NG-13-0287, Response to Request for Additional Information, License Amendment Request to Adopt National Fire Protection Association Standard 805, Performance-Based Standard for Fire Protection for Light Water Reactor Generating Plants
| ML13191A035 | |
| Person / Time | |
|---|---|
| Site: | Duane Arnold  |
| Issue date: | 07/02/2013 |
| From: | Richard Anderson NextEra Energy Duane Arnold |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NG-13-0287 | |
| Download: ML13191A035 (28) | |
Text
NEXTera ENERGY72_ýl DUN ARNOLD July 2, 2013 NG-1 3-0287 10 CFR 50.90 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, DC 20555-0001 Duane Arnold Energy Center Docket No. 50-331 Renewed Op. License No. DPR-49 Response to Request for Additional Information, License Amendment Request to Adopt National Fire Protection Association Standard 805, Performance-Based Standard For Fire Protection For Liaht Water Reactor Generating Plants
References:
- 1) License Amendment Request (TSCR-128): Transition to 10 CFR 50.48(c) - NFPA 805, Performance-Based Standard For Fire Protection For Light Water Reactor Generating Plants (2001 Edition), NG-11-0267, dated August 5,2011 (ML11221A280)
- 2) Clarification of Information Contained in License Amendment Request (TSCR-128): Transition to 10 CFR 50.48(c) - NFPA 805, Performance-Based Standard For Fire Protection For Light Water Reactor Generating Plants (2001 Edition), NG-1 1-0384, dated October 14, 2011
- 3) Letter, K. Feintuch (NRC) to R. Anderson (NextEra Energy),
"Request for Additional Information for Review Regarding License Amendment Request to Adopt National Fire Protection Association Standard 805, dated June 27, 2013
- 4) Response to Request for Additional Information, License Amendment Request to Adopt National Fire Protection Association Standard 805, Performance-Based Standard For Fire Protection For Light Water Reactor Generating Plants, NG-1 3-0240. dated May 29. 2013 In the Reference 1 letter, as clarified by Reference 2, NextEra Energy Duane Arnold, LLC (hereafter NextEra Energy Duane Arnold) submitted a License Amendment Request for the Duane Arnold Energy Center (DAEC) pursuant to Security-Related Information -Withhold From Public Disclosure Under 10 CFR 2.390. Enclosures 2, 3, and 5 of this letter contain security-related information. Upon removal of Enclosures 2, 3, and 5 of this letter, this letter is uncontrolled.
NextEra Energy Duane Arnold, LLC, 3277 DAEC Road, Palo, IA 52324
Document Control Desk NG-1 3-0287 Page 2 of 3 10 CFR 50.90. Subsequently, the NRC Staff requested, via Reference 3, additional information regarding that application. of this letter provides the information requested in Enclosure 1 of Reference 3, specifically, NextEra Energy Duane Arnold's response to Request for Additional Information (RAI) PRA 84.
During discussions with the Staff on June 11, 2013, NextEra Energy Duane Arnold agreed to provide an updated Attachment S of Reference 1. Additionally, during discussion with the Staff on June 18, 2013, and as discussed in Reference 3, NextEra Energy Duane Arnold agreed to add two implementation items to Table S-2 of Attachment S of Reference 1. An updated Attachment S, including the two additional implementation items, is included as Enclosure 2 of this letter.
Enclosures 3, 4 and 5 contain annotated pages of Attachment C, Table 4-3, and page W-2, respectively, of Reference 1. These Enclosures reflect the pages affected by the removal of the commitment made in Attachment S, Table S-1, Item 2, of Reference 1. That commitment, to install an incipient detection modification, was withdrawn in the Reference 4 letter.
This additional information does not impact the 10 CFR 50.92 evaluation of "No Significant Hazards Consideration" previously provided in the referenced application.
This letter makes two new commitments identified as Items 23 and 24 of Table S-2 of Enclosure 2. Enclosure 2 also summarizes all remaining commitments made by NextEra Energy Duane Arnold since our original license amendment request submitted as Reference 1.
If you have any questions or require additional information, please contact J.
Michael Davis at 319-851-7032.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on July 2, 2013 ichard L. Anderso Vice President, Duane Arnold Energy Center NextEra Energy Duane Arnold, LLC Security-Related Information- Withhold From Public Disclosure Under 10 CFR 2.390. Enclosures 2, 3, and 5 of this letter contain security-related information. Upon removal of Enclosures 2, 3, and 5 of this letter, this letter is uncontrolled.
Document Control Desk NG-13-0287 Page 3 of 3
Enclosures:
- 1. Response to Request for Additional Information, License Amendment Request to Adopt National Fire Protection Association Standard 805, Performance-Based Standard For Fire Protection For Light Water Reactor Generating Plants
- 2. Revised Attachment S, "Plant Modifications and Items to be Completed"
- 3. Annotated pages of Attachment C, "NEI 04-02 Table B Fire Area Transition"
Security-Related Information -Withhold From Public Disclosure Under 10 CFR 2.390. Enclosures 2, 3, and 5 of this letter contain security-related information. Upon removal of Enclosures 2, 3, and 5 of this letter, this letter is uncontrolled.
Enclosure 1 to NG-13-0287 Response to Request for Additional Information, License Amendment Request to Adopt National Fire Protection Association Standard 805, Performance-Based Standard For Fire Protection For Light Water Reactor Generating Plants 24 pages follow
- 1. Table I of this enclosure summarizes modifications made to the PRA in response to several previous requests for additional information (RAIs) issued during the review of the LAR to transition to National Fire Protection Associations Standard 805 (NFPA 805), "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition. Address each of the individual modifications as expressed in Table I to confirm the completion of each.
- 2. In licensee's letter dated February 12, 2013 (ADAMS Accession No. ML13046A031),
in response to RAI 58.01, DAEC states that a full update of the NFPA 805 fire PRA application will be performed prior to transition.
Propose a response that includes a regulatory process (e.g., a general license condition or implementation item) that provides assurance that all the proposed changes including those listed in PRA RAI Table 1 will be made and all associated documentation will be finalized before the PRA is used to support future self-approval.
- 3. The response to RAI 82 provides the results of an integrated analysis in Table 5.
The results include fire scenarios for the main control room (MCR).
Please provide the MCR abandonment fire scenarios total CDF/LERF and delta CDF/LERF from this analysis. If there is a difference between the total and delta risk for these fire scenarios, explain the reason for the difference and justification for not including the entire MCR abandonment risk in the calculation of delta risk.
Discuss how the delta risk is calculated for the MCR abandonment scenarios for the different conditional core damage probabilities (CCDPs), which are discussed in the response to RAI 64 (ML13015A350), and how the MCR abandonment recovery actions are included in the delta risk calculation for each CCDP. For example, It is not clear from the response to RAI 64 how the failure to recovery probability and the 0.1 probability of failure of success path equipment are used in the compliant case versus the variant case. Please include additional description of how the compliant versus variant CDF/LERF are estimated for the same scenario.
RESPONSE
- 1. Table I is updated to include confirmation of completed activities.
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response FM 01 In DAEC's letter dated October 15, 2013 (ADAMS The PRA includes the new self-ignited cable fire Accession No. ML122910950), DAEC states that: The scenarios and the change in input for fire scenarios DAEC Fire PRA - NFPA 805 RAI Model Update with thermoplastic cable targets.
Quantification Report has been updated to include the The evaluation for self-ignited cable fires and new self-ignited fire scenarios and the change in input thermoplastic targets was included in the composite for fire scenarios with thermoplastic cable targets. This results presented in Part A and Part B of the response change will be incorporated in the updated FPRA to RAI PRA 82 (ML13122A045 dated May 1, 2013).
model in response to RAI FM 01.
The evaluation has been documented in the NFPA 805 Please confirm that the PRA includes the new self- RAI Model Update Quantification Report.
ignited fire scenarios and the change in input for fire scenarios with thermoplastic cable targets, and that During the full update described in response to RAI any missing documentation will be completed during PRA 58.01, the Fire Scenario Report will be revised to the full update of the NFPA 805 fire PRA application as ensure that the documentation is consistent with the stated in response to RAI PRA 58.01 (See letter dated evaluation.
February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 05 DAEC's letter dated May 23, 2012 (ADAMS Accession The PRA includes a revised MCA in which the barrier No. ML12146A094) included a revised multi elements were summed.
compartment analysis (MCA) in which barrier elements The revised MCA with barrier elements summed was were summed. The revised MCA is included in the included in the composite results presented in Part A composite analysis. DAEC also states that they would: and Part B of the response to RAI PRA 82 Revise Appendix C of the Fire Scenario Report to include barrier elements as discussed in RAI PRA 05.
Appendix C of the Fire Scenario Report has been Confirm that the PRA includes a revised MCA in which revised to include the revised MCA with the barrier barrier elements were summed, and that any missing elements summed.
documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 07 DAEC's letter dated May 23, 2012 (ADAMS Accession The PRA no longer uses a severity factor of 0.01 for No. ML12146A094) included a revised analysis without the diesel generator rooms.
using a severity factor of 0.01 for the diesel generator The revised MCA without the 0.01 severity factor rooms. The revised analysis is included in the applied for the diesel generator rooms was included in composite analysis. DAEC also states that they would: the composite results presented in Part A and Part B of Update Appendix C of the Fire Scenario Report to the response to RAI PRA 82 (ML13122A045 dated reflect changes in MCA scenarios as discussed in RAI May 1, 2013).
PRA 07.
Appendix C of the Fire Scenario Report has been Confirm that the PRA no longer uses a severity factor revised to include the revised MCA.
of 0.01 for the diesel generator rooms, and that any missing documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI- PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 08.01 By letter dated March 6, 2013, (ADAMS Accession No. The PRA screens combinations of MCAs based on ML13070A065), DAEC included a revised MCA to NUREG/CR-6850.
include NUREG/CR-6850 Step 5.c (Section 11.5.4.5) The revised MCA with MCA combinations not screened while determining whether combinations of MCA based on NUREG/CR-6850 Step 5.c was included in should be screened out. The letter also stated that the the composite results presented in Part A and Part B of revised analysis is included in the composite analysis the response to RAI PRA 82 (ML13122A045 dated Table 4-3 of (ADAMS Accession No. ML13122A045),
Accession May 1, 2013).
the License Amendment Request (ADAMS No. ML11221A280) and will be updated to include the During the full update described in response to RAI automatic suppression system required for risk. PRA 58.01, the Fire Scenario Report will be revised to ensure that the documentation is consistent with the Confirm that the PRA screens combinations of MCAs evaluation. Additionally, Table 4-3 of the License based on NUREG/CR-6850, and that any missing Amendment Request will be updated to include the documentation will be completed during the full update automatic suppression system required for risk.
of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI -PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 10 By letter dated April 23, 2012, (ADAMS Accession No. In response to RAI PRA 10 in the letter dated April 23, ML12117A052) DAEC responded that during transition 2012 Duane Arnold committed to enhancing the to NFPA 805, the monitoring program will be enhanced existing monitoring program to satisfy the requirements to satisfy new requirements. of NFPA 805. NFPA 805 Section 2.6 states:
Please confirm that the monitoring program will be "Monitoring. A monitoring program shall be enhanced to satisfy new requirements and, to the established to ensure that the availability and extent applicable, these new requirements will be reliability of the fire protection systems and features reflected in the full update of the NFPA 805 fire PRA are maintained and to assess the performance of the fire protection program in meeting the performance application as stated in response to RAI PRA 58.01 criteria. Monitoring shall ensure that the assumptions (See letter dated February 12, 2013, ADAMS in the engineering analysis remain valid."
Accession No. ML13046A031).
One of the purposes of the monitoring program is to ensure that inputs to the fire PRA remain valid including equipment availability/reliability. Therefore, the enhanced monitoring program meeting the requirements of NFPA 805 does not change the fire PRA and the fire PRA requires no updates due to the enhanced monitoring program.
The LAR was revised in response to RAI Monitoring 1 and a revised LAR section 4.6.2 was provided in the letter NG-12-0255 dated May 23, 2012. This describes the enhanced monitoring program. Implementation of the monitoring program is in Attachment S Table S-2 Item 2.
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 11.01 By letter dated March 6, 2013, (ADAMS Accession No. The PRA does not include manual suppression credit ML13070A065), DAEC included a revised analysis for catastrophic TG fire.
without manual suppression credit. The revised The revised catastrophic TG fire does not credit analysis is included in the composite analysis. (See manual suppression and was included in the composite letter dated April 23, 2012 ADAMS Accession No. results presented in Part A and Part B of the of the ML12117A052 and ML13122A045). response to RAI PRA 82 (ML13122A045 dated May 1, Confirm that the PRA does not include manual 2013).
suppression credit, and that any missing The Fire Scenario Report has been revised to include documentation will be completed during the full update the revised catastrophic TG fire.
of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
PRA 13 By letter dated April 23, 2012 (ADAMS Accession No. Section 2 and Table 2.2-2 of the Plant Partitioning and ML12117A052) DAEC states that they would revise Fire Ignition Frequency report has been updated to Section 2 and Table 2.2-2 of the Plant Partitioning and reflect the expanded justification provided in the Fire Ignition Frequency report to reflect the expanded response to RAI PRA 13.
justification provided in response to RAI PRA 13. No other documentation is required to be updated for Please confirm that any missing documentation will be this item.
completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 14a DAEC's letter dated May 23, 2012 (ADAMS Accession The PRA no longer includes a hot work pre-initiator No. ML12146A094) included a revised cable spreading factor of 0.01.
room (CSR) analysis that removed a hot work pre- The revised CSR analysis that removed the 0.01 hot initiator factor of 0.01. In the response to RAI PRA 82 work pre-initiator factor was included in the composite dated May 1, 2013, (ADAMS Accession No. results presented in Part A and Part B of the of the ML13122A045) it was stated that the revised analysis response to RAI PRA 82 (ML13122A045 dated May 1, is included in the composite analysis. 2013).
Confirm that the PRA no longer includes a hot work The revised CSR analysis has been documented in the pre-initiator factor of 0.01, and that any missing Cable Spreading Room Fire Scenario and documentation will be completed during the full update Quantification Report.
of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 14b DAEC's letter dated May 23, 2012 (ADAMS Accession The PRA's CSR analysis uses the "Very Low" ranking No. ML12146A094) included a revised CSR analysis consistent with FAQ 12-0064.
with the use of the "Very Low" ranking consistent The revised CSR analysis that used the "Very Low" Frequently Asked Question (FAQ) 12-0064, Hot ranking consistent with FAQ 12-0064 was included in Work/Transient Fire Frequency Influence Factors the composite results presented in Part A and Part B of (ADAMS Accession No. ML12346A488). In the the of the response to RAI PRA 82 (ML13122A045 response to RAI PRA 82 dated May 1,2013, (ADAMS dated May 1,2013).
Accession No. ML13122A045), it was stated that the revised analysis is included in the composite analysis. The revised CSR analysis and use of the "Very Low" Confirm that the PRA's CSR analysis uses the "Very ranking Room FirehasScenario been documented in the Cable and Quantification Spreading Report.
and that Low" ranking consistent with FAQ 12-0064, any missing documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 14.01 DAEC's letter dated May 23, 2012 (ADAMS Accession The PRA assumes at least a plant trip for CSR fires, No. ML12146A094) included a revised CSR analysis identifies the contribution from the loss of offsite power, that assumes at least a plant trip for CSR fires, assumes ASC is not available, does not credit prompt identifies the contribution from the loss of offsite power, suppression for general transient fires, and quantifies assumes alternate shutdown capability (ASC) is not LERF.
available, does not credit prompt suppression for The revised CSR analysis that assumed at least a general transient fires, and quantifies large early plant trip, assumed the ASC was not available, did not release frequency (LERF). In the response to RAI PRA credit prompt suppression for general transient fires, 82 dated May 1, 2013, (ADAMS Accession No. and quantified LERF was included in the composite ML13122A045), it was stated that the revised analysis results presented in Part A and Part B of the of the is included in the composite analysis. response to RAI PRA 82 (ML13122A045 dated May 1, Confirm that the PRA assumes at least a plant trip for 2013).
CSR fires, identifies the contribution from the loss of The revised CSR analysis assumptions and input has offsite power, assumes ASC is not available, does not been documented in the Cable Spreading Room Fire credit prompt suppression for general transient fires, Scenario and Quantification Report.
and quantifies LERF, and that any missing documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 16 By letter dated April 23, 2012 (ADAMS Accession No. Table 3.3-1 of the Fire Model Development report and ML12117A052), DAEC stated that Table 3.3-1 of the the HRA in the Fire Scenario report were revised to Fire Model Development Report, the human reliability reflect that the operator action was not credited in the analysis (HRA), and the basic event probability will be FPRA. A basic event probability of 1.0 was applied to updated to reflect the lack of a cue and that the the operator action and was included in the composite operator action is not credited in the FPRA. In addition, results presented in Part A and Part B of the response the basic event probability will be applied in the to RAI PRA 82 (ML13122A045 dated May 1, 2013).
updated FPRA model in response to RAI PRA 01. No other documentation is required to be updated for Confirm that the HRA in the PRA and any missing this item.
documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 33 By letter dated April 23, 2012 (ADAMS Accession No. Section 6 of the Fire Model Development report has ML12117A052), DAEC stated that they would revise been updated to include the details regarding the Section 6 of the Fire Model Development Report to evaluation of long term operator action on LERF include the details regarding the evaluation of long provided in the response to RAI PRA 33.
term operator actions on LERF provided in response to No other documentation is required to be updated for RAI PRA-33. this item.
Confirm that the missing documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 35.01 DAEC's letter dated March 6, 2013, (ADAMS The PRA includes no credit for incipient detection.
Accession No. ML13070A065) included justification for The revised analysis that did not include credit for incipient detection credit and the results of a sensitivity incipient detection was included in the composite study without incipient detection credit. In the response results presented in Part A and Part B of the of the to RAI PRA 82 dated May 1,2013 (ADAMS Accession response to RAI PRA 82 (ML13122A045 dated May 1, No. ML13122A045), it was stated that the revised 2013).
analysis included no credit for incipient detection is included in the composite analysis. Table 4-3, Attachment C, and Attachment S have been updated to show the deletion of incipient detection. The Confirm the PRA includes no credit for incipient changed pages of Table 4-3 and Attachment C are detection, and that conforming changes will be included as Enclosures 4 and 3, respectively, to this completed to all documentation during the full update rsos.Atcmn a encmltl eie of te NPA 05 irePRAapplcaton s sate inresponse. Attachment S has been completely revised of the NFPA 805 fire PRA application as stated in and is included as Enclosure 2 to this response.
dated February response to RAI PRA 58.01 (See letter 12, 2013, ADAMS Accession No. ML13046A031). The revised analysis has been documented in the NFPA 805 RAI Model Update Quantification Report.
During the full update described in response to RAI PRA 58.01, the Fire Scenario Report will be revised to ensure that the documentation is consistent with the analysis.
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 57 DAEC's letter dated April 23, 2012 (ADAMS Accession Section 6 of the Fire Model Development report has No. ML12117A052) included a response to RAI PRA been updated to include the review of PRA Level 2 57 that included a table that listed each PRA level 2 basic events for potential fire impacts provided in the basic event and identified the potential fire impact for response to RAI PRA 57 (ML12117A052 dated April each event. The letter also stated that DAEC would 23, 2012).
revise the Fire Model Development Report to include No other documentation is required to be updated for the table provided in response to RAI PRA 57. this item.
Confirm the documentation will be completed during the full update of the NFPA 805 fire PRA application committed to in response to RAI PRA 58.01 under cover letter dated February 12, 2013 (ADAMS Accession No. ML13046A031).
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 69 In a letter dated March 6, 2013, (ADAMS Accession The PRA includes the results of the electronics No. ML13070A065), it was stated by DAEC that the evaluation inside and outside of the MCR consistent FPRA adequately evaluates electronics in the MCR as with the methods as described in NUREG/CR-6850.
described in NUREG/CR-6850. In a letter dated May 1, The evaluation of electronics inside and outside of the 2013, (ADAMS Accession No. M-13122A045) in MCR consistent with the guidance in NUREG/CR-6850 response to a follow on question related to RAI PRA 69 was included in the composite results presented in Part in RAI PRA 82, a summary was provided related to an A and Part B of the response to RAI PRA 82 evaluation of electronics outside of the MCR that (ML13122A045 dated May 1, 2013).
included walkdowns and use of NUREG/CR-6850 damage temperatures. The evaluation has been documented in the NFPA 805 RAI Model Update Quantification Report.
results of evaluation Confirm that the PRA includes the inside and outside of the MCR that are consistent with During the full update described in response to RAI the methods as described in NUREG/CR-6850, and PRA 58.01, the Fire Scenario report will be revised to that documentation will incorporate the relevant ensure that the documentation is consistent with the discussion during the full update of the NFPA 805 fire analysis.
PRA application committed to in response to RAI PRA 58.01 under cover letter dated February 12, 2013.
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RAI- PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 70 DAEC's letter dated February 12, 2013, (ADAMS The PRA evaluates sealed cabinets according to FAQ Accession No. ML13046A031) identified that the credit 08-0042.
given to sealed electrical cabinets to prevent fire In response to RAI PRA 70, the treatment of sealed spread was consistent with the treatment in FAQ 08- electrical cabinets was confirmed to be consistent with 0042, Fire Propagation From Electrical Cabinets, FAQ 08-0042.
(ADAMS Accession No. ML092110537).
The evaluation has been documented in the NFPA 805 Confirm that the PRA evaluates sealed cabinets RAI Model Update Quantification Report.
according to FAQ 08-0042, and that any missing documentation will be completed during the full update During the full update described in response to RAI of the NFPA 805 fire PRA application as stated in PRA 58.01, the Fire Scenario report will be revised to response to RAI PRA 58.01 (See letter dated February ensure that the documentation is consistent with the 12, 2013, ADAMS Accession No. ML13046A031). analysis.
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RAI - PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 71 RAI PRA 71 questioned the use of a conditional The PRA no longer includes the MCR transient location probability of 0.1 for transient combustibles located conditional probability of 0.1.
near the MCR, and the response to RAI PRA 82 The use of a 0.1 conditional probability for MCR indicated that this probability had been removed. In the transient location was removed and was included in the response to RAI PRA 82 dated May 1, 2013, (ADAMS composite results presented in Part A and Part B of the Accession No. ML13122A045) it was stated stated (sic) of the response to RAI PRA 82 (ML13122A045 dated that the revised analysis is included in the composite May 1, 2013).
analysis.
The evaluation has been documented in the NFPA 805 Confirm that the PRA no longer includes the RAI Model Update Quantification Report.
conditional probability, and that any missing documentation will be completed during the full update During the full update described in response to RAI of the NFPA 805 fire PRA application as stated in PRA 58.01, the Fire Scenario report will be revised to response to RAI PRA 58.01 (See letter dated February ensure that the documentation is consistent with the 12, 2013, ADAMS Accession No. ML13046A031). analysis.
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RAI- PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 72 DAEC's letter dated March 6, 2013, (ADAMS The PRA uses a minimum non-suppression probability Accession No. ML13070A065) included a revised of 0.001.
analysis that used a minimum non-suppression The analysis was revised to include a minimum non-probability of 0.001. In the response to RAI PRA 82 suppression probability of 0.001 and was included in dated May 1, 2013, (ADAMS Accession No. the composite results presented in Part A and Part B of ML13122A045) it was stated that the revised analysis the response to RAI PRA 82 (ML13122A045 dated is included in the composite analysis. May 1, 2013).
Confirm that the PRA uses a minimum non- The Fire Scenario report has been revised to include suppression probability of 0.001, and that any missing the revised analysis with a minimum non-suppression documentation will be completed during the full update probability of 0.001.
of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI- PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 83b In response to the RAI PRA 83b dated May 1,2013, The PRA uses an updated CSR analysis using a HRR (ADAMS Accession No. ML13122A045) it was clarified based on NUREG/CR-6850 guidance.
by DAEC that the heat release rate (HRR) used in the The revised CSR analysis was included in the updated CSR analysis was based on NUREG/CR-6850 composite results presented in Part A and Part B of the guidance. In the response to RAI PRA 82 dated May 1, response to RAI PRA 82 (ML13122A045 dated May 1, 2013, (ADAMS Accession No. ML13122A045) it was 2013).
stated that the revised analysis is included in the composite analysis. The transient HRR used for the revised CSR analysis Confirm that the PRA uses an updated CSR analysis has Fire been documented Scenario in the Cable and Quantification Spreading Room Report.
guidance, using a HRR based on NUREG/CR-6850 and that any missing documentation will be completed during the full update of the NFPA 805 fire PRA application as stated in response to RAI PRA 58.01 (See letter dated February 12, 2013, ADAMS Accession No. ML13046A031).
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RAI- PRA 84 Table 1 RAI Description of Modification and RAI RAI Response LAR Table The disposition of these F&Os are that fire scenario The PRA uses the Hughes Generic Fire Modeling V-3 F&O 1OE-F45 sensitivity case refined the use of the electric results for critical separation distances based on HRR.
4-22, 4-23, panel factor approach to use of the Hughes Generic In response to RAI PRA 67 it was identified that the 4-25 Fire Modeling results for critical separation distances resolution to F&O 4-22, 4-23, and 4-25 included dispositions based on HRR. removal of the electric panel factor approach and use Confirm that the PRA uses the Hughes Generic Fire of the Hughes Generic Fire Modeling results for critical Modeling results for critical separation distances based separation distance based on HRR.
on HRR, and that any missing documentation will be The composite results presented in Part A and Part B completed during the full update of the NFPA 805 fire of the response to RAI PRA 82 (ML13122A045 dated PRA application as stated in response to RAI PRA May 1, 2013) used the Hughes Generic Fire Modeling 58.01 (See letter dated February 12, 2013, ADAMS results and did not use the electric panel factor Accession No. ML13046A031). Also confirm that the electric panel factor approach had not been used in the results reported for RAI PRA 82. The fire scenario report has been revised to be consistent with the analysis.
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RAI- PRA 84 Table 1 RAI Description of Modification and RAI RAI Response PRA 64 A detailed HRA was performed as a basis for justifying In response to RAI PRA 64, the input into the detailed the MCR conditional core damage probability of 0.1 as HRA for the recovery action to start the standby diesel bounding. This HRA is related to a recovery action in generator 1G21 was based on procedure AOP-915.
the LAR to start the emergency diesel generator This recovery action is identified in Table G-1 of the SBDG1 to power the vital bus for ASC. The HRA LAR for component 1G21 and was evaluated in evaluation was provided in response to RAI PRA 64 in Attachment G, Step 4, "Evaluate the Feasibility of a letter dated January 11, 2013 (ADAMS Accession Recovery Actions." Additionally, the detailed HRA No. ML13015A350). input was evaluated in Attachment G, Step 5, "Evaluate Confirm that the inputs to the detailed HRA have been the Reliability of Recovery Actions".
evaluated in the LAR Attachment G, Step 4, "Evaluate the Feasibility of Recovery Actions," and Step 5, "Evaluate the Reliability of Recovery Actions".
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- 2. A revised Attachment S is included as Enclosure 2 to this response. The revised Attachment S contains all the items from RAI PRA 84 Table 1 that are not yet complete and any other updates required due to the response to RAI PRA 58.01.
The updates to the PRA and documentation will be completed as part of the transition period as stated in the License Amendment Request Section 5.4 except for Table S-2 Item 22 which will be completed after Table S-1 Item 1 is implemented and as-built. Table S-2 Item 19 will be completed in accordance with 50.71 (e) but does not impact the PRA and does not prevent self-approval. This schedule is stated in the revised Attachment S included as Attachment S to this response. The items in Table S-2 should be part of the implementation items in the transition license condition.
- 3. The MCR abandonment fire scenarios total CDF/LERF and delta CDF/LERF are:
Risk Metric Total Risk (/yr) Delta Risk (/yr)
CDF 4.07E-08 (1) 3.55E-08 (1)
LERF 4.05E-08 ( 3.54E-08 (1)
Note to Table: (1) Based on the composite sensitivity results presented in Part A of the response to RAI PRA 82 (ML13122A045 dated May 1, 2013).
The total abandonment risk and delta risk are not equal, because some MCR panel fires that are postulated to result in abandonment do not result in fire induced failures of equipment relied upon when alternate shutdown capability (ASC) is established post abandonment. Therefore, the incremental risk is associated with the recovery actions and primary control station (PCS) actions to establish ASC.
The HRA performed for these actions was described in the response to RAI PRA 64 (ML13015A350, dated January 11, 2013). A detailed HRA was performed for the recovery action to start the standby diesel generator 1G21, because this action bounded the other recovery actions and PCS actions. The HRA concluded the risk associated with establishing ASC is bounded by hardware failures of the credited equipment. That is, in these cases the CCDP for the abandonment variant case and compliant case are essentially equal, because the relied upon ASC shutdown success path is free from fire damage and hardware failures bound recovery actions and PCS actions to establish ASC.
The delta risk calculations are discussed in the response to RAI PRA 60.01 (ML13046A031, dated February 12, 2013). An appropriate variant case CCDP was applied to each MCR abandonment scenario based on the potential fire induced failures for the applicable ignition source. Recovery actions were credited for the variant case when postulated fire damage would not affect ASC. However, as Rev 0 Page 22 of 24
RAI - PRA 84 discussed above, the recovery actions were bound by the hardware failures of the credited equipment. If postulated fire damage could affect ASC, then the recovery actions were not credited.
A single compliant case CCDP was applied to each MCR abandonment scenario based on a representative CCDP for the risk associated with the ASC shutdown success path (i.e., shutdown from the PCS). Therefore, the compliant case does not include recovery actions. The compliant case risk was bound by credited equipment hardware failures versus the PCS actions.
The following table demonstrates a delta risk calculation for each CCDP and where recovery actions are credited.
Variant Recovery Compliant Recovery Delta Case Variant Case CCDP Actions Case Actions in De CCDP CCDP Description in Variant CCDP Compliant Calculation Case Case A 0.1 CCDP is applied if a fire does not impact ASC equipment or the equipment is available upon transfer at a primary control station (PCS).
The CCDP for a single success path without offsite power is used and is based on 0.1 - 0.1 =
0.1 postulated essential Yes 0.1 No 0.0 (1) switchgear room fires.
Recovery actions are credited to establish ASC. However, hardware failures associated with a single success path bound the failure of recovery actions.
A spurious conditional spurious probability is applied if a fault impacts ASC equipment and is not Spurious recoverable at the PCS based Probability on the current design and No 0.1 No 0.66-0.1 (e.g., procedures. This value would = 0.56 0.66) be equal to the likelihood of occurrence using the hot short-induced spurious operation probabilities.
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RAI - PRA 84 Variant Variant Case CCDP Recovery Actions Compliant Recoveryin Actions Delta CCDP CaseCaeCD CCDP Description in Variant CCDP Compliant Calculation Case Case credited because the postulated fire damage may not be recoverable.
A 1.0 CCDP is applied if a single or multiple hot short-induced spurious operations (MSO) impacts ASC equipment and is considered not recoverable by ASC based on the current design and procedures. For instance, a 1.0 MSO could result in an No 0.1 No 1.0-0.1 inventory loss greater than the 0.9 assumed one spurious open relief valve used as the design criteria.
Recovery actions are not credited because the postulated fire damage may not be recoverable.
Note to Table: (1) As discussed previously, the hardware failures bound the failure of recovery actions and PCS actions. Therefore, the variant case and compliant case CCDPs are essentially the same. The delta risk calculation is presented as 0.0, because the variant case and compliant case representative CCDPs are taken to be the same.
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