPA 805 Sections 3.4.1 (b), (c), (d), and (e). Also, because the licensee states that the fire brigade members are shared between Units 1 and 2, describe how the compliance basis for ANO-1 affects ANO-2, as approved in the Safety Evaluation for its current license condition for ANO-2 (ADAMS Accession No. ML14356A227).

Attachment to 1CAN091501 Page 3 of 10

Response

NFPA Code section 3.4.1(b). The NFPA 600 code evaluation will not be used as a reference and will not replace or supplement the compliance statements for NFPA Code Section 3.4.1(b).

The original LAR submitted Compliance Statement, Compliance Basis, and Reference Document will remain unchanged.

NFPA Code section 3.4.1(c). The NFPA 600 code evaluation will not be used as a reference and will not replace or supplement the compliance statements for NFPA Code Section 3.4.1(c).

The Compliance Statement, Compliance Basis, and Reference Documents should be comprised of the original LAR submitted Compliance Statement, Compliance Basis, and Reference Document as supplemented by the response to FPE RAI 02. The response to FPE RAI 02 will remain as originally submitted.

NFPA Code section 3.4.1(d). The NFPA 600 code evaluation will not be used as a reference and will not replace or supplement the compliance statements for NFPA Code Section 3.4.1(d).

The original LAR submitted Compliance Statement and Compliance Basis will remain unchanged.

NFPA Code section 3.4.1(e). The NFPA 600 code evaluation will be used as a supplemental reference and will not replace or supplement the compliance statements for NFPA Code Section 3.4.1(e). The original LAR submitted Compliance Statement and Compliance Basis will remain unchanged. CALC-ANOC-FP-08-00005, ANO Code Compliance Report for NFPA 600 2000 Edition, Rev. 1, will be added to the Reference Documents.

The NFPA 600 Code evaluation will not be used to replace or supplement the compliance statements in the Compliance Basis section of LAR Attachment A and the response to FPE RAI 02.

The original LAR NFPA Code Section 3.4.1(c) Compliance Basis as supplemented by the response to FPE RAI 02 has the same intent as the ANO-2 Compliance Basis for the same NFPA code section. ANO meets this NFPA 805 Chapter 3 requirement by means of Operations personnel, shared between ANO-1 and ANO-2 Operations. The composition of the fire brigade as reflected in FPE RAI 02 is also applicable to ANO-2. The staffing change only strengthens compliance since the fire brigade is now entirely manned by Operations personnel. Therefore, the compliance basis for ANO-1 does not affect ANO-2 as approved in the Safety Evaluation for its current license condition (ML14356A227).

FPE RAI 06.01 In its response to FPE RAI 06 in a letter dated June 16, 2015 (ADAMS Accession No. ML15167A503), the licensee stated that for a number of NFPA 805 Chapter 3 attributes, the compliance statement and compliance basis will be changing as described in its response. The NRC staff requests the following additional clarification related to the licensees proposed compliance statement changes:

a) NFPA 805 Section 3.5.7 requires that individual fire pump connections to the yard fire main loop shall be provided and separated with sectionalizing valves between connections. In LAR Attachment A, the licensee stated that it complies and that the fire pump connections to the yard fire main loop are provided and separated with

Attachment to 1CAN091501 Page 4 of 10 sectionalizing valves between connections per ANO-1 License Amendment 35. In its response to FPE RAI 06, the licensee stated that it is revising its compliance statement to Complies by previous NRC Approval; however, excerpts and citations were not provided from its NRC Safety Evaluation Report (SER) to demonstrate previous NRC approval. In its response to FPE RAI 04 in the same letter, the licensee also stated that it is changing its compliance statement from Complies to Complies with Use of EEEEs and the specific changes to its compliance basis were not described. Clarify if NFPA 805 Section 3.5.7 will have two compliance statements (Complies with use of EEEEs and Complies by Previous NRC approval) and describe the bases for the applicable compliance statements. For example, if the licensee Complies by Previous NRC approval, provide the specific excerpts from its submittal(s) and the SER(s) that substantiate the approval. If the licensee Complies with Use of EEEEs, provide the specific NFPA code that was evaluated and the basis for its applicability to demonstrate compliance with these specific Chapter 3 requirements.

b) NFPA 805 Section 3.6.1 requires that for all power block buildings, Class III standpipe and hose systems will be installed in accordance with NFPA 14, Standard for the Installation of Standpipe, Private Hydrant, and Hose Stations. In LAR Attachment A, the licensee stated that it Complies with Use of EEEEs and that the requirement was evaluated by the NFPA 14 code compliance evaluation. In its response to FPE RAI 06, the licensee revised its compliance statement to Complies with Clarification and its compliance basis to state that the Chapter 3 requirement was evaluated by the NFPA 14 code compliance evaluation and that the standpipe and hose systems are considered Class II and have been evaluated for acceptability. The licensee further stated that the ANO-1 License Amendment 35 SER is considered for information only and does not support compliance. The NRC-endorsed guidance in NEI 04-02, Guidance for Implementing a Risk-Informed, Performance-Based Fire Protection Program Under 10 CFR 50.48(c), Revision 2, Section 4.3.1, describes the compliance statement of Complies with Clarification as items that are not in literal compliance with NFPA 805, but should transition as complies. The example given in NEI 04-02 illustrates this strategy is applied in circumstances such as compliance methods that could be considered editorial in nature. The licensees compliance basis is not considered to be an editorial clarification, such as described in NEI 04-02, and is outside the guidance in NEI 04-02 for being considered a clarification. Provide a more appropriate compliance statement such as Complies by Previous NRC Approval and the cited excerpts from the submittal(s) and the SER(s) that substantiate the approval, or submit a performance-based method in accordance with 10 CFR 50.48(c)(2)(vii).

c) NFPA 805 Section 3.11.2 requires that fire barriers required by NFPA 805 Chapter 4 include a specific fire-resistance rating and that these fire barriers be designed and installed to meet the specific fire resistance rating using assemblies qualified by fire tests. In LAR Attachment A, the licensee states it Complies with use of EEEEs and cites excerpts from ANO-1 License Amendment 35, Section 4.11 and refers to an implementation item in LAR Attachment S (Table S-1, Item S1-31). In its response to FPE RAI 06, the licensee stated that its compliance basis will be revised to state that the requirement was evaluated by an engineering evaluation and that the ANO-1 License Amendment 35 SER is considered for information only and does not support compliance. Clarify if the compliance basis noted in FPE RAI 06 will replace the compliance basis in LAR Attachment A in its entirety and confirm if the implementation item that was described in the LAR Attachment A, compliance basis is still applicable.

Attachment to 1CAN091501 Page 5 of 10

Response

a) The Compliance Statement for NFPA 805, Section 3.5.7, should be revised to Complies with Previous NRC Approval.

The Compliance Basis should be revised to state:

Fire pump connections to the yard fire main loop are provided and separated with sectionalizing valves between connections per ANO-1 License Amendment 35, Section 4.3.1.3, which states:

Each of the two fire pumps has a separate discharge into the 12-inch underground fire loop which encircles both Unit 1 and Unit 2. Valving is arranged so that a single break in the discharge piping will not remove both fire pumps from service. Yard fire hydrants, fixed water suppression systems, and interior fire hose stations are supplied by the fire loop. Sectionalizing valves are provided on the loop to allow isolation of various sections for maintenance or repair.

Also, Reference Document CALC-ANOC-FP-09-00006, ANO Code Compliance Report for NFPA 20 1969 Edition, Rev. 0, should be removed.

b) The Compliance Statement for NFPA 805, Section 3.6.1, should be revised to N/A.

The Compliance Basis should be revised to state:

The standpipe and hose systems at ANO are Class II and have been evaluated by the NFPA 14 Code Compliance Evaluation.

The Reference Document section should be revised to remove ANO-1 License Amendment 35, Safety Evaluation Report, 8/22/1978, Item 4.3.1.4.

c) Further investigation has determined that the Compliance Statement for NFPA 805, Section 3.11.2, should be revised to Complies by previous NRC Approval.

The Compliance Basis should be revised to delete:

This requirement was evaluated by EC1956, ANO-1 & 2 Fire Area/Fire Zone Compliance.

Please add the following to the Compliance Basis:

NOTE: Subsequent to the NRCs approval of fire barriers as described above, Fire Area B was divided up into multiple Fire Areas in order to accomplish Appendix R post fire safe shutdown strategies, which are now applicable to NFPA 805 analysis scenarios.

EC-1527 and EC-1956 provided inspection criteria/documentation necessary to allow the fire barriers associated with the redefined fire areas to be rated as 3-hour barriers.

The fire barriers identified in EC-1527 that contain penetrations will be inspected and modified or provided with an adequate-for-the-hazard evaluation as necessary per Attachment S, Table S-1, Implementation Item S1-31.

The Reference Document EC-1527, Provide As-Built FB Drawings for NRC Rated Barriers, Rev. 0, should be added consistent with the response to FPE RAI 06.

Attachment to 1CAN091501 Page 6 of 10 PRA RAI 01.e.01 In its response to PRA RAI 01.e in a letter dated July 21, 2015 (ADAMS Accession No. ML15203A205), the licensee stated that the updated state of knowledge correlation (SOKC) using hot short probabilities and hot short duration probabilities based on NUREG/CR-7150, Volume 2, Expert Elicitation Exercise for Nuclear Power Plant Fire-Induced Electrical Circuit Failure (ADAMS Accession No. ML14141A129), will be incorporated into the uncertainty analysis update. Confirm that the updated SOKC using hot short probabilities and hot short duration probabilities based on NUREG/CR-7150, Volume 2, will be incorporated into the integrated analysis provided in response to PRA RAI 03.

Response

The integrated analysis to be provided in response to Probabilistic Risk Assessment (PRA)

RAI 03 will be updated to reflect the hot short probabilities and hot short duration probabilities based on NUREG/CR-7150, Volume 2. The SOKC, using these same probabilities, will be incorporated into the uncertainty analysis that will support the integrated analysis provided in response to PRA RAI 03.

Probabilistic Risk Assessment (PRA) RAI 01.g.01 In its response to PRA RAI 01.g in a letter dated June 16, 2015 (ADAMS Accession No. ML15167A503), the licensee explained that the Human Reliability Analysis (HRA) methodology used for the Fire PRA was revised after the LAR was submitted to be consistent with the approach used to address HRA RAIs for ANO-2 and that a focused scope peer review of the revised HRA was performed in June 2014. The NRC staff understands that the Facts and Observation (F&Os) from the HRA focused scope peer review superseded the previous HRA peer review F&Os. Provide the F&Os from the June 2014 focused scope peer review on the fire HRA along with dispositions explaining how the F&Os have been resolved or will be resolved in the integrated analysis provided in response to PRA RAI 03.

Response

The following Finding level F&Os resulted from the ANO-1 focused scope peer review which addressed High Level Requirements HRA-C and HR-G. The disposition for each of these F&Os is provided below and the results will be incorporated into the integrated analysis response to PRA RAI 03.

F&O HR-G3-01 Finding: Detailed analysis of HPI-HFC-FO-CRSPR-EF and HPI-HFC-FO-CRSPR-IF are two examples where the time available is less than the time required.

Disposition: This finding identified two examples in which human error probabilities (HEPs) that require more time to perform the action than what is allowed per the system time window were set to 1.0 failure probability. The specific events, HPI-HFC-FO-CRSPR-EF and HPI-HFC-FO-CRSPR-IF were re-examined by conducting simulator runs and detailed fire HRA. As a result, the timing information was updated such that the time available is greater than the time required for the

Attachment to 1CAN091501 Page 7 of 10 Operator action. Other instances in which a 1.0 failure probability was used and the time available is less than the time required will also be corrected. The revised failure probabilities will be included in the integrated analysis results for PRA RAI 03.

F&O HR-G3-02 Finding: All assumptions that impact feasibility of operator actions need to be validated before the HEPs can be applied, specifically:

Assumptions regarding availability of instrumentation credited for diagnosis should be verified available in the fire scenarios where the human failure event (HFE) is credited. This includes instrumentation credited as diverse to instrumentation that is rendered unavailable due to fire. Note that these assumptions may be implicit in analyses where cues and indications are stated without any statements regarding availability in the fire scenarios where the HFE is credited.

Related to the above are assumptions made with regards to explicit modeling of instrumentation.

Assumptions regarding procedure changes need to be validated.

Disposition: The appropriate cues necessary for Operations to perform necessary actions had been assessed during the development of the HRAs credited in the Fire PRA. In order to ensure that the Fire PRA model explicitly captures the dependence of this instrumentation, the cues are being incorporated into the Fire PRA model.

Once completed, the results will be quantified and evaluated to determine if any additional actions, including modifications, will be needed to ensure that instrumentation needed for diagnosis remains available. The integrated analysis to be provided in response to PRA RAI 03 will include this dependency and the fire impact on these cues.

F&O HR-G7-01 Finding: Based on a review of Figure 5 in PRA-A2-01-003S03, the dependency approach does not consider availability of resources, which can be important for fire PRA.

Disposition: The HRA analysis was migrated from the HRA Toolbox Software to EPRIs HRA Calculator which accounts for resources and timing in the dependency analysis.

The dependency analysis considers the available resources relative to the timing sequence of the joint HEPs. The integrated analysis results to be provided in response to PRA RAI 03 will include the HRA dependency analysis performed to address this F&O from the peer review.

Attachment to 1CAN091501 Page 8 of 10 PRA RAI 04.01 In a letter dated June 16, 2015 (ADAMS Accession No. ML15167A503), the licensee responded to PRA RAI 04. The response to PRA RAI 04 does not describe planned administrative controls in enough detail to justify use of a reduced Heat Release Rate (HRR) of 69 kW in the Fire PRA for the seven fire zones identified in the response. The response partially describes administrative controls by explaining that transient combustibles are prohibited without performing an evaluation and/or establishing appropriate compensatory measures. However, the response does not indicate what evaluations will be performed or explain what kinds of compensatory measures may be implemented. It is not clear from the description, for example, whether quantities of combustible materials that have the potential to result in fires exceeding the reduced HRR credited in the Fire PRA will be allowed into these areas. If such quantities are allowed, it is not clear how administrative controls ensure a basis for use of the reduced HRRs in the Fire PRA. One type of compensatory action referred to in the response is continuous fire watch for any transient combustibles materials left unattended for maintenance activities. The NRC staff notes that a continuous fire watch would have the effect of reducing the frequency of possible fire scenarios opposed to limiting the size of the fire and the associated HRR. In light of these observations:

Describe the kinds of evaluations that will be performed for transient combustibles brought into these controlled areas, what the evaluation will be used for, and whether administrative controls will preclude quantities that could lead to fires greater than 69 kW. If combustible materials are allowed into these areas that could lead to fires greater than 69 kW, then describe what materials would be allowed, any limitations on such materials, and why use of a reduced HRR of 69 kW for these materials is justified.

Response

The use of the 69 kW HRR in these areas is a means to acknowledge that strict administrative controls are required. However, it is realized that occasional maintenance activities will require combustible materials exceeding 69 kW to be taken into fire areas where a 69 kW HRR was assumed in the analysis. Therefore, compensatory actions or additional evaluations are required.

EN-DC-161, Control of Combustibles, describes two types of evaluations that may be performed in relationship to transient combustibles. When preparing for a maintenance activity, maintenance personnel perform an evaluation in which the types of materials that will be taken into the area for the maintenance activity are considered. Based on the classification of the fire zone and the quantity and types of materials, compensatory measures may be established. For zero transient combustible areas, which include those areas for which a reduced HRR of 69 kW has been assumed, the evaluation would conclude that a continuous fire watch is required if the materials are left unattended. Typically, maintenance personnel will remain in the area until the materials used to support the maintenance activity are removed from the area. If for some reason maintenance personnel will not be present, a continuous fire watch will be established in accordance with OP-1000.120, ANO Fire Impairment Program. This provides more stringent controls for these areas than what is required for other fire zones, with the intent of preventing or rapidly detecting postulated fires in these critical areas.

Attachment to 1CAN091501 Page 9 of 10 The second type of evaluation is a transient combustible evaluation (TCE). This evaluation process is entered when the quantity of combustible materials required to support plant activities exceeds threshold values specified in EN-DC-161, and the proceduralized compensatory measures for the area cannot be met. For zero transient areas, a TCE would be required when transient combustibles need to be left in an area unattended (e.g., when radiological conditions result in a large dose to personnel such that it is not reasonable for a fire watch to remain in the area). In this case, the evaluation would consider the proximity of the transient combustible to fixed ignition sources and other transient combustibles that may be in the area. The evaluation and compensatory actions ensure that any potential ignition sources that are taken into the area are limited and, where possible, separated from combustible materials.

The following general guidance included in EN-DC-161 applies to transient combustibles:

Transient combustibles should be kept to minimum and be limited to those materials and quantities necessary to support the work activity.

When practical, combustible materials should be stored in a noncombustible container(s)

(e.g., gang box) with the lid closed.

Waste, debris, scrap, packing materials, or other combustibles shall be removed from an area immediately following the completion of work or at the end of the shift, whichever comes first.

Based on a review of the maintenance activities in those fire areas where the reduced 69 kW HRR was assumed, the type of combustible materials taken into five of these areas (Fire Zones 97-R, 105-T, 112-I, 144-D, and 162-A) are generally treated wood, cables, and electrical tools. Maintenance activities are minor and infrequent. The remaining two areas (Fire Zones 73-W and 98-J) are high traffic pathways which result in various attended miscellaneous combustibles passing through the area. Typical maintenance activities in these two areas are associated with resin transfer, battery bank testing, and chiller maintenance, and are likewise infrequent.

It should also be noted that hose reels and fire extinguishers are either located in each of these areas or in close proximity. In addition, fire detection and either full area or partial area suppression are provided in each area except Fire Zone 162-A, Stairwell, No. 1. EN-DC-161 prohibits storage of combustible materials in stairwells and also states that transient combustible materials should not block or impede access/egress paths, stairwells, fire protection equipment, plant equipment, or interfere with emergency lighting illumination paths.

In conclusion, administrative controls are in place to ensure the NFPA 805 fire protection program defense-in-depth concept is achieved when transient combustibles are introduced into the plant. The higher level of control for these areas, where the use of a reduced HRR of 69 kW was assumed, includes procedural work controls or engineering evaluations, which serve to limit the potential fire size and impact. The evaluations performed to support transient combustibles in these areas include the implementation of appropriate controls to limit the quantity and configuration of these combustibles. Appropriate compensatory actions (i.e., continuous personnel presence) ensure early detection and manual suppression that would limit the size of a fire.

Attachment to 1CAN091501 Page 10 of 10 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)