ML14308A247

Attachment 1: Palisades Nuclear Plant, Response to Request for Additional Information License Amendment Request to Adopt NFPA 805 Performance-Based Standard for Fire Protection for Light Water Reactors

ML14308A247
Person / Time
Site:	Palisades
Issue date:	11/04/2014
From:	Entergy Nuclear Operations
To:	Document Control Desk, Office of Nuclear Reactor Regulation
Shared Package
ML14308A344	List: ML14308A247 PNP 2014-097, Response to Request for Additional Information License Amendment Request to Adopt NFPA 805 Performance-Based Standard for Fire Protection for Light Water Reactors
References
PNP 2014-097
Download: ML14308A247 (4)

Text

ATTACHMENT 11 ATTACHMENT RESPONSE TO RESPONSE TO REQUEST REQUEST FOR ADDITIONAL INFORMATION FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REGARDING LICENSE AMENDMENT REQUEST REQUEST TO TO ADOPT NFPA NFPA 805805 PERFORMANCE-BASED STANDARD PERFORMANCE-BASED STANDARD FOR FOR FIREFIRE PROTECTION PROTECTION FOR FOR LIGHT WATER LIGHT WATER REACTORS REACTORS NRC REQUEST NRC PRA RAI 01.j.01.01 O1.j.O1.O1 By letter dated August 14, 2014 (ADAMS Accession No. ML14226A498), 14226A498), the response to PRA RAI 01.j.01 states that several 480V motor control centers (MCCs) do not postulate damage beyond the ignition source given that the MCCs are considered by the licensee to be well-sealed and robustly secured. Note that with respect to this issue, new guidance is being developed in draft FAQ 14-0009 to provide clarification of NUREG/CR-6850, "EPRIINRC-RES NUREGICR-6850, EPRI/NRC-RES Fire PRA Methodology for Assessing Software Quality guidance on well-sealed and robustly secured cabinets housing circuits with Quality" voltages of greater than 440V. Relevant NRC Staff comments are provided in "NRC NRC Comments on MCC Treatment White Paper PaperAugust August29, 29, 2014" 2014 (Comments) (ADAMS Accession number ML 14245A 133). The NRC comments support the use of a value of ML14245A133).

0.11 to characterize the likelihood that such a fire can breach a well-sealed MCC cabinet O.

and damage all cables within 6" 6 from the top of the cabinet. While the NRC staff acknowledges that this guidance is considered draft, it may be used to determine the acknowledges acceptability of transition risk.

i) Describe how fires breaching well-sealed cabinets are modelled consistent with current draft guidance; and, ii) Provide updated aggregate NFPA -805 Transition PRA results (currently NFPA-805 summarized in the response to RAI 30) including fires that breach well-sealed cabinets. NFPA-805 Transition PRA results include total fire CDF and LERF, and ACDF L1CDF and IXLERF L1LERF associated with transition. Confirm this update will be in the Fire PRA model to be used for self approval (i.e.,

implementation item).

ENO ENO RESPONSE I)i) Based Based on on the current draft draft guidance guidance [1], scenarios originating within within motor motor control control centers (MCCs)

(MCCs) with aa voltage voltage 440V 440V or or greater were updated greater were updated to to consider consider damage damage beyond beyond the MCCMCC with aa 0.10.1 conditional conditional probability.

probability. These These scenarios scenarios also also considered immediate immediate damage damage to targets within 6" from the within 6 the top of the top of the cabinet.

cabinet. Further Further modeling of fire modeling of fire propagation propagation and and damage damage was was done done using using existing existing models.

models. NoNo reevaluation reevaluation of the phenomenological of the phenomenological fire fire modeling modeling was was performed performed forfor MCCs MCCs where where all all cables cables are are located located higher higher than than 6 above the cabinet. These MOOs 6" above the cabinet. These MCCs were analyzed were analyzed with with the the same same 0.10.1 Page Page 11 of of 44

ATTACHMENT 11 ATTACHMENT RESPONSE TO RESPONSE TO REQUEST REQUEST FOR FOR ADDITIONAL ADDITIONAL INFORMATION INFORMATION REGARDING REGARDING LICENSE LICENSE AMENDMENT AMENDMENT REQUEST REQUEST TO TO ADOPT ADOPT NFPA NFPA 805 805 PERFORMANCE-BASED STANDARD PERFORMANCE-BASED STANDARD FOR FOR FIRE FIRE PROTECTION PROTECTION FOR FOR LIGHT WATER REACTORS LIGHT REACTORS probability. Scenarios that did not consider damage conditional probability. damage beyond beyond the updated to include a severity factor of 0.9.

MCC were updated References

1. NRC Comments on MCC Treatment White Paper August 29, 2014"

1. "NRC 2014 (Comments) (ADAMS Accession numb~r number ML ML114245A 4245A1133) 33) ii) Updated aggregate NFPA-805 Transition PRA results that include fires that breach well-sealed cabinets are provided below. The treatment of the potential for fire damage external to well-sealed cabinets that complies with current guidance will be included in the Fire PRA model to be used for self-approval. See the revised Attachment S, 5, Table S-3, Item 3 provided in Attachment 2.

The updated ~CDF ACDF and ~LERFALERF results indicate a net decrease in CDF ODE and LERF. Therefore, the change in risk satisfies RG 11.174. .174.

Also included below is the impact on overall baseline risk using NUREGICR-6850 ignition frequencies per Footnote 10 of Supplement 1.

NUREG/CR-6850 The updated results do not exceed the RG 1.174 risk acceptance guidelines when included in the summation in Table PRA RAI20.01-1. RAI 20.01-1.

Therefore, the overall baseline risk satisfies RG 1.174.

Table PRA RAI 01.j.01.01-1: NFPA NFPA 805 SOS Transition PRA Results Fire CDF I LERF Fire ~ CDF I A Fire A/j. ~ LERF

/j.

Fire Fire Area Total 4.4E-05 I 3.8E-06 4.4E-OS/3.SE-06 -2.6E-04// -1

-2.6E-04 -1.SE-OS

.5E-05 Multi-Compartment Multi-Compartment Analysis .8E-07 I/3.4E-OS 11.SE-07 / 3.4E-08 3.4E-OS Post-Transition Post-Transition Plant Plant 4.4E-05 I 3.8E-06 4.4E-OS/3.SE-06 Post-Transition Plant(*)

Post-Transition Plant(*) 5.1 E-05 I 4.8E-06 S.1E-OS/4.SE-06

(*)using

(*)Using NIJREGICR-6850 NUREG/CR-6SS0 Original Original Fire Fire Frequencies Frequencies per per Footnote Footnote 10 10 of of Supplement Supplement 11 Page Page 22 of of44

ATTACHMENT 11 ATTACHMENT RESPONSE TO RESPONSE TO REQUEST REQUEST FOR FOR ADDITIONAL ADDITIONAL INFORMATION INFORMATION REGARDING REGARDING LICENSELICENSE AMENDMENT REQUEST TO REQUEST ADOPT NFPA TO ADOPT NFPA 805 805 PERFORMANCE-BASED STANDARD PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR FIRE PROTECTION FOR FOR LIGHT WATER REACTORS LIGHT REACTORS NRC REQUEST NRC REQUEST PRA RA130.01 RAI 3OO1 The response to PRA RAI 30 suggests that weaknesses associated with the Fire Probabilistic Risk Assessment (FPRA) HRA dependency analysis, namely PRA RAls RAIs 01.h and 03 regarding updating the dependency analysis and PRA RAI 01.h.01 regarding its treatment of location, have not been incorporated in FPRA or the updated Attachment W results provided as Attachment 4 to the letter dated August 14, 2014.

i) Are the updated dependency and location evaluations included in the updated Attachment W?

ii) If not, indicate whether incorporating the updated evaluations might cause the RG 1.174, I~n An Approach for Using Probabilistic Risk Assessment in Risk- Risk Informed Decisions on Plant-Specific Changes to the Licensing Basis" Basis acceptance guidelines to be exceeded and provide confidence (e.g., with an updated Implementation Item 3) that these evaluations will be completed before using the PRA to support self-approval.

ENO RESPONSE i) The Attachment W results do not address the updated dependency and location evaluations.

ii) Attachment S, Table S-3, Item 3 has been expanded to include incorporation of the updated dependency dependency and location evaluations into the FPRA. This update will be inin the Fire PRA model to be used for self approval. See the revised Attachment S, Table S-3, Item 3 provided in Attachment 2.

NRC REQUEST PRA RAI 30.a.O1 RAI30.a.01 The response to PRA RAI RAI 30 states states that the FPRA modelmodel to be be used at at the beginning of of the the self-approval self-approval ofof post-transitio post-transitionn changes changes would Iwould exclude modifications notnot implemented at at the the time time". Noting Noting that all all PRA -credited implementation items PRA-credited items and and modifications modifications must must bebe completed prior to use prior to use of the FPRA of the FPRA model model for self-approval, clarify clarify this statement.

statement.

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ATTACHMENT 11 RESPONSE TO REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO ADOPT NFPA 805 PERFORMANCE-BASED STANDARD FOR FIRE PROTECTION FOR FOR LIGHT WATER REACTORS ENO RESPONSE ENO understands that all PRA-credited implementation items and modifications must END be completed prior to the use of the FPRA model for self-approval.

NRC REQUEST PRA RAI 30.c.01 With respect to PRA RAI 30 and Attachment W:

a. Confirm that the updated Attachment W results provided in Attachment 4 to the letter dated August 14, 2014 reflect all the revisions to VFDRs and recovery actions identified in Attachment 2 to the same letter.

b. The revised Attachment W, Table W-2, provides negative ~CDF ACDFandALERF and ~LERF Transition risk. Implementation Item 8 indicates that the final risk estimates that will be developed after all modifications and method changes associated with transition are completed will be assessed against these negative values instead of the RG AG 1.1.174 174 acceptable risk increase guidelines. RGAG 1. 174 acceptance 1.174 guidelines may also be used. If changes to the proposed language in Implementation Item 8 are desired to reflect this, please provide updated proposed language for Implementation Item 8.

ENO RESPONSE

a. The updated Attachment W results provided in Attachment 4 to the letter dated August 14,14, 2014 reflects the revisions to VFDRs and recovery actions indentified in Attachment 2 to the letter dated August 14,14, 2014.

ENO has revised Attachment S, Table S-3, Item 8 to update the language to

b. END reference the RG 1.174 acceptance guidelines. See the revised Attachment S, Table S-3, Item 8 provided in Attachment 2.

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