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| | number = ML15125A328 | | | number = ML15125A328 |
| | issue date = 05/08/2015 | | | issue date = 05/08/2015 |
| | title = McGuire Nuclear Station, Units 1 and 2: Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program (TAC Nos. MF2934 and MF2935) | | | title = Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program |
| | author name = Martin R E | | | author name = Martin R |
| | author affiliation = NRC/NRR/DORL/LPLII-1 | | | author affiliation = NRC/NRR/DORL/LPLII-1 |
| | addressee name = Capps S D | | | addressee name = Capps S |
| | addressee affiliation = Duke Energy Carolinas, LLC | | | addressee affiliation = Duke Energy Carolinas, LLC |
| | docket = 05000369, 05000370 | | | docket = 05000369, 05000370 |
| | license number = NPF-009, NPF-017 | | | license number = NPF-009, NPF-017 |
| | contact person = Martin R E | | | contact person = Martin R |
| | case reference number = TAC MF2934, TAC MF2935 | | | case reference number = TAC MF2934, TAC MF2935 |
| | document type = Letter, Request for Additional Information (RAI) | | | document type = Letter, Request for Additional Information (RAI) |
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| =Text= | | =Text= |
| {{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, i:>.C. 20555-0001 Mr. Steven D. Capps Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078-8985 May 8, 2015 SUBJECT: MCGUIRE NUCLEAR STATION, UNITS 1 AND 2: REQUEST FOR | | {{#Wiki_filter:UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, i:>.C. 20555-0001 May 8, 2015 Mr. Steven D. Capps Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078-8985 |
| * ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT A RISK-INFORMED, PERFORMANCE-BASED FIRE PROTECTION PROGRAM (TAC NOS. MF2934 AND MF2935) Dear Mr. Capps: By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13276A126), Duke Energy Carolinas, LLC (Duke) submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association (NFPA) Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition. The U.S. Nuclear Regulatory Commission staff is continuing its review and has determined that additional information is needed in the fire modeling area as discussed in the Enclosure. Docket Nos. 50-369 and 50-370 Enclosure: As stated cc w/encl: Distribution via Listserv Sincerely, Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation REQUEST FOR ADDITIONAL INFORMATION ADOPTION OF NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 FOR FIRE PROTECTION DUKE ENERGY CAROLINAS, LLC (DUKE) MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-369, 50-370 By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13276A 126), Duke submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition (NFPA 805). The U.S. Nuclear Regulatory Commission (NRC) staff is continuing its review and has determined that additional information is needed in the fire modeling area as follows. Fire Modeling (FM) RAI 01.j.01 NFPA 805, Section 2.4.3.3, states, in part, that the probabilistic risk assessment (PRA) approach, methods, and data shall be acceptable to the NRC. License Amendment Request (LAR) Section 4.5.1.2, "Fire Model Utilization in the Application," states, in part, that fire modeling was performed as part of the Fire PRA development. In a letter dated January 26, 2015 (ADAMS Accession No. ML 15036A084), the licensee responded to FM RAI 01.j and explained that, to account for fire propagation in cable trays, the vertical zone of influence (ZOI) was extended to the ceiling and that the horizontal ZOI encompasses the 35° angle as discussed in NUREG/CR-6850. The licensee further referred to tests conducted by EPRI and NEI to justify ignoring flame spread over armored cable with a PVC jacket beyond the 35° cone. Subsequently, in its response to FM RAI 02.b the licensee stated that a recent review of FPRA-related cables indicates that approximately 15% are thermoplastic, and that 24% of the total cable population in the plant is thermoplastic. The EPRl/NEI tests that the licensee refers to involved a cable tray that was located approximately 5 ft. above and to the side of the 350 kW ignition source. In both tests the PVC jacket started to melt and drip to the floor, but did not ignite. The objective of these two tests was to assess the performance of jacketed armored cables located in the hot gas layer (HGL). The results do not apply to cable trays that are located directly above the ignition source. In light of this observation and the licensee's recent finding that approximately 24% of the cables in the plant are thermoplastic, re-quantify the impact of fire propagation in cable trays and the heat release rate (HRR) contribution from the cables on target damage and plant risk. Where applicable, consider the contribution from non-FPRA cables and non-cable secondary combustibles in the revised ZOI and HGL analyses. Enclosure | | |
| -2 -FM RAI 01.k.01 NFPA 805, Section 2.4.3.3, states, in part, that the PRA approach, methods, and data shall be acceptable to the NRC. LAR Section 4.5.1.2, "Fire Model Utilization in the Application," states, in part, that fire modeling was performed as part of the Fire PRA development. In a letter dated November 12, 2014 (ADAMS Accession No. ML 14328A628), the licensee responded to FM RAI 01.k and stated that location effects on the ZOI of transient fires within 2 ft. of a wall or corner were accounted for by multiplying the HRR by 2 or 4, respectively. In a letter dated January 26, 2015 (ADAMS Accession No. ML 15036A084), the licensee revised its response to FM RAI 01.k, in particular the part pertaining to wall and corner effects on the ZOI
| | ==SUBJECT:== |
| * for transient fires. In the revised response the licensee stated that "The hypothetical transient fuel packages were placed where targets such as cable trays or risers would be impacted. Since the target damage could be achieved by placement of the ignition source away from the wall or corner (i.e., an open location transient fuel package), no further adjustments were applied." It is stated in Section 11.7.1.6 of NUREG/CR-6850, Volume 2, that "[Transient] ignition sources should be located near areas of the room where critical targets are located, including points" where targets from two different safety divisions can be damaged by the same fire." It is not clear from the licensee's revised response that this guidance was followed. Explain how the licensee ensured that critical targets or pinch-points located close to a wall or corner were identified and considered in the transient fire target damage analysis. FM RAI 02.b.01 LAR Section 4.5.1 states, in part, that "In accordance with the guidance in RG 1.205, a Fire PRA model was developed for MNS consistent with the requirements of Part 4 "Requirements for Fires At Power PRA," of the American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS) combined PRA Standard, ASME/ANS RA-Sa-2009, "Standard for Level 1 /Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Application," ... " ASME/ANS Standard RA-Sa-2009, Part 4, requires damage thresholds be established to support the FPRA. In a letter dated February 27, 2015 (ADAMS Accession No. ML 15083A223), the licensee responded to FM RAI 02.b, and stated that the higher damage thresholds associated with thermoset cables were used based on the assumption that the cables at McGuire Nuclear Station, Units 1 and 2, are predominately constructed with EPR or XLPE (thermoset) insulation, a galvanized steel interlocking armor, and a thin flame retardant polyvinylchloride (PVC) exterior jacket. The licensee further stated that a subsequent review of cable information showed that there is a higher percentage of thermoplastic insulation in the plant than initially considered, that approximately 15% of the roughly 12,000 FPRA-related ca81es are thermoplastic cables (and approximately 24% of the total plant cable population), and that these thermoplastic related cables are relatively evenly distributed throughout tne plant with only six fire areas being appreciably above the overall average. | | MCGUIRE NUCLEAR STATION, UNITS 1 AND 2: REQUEST FOR |
| -3 -The licensee also identified five conservatisms in the present analysis that may (partly) offset the impact of the presence of thermoplastic cables on the Fire PRA. To quantify this impact the licensee performed a sensitivity analysis and determined that a more thorough evaluation of the thermoplastic cable insulation impact does not result in a risk increase greater than 1 E-06/year for CDF or 1 E-07/year for LERF. Finally, the licensee stated that the thermoplastic cable impact on the risk will be re-evaluated when the results of ongoing NRG/industry research on the severity of cabinet fires will be published. This re-evaluation is an implementation item and will be added to Table S-3 of the LAR. The sensitivity analysis described in Attachment 2 to the response to FM RAI 02.b appears to assume that cable fires do not propagate in stacks of horizontal trays. In light of the fact that the response to FM RAI 01.j.01 is likely to invalidate this assumption, revise the aforementioned , sensitivity analysis taking ignition of and fire propagation in cable trays into account. FM 02.c.01 NFPA 805, Section 2.4.3.3, states, in part, that the PRA approach, methods, and data shall be acceptable to the NRC. LAR Section 4.5.1.2, "Fire Model Utilization in the Application,'' states, in part, that fire modeling was performed as part of the Fire PRA development. In a letter dated October 13, 2014 (ADAMS Accession No. ML 14297A162), the licensee responded to FM RAI 02.c, and subsequently revised the response in a letter dated December 12, 2014 (ADAMS Accession No. ML 14365A071). Both the initial and the revised response contain the following statement: "The heat release rate contribution from the small amount of flame-retardant, self-extinguishing jacket material that might collect on the top surface of the ignition surface (e.g., electrical panel) is considered negligible in comparison with the peak HRR of the ignition source and is therefore considered insignificant with respect to the postulated target damage." The licensee's Design Basis Specification for Fire Protection indicates that approximately 45% of the combustible mass of power cables and 60% of the combustible mass of control cables is outside the armor. Provide a quantitative assessment to justify the licensee's conjecture that the HRR contribution from the jacket material is negligible and its impact on the postulated target damage is insignificant.
| | * ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT A RISK-INFORMED, PERFORMANCE-BASED FIRE PROTECTION PROGRAM (TAC NOS. MF2934 AND MF2935) |
| * Mr. Steven D. Capps Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078-8985 May 8, 2015 SUBJECT: MCGUIRE NUCLEAR STATION, UNITS 1 AND 2: REQUEST FOR ADDITIONAL INFORMATION REGARDING LICENSE AMENDMENT REQUEST TO IMPLEMENT A RISK-INFORMED, PERFORMANCE-BASED FIRE PROTECTION PROGRAM (TAC NOS. MF2934 AND MF2935) Dear Mr. Capps: By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML 13276A 126), Duke Energy Carolinas, LLC (Duke) submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association (NFPA) Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition. The U.S. Nuclear Regulatory Commission staff is continuing its review and has determined that additional information is needed in the fire modeling area as discussed in the Enclosure. Docket Nos. 50-369 and 50-370 Enclosure: | | |
| * As stated cc w/encl: Distribution via Listserv DISTRIBUTION: PUBLIC LPL2-1 R/F RidsAcrsAcnw_MailCTR Resource RidsNrrDeEicb Resource RidsNrrLASFigueroa Resource ADAMS Accession No. ML 15125A328 Sincerely, /RA/ Bob Martin, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation RidsNrrDorllpl2-1 Resource RidsNrrPMMcGuire Resource RidsRgn2MailCenter Resource *via E-mail OFFICE N RR/LPL2-1 /PM NRR/LPL2-1/LA NRR/DRA/AFPB NRR/LPL2-1/BC NRR/LPL2-1/PM NAME BMartin SFigueroa AKlein* RPascarelli BMartin DATE 05/07/15 05/06/15 04/17/15 05/08/15 05/08/15 OFFICIAL RECORD COPY
| | ==Dear Mr. Capps:== |
| }} | | |
| | By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13276A126), Duke Energy Carolinas, LLC (Duke) submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association (NFPA) Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition. |
| | The U.S. Nuclear Regulatory Commission staff is continuing its review and has determined that additional information is needed in the fire modeling area as discussed in the Enclosure. |
| | Sincerely, |
| | ~~or Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-369 and 50-370 |
| | |
| | ==Enclosure:== |
| | As stated cc w/encl: Distribution via Listserv |
| | |
| | REQUEST FOR ADDITIONAL INFORMATION ADOPTION OF NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 FOR FIRE PROTECTION DUKE ENERGY CAROLINAS, LLC (DUKE) |
| | MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-369, 50-370 By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13276A126), Duke submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition (NFPA 805). The U.S. Nuclear Regulatory Commission (NRC) staff is continuing its review and has determined that additional information is needed in the fire modeling area as follows. |
| | Fire Modeling (FM) RAI 01.j.01 NFPA 805, Section 2.4.3.3, states, in part, that the probabilistic risk assessment (PRA) approach, methods, and data shall be acceptable to the NRC. License Amendment Request (LAR) Section 4.5.1.2, "Fire Model Utilization in the Application," states, in part, that fire modeling was performed as part of the Fire PRA development. |
| | In a letter dated January 26, 2015 (ADAMS Accession No. ML15036A084), the licensee responded to FM RAI 01.j and explained that, to account for fire propagation in cable trays, the vertical zone of influence (ZOI) was extended to the ceiling and that the horizontal ZOI encompasses the 35° angle as discussed in NUREG/CR-6850. The licensee further referred to tests conducted by EPRI and NEI to justify ignoring flame spread over armored cable with a PVC jacket beyond the 35° cone. Subsequently, in its response to FM RAI 02.b the licensee stated that a recent review of FPRA-related cables indicates that approximately 15% are thermoplastic, and that 24% of the total cable population in the plant is thermoplastic. |
| | The EPRl/NEI tests that the licensee refers to involved a cable tray that was located approximately 5 ft. above and to the side of the 350 kW ignition source. In both tests the PVC jacket started to melt and drip to the floor, but did not ignite. The objective of these two tests was to assess the performance of jacketed armored cables located in the hot gas layer (HGL). |
| | The results do not apply to cable trays that are located directly above the ignition source. |
| | In light of this observation and the licensee's recent finding that approximately 24% of the cables in the plant are thermoplastic, re-quantify the impact of fire propagation in cable trays and the heat release rate (HRR) contribution from the cables on target damage and plant risk. Where applicable, consider the contribution from non-FPRA cables and non-cable secondary combustibles in the revised ZOI and HGL analyses. |
| | Enclosure |
| | |
| | FM RAI 01.k.01 NFPA 805, Section 2.4.3.3, states, in part, that the PRA approach, methods, and data shall be acceptable to the NRC. LAR Section 4.5.1.2, "Fire Model Utilization in the Application," states, in part, that fire modeling was performed as part of the Fire PRA development. |
| | In a letter dated November 12, 2014 (ADAMS Accession No. ML14328A628), the licensee responded to FM RAI 01.k and stated that location effects on the ZOI of transient fires within 2 ft. of a wall or corner were accounted for by multiplying the HRR by 2 or 4, respectively. In a letter dated January 26, 2015 (ADAMS Accession No. ML15036A084), the licensee revised its response to FM RAI 01.k, in particular the part pertaining to wall and corner effects on the ZOI |
| | * for transient fires. In the revised response the licensee stated that "The hypothetical transient fuel packages were placed where targets such as cable trays or risers would be impacted. Since the target damage could be achieved by placement of the ignition source away from the wall or corner (i.e., an open location transient fuel package), no further adjustments were applied." |
| | It is stated in Section 11.7.1.6 of NUREG/CR-6850, Volume 2, that "[Transient] ignition sources should be located near areas of the room where critical targets are located, including "pinch-points" where targets from two different safety divisions can be damaged by the same fire." It is not clear from the licensee's revised response that this guidance was followed. |
| | Explain how the licensee ensured that critical targets or pinch-points located close to a wall or corner were identified and considered in the transient fire target damage analysis. |
| | FM RAI 02.b.01 LAR Section 4.5.1 states, in part, that "In accordance with the guidance in RG 1.205, a Fire PRA model was developed for MNS consistent with the requirements of Part 4 "Requirements for Fires At Power PRA," of the American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS) combined PRA Standard, ASME/ANS RA-Sa-2009, "Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Application," ... " ASME/ANS Standard RA-Sa-2009, Part 4, requires damage thresholds be established to support the FPRA. |
| | In a letter dated February 27, 2015 (ADAMS Accession No. ML15083A223), the licensee responded to FM RAI 02.b, and stated that the higher damage thresholds associated with thermoset cables were used based on the assumption that the cables at McGuire Nuclear Station, Units 1 and 2, are predominately constructed with EPR or XLPE (thermoset) insulation, a galvanized steel interlocking armor, and a thin flame retardant polyvinylchloride (PVC) exterior jacket. The licensee further stated that a subsequent review of cable information showed that there is a higher percentage of thermoplastic insulation in the plant than initially considered, that approximately 15% of the roughly 12,000 FPRA-related ca81es are thermoplastic cables (and approximately 24% of the total plant cable population), and that these thermoplastic FPRA-related cables are relatively evenly distributed throughout tne plant with only six fire areas being appreciably above the overall average. |
| | |
| | The licensee also identified five conservatisms in the present analysis that may (partly) offset the impact of the presence of thermoplastic cables on the Fire PRA. To quantify this impact the licensee performed a sensitivity analysis and determined that a more thorough evaluation of the thermoplastic cable insulation impact does not result in a risk increase greater than 1 E-06/year for CDF or 1 E-07/year for LERF. Finally, the licensee stated that the thermoplastic cable impact on the risk will be re-evaluated when the results of ongoing NRG/industry research on the severity of cabinet fires will be published. This re-evaluation is an implementation item and will be added to Table S-3 of the LAR. |
| | The sensitivity analysis described in Attachment 2 to the response to FM RAI 02.b appears to assume that cable fires do not propagate in stacks of horizontal trays. In light of the fact that the response to FM RAI 01.j.01 is likely to invalidate this assumption, revise the aforementioned , |
| | sensitivity analysis taking ignition of and fire propagation in cable trays into account. |
| | FM 02.c.01 NFPA 805, Section 2.4.3.3, states, in part, that the PRA approach, methods, and data shall be acceptable to the NRC. LAR Section 4.5.1.2, "Fire Model Utilization in the Application,'' states, in part, that fire modeling was performed as part of the Fire PRA development. |
| | In a letter dated October 13, 2014 (ADAMS Accession No. ML14297A162), the licensee responded to FM RAI 02.c, and subsequently revised the response in a letter dated December 12, 2014 (ADAMS Accession No. ML14365A071). Both the initial and the revised response contain the following statement: "The heat release rate contribution from the small amount of flame-retardant, self-extinguishing jacket material that might collect on the top surface of the ignition surface (e.g., electrical panel) is considered negligible in comparison with the peak HRR of the ignition source and is therefore considered insignificant with respect to the postulated target damage." |
| | The licensee's Design Basis Specification for Fire Protection indicates that approximately 45% |
| | of the combustible mass of power cables and 60% of the combustible mass of control cables is outside the armor. |
| | Provide a quantitative assessment to justify the licensee's conjecture that the HRR contribution from the jacket material is negligible and its impact on the postulated target damage is insignificant. |
| | * ML15125A328 *via E-mail OFFICE N RR/LPL2-1 /PM NRR/LPL2-1/LA NRR/DRA/AFPB NRR/LPL2-1/BC NRR/LPL2-1/PM NAME BMartin SFigueroa AKlein* RPascarelli BMartin DATE 05/07/15 05/06/15 04/17/15 05/08/15 05/08/15}} |
Letter Sequence RAI |
|---|
|
|
MONTHYEARML13354B8792013-12-31031 December 2013
Acceptance Review Results License Amendment Request to Adopt National Fire Protection Association 805 Performance-Based Standard for Fire Protection for Light-Water Reactor Generating Plants
Project stage: Acceptance Review
ML14014A2792014-01-15015 January 2014
Acceptance of Requested Licensing Action License Amendment Request to Adopt National Fire Protection Association (NFPA) 805 Performance-Based Standard for Fire Protection for Light-Water Reactor Generating
Project stage: Acceptance Review
ML14204A8002014-07-24024 July 2014
Regulatory Audit in Support of the License Amendment Request to Implement a Risk-Informed, Performance-Based, Fire Protection Program
Project stage: Other
ML14233A3662014-08-28028 August 2014
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
Project stage: RAI
ML14295A3072014-10-27027 October 2014
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
Project stage: RAI
MNS-14-090, Response to August 28, 2014 NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2014-11-12012 November 2014
Response to August 28, 2014 NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
MNS-14-095, Response to August 28, 2014, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2014-12-12012 December 2014
Response to August 28, 2014, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
MNS-15-002, Response to August 28, 2014, & October 27, 2014, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2015-01-26026 January 2015
Response to August 28, 2014, & October 27, 2014, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
ML15099A5872015-04-14014 April 2015
Duke Energy Slides for April 14 Meeting on NFPA-805 for Catawba, McGuire and Robinson
Project stage: Meeting
ML15125A3282015-05-0808 May 2015
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
Project stage: RAI
ML15147A6282015-06-18018 June 2015
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
Project stage: RAI
MNS-15-052, Response to June 18, 2015, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2015-07-15015 July 2015
Response to June 18, 2015, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
ML15225A4892015-08-18018 August 2015
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
Project stage: RAI
MNS-15-066, Response to NRC June 18, 2015 and May 8, 2015 Requests for Additional Information Re License Amendment Request to Implement Risk-Informed Performance-Based Fire Protection Program2015-08-20020 August 2015
Response to NRC June 18, 2015 and May 8, 2015 Requests for Additional Information Re License Amendment Request to Implement Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
MNS-15-070, Response to August 18, 2015, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2015-09-0909 September 2015
Response to August 18, 2015, NRC Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
MNS-15-099, Submittal Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2016-01-14014 January 2016
Submittal Regarding License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
MNS-16-039, Submittal Revising Attachment s of License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program2016-04-26026 April 2016
Submittal Revising Attachment s of License Amendment Request to Implement a Risk-Informed Performance-Based Fire Protection Program
Project stage: Request
ML16175A0222016-07-12012 July 2016
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
Project stage: RAI
MNS-16-077, Responding to Request for Additional Information Related to License Amendment Request to Implement a Risk-informed Performance-Based Fire Protection Program2016-09-29029 September 2016
Responding to Request for Additional Information Related to License Amendment Request to Implement a Risk-informed Performance-Based Fire Protection Program
Project stage: Request
ML16302A1122016-11-0404 November 2016
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program (CAC Nos. MF2934 and MF2935)
Project stage: RAI
ML16077A1352016-12-0606 December 2016
Issuance of Amendments Regarding National Fire Protection Association Standard NFPA 805
Project stage: Approval
2015-06-18
[Table View] |
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Category:Letter
MONTHYEARIR 05000369/20240032024-11-0404 November 2024
Integrated Inspection Report 05000369/2024003 and 05000370/2024003
ML24303A4212024-10-30030 October 2024
Mcguire Nuclear Station, Units 1 & 2, Notification of an NRC Fire Protection Team Inspection FPTI NRC 05000369/2025010, 05000370/2025010 and Request for Information RFI
IR 05000369/20244022024-10-0808 October 2024
Security Baseline Inspection Report 05000369/2024402 05000370/2024402
IR 05000369/20240052024-08-26026 August 2024
Updated Inspection Plan for McGuire Nuclear Station, Units 1 and 2, (Report 05000369-2024005 and 05000370-2024005)
IR 05000369/20244042024-08-0101 August 2024
Cover Letter Security Baseline Inspection Report 05000369/2024404 and 05000370/2024404
IR 05000369/20253012024-07-29029 July 2024
Notification of Licensed Operator Initial Examination 05000369/2025301 and 05000370/2025301
IR 05000369/20244032024-07-25025 July 2024
– Cyber Security Inspection Report 05000369/2024403 and 05000370/2024403 Rev
IR 05000369/20240022024-07-24024 July 2024
Integrated Inspection Report 05000369/2024002 and 05000370/2024002
ML24183A0972024-07-12012 July 2024
ISFSI; Catawba 1, 2 & ISFSI; McGuire 1, 2 & ISFSI; Oconee 1, 2, 3 & ISFSI; Shearon Harris 1; H. B. Robinson 2 & ISFSI; and Radioactive Package Shipping Under 10 CFR 71 (71-266 & 71-345) – Review of QA Program Changes EPID L-2024-LLQ-0002
IR 05000369/20244012024-07-0303 July 2024
– Security Baseline Inspection Report 05000369/2024401 and 05000370/2024401
ML24176A2802024-06-26026 June 2024
Notification of Target Set Inspection and Request for Information (NRC Inspection Report 05000369-2024404 and 05000370-2024404)
IR 05000369/20240112024-06-0404 June 2024
Biennial Problem Identification and Resolution Inspection Report 05000369/2024011 and 05000370/2024011
ML24149A1772024-05-28028 May 2024
NRC Response to Duke Energy 2025 FOF Schedule Change Request (Catawba and McGuire)
IR 05000369/20240012024-05-0808 May 2024
Integrated Inspection Report 05000369-2024001 and 05000370-2024001 and 07200038-2024001
ML24110A0382024-04-30030 April 2024
– Correction to Issuance of Amendment Nos. 330 and 309, Regarding Implementation of Technical Specifications Task Force (TSTF) Traveler TSTF 505, Revision 2, Provide Risk-Informed Extended Completion Times - Ritstf
ML24100A8742024-04-10010 April 2024
Information Request for the Cybersecurity Baseline Inspection, Notification to Perform Inspection 05000369/2024403; and 05000370/2024403
ML24052A3062024-04-0808 April 2024
Issuance of Amendment Nos. 331 & 310, Regarding Adoption of Title 10 of Code of Federal Regulations Section 50.69, Risk-Informed Categorization and Treatment of Structures, Systems and Components for Nuclear Power Plants
ML24031A5402024-03-26026 March 2024
Issuance of Amendment Nos. 330 and 309 Regarding Implementation of TSTF 505,Rev. 2, Provide Risk-Informed Extended Completion Times - RITSTF Initiative 4B
ML24085A2402024-03-21021 March 2024
Requalification Program Inspection - McGuire Nuclear Station
IR 05000369/20230062024-02-28028 February 2024
Annual Assessment Letter for McGuire Nuclear Station, Units 1 and 2 - NRC Inspection Report 05000369/2023006 and 05000370/2023006
ML24024A2182024-02-0505 February 2024
Exemption from Select Requirements of 10 CFR Part 73 (Security Notifications, Reports, and Recordkeeping and Suspicious Activity Reporting)
IR 05000369/20230042024-01-31031 January 2024
Integrated Inspection Report 05000369/2023004 and 05000370/2023004
ML24019A1392024-01-25025 January 2024
TSTF 505 and 50.69 Audit Summary
ML24019A2002024-01-24024 January 2024
Notification of Inspection and Request for Information for NRC Problem Identification and Resolution Inspection
IR 05000369/20234022023-12-14014 December 2023
– Material Control and Accounting Program Inspection Report 05000369/2023402 and 05000370/2023402
05000369/LER-1923-001, Automatic Actuation of the 1A Motor Driven Auxiliary Feedwater Pump Due to Human Error2023-12-13013 December 2023
Automatic Actuation of the 1A Motor Driven Auxiliary Feedwater Pump Due to Human Error
ML23317A2272023-11-17017 November 2023
William B. McGuire Nuclear Station, Units 1 and 2 - Transmittal of Dam Inspection Report - Non-Proprietary
ML23317A3462023-11-14014 November 2023
Duke Fleet - Correction Letter to License Amendment Nos. 312 & 340 Issuance of Amendments Regarding the Adoption of Technical Specifications Task Force Traveler TSTF-554, Revision 1
IR 05000369/20230032023-10-24024 October 2023
Integrated Inspection Report 05000369/2023003 and 05000370/2023003; and Inspection Report 07200038/2023001
IR 05000369/20240102023-10-13013 October 2023
Notification of McGuire Nuclear Station Comprehensive Engineering Team Inspection – U.S. Nuclear Regulatory Commission Inspection Report 05000369, 370/2024010
IR 05000369/20230102023-10-13013 October 2023
Age Related Degradation Inspection Report 05000369/2023010 and 05000370/2023010
ML23256A0882023-09-25025 September 2023
Issuance of Alternative to Steam Generator Welds
IR 05000369/20233012023-09-20020 September 2023
William B. McGuire Nuclear Station - NRC Examination Report 05000369/2023301 and 05000370/2023301
ML23230A0652023-08-31031 August 2023
William B. McGuire Nuclear Station, Units 1 and 2 - Relief Request Use of Later Edition of ASME Code
ML23195A0782023-08-29029 August 2023
Issuance of Amendments Regarding the Adoption of Technical Specifications Task Force Traveler TSTF-554, Revision 1
IR 05000369/20230052023-08-25025 August 2023
Updated Inspection Plan for McGuire Nuclear Station Units 1 and 2 (Report 05000369/2023005 and 05000370/2023005)
IR 05000369/20234012023-08-0404 August 2023
– Security Baseline Inspection Report 05000369/2023401 and 05000370/2023401 (OUO-SRI) Cover
IR 05000369/20230022023-07-28028 July 2023
Integrated Inspection Report 05000369/2023002 and 05000370/2023002
IR 05000369/20234202023-07-24024 July 2023
– Security Baseline Inspection Report 050003692023420 and 050003702023420
ML23206A0092023-07-24024 July 2023
William B. McGuire Nuclear Station – Operator Licensing Written Examination Approval 05000369/2023301 and 05000370/2023301
ML23207A0762023-07-14014 July 2023
EN 56557 - Update to Part 21 Report Re Potential Defect with Trane External Auto/Stop Emergency Stop Relay Card Pn: XI2650728-06
ML23159A2712023-06-20020 June 2023
William B. McGuire Nuclear Station, Unit 1 - Relief Request Impractical Reactor System Welds
ML23237A2672023-06-13013 June 2023
June 13, 2002 - Meeting Announcement - McGuire and Catawba Nuclear Stations 50-369, 50-370 and 50-413, 50-414
ML23159A0052023-06-0505 June 2023
56557-EN 56557 - Paragon - Redlined
ML23124A0862023-05-0303 May 2023
Cycle 29, Revision 1, Core Operating Limits Report (COLR)
ML23118A0762023-05-0101 May 2023
Approval for Use of Specific Provision of a Later Edition of the American Society of Mechanical Engineers Boiler and Pressure Vessel Code, Section XI
IR 05000369/20230012023-05-0101 May 2023
Integrated Inspection Report 05000369/2023001 and 05000370/2023001
ML23115A2122023-05-0101 May 2023
Review of the Spring 2022 Steam Generator Tube Inspection Report
ML23094A1832023-04-18018 April 2023
Audit Plan TSTF-505, Rev. 2, RITSTF Initiative 4B & 10 CFR 50.69, Risk-Informed Categorization & Treatment of Structures, Systems & Components for Nuclear Power Reactors (EPIDs L-2023-LLA-0021 & L-2023-LLA-0022)
ML22332A4932023-03-10010 March 2023
William States Lee III 1 and 2 - Issuance of Amendments Regarding the Relocation of the Emergency Operations Facility
2024-08-26
[Table view]
Category:Request for Additional Information (RAI)
MONTHYEARML24197A1702024-07-15015 July 2024
Request for Additional Information Two Proposed Alternatives (RA-23-0242) for the Inspection of Reactor Vessel Closure Head Penetrations
ML23151A3482023-05-30030 May 2023
Duke Fleet - Request for Additional Information Proposed Alternative for Pressurizer Welds in Accordance with 10 CFR 50.55a(z)(1)
ML23142A2732023-05-22022 May 2023
Duke Fleet - Request for Additional Information Proposed Alternative for Steam Generator Welds in Accordance with 10 CFR 50.55a(z)(1)
ML23030B9032023-01-30030 January 2023
Formal Release of RAIs for McGuire Unit 1, Relief Request Impractical RPV Rx Coolant System Welds, Due March 1, 2023 (Email)
ML23017A2232023-01-13013 January 2023
Request for Additional Information (RAI) Issuance for McGuire Unit 1 Steam Generator Tube Inspection Report (Email)
ML22175A0162022-06-24024 June 2022
Notification of Inspection and Request for Information for NRC Problem Identification and Resolution Inspection
ML22115A1412022-04-25025 April 2022
NRR E-mail Capture - Duke Common EOF Relocation - Request for Addition Information
ML22102A2962022-04-13013 April 2022
Request for Withholding Information from Public Disclosure Response to Request for Additional Information
ML22063B1782022-03-0909 March 2022
Request for Additional Information Regarding LAR for Revision to the Conditional Exemption of the End of Cycle Moderator Temperature Coefficient Measurement Methodology (EPID L-2021-LLA-0198) NON-PROPRIETARY
ML22010A0732022-01-0606 January 2022
50.59 Inspection Information Request
ML21354A8612021-12-15015 December 2021
NRR E-mail Capture - Request for Additional Information - Duke Fleet Request RA-19-0352 - Alternative for RPV Closure Stud Exams (L-2020-LLR-0156)
ML21267A2782021-09-23023 September 2021
50.59 Inspection Information Request
ML21252A0532021-09-0808 September 2021
NRR E-mail Capture - Formal Release of Rais, 30 Day Response, Mcguire Relief Request, Ref: Later Edition Addenda ASME Code, Section XI, 50.55a(g)(4)(iv)
ML21103A0542021-04-13013 April 2021
NRR E-mail Capture - Extension to Request for Additional Information AMS Topical Report AMS-TR-0720R1
ML21067A6742021-03-0505 March 2021
NRR E-mail Capture - Final Request for Additional Information AMS Topical Report AMS-TR-0720R1
ML21049A2632021-02-0404 February 2021
NRR E-mail Capture - Request for Additional Information - Duke Energy Fleet License Amendment Request to Revise Emergency Plan
ML21020A0682021-01-20020 January 2021
Notification of an NRC Fire Protection Team Inspection (FPTI) (NRC Inspection Report 05000369/2021011 and 05000370/2021011) and Request for Information (RFI)
ML20346A0212020-12-10010 December 2020
NRR E-mail Capture - Formal Release of RAIs - License Amendment to Change TS 3.8.1 Due Jan. 29, 2021
ML20323A4072020-11-18018 November 2020
NRR E-mail Capture - Request for Additional Information - Brunswick License Exemption Request from 10CFR73 Annual Force on Force Exercise Requirements (EPIC L-2020-LLE-0180)
ML20216A3512020-08-0303 August 2020
Mcquire U-1 ISI RFI
ML20101L3132020-04-10010 April 2020
Notification of Inspection and Request for Information
ML20071D0962020-03-0505 March 2020
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station Unit 1 Delay in Update of the Code of Record for in Service Inspections
ML20050D3382020-02-21021 February 2020
Letter RAI 1 MAGNASTOR-Catawba and McGuire Exemptions with Enclosure
ML19354B6372020-01-0707 January 2020
Exemption Request for NAC Magnastor Cask Loaded to Incorrect Helium Backfill Density Request for Additional Information
ML19011A1372019-01-10010 January 2019
NRR E-mail Capture - Duke Energy Fleet RAIs - Relief Request 18-GO-001 - Proposed Alternative for Depth Sizing Qualification Examination of Welds (L-2018-LLR-0117)
ML19007A3422018-12-21021 December 2018
NRR E-mail Capture - Duke Energy Fleet Draft RAIs - Relief Request 18-GO-001 - Proposed Alternative for Depth Sizing Qualification Examination of Welds (L-2018-LLR-0117)
ML18352A8052018-12-18018 December 2018
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - MRP-227 Review
ML18306A9372018-11-0202 November 2018
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - Esps LAR
ML18285A0812018-10-11011 October 2018
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - TORMIS LAR
RA-18-0011, Response to Request for Supplemental Information Regarding Duke Energy'S Response to GL 2016-01 Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools2018-05-30030 May 2018
Response to Request for Supplemental Information Regarding Duke Energy'S Response to GL 2016-01 Monitoring of Neutron-Absorbing Materials in Spent Fuel Pools
ML18138A4662018-05-18018 May 2018
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - TORMIS LAR
ML18088B2822018-03-29029 March 2018
Requalification Program Inspection - McGuire Nuclear Station
ML18057A2182018-02-23023 February 2018
Enclosurequest for Additional Information (Letter to A. Zaremba Request for Additional Information for Review of Duke Energy'S Decommissioning Funding Plan Update)
ML17331B1492017-11-21021 November 2017
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - Nsws One-Time LAR (CACs MG0242 and MG0243, EPID L-2017-LLA-0299)
ML17317B0932017-11-13013 November 2017
NRR E-mail Capture - Request for Additional Information - McGuire Nuclear Station, Units 1 and 2 - Irlt (CACs MF9020 and MF9021; EPID L-2016-LLA-0032)
ML17230A1512017-08-15015 August 2017
Notification of Inspection of Inspection and Request for Information
ML17192A4842017-07-11011 July 2017
NRR E-mail Capture - Duke Energy Fleet RAIs Alternative for Reactor Pressure Vessel Flange Threads Examination (MF9513 to MF9521)
ML17135A0322017-05-12012 May 2017
NRR E-mail Capture - Request for Additional Information - McGuire TSTF-197
ML17114A4992017-04-17017 April 2017
Emergency Preparedness Inspection and Request for Information
ML16302A1122016-11-0404 November 2016
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program (CAC Nos. MF2934 and MF2935)
MNS-16-077, Responding to Request for Additional Information Related to License Amendment Request to Implement a Risk-informed Performance-Based Fire Protection Program2016-09-29029 September 2016
Responding to Request for Additional Information Related to License Amendment Request to Implement a Risk-informed Performance-Based Fire Protection Program
ML16228A2612016-08-15015 August 2016
Email - McGuire Unit No. 1: Request for Additional Informati- Relief Request 16-MN-003 Alternative to Defect Removal Prior to Performing Temporary Repair Activities on Three-Inch-Diameter Nuclear Service Water System Piping.
ML16194A2862016-07-12012 July 2016
E-Mail - Mcguirai Ice Condenser Door Position Alternate Verification, (ML16089A228) CAC Nos. MF7526 and MF7527
ML16175A0222016-07-12012 July 2016
Request for Additional Information Regarding License Amendment Request to Implement a Risk-Informed, Performance-Based Fire Protection Program
ML16014A6882016-01-20020 January 2016
Request for Additional Information Regarding License Amendment Request to Revise Emergency Action Level Scheme
ML15348A2602015-12-17017 December 2015
Request for Additional Information Regarding License Amendment Request to Use an Alternative Fission Gas Gap Release Fraction
ML15320A3862015-11-19019 November 2015
RAI LAR to Adopt TSTF-523
ML15314A3592015-11-10010 November 2015
Duke Energy Draft RAIs Request to Adopt TSTF-523 (CAC Nos. MF6413-MF6422)
ML15314A3562015-11-10010 November 2015
E-mail from J. Whited to A. Zaremba Duke Energy Draft RAIs License Amendment Request to Adopt TSTF-523 (CAC Nos. MF6413-MF6422)
ML15289A5552015-10-26026 October 2015
Request for Additional Information Regarding License Amendment Request Nuclear Service Water System Allowed Outage Time Extension
2024-07-15
[Table view] |
Text
UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, i:>.C. 20555-0001 May 8, 2015 Mr. Steven D. Capps Vice President McGuire Nuclear Station Duke Energy Carolinas, LLC 12700 Hagers Ferry Road Huntersville, NC 28078-8985
SUBJECT:
MCGUIRE NUCLEAR STATION, UNITS 1 AND 2: REQUEST FOR
Dear Mr. Capps:
By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13276A126), Duke Energy Carolinas, LLC (Duke) submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association (NFPA) Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition.
The U.S. Nuclear Regulatory Commission staff is continuing its review and has determined that additional information is needed in the fire modeling area as discussed in the Enclosure.
Sincerely,
~~or Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-369 and 50-370
Enclosure:
As stated cc w/encl: Distribution via Listserv
REQUEST FOR ADDITIONAL INFORMATION ADOPTION OF NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 FOR FIRE PROTECTION DUKE ENERGY CAROLINAS, LLC (DUKE)
MCGUIRE NUCLEAR STATION, UNITS 1 AND 2 DOCKET NOS. 50-369, 50-370 By letter dated September 26, 2013 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML13276A126), Duke submitted a license amendment request to change its fire protection program to one based on the National Fire Protection Association Standard-805, "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants," 2001 Edition (NFPA 805). The U.S. Nuclear Regulatory Commission (NRC) staff is continuing its review and has determined that additional information is needed in the fire modeling area as follows.
Fire Modeling (FM) RAI 01.j.01 NFPA 805, Section 2.4.3.3, states, in part, that the probabilistic risk assessment (PRA) approach, methods, and data shall be acceptable to the NRC. License Amendment Request (LAR) Section 4.5.1.2, "Fire Model Utilization in the Application," states, in part, that fire modeling was performed as part of the Fire PRA development.
In a letter dated January 26, 2015 (ADAMS Accession No. ML15036A084), the licensee responded to FM RAI 01.j and explained that, to account for fire propagation in cable trays, the vertical zone of influence (ZOI) was extended to the ceiling and that the horizontal ZOI encompasses the 35° angle as discussed in NUREG/CR-6850. The licensee further referred to tests conducted by EPRI and NEI to justify ignoring flame spread over armored cable with a PVC jacket beyond the 35° cone. Subsequently, in its response to FM RAI 02.b the licensee stated that a recent review of FPRA-related cables indicates that approximately 15% are thermoplastic, and that 24% of the total cable population in the plant is thermoplastic.
The EPRl/NEI tests that the licensee refers to involved a cable tray that was located approximately 5 ft. above and to the side of the 350 kW ignition source. In both tests the PVC jacket started to melt and drip to the floor, but did not ignite. The objective of these two tests was to assess the performance of jacketed armored cables located in the hot gas layer (HGL).
The results do not apply to cable trays that are located directly above the ignition source.
In light of this observation and the licensee's recent finding that approximately 24% of the cables in the plant are thermoplastic, re-quantify the impact of fire propagation in cable trays and the heat release rate (HRR) contribution from the cables on target damage and plant risk. Where applicable, consider the contribution from non-FPRA cables and non-cable secondary combustibles in the revised ZOI and HGL analyses.
Enclosure
FM RAI 01.k.01 NFPA 805, Section 2.4.3.3, states, in part, that the PRA approach, methods, and data shall be acceptable to the NRC. LAR Section 4.5.1.2, "Fire Model Utilization in the Application," states, in part, that fire modeling was performed as part of the Fire PRA development.
In a letter dated November 12, 2014 (ADAMS Accession No. ML14328A628), the licensee responded to FM RAI 01.k and stated that location effects on the ZOI of transient fires within 2 ft. of a wall or corner were accounted for by multiplying the HRR by 2 or 4, respectively. In a letter dated January 26, 2015 (ADAMS Accession No. ML15036A084), the licensee revised its response to FM RAI 01.k, in particular the part pertaining to wall and corner effects on the ZOI
- for transient fires. In the revised response the licensee stated that "The hypothetical transient fuel packages were placed where targets such as cable trays or risers would be impacted. Since the target damage could be achieved by placement of the ignition source away from the wall or corner (i.e., an open location transient fuel package), no further adjustments were applied."
It is stated in Section 11.7.1.6 of NUREG/CR-6850, Volume 2, that "[Transient] ignition sources should be located near areas of the room where critical targets are located, including "pinch-points" where targets from two different safety divisions can be damaged by the same fire." It is not clear from the licensee's revised response that this guidance was followed.
Explain how the licensee ensured that critical targets or pinch-points located close to a wall or corner were identified and considered in the transient fire target damage analysis.
FM RAI 02.b.01 LAR Section 4.5.1 states, in part, that "In accordance with the guidance in RG 1.205, a Fire PRA model was developed for MNS consistent with the requirements of Part 4 "Requirements for Fires At Power PRA," of the American Society of Mechanical Engineers (ASME) and American Nuclear Society (ANS) combined PRA Standard, ASME/ANS RA-Sa-2009, "Standard for Level 1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Application," ... " ASME/ANS Standard RA-Sa-2009, Part 4, requires damage thresholds be established to support the FPRA.
In a letter dated February 27, 2015 (ADAMS Accession No. ML15083A223), the licensee responded to FM RAI 02.b, and stated that the higher damage thresholds associated with thermoset cables were used based on the assumption that the cables at McGuire Nuclear Station, Units 1 and 2, are predominately constructed with EPR or XLPE (thermoset) insulation, a galvanized steel interlocking armor, and a thin flame retardant polyvinylchloride (PVC) exterior jacket. The licensee further stated that a subsequent review of cable information showed that there is a higher percentage of thermoplastic insulation in the plant than initially considered, that approximately 15% of the roughly 12,000 FPRA-related ca81es are thermoplastic cables (and approximately 24% of the total plant cable population), and that these thermoplastic FPRA-related cables are relatively evenly distributed throughout tne plant with only six fire areas being appreciably above the overall average.
The licensee also identified five conservatisms in the present analysis that may (partly) offset the impact of the presence of thermoplastic cables on the Fire PRA. To quantify this impact the licensee performed a sensitivity analysis and determined that a more thorough evaluation of the thermoplastic cable insulation impact does not result in a risk increase greater than 1 E-06/year for CDF or 1 E-07/year for LERF. Finally, the licensee stated that the thermoplastic cable impact on the risk will be re-evaluated when the results of ongoing NRG/industry research on the severity of cabinet fires will be published. This re-evaluation is an implementation item and will be added to Table S-3 of the LAR.
The sensitivity analysis described in Attachment 2 to the response to FM RAI 02.b appears to assume that cable fires do not propagate in stacks of horizontal trays. In light of the fact that the response to FM RAI 01.j.01 is likely to invalidate this assumption, revise the aforementioned ,
sensitivity analysis taking ignition of and fire propagation in cable trays into account.
FM 02.c.01 NFPA 805, Section 2.4.3.3, states, in part, that the PRA approach, methods, and data shall be acceptable to the NRC. LAR Section 4.5.1.2, "Fire Model Utilization in the Application, states, in part, that fire modeling was performed as part of the Fire PRA development.
In a letter dated October 13, 2014 (ADAMS Accession No. ML14297A162), the licensee responded to FM RAI 02.c, and subsequently revised the response in a letter dated December 12, 2014 (ADAMS Accession No. ML14365A071). Both the initial and the revised response contain the following statement: "The heat release rate contribution from the small amount of flame-retardant, self-extinguishing jacket material that might collect on the top surface of the ignition surface (e.g., electrical panel) is considered negligible in comparison with the peak HRR of the ignition source and is therefore considered insignificant with respect to the postulated target damage."
The licensee's Design Basis Specification for Fire Protection indicates that approximately 45%
of the combustible mass of power cables and 60% of the combustible mass of control cables is outside the armor.
Provide a quantitative assessment to justify the licensee's conjecture that the HRR contribution from the jacket material is negligible and its impact on the postulated target damage is insignificant.
- ML15125A328 *via E-mail OFFICE N RR/LPL2-1 /PM NRR/LPL2-1/LA NRR/DRA/AFPB NRR/LPL2-1/BC NRR/LPL2-1/PM NAME BMartin SFigueroa AKlein* RPascarelli BMartin DATE 05/07/15 05/06/15 04/17/15 05/08/15 05/08/15
