thomas d. gatlin vice president, nuclear …803.345.4342 a scana company april 1, 2013 rc-13-0054...

Thomas D. GatlinVice President, Nuclear Operations

803.345.4342

A SCANA COMPANY

April 1, 2013RC-13-0054

U.S. Nuclear Regulatory CommissionDocument Control DeskWashington, D.C. 20555-0001

Attn: E. A. Brown

Dear Sir / Madam:

Subject: VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) UNIT 1DOCKET NO. 50-395OPERATING LICENSE NO. NPF-12LICENSE AMENDMENT REQUEST - LAR-06-00055LICENSE AMENDMENT REQUEST TO ADOPT NFPA 805ADDITIONAL INFORMATION REGARDING RESPONSETO REQUEST FOR ADDITIONAL INFORMATION

References: 1. Letter from Thomas D. Gatlin to NRC Document Control Desk, datedNovember 15, 2011, License Amendment Request - LAR-06-00055,"License Amendment Request to Adopt NFPA 805 Performance-BasedStandard for Fire Protection for Light Water Reactor Electric GeneratingPlants (2001 Edition)"

2. NRC Letter from Robert E. Martin to Thomas D. Gatlin dated July 26, 2012,"Virgil C. Summer Nuclear Station Unit 1 (VCSNS) - Request for AdditionalInformation (TAC NO. ME7586)" ADAMS Accession No. ML12202A027

3. Letter from Thomas D. Gatlin to NRC Document Control Desk, dated October10, 2012, License Amendment Request - LAR-06-00055, "LicenseAmendment Request to Adopt NFPA 805 Response to Request for AdditionalInformation"

4. Letter from Thomas D. Gatlin to NRC Document Control Desk, datedFebruary 1, 2013, License Amendment Request - LAR-06-00055,LicenseAmendment Request to Adopt NFPA 805 Additional Information RegardingResponse to Request for Additional Information"

South Carolina Electric & Gas Company (SCE&G), acting for itself and as agent for SouthCarolina Public Service Authority, has identified additional information that will further explainthe responses to Probability Risk Assessment (PRA) Request for Additional Information (RAI)Numbers 07, 09, 66, and 68.

Virgil C. Summer Station -Post Office Box 88 • Jenkinsville, SC • 29065 • F (803) 345-5209 VIP

Document Control DeskCR-06-00055RC-13-0054 of 2

The additional information is being provided as a result of a February 25, 2013 teleconferenceregarding References 3 and 4. The attachment to this letter provides the additional information.

This letter contains two new regulatory commitments, as outlined in Attachment I1: Increase thescope of circuit protection modifications and Update Generic Methodology Calculation,DC078OB-001.

If you have any questions regarding this submittal, please contact Mr. Bruce L. Thompson at(803) 931-5042.

I certify under penalty of perjury that the foregoing is correct and true.

E,~ecuted on Thomas D. Gatlin

TSFTDG/wm

Attachment I: Probability Risk Assessment Additional InformationAttachment I1: List of Regulatory Commitments

c: K. B. MarshS. A. ByrneJ. B. ArchieN. S. CamsJ. H. HamiltonJ. W. WilliamsW. M. CherryV. M. McCreeE. A. BrownNRC Resident InspectorS. E. JenkinsPaulette LedbetterK. M. SuttonNSRCRTS (CR-06-00055)File (813.20)PRSF (RC-13-0054)

Document Control DeskCR-06-00055Attachment IRC-13-0054Page 1 of 32

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) Unit 1DOCKET NO. 50-395

OPERATING LICENSE NO. NPF-12

ATTACHMENT I

PROBABILITY RISK ASSESSMENT ADDITIONAL INFORMATION


PRA RAI 07

Section 10 of NUREGICR-6850 Supplement I states that a sensitivity analysis should beperformed when using the fire ignition frequencies in the Supplement instead of the fireignition frequencies provided in Table 6-1 of NUREGICR-6850. Provide the sensitivityanalysis of the impact on using the Supplement I frequencies instead of the Table 6-1frequencies on CDF, LERF, ACDF, and ALERF for all of those bins that are characterizedby an alpha that is less than or equal to one. If the sensitivity analysis indicates that thechange in risk acceptance guidelines would be exceeded using the values in Table 6-1,justify not meeting the guidelines.

SCE&G Response

The VCSNS Fire PRA uses the ignition frequencies (IGF) from the latest guidance related to firePRAs as given in Supplement 1 to NUREG/CR-6850. Supplement 1 to NUREG/CR-6850(Section 10.2) addresses the use of the ignition frequencies therein as follows:

"The NRC accepts use of these revised fire bin ignition frequencies for fire PRAs conducted forNFPA-805 transition for best-/point-estimate calculations of fire risk (core damage frequency[CDF] and large early release frequency [LERF]), including delta-risk values from plant changeevaluations, with the following provision. The fire PRA, including plant change evaluations,must also evaluate the sensitivity of the risk and delta-risk results to evaluations performedusing the current fire bin ignition frequencies in EPRI 1011989, NUREG/CR-6850, Chapter 6,"Fire Ignition Frequencies," Table 6-1, "Fire Frequency Bins and Generic Frequencies," andAppendix C, "Determination of Generic Fire Frequencies," Table C-3, "Generic Fire IgnitionFrequency Model for U.S. Nuclear Power Plants." For those cases where the results from thissensitivity analysis indicate a change in the potential risk significance associated with elementsof the fire PRA or plant change evaluations that affects the decisions being made (e.g., what isacceptable with the new frequencies from EPRI 1016735 might not be acceptable with thecurrent applicable set from EPRI 1011989, NUREG/CR-6850), the licensee must address thissituation by considering fire protection, or related, measures that can be taken to provideadditional defense in-depth."

With respect to the required sensitivity analysis, a footnote provides the following clarification:

"The sensitivity analyses should be performed for a fire ignition frequency bin using the mean ofthe fire ignition frequency bins contained in NUREG/CR-6850. Furthermore, sensitivityanalyses only need to be performed for those bins characterized by an alpha from the EPRI1016735 analysis that is less than or equal to 1. Note that an alpha value less than or equal to1 is characteristic of a reverse-J shaped probability density function, i.e., the same shape as thenon-informative prior distributions used in EPRI 1016735. This reverse-J shape is indicative ofthe large uncertainty in the bin fire frequency due to the sparsity of data for that bin, andtherefore, the potential for significant changes should the post-2000 fire event data differsignificantly from the 1991-2000 data. The required sensitivity analysis is, for the purpose ofthis interim solution, judged to provide an adequate indication of the effects on risk and delta-risk in such a case."


Results of the Sensitivity Analysis:

Note that SCE&G has revised the license amendment request (LAR) baseline model to correcterrors in the main control board (MCB) conditional core damage probabilities (CCDPs) (seePRA RAI 66 for details), delete Control Power Transformer (CPT) credit (see PRA RAI 09 fordetails), and reflect increased scope of circuit protection modifications (see PRA RAI 66 fordetails). The results of the sensitivity study for ignition frequency bins with alpha values lessthan or equal to one are shown in the following table.

K ACDF - -7AALERFCDF frm -~ AERF ;CA~LERFnirCDFfrom. LERF from fromCompliant :Compliant Compliant Co-pliant

Revised Baseline 5.9E-05 3.OE-06 7.OE-07 4.3E-09PlantSensitivity CasePlant (ie: Revised 1.1E-04 3.8E-06 8.OE-07 1.6E-06 5.3E-09 1.OE-09Baseline withUpdated IGFs)

Note for table above: The CDF and LERF given above are associated with fire initiating eventsbut are reasonable proxies for the total plant risk. This is due to the fact that the other hazardsfor which CDF and LERF estimates are currently available (internal events at power (includinginternal floods), respectively equal to 4.36E-06/yr and 1.04E-07/yr) represent less than 10percent of the fire-induced CDF and LERF in the sensitivity case.

The combination CDF and Delta CDF using the NUREG/CR-6850 ignition frequencies exceedsthe risk acceptance guidelines illustrated for Region II and III of Figure 4 in Regulatory Guide1.174. Both the LERF and Delta LERF values are within Region III of Figure 5 in RegulatoryGuide 1.174.

For the plant CDF, approximately 80% of the contribution to the increase is from the maincontrol board scenarios in CB17.01 for sequences involving consequential LOCAs. A source ofconservatism in both the base case Fire PRA and the sensitivity case influencing these resultsis the use of NUREG/CR-6850 Figure L-1 probabilities for unqualified cables. A review of thecable routing system suggests that the cables inside the main control board are mostly qualifiedand non-Kerite. Using the qualified cable curve in Figure L-1 of NUREG/CR-6850 would resultin a CDF reduction of a factor of two to three depending on the distance. Consequently, a CDFreduction due to the contribution of main control board fires considering qualified cable wouldplace the combination of CDF and Delta CDF in Region II of Figure 4 in Regulatory Guide1.174.

In addition to this conservatism in the results for fire area C017.01, consistent with the guidancein Section 10.2 of Supplement 1 to NUREG/CR-6850, VCSNS has identified fire protection andrelated measures that provide additional defense-in-depth (DID) in CB17.01, as justification forthe sensitivity analysis results not meeting the acceptance guidelines.

Document Control DeskCR-06-00055Attachment IRC-1 3-0054Page 4 of 32

VCSNS has governing procedures in place for fire protection activities involving control oftemporary storage areas and control of hot work. These procedures are not credited explicitly inthe Fire PRA (i.e., the Fire PRA does not include failure probabilities to follow the requirementsof these procedures) for postulating transient fires within a Fire Area. The procedures areconsidered in the Fire PRA consistent with the guidelines in NUREG/CR-6850 for selecting theappropriate credit for prompt suppression and hot work manual suppression curve for theappropriate scenarios and for determining the influence factors serving as weighting factors fortransient fire ignition frequencies. Consequently, the specific provisions of these procedures arecredited for DID for: (1) controlling transient combustibles throughout the plant; and (2)assigning compensatory measures to maintenance activities that may temporarily change theplant configuration.

PRA RAI 09

It was recently stated at the industry fire forum that the Phenomena Identification andRanking Table Panel (PIRT) being conducted for the circuit failure tests from theDESIREE-FIRE and CAROL-FIRE tests may be eliminating the credit for Control PowerTransformers (CPTs) (about a factor 2 reduction) currently allowed by Tables 10-1 and10-3 of NUREG/CR-6850, Vol. 2, as being invalid when estimating circuit failureprobabilities. Provide a sensitivity analysis that removes this CPT credit from the PRAand provide new results that show the impact of this potential change on CDF, LERF,ACDF, and ALERF. If the sensitivity analysis indicates that the change in risk acceptanceguidelines would be exceeded after eliminating CPT credit, please justify not meeting theguidelines.

SCE&G Response

In anticipation that the PIRT discussions would result in elimination of the CPT credit, VCSNShas removed CPT credit from the Fire PRA. A sensitivity study was conducted by adding CPTcredit back into the model. The impact of this credit on both CDF and LERF, as shown in thefollowing table, is small and not significant.

. . ACDFfrom .CDge in . .. mALERF, Change in-CDF. ' ACDF from LER!1 f r frCompian Compliant,~~li~l Cipin

RevisedBeine 5.8E-05 3.OE-06 7.OE-07 4.3E-09Baseline Plant

Sensitivity CasePlant 5.6E-05 3.OE-06 1.6E-08 5.8E-07 5.7E-09 1.4E-09(CPT credited)

PRA RAI 66

FSS-B2-01: It is not clear from the MCR abandonment document what the criteria are forCR abandonment for MCB fires. Secondly, from the MCB scenarios the conditional coredamage probability (CCDP) does not appear correct for the specified number of panelsas given in Appendix B of the Fire Risk Quantification Task 14 document. For example,


for scenario CB 17.01 MCB 11-10-1, 11-9-1, and 11-8-1, 2, 3, and 4 panels are failedrespectively, yet the CCDP from the quantification document specified that the CCDP islargest when only 2 panels are damaged. Also for scenarios CB17.01 MCB 18-18-1, 18-17-1, 18-16-1, and 18-15-1 the CCDP is the same for each scenario even though 1, 2, 3, and 4panels are damaged respectively. Provide the criteria for CR evacuation for MCB fires,and justify the CCDPs provided for the various number of panels damaged. The responseshould take into account a further examination of the CCDPs for MCB fires thanidentified in this question to evaluate if the CCDP problem is more extensive thandiscussed in this question. Provide updated CDF, LERF, ACDF, and ALERF values forMCB scenarios.

SCE&G Response

The criteria for main control room (MCR) abandonment are discussed in the response to PRARAI 08.

The CCDP issue was an error in the model that was due to the FRANX software treatment ofmutually exclusive events. The top logic structure of the fault tree (shown below) includes NOTlogic that removes cutsets associated with mutually exclusive events. When the FRANX modelsets the failures associated with the fire, it sets all of the failed events to TRUE and thencompresses the tree and solves it. If two events are mapped to a scenario that appears in themutually exclusive logic gate (FIREMEX), the gate @CDFALLF is set to FALSE. This meansthat only the MCR abandonment logic is considered for the scenario. This was the root causeof the issue that resulted in abnormal CCDP results for the main control board scenarios.

Correcting this mutually exclusive event treatment resulted in an unacceptable CDF. Anothercutset review was conducted which identified additional detailed modeling and increased thescope of circuit protection modifications which reduced the model CDF to approximately'thesame value in the LAR. The model has been updated to reflect these changes. In addition, themodel has been updated to reflect elimination of CPT credit, and additional transient zonescenarios as discussed in PRA RAI 68. The updated results for the MCB scenarios are listed inthe table below including CDF, LERF, ACDF and ALERF.


Table 1: Main Control Board Fire Scenarios - Results

LAi/.UIMLb-IU-IU-I b.U41-Ub i.//t-U1 6,)Z:-U/ Note 1 b.bZt-U4 J.it-UV Note iCB17.01_MCB-10-6-1 4.92E-07 8.76E-01 4.31E-07 Note 1 1.79E-02 8.80E-09 Note 1CB17.01_MCB-10-7-1 4.92E-07 8.76E-01 4.31E-07 Note 1 1.79E-02 8.80E-09 Note 1CB17.01 MCB-10-8-1 8.21E-07 8.76E-01 7.19E-07 Note 1 1.79E-02 1.47E-08 Note 1

CB17.01 MCB-10-9-1 1.67E-06 9.48E-01 1.59E-06 Note 1 3.26E-02 5.45E-08 Note 1CB17.01 MCB-1-1-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1

CB17.01 MCB-11-10-1 1.67E-06 1.77E-01 2.97E-07 Note 1 6.62E-04 1.11E-09 Note 1

CB17.01 MCB-11-11-1 5.04E-06 2.82E-02 1.42E-07 Note 1 1.19E-05 6.01E-11 Note 1CB17.01_MCB-11-8-1 4.92E-07 8.76E-01 4.31E-07 Note 1 1.79E-02 8.80E-09 Note 1CB17.01 MCB-11-9-1 8.21E-07 9.48E-01 7.78E-07 Note 1 3.26E-02 2.67E-08 Note 1

CB17.01 MCB-12-10-1 8.21E-07 1.77E-01 1.45E-07 Note 1 6.62E-04 5.43E-10 Note 1CB17.01_MCB-12-11-1 1.67E-06 2.82E-02 4.71E-08 Note 1 1.19E-05 2.OOE-11 Note 1


CB17.01_MCB-12-9-1 4.92E-07 9.48E-01 4.66E-07 Note 1 3.26E-02 1.60E-08 Note 1

CB17.01_MCB-13-10-1 4.92E-07 1.77E-01 8.72E-08 Note 1 6.62E-04 3.26E-10 Note 1

CB17.01 MCB-13-11-1 8.21E-07 2.84E-02 2.33E-08 Note 1 1.20E-05 9.89E-12 Note 1CB17.01 MCB-13-12-1 1.67E-06 2.84E-02 4.76E-08 Note 1 1.20E-05 2.02E-11 Note 1CB17.01 MCB-13-13-1 5.04E-06 8.49E-03 4.27E-08 Note 1 3.58E-06 1.80E-11 Note 1


1AF 0LER UERýI~CB17.01 MCB-14-11-1 4.92E-07 2.84E-02 1.40E-08 Note 1 1.20E-05 5.93E-12 Note 1CB17.01 MCB-14-12-1 8.21E-07 2.84E-02 2.33E-08 Note 1 1.20E-05 9.89E-12 Note 1CB17.01 MCB-14-13-1 1.67E-06 8.49E-03 1.42E-08 Note 1 3.58E-06 5.99E-12 Note 1CB17.01 MCB-14-14-1 5.04E-06 8.49E-03 4.27E-08 Note 1 3.58E-06 1.80E-11 Note 1CB17.01_MCB-15-12-1 4.92E-07 2.84E-02 1.40E-08 Note 1 1.20E-05 5.93E-12 Note 1CB17.01_MCB-15-13-1 8.21E-07 8.49E-03 6.97E-09 Note 1 3.58E-06 2.94E-12 Note 1CB17.01_MCB-15-14-1 1.67E-06 8.49E-03 1.42E-08 Note 1 3.58E-06 5.99E-12 Note 1CB17.01_MCB-15-15-1 5.04E-06 7.58E-03 3.82E-08 Note 1 3.20E-06 1.61E-11 Note 1CB17.01_MCB-16-13-1 4.92E-07 8.49E-03 4.18E-09 Note 1 3.58E-06 1.76E-12 Note 1CB17.01 MCB-16-14-1 8.21E-07 8.49E-03 6.97E-09 Note 1 3.58E-06 2.94E-12 Note 1CB17.01_MCB-16-15-1 1.67E-06 7.58E-03 1.27E-08 Note 1 3.20E-06 5.35E-12 Note 1CB17.01 MCB-16-16-1 5.04E-06 7.58E-03 3.82E-08 Note 1 3.20E-06 1.61E-11 Note 1CB17.01 MCB-17-14-1 4.92E-07 8.49E-03 4.18E-09 Note 1 3.58E-06 1.76E-12 Note 1

CB17.01 MCB-17-15-1 8.21E-07 7.58E-03 6.22E-09 Note 1 3.20E-06 2.62E-12 Note 1CB17.01_MCB-17-16-1 1.67E-06 7.58E-03 1.27E-08 Note 1 3.20E-06 5.35E-12 Note 1CB17.01_MCB-17-17-1 5.04E-06 4.82E-03 2.43E-08 Note 1 2.03E-06 1.02E-11 Note 1CB17.01 MCB-18-15-1 4.92E-07 7.58E-03 3.73E-09 Note 1 3.20E-06 1.57E-12 Note 1CB17.01 MCB-18-16-1 8.21E-07 7.58E-03 6.22E-09 Note 1 3.20E-06 2.62E-12 Note 1CB17.01 MCB-18-17-1 1.67E-06 4.82E-03 8.08E-09 Note 1 2.03E-06 3.40E-12 Note 1CB17.01 MCB-18-18-1 5.04E-06 4.65E-03 2.34E-08 Note 1 1.96E-06 9.85E-12 Note 1CB17.01_MCB-2-1-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01 MCB-2-2-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01 MCB-3-1-1 1.67E-06 4.67E-03 7.82E-09 Note 1 1.97E-06 3.29E-12 Note 1CB17.01_MCB-3-2-1 1.67E-06 4.67E-03 7.82E-09 Note 1 1.97E-06 3.29E-12 Note 1CB17.01 MCB-3-3-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01_MCB-4-1-1 1.67E-06 4.67E-03 7.82E-09 Note 1 1.97E-06 3.29E-12 Note 1CB17.01_MCB-4-2-1 1.67E-06 4.67E-03 7.82E-09 Note 1 1.97E-06 3.29E-12 Note 1CB17.01_MCB-4-3-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01 MCB-4-4-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1

CB17.01 MCB-5-1-1 1.67E-06 4.67E-03 7.82E-09 Note 1 1.97E-06 3.29E-12 Note 1CB17.01 MCB-5-2-1 1.67E-06 4.67E-03 7.82E-09 Note 1 1.97E-06 3.29E-12 Note 1CB17.01 MCB-5-3-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01 MCB-5-4-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01 MCB-5-5-1 5.04E-06 4.67E-03 2.35E-08 Note 1 1.97E-06 9.90E-12 Note 1CB17.01_MCB-6-1-1 8.21E-07 1.04E-01 8.56E-08 Note 1 4.41E-05 3.62E-11 Note 1CB17.01 MCB-6-2-1 8.21E-07 1.04E-01 8.56E-08 Note 1 4.41E-05 3.62E-11 Note 1CB17.01 MCB-6-3-1 1.67E-06 1.04E-01 1.74E-07 Note 1 4.41E-05 7.38E-11 Note 1CB17.01_MCB-6-4-1 1.67E-06 1.04E-01 1.74E-07 Note 1 4.41E-05 7.38E-11 Note 1CB17.01_MCB-6-5-1 1.67E-06 1.04E-01 1.74E-07 Note 1 4.41E-05 7.38E-11 Note 1CB17.01_MCB-6-6-1 5.04E-06 1.04E-01 5.25E-07 Note 1 4.41E-05 2.22E-10 Note 1CB17.01_MCB-7-1-1 8.21E-07 1.04E-01 8.56E-08 Note 1 4.41E-05 3.62E-11 Note 1CB17.01_MCB-7-2-1 8.21E-07 1.04E-01 8.56E-08 Note 1 4.41E-05 3.62E-11 Note 1CB17.01_MCB-7-3-1 1.67E-06 1.04E-01 1.74E-07 Note 1 4.41E-05 7.38E-11 Note 1CB17.01_MCB-7-4-1 1.67E-06 1.04E-01 1.74E-07 Note 1 4.41E-05 7.38E-11 Note 1



¶- : Delta,' I Deltag~ ~Scnari**~~'~' ~ ~ 'ICCDP CDFCLERP LRF

CB17.01 MCB-7-6-1 5.04E-06 1.04E-01 5.25E-07 Note 1 4.41E-05 2.22E-10 Note 1CB17.01 MCB-7-7-1 5.04E-06 1.04E-01 5.25E-07 Note 1 4.41E-05 2.22E-10 Note 1CB17.01 MCB-8-1-1 4.92E-07 1.07E-01 5.25E-08 Note 1 1.53E-04 7.51E-11 Note 1CB17.01 MCB-8-2-1 4.92E-07 1.07E-01 5.25E-08 Note 1 1.53E-04 7.51E-11 Note 1CB17.01_MCB-8-3-1 8.21E-07 1.07E-01 8.77E-08 Note 1 1.53E-04 1.25E-10 Note 1CB17.01_MCB-8-4-1 8.21E-07 1.07E-01 8.77E-08 Note 1 1.53E-04 1.25E-10 Note 1CB17.01_MCB-8-5-1 8.21E-07 1.07E-01 8.77E-08 Note 1 1.53E-04 1.25E-10 Note 1CB17.01_MCB-8-6-1 8.21E-07 1.07E-01 8.77E-08 Note 1 1.53E-04 1.25E-10 Note 1CB17.01 MCB-8-7-1 1.67E-06 1.07E-01 1.79E-07 Note 1 1.53E-04 2.56E-10 Note 1CB17.01 MCB-8-8-1 5.04E-06 1.07E-01 5.38E-07 Note 1 1.53E-04 7.69E-10 Note 1CB17.01_MCB-9-3-1 4.92E-07 8.69E-01 4.27E-07 Note 1 1.70E-02 8.37E-09 Note 1CB17.01_MCB-9-4-1 4.92E-07 8.69E-01 4.27E-07 Note 1 1.70E-02 8.37E-09 Note 1CB17.01 MCB-9-5-1 4.92E-07 8.69E-01 4.27E-07 Note 1 1.70E-02 8.37E-09 Note 1CB17.01_MCB-9-6-1 8.21E-07 8.69E-01 7.13E-07 Note 1 1.70E-02 1.40E-08 Note 1CB17.01 MCB-9-7-1 8.21E-07 8.69E-01 7.13E-07 Note 1 1.70E-02 1.40E-08 Note 1CB17.01 MCB-9-8-1 1.67E-06 8.69E-01 1.45E-06 Note I 1.70E-02 2.85E-08 Note 1CB17.01 MCB-9-9-1 5.04E-06 9.44E-01. 4.75E-06 Note 1 3.14E-02 1.58E-07 Note 1

Note for Table 1: There are no VFDRs in the MCB scenarios so the baseline and compliantplant MCB scenarios are identical with no delta in CDF or LERF.

PRA RAI 68

In the Generic Fire Methodology report, the transient zone describes the zone of damagefrom the fixed or transient ignition source. According to page 12 of 73 of this report, thetransient zone bounds the effect of flame spread or propagation since an extended rangeof 4 feet beyond the transient zone boundaries was examined for PRA targets. Explainhow the transient zone boundary takes into account fire growth over time, or propagationinto adjacent transient zones via secondary combustible fires. Should the finding be thatthe 4 feet margin does not account adequately for these issues, the PRA should beupdated accordingly.

SCE&G Response

Transient zone boundaries are conservatively established by using walk down results andqualitative criteria, such as where separation between potential targets exists. The transientignition source is assumed to be located anywhere within the transient zone boundary, so alltargets within the boundary are assumed failed. In response to a peer review commentquestioning the adequacy of this strategy when the transient source is located on or near theboundary, a review of the transient fire zone of influence determined that 4 feet was a boundingdistance. Therefore, the target selection boundary was expanded to include all targets outside,but within 4 feet of, the transient zone boundary.

In practice, this results in an overlap in the boundaries of transient zone areas. The resultingoverlap ensures that scenarios postulated at or near a boundary would include nearby targets


that are actually within a different scenario area. The overlap distance of 4 ft is justified asfollows:

a. Considering the 98th percentile of a transient fire of approximately 317 kW, a damagecriterion for targets of approximately 6 kW/m 2, and a radiation fraction of 0.3, the radius r of thezone of influence based on flame radiation is estimated, using the methodology in Chapter 5,Section 5.3.1 of NUREG-1805, to be 1.1 m or 3.6 ft.

b. When a fixed ignition source is present in the transient zone area, there are two possibilitieswith regard to its location relative to the boundaries of the scenario area. First, the fixed ignitionsource may be completely within the boundaries and not near any of them (i.e., at least 4 ft fromthe boundaries). In this case, the separation from the boundary, and the fact that the space upto 4 ft from the boundaries has been examined to include nearby targets, bounds any need toassign targets outside the scenario area to fire scenarios that originate in the fixed ignitionsource. Second, a fixed ignition source may be located on or close to the boundary betweenadjacent scenario areas. This layout of scenario areas is particularly necessary in electricalrooms where electrical cabinets are targets themselves and must be accounted for in transientfire scenarios postulated on either side of the cabinets. In such cases, to capture all appropriatetargets in fire scenarios that originate in the fixed ignition source, the fixed ignition source isassigned to all of the applicable adjacent scenario areas.

When analyzing the worst case fire scenario in each fire zone, the propagation from the initialignition source to overhead cable trays is considered. As explained in Fire Modeling: GenericMethodology, DC0780B-001, the fire propagation model from cable tray to cable tray (35 degreeangle vertical propagation profile) as a function of time described in Appendix R of NUREG/CR6850 is implemented for determining the heat release rate generated by trays in a stackassuming an initial tray is on fire. This model is intended to account for horizontal flame spreadin fire durations on the order of the propagation times (i.e., 15 to 20 minutes). In responding tothis RAI, this method has been expanded so that propagation to adjacent transient zones isincluded.

To account for potential fire propagation beyond the 4-ft overlap and into the neighboringtransient zones, additional analysis was performed and is described in the following paragraphs.Based on walkdowns performed by plant personnel on March 4-6, 2013, and based on thereview of drawings for those transient zones unavailable for walkdowns, a list was compiled oftransient zones that contain cable trays that extend across the transient zone boundaries,which, if ignited, could result in fire spreading to adjacent transient zones. The results of thewalkdowns and drawing review are provided in Table 2.


Table 2: Walkdown and Drawing Review Results for Potential for Fire Propagation Across Transient Zone Boundaries

AB01.04 AB01.04-T1 One (1) cable tray from T1-T2 Walkdown

AB301.04 AB101.04-T10 Not Applicable Walkdown

AB01.04 AB01.04-T11 Not Applicable D- 214-073

AB01.04 AB01.04-T12 Not Applicable D- 214-073A1301.04 AB301.04-T13 Not Applicable D- 214-073

AB301.04 ABO1.04-T2 Four (4) Cable trays going from T2-T8 and Two (2) cable trays going from T2-T7 Walkdown

ABO1.04 AB101.04-T3 Not Applicable Walkdown

ABO1.04 ABO1.04-T4 Not Applicable Walkdown

AB301.04 ABO1.04-T5 Not Applicable Walkdown


AB301.04 AB101.04-T7 Two (2) cable trays going from T2-T7 and Two Cable trays going from T7-T9 Walkdown

AB301.04 ABO1.04-T8 Four (4) Cable Trays going from T2-T8 Walkdown

AB301.04 AB101.04-T9 Two (2) cable trays going from T7-T9 Walkdown

AB301.08.02 AB101.08.02-T1 At least 3 cable trays going from T2-T1 D-214-074

AB01.08.02 ABO1.08.02-T2 At least 3 cable trays going from T1-T2 D-214-074

AB01.08.02 ABO1.08.02-T3 One (1) cable tray going from T3-T4 D-214-074

AB301.08.02 ABO1.08.02-T4 Two (2) cable trays going from T3-T4 and Two (2) cable tray from T4-T5 D-214-074

AB301.08.02 ABO1.08.02-T5 Two (2) cable tray from T4-T5 D-214-074


AB301.09 ABO1.09-T2 Not Applicable D- 214-073


ABO1.09 AB101.09-T4 T3-T4 One cable tray D- 214-073



ABO1.10 ABO1 .10-T1 1 Not Applicable Walkdown



•..,• , .':•.i,!',•,;.l#•',:';,i•[:[•.k•.i . ..................... .... ... .... ... ... "....... .......... .. "CJ'mactet4r" Traffnsidbit~Zon . :Sk , WadonOrDrawingýAB01.10 AB01.10-T13 Two (2) Cable Trays from T13-T14 Walkdown

AB01.10 AB01.10-T14 Two (2) Cable Trays from T14-T13 Walkdown

ABO1.10 AB01.10-T15 One (1) cable tray from T15-T14 Walkdown


ABO1.10 AB01.10-T17 Not Applicable D-214-076



ABO1.10 ABOI.10-T4 Not Applicable Walkdown


AB301.10 ABO1.10-T6 Not Applicable D- 214-077




ABO1.17 AB01.17-T1 Not Applicable D- 214-077

ABO1.17 ABO1.17-T2 Not Applicable D- 214-077



ABO1.18.01 AB01.18.01-T1 Cable trays coming from T1-T5 ABO1.18.02 (not applicable: covered by multicompartment Walkdownanalysis)

ABO1.18.01 AB01.18.01-T10 Not Applicable Walkdown

ABO1.18.01 ABO1.18.01-T11 Not Applicable Walkdown



ABO1.18.01 ABO1.18.01-T3 Three (3) cable trays T4-T3 Walkdown


ABO1.18.01 ABOI.18.01-T5 Four (4) cable trays T5-T4 Walkdown




,o mnpa 6ent, Transient CZone - - comment=, -_-Wkdownr.OrDiawirg-ABO1.18.01 ABO1.18.01-T8 Not Applicable Walkdown



AB301.18.02 AB01.18.02-T10 Not Applicable Walkdown

AB301.18.02 ABO01.18.02-T1 1 T5-T1 1 one cable tray Walkdown

AB301.18.02 ABO1.18.02-T12 Not Applicable Walkdown



ABO 1.18.02 ABO01.1 8.02-T2 Not Applicable Walkdown

ABO1.18.02 ABO1.18.02-T3 T3-T11 Walkdown

ABO1.18.02 ABO1.18.02-T4 Three (3) cable trays from T5-T4 Walkdown

ABO1.18.02 ABO1.18.02-T5 Five (5) cable trays from T5-T7 Walkdown

AB301.18.02 AB101.18.02-T7 Five (5) cable trays from T5-T7 Walkdown

ABO1.18.02 AB01.18.02-T8 Six(6) T8-T9 Walkdown

AB01.18.02 ABO1.18.02-T9 Four (4) T9-T10 Walkdown

AB01.21.01 AB01.21.01-T1 Two (2) cable trays from T1-T2 Walkdown

ABO1.21.01 ABO1.21.01-T2 Two (2) cable trays from T2-T1 Walkdown

AB01.21.01 ABO1.21.01-T3 One (1) cable tray from T3-ABO1.21.02 T1 (not applicable: covered by multicompartment Walkdownanalysis)

AB01.21.02 AB01.21.02-T1 Eight (8) cable trays from T1- T3 Walkdown

AB01.21.02 AB01.21.02-TIO Not Applicable Walkdown

ABO1.21.02 AB01.21.02-T1 1 Eight (8) cable trays from T7- T1 1 and Three(3) going from Ti 1-T1 2 Walkdown

AB01.21.02 AB01.21.02-T12 Three(3) going from T12-T11 Walkdown

AB301.21.02 AB01.21.02-T1 3 Two (2) cable trays from T5-T1 3 Walkdown



AB301.21.02 ABO1.21.02-T2 Not Applicable Walkdown

AB301.21.02 ABO1.21.02-T3 Eight (8) cable trays from Ti- T3 and Eight (8) cable trays from T3-T5 Walkdown


m. p. . ..e...... .... .... Cor en, aiAB301.21.02 ABO1.21.02-T5 Eight (8) cable trays from T3-T5, Two (2) cable trays from T5-13, and Eight (8) cable trays Walkdown

from T5-T7AB301.21.02 ABO1.21.02-T6 Not Applicable WalkdownAB301.21.02 ABO1.21.02-T7 Eight cable trays from T5-T7 and Eight (8) cable trays from T7-T1 1 Walkdown

AB301.21.02 ABO1.21.02-T8 Not Applicable WalkdownABO1.29 AB01.29-T1 Two (2) cable trays from AB.01.21.02 (not applicable: covered by multicompartment WalkdownABO1.29 ABO1.29-T2 One (1) cable tray from T1 -T2 WalkdownA1301.29 AB01.29-T3 One (1) cable tray from T2-T3 WalkdownAB01R.29 AB101.29-T4 Two (2) cable trays from T3-T4 Walkdown

CB01.01 CB01.01-T1 Not Applicable D-214-041CB01.01 CB01.01-T2 Not Applicable D-214-041

CB01.01 CB01.01-T3 Approximately 2 cable trays from T3-T4 and One cable tray from T3-T6 D-214-041CB01.01 CB101.01-T4 Six (6) cable trays from T4-T5 D-214-041

C101.01 CB01.01-T5 Six (6) cable trays from T4-T5 and Approximately 5 cable trays going from T5- CB02 T1 D-214-041(not applicable: covered by multicompartment analysis)

CB301.01 CB01.01-T6 One (1) cable tray from T4-T6 and Approximately 8 cable trays going from T6- CB02 (not D-214-041applicable: covered by multicompartment analysis)

CB02 CB02-TI One (1) cable trays from T1-T2 and Three (3) cable trays from CB02 T1 - CB05 T1 (not D-214-046applicable: covered by multicompartment analysis)

CB02 CB02-T2 Four cable trays from T1-T2 D-214-046CB02 CB02-T3 Not Applicable D-214-046CB04 CB04-TIO Approximately Seventeen (17) cable trays from T9-T10 WalkdownCB04 CB04-Ti 1 Seven (7) cable trays from T1 0-T1i1 WalkdownCB04 CB04-T12 Four (4) cable trays from T3-T12 WalkdownCB04 CB04-T13 Five (5) cable trays from T3-T13 Walkdown

CB04 CB04-T3 Five (5) cable trays from T3-T13 and One (1) from T3-T12 Walkdown

CB04 CB04-T5 Six (6) cable trays from T5-T6 WalkdownCB04 CB04-T6 Six (6) cable trays from T6-T5 WalkdownCB04 CB04-T7 Thirteen (13) cable trays from T7-T8 Walkdown


Mompartinent !rarns ... n Walk-

CB04 CB04-T8 Thirteen (13) cable trays from T8-T7 Walkdown

CB04 CB04-T9 Seventeen (17) cable trays from T9-T1 0 Walkdown

CB05 CB05-Ti Three (3) cable trays from CB02 T1 - CB05 T1 (not applicable: covered by D-214-046multicompartment analysis)CB05 CB05-T2 Not Applicable D-214-046

CB05 CB05-T3 Not Applicable D-214-046CB17.01 CB17.01-T1 Not Applicable D-214-050

CB20 CB20-Ti Three (3) cable trays from T1-T2 D-214-050

CB20 CB20-T2 Three (3) cable trays from TI-T2 and Four (4) cable trays from T2-T3 walkdown

CB20 CB20-T3 Four (4) cable trays from T2-T3 and Two (2) cable trays from T3-T4 walkdown

CB20 CB20-T4 Two (2) cable trays from T3-T4 walkdown

IB20 IB20-Tl One (1) cable tray from T8-T1 D-214-135

IB20 IB20-TlO Four (4) cable trays from T10-T9 D-214-135

IB20 IB20-Tl 1 One (1) cable tray from Ti1-10 D-214-135

IB20 1120-T2 Two (2) cable trays from T2-T3 D-214-135

IB20 11B20-T3 Four (4) cable trays from T4-T3 D-214-135

IB20 1120-T4 Four (4) cable trays from T9-T4 D-214-135

IB20 1120-T5 One (1) cable tray from T5-T4 and One (1) cable tray from T8-T4 D-214-135

IB20 1120-T8 Four (4) cable trays from T9-T8 and One (1) cable tray from T8-T1 D-214-135

IB20 1120-T9 Four (4) cable trays from T9-T4 and Four (4) cable trays from T10-T9 D-214-135

IB21.01 IB21.01-Ti Three (3) cable trays from T1-T6 Walkdown

1121.01 IB21.01-T2 One (1) cable tray from T2-T7 Walkdown

IB21.01 1121.01-T3 One (1) cable tray from T3-T7 Walkdown

1121.01 1121.01-T4 Not Applicable Walkdown

1121.01 1121.01-T5 Approximately Seven (7) cable trays from T6-T5 Walkdown

1R21.01 1121.01-T6 Approximately Seven (7) cable trays from T6-T5 and Three (3) cable trays from T1-T6 Walkdown

1121.01 1R21.01-T7 One cable tray from T3-T7 and One cable tray from T2-T7 Walkdown

1R21.01 IB21.01-T8 Not Applicable Walkdown

1125.01.02 IB25.01.02-TI Seven (7) cable trays from T2-T1 Walkdown


oi...Com a0t enf ransientone mmnt , WaIkdown•D raýwihj".,1125.01.02 1125.01.02-T2 Eight (8) cable trays from T3-T2 Walkdown1125.01.02 IB25.01.02-T3 Four (4) cable trays from T4-T3 and Four (1) cables trays from T3-T6 Walkdown1125.01.02 1125.01.02-T4 Four (4) cable trays from T4-T3 and One (1) cable tray from T4-T7 Walkdown1B25.01.02 1125.01.02-T5 Five (5) cable trays from T5-T6 Walkdown1B25.011.02 1825.01.02-T6 Five (5) cable trays from T5-T6 Walkdown1125.01.02 IB25.01.02-T7 Four (4) cable trays from T6-T7 and One (1) cable tray from T4-T7 Walkdown1125.01.02 IB25.01.02-T8 Four (4) cable trays from T5-T8 Walkdown1125.01.03 IB25.01.03-Ti Three (3) cable trays from T2-TI Walkdown1125.01.03 1125.01.03-T2 Three (3) cable trays from T2-T1 and Three (3) cable trays from T2-T4 Walkdown

1125.01.03 IB25.01.03-T3 Not Applicable Walkdown1125.01.03 IB25.01.03-T4 Three (3) cable trays from T4-T2 Walkdown1125.01.03 1825.01.03-T5 Not Applicable Walkdown

IB25.011.03 IB25.01.03-T6 One (1) cable tray from T4-T6 Walkdown1125.01.05 IB25.01.05-Ti Four (4) cable trays from 1B25.1.3 TI- 1125.1.2 T7 (not applicable: covered by Walkdown

multicompartment analysis)1125.01.05 IB25.01.05-T2 Not Applicable Walkdown1125.01.05 1125.01.05-T3 One (1) cable tray from T3- 1125.1.2 T4 (not applicable: covered by multicompartment Walkdown1125.01.05 1825.01.05-T4 Not Applicable Walkdown1125.01.05 IB25.01.05-T5 Five (5) cable trays from T5-T3 Walkdown1125.06.02 IB25.06.02-Ti Not Applicable WalkdownT101.01 TB01,01-T1 Nine (9) cable trays T2-T1 and Eight (8) cable trays from T1-T5 Walkdown

TBO1.01 TB01.01-T10 Six (6) cable trays from T12-T10 and Two (2) cable trays from T1 0-13 and Six (6) cable Walkdowntrays from T2-T10

TBO1.01 TB01.01-T1 1 Four (4) cable trays from T11 -T13 WalkdownTB01.01 TB01.01-T12 Six (6) cable trays from T12-T10 WalkdownTB301.01 TB01.01-T13 Two (2) cable trays from T10-13 and Four (4) cable trays from T11 -T13 WalkdownTBO1.01 TB01.01-T14 Ten (10) cable trays T9-T14 WalkdownTB301.01 TB01.01-T2 Six (6) cable trays from T2-T10 and Nine (9) cable trays T2-T1 WalkdownTB301.01 TB101.01-T4 Not Applicable Walkdown


Wa~d~dn O~DrWingTB01.01 TBO1.01-T5 Eight (8) cable trays from T1-T5 Walkdown

TBO1.01 TBO1.01-T7 Not Applicable Walkdown

TBO1.01 TBO1.01-T9 Ten (10) cable trays T9-T14 Walkdown

TBO1.02 TB01.02-T1 Ten (10) cable trays T1-T2 Walkdown

TB01.02 TB01.02-Ti0 Four (4) cable trays from T9-T10 and Four (4) cable trays from T1 0-T11 Walkdown

TBO1.02 TBO1.02-T1 1 Four (4) cable trays from T1 0-Ti 1 and Four (4) cable trays from T1 2-T11 Walkdown

TBO1.02 TB01.02-T12 Four (4) cable trays from T1 2-T11 Walkdown

TBO1.02 TBO1.02-T2 Ten (10) cable trays from T1-T2 Walkdown

TBO1.02 TB01.02-T3 Not Applicable Walkdown

TBO1.02 TBO1.02-T7 Five (5) cable trays from T7-T9 Walkdown

TBO1.02 TBO1.02-T8 Eight (8) cable trays from TI-T8 Walkdown

TBO1.02 TBO1.02-T9 Five (5) cable trays from T7-T9 Walkdown

TB02 TB02-T I Four (4) cable trays from T1-T2 and Four (4) cable trays from T1-T3 Walkdown

TB02 TB02-T2 Four (4) cable trays from T1-T2 and Five (5) cable trays from T2-T3 Walkdown

TB02 TB02-T3 Four (4) cable trays from T1-T3 and Five (5) cable trays from T2-T3 Walkdown


Based on Table 2 results, a matrix of all applicable exposing and exposed transient zonescombinations was compiled. These scenarios do not include fire zones in which a hot gas layerscenario is postulated. In fire zones where a hot gas layer is already postulated, propagation toadjacent transient zones is not necessary because the hot gas layer scenario occurs at timesshorter than propagation to adjacent transient zones and consists of damage to the full firezone. The list of scenarios was separated based on ungrouped and grouped exposing transientzones to facilitate the analysis. An ungrouped transient zone is one in which detailed firemodeling is applied and separate fire scenarios are postulated for all the fixed and transientignition sources within the transient zone. A grouped transient zone is one in which all the fixedand transient ignition sources are failed completely at time zero.

Starting with the ungrouped transient zones, a total of 170 new scenarios were added to theFire PRA model. The new scenarios are intended to capture fires that fail the transient zone,and subsequently propagate to adjacent transient zones. Table 3 lists the new scenarios addedto the model for the ungrouped scenarios. The table includes the following information: the firezone where the scenario is postulated; the ignition source ID; a description for the ignitionsource; the equipment type, which is a mapping to the generic ignition frequency model;equipment type description; and a scenario progression number. The scenario progressionnumber indicates the sequence in which the scenario is postulated. A scenario progressionvalue of 2 indicates that this new scenario propagating to adjacent transient zones is the secondin the progression, where the first scenario is damage to the transient zone of fire origin. Ascenario progression value of 3 indicates that this new scenario that is propagating to adjacenttransient zones is the third in the progression, where the first scenario is damage to the ignitionsource and immediate cable trays above, and the second scenario is damage to the transientzone of fire origin. These scenarios were quantified for fire ignition frequency, core damagefrequency (CDF) and large early release frequency (LERF). The resulting risk values are notamong the top contributors in the plant, and do not impact current compliance with theperformance criteria.

Table 3: New Scenarios Added to the Fire PRA Model for Ungrouped Transient Zones

Fire Zone :Equipment IDD Equipment Description Equpment. EquiSenariypeo.-,Type- b escrip ion cnal

ABOl .21.02 AB3l .21.02-Ti Transient fire #1 postulated at TRCAR Transients 2floor level.AB.• .'..-....l ,.• 2 .02 • AB . t,• •J_--.."•.i,..-t:: • " -: =.. . . . •:l =., ..21 0 - i r n.-ie :"'. .: .,•• - -. " 2..g:•••••• ,.

A1012102A1012102T1 Transient fire #1 postulated at TRWCAR weldng/cutings-floor level.wedn/utg

AB301.21.02 ABO1.21.02-T3 Transient fire #3 postulated at TRCAR Transients 2floor level.AB301.21.02 ABO1.21.02-T3 Transient fire #3 postulated at TRWCAR Trans. fires - 2

floor level. welding/cutting

A301.21.02 AB01.21.02-T3 Transient fire #3 postulated at TRCAR Transients 2floor level.

AB01 .21.02 AB01 .21 .02-T5 Transient fire #5 postulated at TRCAR Transients 2floor level.


ID~ ~quipiment. E entTyploe Equipm~ent ID Equipm'enft'Description- uipmen Tp scenario

TypeA Description,0

AB01.21.02 AB01.21.02-T5 Transient fire #5 postulated at TRWCAR Trans. fires - 2floor level. welding/cutting

AB01.21.02 APN9014 RECEPTACEL PANEL 14 EC Electrical cabinets 2

ABO1.21.02 XAH0033 AUX BLDG MCC-SWGR AIR Ventilation 2HANDLING UNIT Subsystems

ELEC H2 RECOMBINERAB01.21.02 'XPN0049A POWER SUPPLY PANEL EC Electrical cabinets 2

AB01.21.02 XPNO050A ELEC H2 RECOMBINER EC Electrical cabinets 2CONTROL PANEL

POST ACCIDENT H2AB01.21.02 XPN7258A ANALYZER REMOTE PNLA EC Electrical cabinets 2

CONTAINMENTABO1.21.02 XPN7268A AMTOSPHERE SAMPLING EC Electrical cabinets 2

PANEL

ABO1.21.02 XPN98-FS PRE-ACTION SPRINKLER EC Electrical cabinets 2SYSTEM

AB01.21.02 XTF9014 Transformer PX Transformers 2

AB01.21.02 XXS0061-PS VENTED BOX WITH CABLES EC Electrical cabinets 2

CB01.01 CB01.01-T3 Transient fire (postulated at TRCAR Transients 2floor level) #3

CB01.01 CB01.01-T3 Transient fire (postulated at TRWCAR Trans. fires - 2floor level) #3 welding/cutting





CB01.01 CB01.01-T6 Transient fire (postulated at TRCAR Transients 2floor level)

CB01.01 CB01.01-T6 Transient fire (postulated at TRWCAR Trans. fires - 2floor level) I welding/cutting

CB02 CB02-T1 Transient fire # 1 postulated at TRCAR Transients 2floor level.


vEquipment ~-'Equipm~ent TypeFire Zone Equipment ID~2 ý ,Equiprnent Description -> Sc6enario2.... ...... ... = " - . •. Desc_ ription3tt

CB02 CB02-Tl Transient fire # 1 postulated at TRWCAR Trans. fires - 2floor level. welding/cutting

CB04 CB04-TlO Scenario area for transient TRCAR Transients 2combustible fires, etc.

CB04 CB04-Tl 0 Scenario area for transient TRWCAR Trans. fires - 2combustible fires, etc. welding/cutting

CB04 CB04-T 1I Scenario area for transient TRCAR Transients 2combustible fires, etc.

CR04 CB04-Ti I Scenario area for transient TRWCAR Trans. fires - 2combustible fires, etc. welding/cutting

CB04 CB04-T12 Scenario area for transient TRCAR Transients 2combustible fires, etc.

CR04 CRO4-T12 Scenario area for transient TRWCAR Trans. fires - 2combustible fires, etc. welding/cutting


CR04 CB04-Tl3 Scenario area for transient TRWCAR Trans. fires - 2combustible fires, etc. welding/cutting


CR04 CRO4-T8 Scenario area for transient TRWCAR Trans. fires - 2combustible fires, etc. welding/cutting

IB21.01 IB21.01-T1 Transient fire # 1 postulated at TRPW Transients 2floor level.

11321.0 11R2i.01-Ti Transient fire # 1 postulated at TRWPW Trans. fires - 2floor level. welding/cutting

121.011 XCA0001A XCAiA-CR - XCA000iA S.S. EC Electrical cabinets 2POWER CABINET 1AC

1121.01 XCA0001B XCA1B-CR EC Electrical cabinets 2

IR211.01 XCA0002A XCA2A-CR EC Electrical cabinets 2

IB21.01 XCA0002B XCA2B-CR EC Electrical cabinets 2

XCA0004 DC HOLD CAB1121.01 XCA0004 (INCLUDING P/A EC Electrical cabinets 2

CONVERTER)

1121.01 XCA001 1 XCA0011 EC Electrical cabinets 2


SEquipment EqimntTpDypecriptiptin

1121.01 XCLOO03 XCL3CR EC Electrical cabinets 2

1121.01 XXS0047-PS VENTED BOX WITH CABLES EC Electrical cabinets 2

11325.01.02 APN4011 IB WELD. RECEPT. 480/277 EC Electrical cabinets 3DIST PANEL

1B25.01.02 APN8033 LIGHTING PANEL EC Electrical cabinets 2

1125.01.02 APN8035A LIGHTING PANEL EC- Electrical cabinets 3

1B25.01.02 APN8036B LIGHTING PANEL EC Electrical cabinets 3

1125.01.02 APN9008 RECEPTACLE PANEL 8 EC Electrical cabinets 2

1125.01.02 DPN1HX DPN-1HX-ED EC, Electrical cabinets 3

1825.01.02 IB25.01.02-T2 Scenario area for transient TRPW Transients 2combustible fires, etc.

1125.01.02 IB25.01.02-T2 Scenario area for transient TRWPW Trans. fires - 2combustible fires, etc. welding/cutting


1125.01.02 IB25.01.02-T3 Scenario area for transient TRWPW Trans. fires - 2combustible fires, etc. welding/cutting


Scenario area for transient TRWPW Trans. fires -combustible fires, etc. welding/cutting

IB25.01.02 IB25.01.02-T5 Transient fire (postulated at TRPW Transients 2floor level)

IB25.01.02 IB25.01.02-T5 Transient fire (postulated at TRWPW Trans. fires - 2floor level) welding/cutting


825.01.02 11825.01 .02-T6 Scenario area for transient TRWPW Trans. fires - 2combustible fires, etc. welding/cutting


1325.011.02 1825.01.02T7 Scenario area for transient TRWPW Trans. fires - 2combustible fires, etc. welding/cutting


Equipent., arean foTtrnsenFire Zone qimn ID Equipmen uint DesEquipment T Se.cenario

Equimen DesripionType esrptioh

1B25.01.02 IB25.01.02-T8 Scenario area for transient TRPW Transients 2combustible fires, etc.1825.01 .02-T8 Scenario area for transient TRWPW Trans. fires -

combustible fires, etc. welding/cutting

1125.01.02 XBC1X BATTERY CHARGER 1X BC Battery Chargers 3

IB25.01.02 XBC1X-2X BATTERY CHARGER 1X-2X BC Battery Chargers 3

825.01 .02 XPPOO001 B COMPONENT COOLING PMP Pumps 2PUMP B

11325.01.02 XPPOO001B COMPONENT COOLING Fire with 100% ofPUMP B Oil

825.01.02 XPPOO001 B COMPONENT COOLING Z02 Fire with 10% of 2PUMP B Oil

11325.01.02 XPPOO45B SERVICE WATER BOOSTER PMP Pumps 2PUMP B

11325.01.02 XPPO45B SERVICE WATER BOOSTER Fire with 100% ofPUMP B Oil

825.01 .02 XPPOO45B SERVICE WATER BOOSTER Z02 Fire with 10% of 2

PUMP B Oil

COMPONENT COOLINGIB25.01.02 XPP0058A BOOSTER PUMP A ZOl Fire with 100% of 3

XPP0058A-CCCOMPONENT COOLING Fire with 10% of

1B25.01.02 XPP0058A BOOSTER PUMP A Z02 OilXPP0058A-CC Oil

IB25.01.02 XPP0058B COMP COOLING BOOSTER ZO1 Fire with 100% of 3PUMP B XPP0058B-CC Oil

1825.01.02 XPPOO58B COMP COOLING BOOSTER Z02 Fire with 10% of 2PUMP B XPP0058B-CC Oil

18325.01.02 XPPOO58C COMPONENT COOLING PMP Pumps 2BOOSTER PUMP C

1825.01.02 XPPOO58C COMPONENT COOLING Fire with 100% ofBOOSTER PUMP C Oil

1825.01.02 XPPOO58C COMPONENT COOLING Z02 Fire with 10% of 2BOOSTER PUMP C Oil

IB25.01.02 XXS-0054-PS VENTED BOX WITH CABLES EC Electrical cabinets 3

IB25.01.03 10451 Cooling Unit Fans VSS Ventilation 2____ ___ __ ____ ___ ___ ____________________Subsystems


eEquipmentA~r6 Zo n ev..EquipmenitID Equiipment DescriTtpen

1825.01.03 1825.01 .03-T6 Scenario area for transient TRPWcombustible fires, etc.

11325.01.03 IB25.01.03-T6 Seaiarafrtnsnt TRWPWcombustible fires, etc.

11325.1.03 XN0044 CHILLER WATER TANK & EPUMP CONTROL PANEL

11325.01.03 XPN5121 LCNT A FRECXPP0102A&B

B25.01.03 XPN5554 DC SYS TR X GND DET& UV ECRELAY PNL

1125.01.03 XTF9008-EM TRANSFORMER PX

T13O1.01 RML001 1 WI BACKWASH EFFLUENT ECRAD MONITOR

TB01.01 TB01.01-T1 Transient fire # 1 postulated at TRTBfloor level.

TB101.01 TB01.01-T1 Transient fire # 1 postulated at TRWTBfloor level.

TB101.01 TB01.01-T5 Transient fire # 5 postulated at TRTBfloor level.

TB01.01 TBO1.01-T5 Transient fire # 5 postulated at TRWTBfloor level.

TB01.01 xdr0004A Instrument Air Dryer EC

TROl 01 XPNO051A CONDENSATE PUMP DRIVE ECCONTROL PANEL A

T13O1.01 XPNO051 B CONDENSATE PUMP DRIVE ECCONTROL PANEL B

TBO1.01 XPNO051 C CONDENSATE PUMP DRIVE ECCONTROL PANEL C

T1301.01 XPNO091 IAM MOUNTING PANEL FOR ECCB PRE-ACTION SYS

TB01.01 XPNO130 SIMPLEX 4100 UT TB-2 EC

TBO1.01 XPNO208 STATOR LEAK MONITORING EGSYS PANEL

TBO1.01 XPN5143 LOC CONTR STAT FOR ECXPP0042B

TBOI.01 XPN5144 LOC CONTR STAT FOR ECXPP0042C


.Fire Zone~ '.' q`0 m$' t1,Equipmentlecr o

TB01.01 XPN5171 LOC CONTR STA

TBO1.01 XPN7201 XPN 7201 Hydrogen & StatorCooling Water Control Panel

WI BACKWASH TRANSFERTB01.01 XPP0153APU APUMP A

WI BACKWASH TRANSFERTB01.01 XPP0153B PMPUMP B

WI LINER TRANSFER PUMPTB01.01 XPP0168AAA

TBO1.01 XPP0168B WI LINER TRANSFER PUMPB

GEN BKR CLOSED CYCLECLG BOOSTER PUMP A

GEN BKR CLOSED CYCLECLG BOOSTER PUMP B

MAIN SEAL OIL PUMPTB.01 XPT0001-PPXPT0001-PP

MAIN SEAL OIL PUMPTB01.01 XPTO00OI-PP1XTO1-PXPT0001-PP1

MAIN SEAL OIL PUMPTB01.01 XPT0001-PP1XTO1-P

XPT0001-PP1

TBO1.01 XPT0001-PP2 Seal Oil Recirculation Pump

TB01.01 XPT0001-PP2 Seal Oil Recirculation Pump

T1301.01 XPT0001-PP2 Seal Oil Recirculation Pump

EMERGENCY SEAL OILTB01.01 XPT001-PP3XPT001-PP3

TBO1.01 XPT0001-PP3 EMERGENCY SEAL OIL

PUMP XPT0001-PP3

EMERGENCY SEAL OIL

TB01 .01 XPT0001-PPMPPT30 -PPUMP XPT0001-PP3

TB01.01 XPT0001-PP4 SEAL OIL VACUUM PUMP




,•r o-e, *q••re Zoe Euipment I D , 50.u.pmyn Desc'riptio . "qui' ent.. -o.Type.D escrip tionTy e io -,.

TBO1.01 XPT0002-PP1

TBO1.01

TBO1.01

TBO1.01

T1301.01

TBO1.01

TBO1.01

TBO1.02

TBO1.02

TBO1.02

TB01.02

T1301.02

TBO1.02

TBO1.02

TBO1.02

TB01.02

TB01 .02

X1

x

x

x

x

x

-1

PT0002-PP1

PT0002-PP1

PT0002-PP2

PT0002-PP2

PT0002-PP2

XSX0004

APN4015

APN5016

TB01.02-T1

TB01.02-T1

TBO1.02-T7

TBO1.02-T7

TBO1.02-T8

TBO1.02-T8

XBDO005

XEX0002

-X0002-PPT1

STATOR COOLING PUMP A



STATOR COOLING PUMP B



STARTER FOR MAIN TURBEMER SEAL OIL PUMP-

VENTED BOX

TURBINE BLDG 480/277 VACDIST PANEL

TURBINE BLDG 208/120 VACDIST PANEL

Transient fire # 1 postulated atfloor level.

Transient fire # 1 postulated atfloor level.

Transient fire # 7 postulated atfloor level

Transient fire # 7 postulated atfloor level

Transient fire (postulated atfloor level)

Transient fire (postulated atfloor level)

Gen ISO Phone Duct Fans

ALTERREXEXCITER/REGULATOR

CUBICAL

VOLT REGULATOR PWR POTXFMR PPT-1

- - ~.PMP

zol

Z02

PMP

ZO1

Z02

EC

EC

EC

TRTB

TRWTB

TRTB

TRWTB

TRTB

TRWTB

VSS

EC

PX

i

Pumps

Fire with 100% ofOil

Fire with 10% ofOil

Pumps

Fire with 100% ofOil

Fire with 10% ofOil

Electrical cabinets

i

2

-4-

Electrical cabinets

-4

2

2

2

2

2

-4

I IL

Electrical cabinets

Transients

Trans. fires -welding/cutting

Transients


Transients


VentilationSubsystems

Electrical cabinets

Transformers(Oil/dry)

-4------

4-

-1-- i4

TBO1.02 XE 2

TBO1.02 XEXOOO2-PPT2 VOLT REGULATOR PWR POT Transformers 2XFMR PPT-2 (Oil/dry)


Fire Zone1 Eqim~ ID~E upent Dbescripion'uimtTp Scenari'!Type bDescription-

TBO1.02 XFN0088A GENERATOR NEUTRAL Ventilation 2COOLING FAN A Subsystems

TB31.02 XFN0088B GENERATOR NEUTRAL Ventilation 2

COOLING FAN B Subsystems

MCC - XMCBIYTURBINETB01.02 XMC1B1Y BLDG MOTOR CONTROL EC Electrical cabinets 2

CENTER 1BIY

TBO1.02 XPNO087 Control Panel XPN-87 WI EC Electrical cabinets 2(large walk-in)

CONDENSATE POLISHERTBO1.02 XPN5437 DEWATERPNGICNTR EC Electrical cabinets 2DEWATERING CNTRL PNL

GENERATOR WINDINGTBO1.02 XPN7276 TEMERATUR SCNNE EC Electrical cabinets 2TEMPERATURE SCANNER

TBO1.02 XPP0151A WI DEMINERALIZER A PMP Pumps 2HOLDING PUMP

T101.02 XPP0151A WI DEMINERALIZER A Fire with 100% of 2HOLDING PUMP Oil

TBO1.02 XPP0151A WI DEMINERALIZER A Z02 Fire with 10% of 2HOLDING PUMP Oil

TBO1.02 XPP0151B WI DEMINERALIZER B PMP Pumps 2HOLDING PUMP

TBO1.02 XPP0151B WI DEMINERALIZER B Fire with 100% of 2HOLDING PUMP Oil

TBO1.02 XPP0151B WI DEMINERALIZER B Z02 Fire with 10% of 2HOLDING PUMP Oil

TBO1.02 XPP0151C WI DEMINERALIZER C PMP Pumps 2HOLDING PUMP

TB31.02 XPP0151C WI DEMINERALIZER C Fire with 100% of 2HOLDING PUMP Oil

TBO1.02 XPP0151C WI DEMINERALIZER C Z02 Fire with 10% of 2HOLDING PUMP Oil

TBO1.02 XPP0152 WI PRECOAT TRANSFER PMP Pumps 2PUMP

TBO1.02 XPP0152 WI PRECOAT TRANSFER Fire with 100% of 2PUMP Oil

T131.02 XPP0152 WI PRECOAT TRANSFER Z02 Fire with 10% of 2PUMP Oil

T13O1.02 XPP0167 WI SPENT RESIN LINER PMP PumpsDEWATERING PUMP


F ir Z o ne.•. .... ;, E q u ipm.en..:iE q u ip m en t "T-p e..*

FrZoe Eq ,uip ment ID~ Equipment Description Eqimn qipetTp c e n ario-*-~Tp D ' ~ escription

TB101.02 XSR0007 Sodium Analyzer Rack EC Electrical cabinets 2

TB01.02 XSR0008 FILTER/DEMINX SODIUM EC Electrical cabinets 2SAMPLING RACK

TB01.02 XSW1A1 939 KVA RUNNING LOAD EC Electrical cabinets 2

TB01.02 XSW1A1 939 KVA RUNNING LOAD LVHEAF Low voltage 2HEAF

TB01.02 XTF01A1 TRANSFORMER,1OKVA,XSW HVHEAF High voltage 2WA1 HEAF

TB01.02 XTF01A1 TRANSFORMER,1OKVA,XSW PX Transformers 2WA1 (Oil/dry)

TB01.02 XTF1A1 TRANSFORMER XTF1A1-ES HVHEAF High voltage 2HEAF

TransformersTB101.02 XTF1A1 TRANSFORMER XTF1A1-ES PX TOil/dry) 2

(Oil/dry)TB01.02 XTF5016 TRANSFORMER PX Transformers 2

(Oil/dry)

TB01 .02 XTF9043-TI TRANSFORMER Trnsomes2_____ ____ ____ _____ _ __ _____ ____ _____ ____(Oil/dry) _ _ _ _ _


For the grouped transient zones, in which all the fixed and transient ignition sources are failedcompletely at time zero, a slightly different analysis is necessary from the preceding analysis,which involves ungrouped transient zones only. Since grouped transient zones do not haveseparate fire scenarios for each ignition source, adding scenarios to the Fire Modeling Databaseis not readily accomplished. Therefore, for the grouped transient zones, the matrix of exposedand exposing transient zones is used to identify risk contributing transient zone combinations.The CDF for all the scenarios with propagation are calculated and summed and are comparedto the CDF of the scenarios in which propagation was not included.

The scenarios for which walkdowns show that cable trays extend across transient zoneboundaries for grouped transient zones are provided in Table 4. For each scenario, the coredamage frequency (CDF) was calculated as follows:

CDF = IGF x (PNs x CCDPWith prop + (1-PNS) x CCDPno prop)

where IGF is the ignition frequency for the exposing transient zone as a whole, which is acombination of all ignition sources (i.e., transient and fixed ignition sources) within that transientzone; PNS is the nonsuppression probability, calculated with the equation exp(-At), where t istime to damage and A is a suppression curve constant, which varies for different types of fires,as discussed in Supplement 1 of NUREG/CR-6850. CCDPWith prop is the conditional coredamage probability for the scenario in which all the targets in both transient zones (i.e. exposingand exposed transient zones) are damaged, calculated with the Fire PRA model; CCDPno prop isthe conditional core damage probability for the scenario in which the fire does not spread to theadjacent transient zone and only the targets in the exposing transient zone are damaged. Forthose exposing transient zones, such as ABO1.21.02-T1 1, which are paired with more than oneexposing transient zone, the CCDP for the highest scenario was used for CCDPWith prop in thecalculation. The time to damage was calculated to be 67 minutes, based on the flame spreadrate of 0.059 ft/min (0.3 mm/s) for thermoset cables recommended in NUREG/CR-701 0 and thedistance of 4 ft that the fire would need to propagate through the overlap cable trays to reachtargets in the adjacent transient zone. The suppression curve constant, A, in the PNS equation,varies with the type of fire and was conservatively taken to be the highest value for any of theignition sources in the exposing transient zone. A minimum PNS value of 0.001 was used, asrecommended in Supplement 1 to NUREG/CR-6850. In some cases, PNS was set equal to 1.0because the CCDPwith prop was the same or only slightly larger than CCDPno prop., suggesting thatno new targets would be impacted by a propagating fire into the adjacent transient zone. Thetotal CDF values are listed in Table 4. The last column in Table 4 gives the CDF alreadyincluded in the Fire PRA quantification. The totals are summed at the bottom of Table 4. Theresults show that the additional CDF contribution by including the propagation between transientzones due to grouped transient zones is 1.4E-06, which does not affect the compliance limits forCDF, LERF, or delta values. The Generic Methodology calculation, DC0780B-001 will beupdated to reflect this analysis.


Table 4: CDF for Grouped Transient Zones with Potential for Propagation to Adjacent Transient Zones

,SenrioAI E .iposinig', C.CDPb _ VCP vvithBaeae bD -N Totalg P'; • : .... 6•p-r' ...... D'

ABO1.04-T1 -TO-ABO1.04-T2 2.12E-05 0.001 2.02E-08 1.28E-03 2.76E-1 1 4.28E-13

ABO1.04-T2-TO-ABO1.04-Ti 1.90E-04 0.001 1.28E-03 1.28E-03 2.43E-07 2.43E-07

ABO1.04-T2-TO-ABO1.04-T7 1.90E-04 0.001 1.28E-03 1.28E-03 Note 1 Note 1

ABO1.04-T2-TO-ABO1.04-T8 1.90E-04 0.001 1.28E-03 1.28E-03 Note 1 Note 1

ABO1.04-T7-TO-ABO1.04-T2 5.21 E-05 0.001 2.02E-08 1.28E-03 7.28E-1 1 1.05E-12

ABO1.04-T7-TO-ABO1.04-T9 5.21 E-05 0.001 2.02E-08 2.21 E-05 Note 1 Note 1

ABO1.04-T8-TO-ABO1.04-T2 2.45E-04 0.001 7.64E-05 1.28E-03 1.90E-08 1.87E-08

ABO1.04-T9-TO-ABO1.04-T7 1.14E-04 1 2.21 E-05 2.21E-05 2.52E-09 2.52E-09

ABO1.08.02-T1 -TO-ABO1.08.02-T2 6.61 E-06 0.001 2.95E-07 1.28E-03 1.04E-11 1.95E-12

ABO1.08.02-T2-TO-ABO1.08.02-T1 1.11E-05 0.001 1.28E-03 1.28E-03 1.42E-08 1.42E-08

ABO1.08.02-T3-TO-ABO1.08.02-T4 8.69E-06 0.001 1.28E-03 1.28E-03 1.11 E-08 1.11 E-08


ABO1.08.02-T4-TO-ABO1.08.02-T5 1.20E-05 1 1.28E-03 1.28E-03 Note 1 Note 1

ABO1.08.02-T5-TO-ABO1.08.02-T4 1.02E-05 0.001 5.46E-07 1.28E-03 1.86E-1 1 5.57E-12



ABO1.10-T13-TO-ABO1.10-T14 3.24E-04 1 2.72E-06 2.72E-06 8.81E-10 8.81E-10

ABO1.10-T14-TO-ABO1.10-T13 4.12E-04 1 2.72E-06 2.72E-06 1.12E-09 1.12E-09

AB01.10-T14-TO-ABO1.10-T15 4.12E-04 1 NA NA Note 2 NA

ABO1.10-T15-TO-ABO1.10-T14 6.69E-05 1 NA NA Note 2 NA

ABO1.18.01-T3-TO-ABO1.18.01-T4 1.04E-04 1 NA NA Note 2 NA





-,CCDP no--wih~.Scenario ID 4.MRI CCD Exosn Ttl Dihk opopprp ionFPS . propagakioný- AtY i

AB0 1.18.02-T10 -TO-AB1. 18.02-T9 1.45E-05 1 4.12E-07 4.12E-07 5.97E-12 5.97E-12

AB1. 18.02-T11 TO-AB1. 18.02-T3 5.78E-05 0.006 1.78E-05 5.03E-05 1.04E-09 1.03E-09

AB01.18.02-T11-TO-AB01.18.02-T5 5.78E-05 1 1.78E-05 5.03E-05 Note 1 Note 1

ABO1.18.02-T3-TO-AB01.18.02-Ti 1 1.85E-04 0.001 3.05E-07 5.03E-05 6.64E-1 1 5.64E-1 1


ABO1.1 8.02-T5-TO-ABO1.18.02-T1 1 2.32E-04 0.001 2.09E-08 5.03E-05 1.74E-1 1 4.85E-12



ABOI.18.02-T7-TO-ABOI.18.02-T5 1.1 2E-05 1 2.02E-08 8.67E-07 9.71 E-12 2.26E-13

ABO1 .1 8.02-T8-TO-ABO1 .1 8.02-T9 1.73E-05 1 2.02E-08 2.02E-08 3.49E-13 3.49E-13

ABO1 .1 8.02-T9-TO-ABO1 .18.02-T1 0 1.29E-05 1 2.02E-08 4.12E-07 5.31 E-12 2.61E-13


ABO1.21.01-Ti-TO-ABO1.21.01-T2 1.76E-04 1 1.62E-04 1.05E-05 1.85E-09 2.85E-08

ABO1.21.01-T2-TO-ABO1.21.01-Ti 1.25E-04 1 1.05E-05 1.05E-05 1.31 E-09 1.31 E-09

ABO1.21.02-Ti 1 -TO-ABO1.21.02-Ti 2 6.37E-04 0.001 4.14E-07 2.26E-04 4.18E-10 2.64E-1 0


ABO1.21.02-Ti 2-TO-ABO1.21.02-Ti 1 4.01 E-04 0.001 4.12E-07 2.26E-04 2.63E-10 1.65E-1 0

ABO1.21.02-T13-TO-ABO1.21.02-T5 6.98E-05 1 2.90E-05 2.90E-05 2.02E-09 2.02E-09

ABO1.21.02-T7-TO-ABO1.21.02-TI1 6.13E-05 1 4.14E-07 4.14E-07 Note 1 Note 1

ABO1.21.02-T7-TO-ABO1.21.02-T5 6.13E-05 0.001 4.14E-07 2.90E-05 2.73E-1 1 2.54E-1 1


ABO1.29-T2-TO-ABO1.29-Ti 9.01 E-04 1 NA NA Note 2 NA

ABO1.29-T2-TO-ABO1.29-T3 9.01 E-04 1 NA NA Note 2 NA





n 0poaain~poaain~

CB02-T2-TO-CB02-Ti 1.53E-05 1 NA NA Note 2 NA

C804-T3-TO-CB04-T12 1.87E-05 0.001 1.65E-03 2.56E-03 Note 1 Note 1

CBO4-T3-TO-CB04-T1 3 1 .87E-05 0.001 1 .65E-03 1 .37E-01 3.34E-08 3.09E-08

C B04-T5-TO-C B04-T6 1.51 E-05 0.001 6.77E-04 6.45E-04 1 .02E-08 1 .02 E-08

C B04-T6-TO-CB04-T5 1.59E-05 0.001 6.95E-04 6.45E-04 1.10E-08 1.11E-08

CB04-T7-TO-CBO4-T8 9.84E-06 1 NA NA Note 2 NA

CB04-T9-TO-CB04-T10 3.92E-06 1 NA NA Note 2 NA

CB20-T1-TO-CB20-T2 1 .53E-05 1 NA NA Note 2 NA






IB20-T1 0-TO-IB20-T1 1 4.01 E-04 0.001 7.11 E-06 7.11 E-06 2.85E-09 2.85E-09

I B20-T10-TO-1B20-T9 4.01 E-04 1 7.11E-06 7.11E-06 Note 1 Note 1

IB20-T1 1-TO-I1B20-T1 0 4.00E-04 0.001 7.11 E-06 7.11 E-06 2.84E-09 2.84E-09

IB20-T1-TO-IB20-T8 7.50E-04 0.479 1.96E-05 9.87E-05 4.31E-08 1.47E-08

I B20-T2-TO-I B20-T3 7.55E-04 0.479 1 .96E-05 1 .96E-05 1 .48 E-08 1 .48 E-08

I B20-T3-TO-I B20-T2 5.34E-04 0.479 1 .96E-05 1 .96E-05 1 .05E-08 1 .05E-08

IB20-T3-TO-IB20-T4 5.34E-04 1 1.96E-05 1.96E-05 Note 1 Note 1



IB20-T4-TO-IB20-T8 1.1 7E-04 0.479 1 .96E-05 9.87E-05 6.72E-09 2.29E-09


IB20-T5-TO-1B20-T4 3.78E-04 0.479 1.96E-05 1.96E-05 7.41E-09 7.41E-09

IB20-T8-TO-IB20-T1 2.62E-04 0.479 9.87E-05 9.87E-05 2.59E-08 2.59E-08


Scenaio IDExposing ccDR.l n CCDP with.Scearo I, NSTotl ~n rnqnrn.,ana+mn.IGF PNSpa propagationsTtICD Yconsider'ed

1B20-T8-TO-IB20-T4 2.62E-04 0.479 9.87E-05 9.87E-05 Note 1 Note 1

1B320-T8-TO-1B320-T9 2.62E-04 0.479 9.87E-05 9.87E-05 Note 1 Note 1

IB20-T9-TO-IB20-T10 4.OOE-04 1 7.11 E-06 7.11 E-06 Note 1 Note 1

I820-T9-TO-IB20-T4 4.OOE-04 1 7.11 E-06 7.11 E-06 Note I Note 1

IB20-T9-TO-IB20-T8 4.00E-04 0.001 7.11 E-06 9.87E-05 2.88E-09 2.84E-0911321.01 -T2-TO-1B21 .01 JT7 9.04E-06 1 2.74E-06 2.74E-06 2.48E-1 1 2.48E-1 1

IB21.01-T3-TO-IB21.01-T7 6.02E-06 1 2.74E-06 2.74E-06 1.65E-1 1 1.65E-1 1

1821.01 -T5-TO-IB21 .01 -T6 1 .03E-04 0.479 2.85E-05 2.85E-05 2.94E-09 2.94E-09

IB21.01-T6-TO-IB21.01 -T1 2.78E-06 1 2.85E-05 4.97E-05 1.38E-10 7.92E-1 118321 .01-T6-TO-1B321 .01-T5 2.78E-06 1 2.85E-05 2.85E-05 Note 1 Note 1

IB21.01-T7-TO-I821.01-T2 1.26E-05 1 2.74E-06 2.74E-06 3.45E-1 1 3.45E-11I

11321 .01 -T7-TO-IB21 .01-T3 1.26E-05 1 2.74E-06 2.74E-06 Note 1 Note 1

1825.01.03-Ti -TO-IB25.01 .03-T2 1.1 9E-05 0.001 4.83E-06 5.94E-04 6.45E-1 1 5.75E-1 1

IB25.01.03-T2-TO-IB25.01.03-T1 9.87E-05 0.006 5.94E-04 5.94E-04 5.86E-08 5.86E-08

8B25.01 .03-T2-TO-1B25.01 .03-T4 9.87E-05 1 5.94E-04 5.94E-04 Note 1 Note 1

1825.01 .03-T4-TO-1825.01 .03-T2 5.67E-06 0.006 2.44E-08 5.94E-04 2.08E-1 1 1 .38E-1 3

1825.01 .03-T4-TO-IB25.01 .03-T6 5.67E-06 1 2.44E-08 2.55E-05 Note 1 Note 1

1825.01 .05-T3-TO-1825.01 .05-T5 1 .07E-05 1 3.1 5E-07 3.1 5E-07 3.37E-1 2 3.37E-1 2

1825.01 .05-T5-TO-1825.0i .05-T3 1 .29E-05 1 3.1 5E-07 3.1 5E-07 4.06E-1 2 4.06E-1 2

TBO1.01-T1O-TO-TBO1.01-T12 1.05E-03 1 2.02E-08 2.02E-08 Note 1 Note I

TBOI.01-T1O-TO-TBOi.01-T13 1.05E-03 1 2.02E-08 2.02E-08 Note 1 Note 1

TBO1.01-T1O-TO-TBOI.0i-T2 1.05E-03 0.187 2.02E-08 1. 11E-05 2.20E-09 2.12E-1 1

TBOI.01 -T1 1-TO-TBOI.0i -T1 3 4.01 E-04 1 2.02E-08 2.02E-08 8.10E-12 .8.10E-12

T13i1.01 -TI 2-TO-TBOI .01 -Ti 0 1. 14E-03 1 2.02E-08 2.02E-08 2.30E-1 I 2.30E-1 1

TBOi.0i -T1 3-TO-TBO1.0i -T1i0 7.99E-04 1 2.02E-08 2.02E-08 1.61 E-1i 1i.61 E-1i1

TBOi.0i -T1 3-TO-TBO1.01 -T1i1 7.99E-04 I 2.02E-08 2.02E-08 Note 1 Note 1


,,E.:osing :. •DP no C.D.with 707,Case.•. .9 N.. ,,I . "M k 'Totpropagl p gaono propagationcons d,

... =. ......... ... .. •. , , f." .,.,

TBO1.01-T14-TO-TBO1.01 T9 1.07E-03 0.187 1.11E-05 1.11E-05 1. 19E-08 1.19E-08

TB01.01-T2-TO-TBO1.01 -T1 6.89E-04 0.187 1.11E-05 6.45E-04 8.95E-08 7.65E-09

TB01.01-T2-TO-TBO1.01-T10 6.89E-04 1 1.11E-05 1.11E-05 Note 1 Note 1

TB01.01-T9-TO-TB01.01-T14 2.94E-04 0.187 1.11 E-05 1.11 E-05 3.26E-09 3.26E-09


TB01.02-T1 0-TO-TBO1.02-T9 6.28E-04 0.187 2.02E-08 1.11 E-05 1.32E-09 1.27E-1i1

TB01.02-T1 1 -TO-TBO1.02-Ti 0 6.38E-03 1 2.02E-08 2.02E-08 1.29E-10 1.29E-10


TB01.02-T1 2-TO-TBOI.02-T 1i 5.76E-04 1 2.02E-08 2.02E-08 1. 1 6E-1i1 1.16E-11

TB01.02-T2-TO-TB01.02-T1 5.59E-04 0.187 1.17E-04 6.41E-03 7.24E-07 6.54E-08


TBO1.02-T9-TO-TBO1.02-T7 3.56E-04 0.187 1.11 E-05 6.41 E-03 4.31 E-07 3.95E-09

TB02-Tl -TO-TB02-T2 9.06E-04 0.479 6.24E-04 6.44E-04 5.74E-07 5.65E-07

TB02-TI-TO-TB02-T3 9.06E-04 0.479 6.24E-04 6.24E-04 Note 1 Note 1

TB02-T2-TO-TB02-T1 6.83E-04 0.479 6.44E-04 6.44E-04 4.40E-07 4.40E-07

TB02-T2-TO-TB02-T3 6.83E-04 0.479 6.44E-04 6.44E-04 Note 1 Note 1

TB02-T3-TO-TB02-T1 5.89E-04 0.479 4.14E-07 6.24E-04 Note 1 Note 1

TB02-T3-TO-TB02-T2 5.89E-04 0.479 4.14E-07 6.44E-04 1.82E-07 2.44E-10

SUM 3.06E-06 1.69E-06

Total CDF Increase Due to Propagation Across Transient Zone Boundaries 1.37E-06

Notel: This scenario has a CCDP that is equal to or less than another scenario involving the same exposing transient zone.the ignition frequency correctly, only one combination per exposing transient zone is included in the calculation.

Note 2: One or both of the CCDP values is less than 2E-08, and therefore not a significant risk contributor.

In order to apportion

Document Control DeskCR-06-00055Attachment IIRC-13-0054Page 1 of 1

VIRGIL C. SUMMER NUCLEAR STATION (VCSNS) Unit 1DOCKET NO. 50-395

OPERATING LICENSE NO. NPF-12

ATTACHMENT II

LIST OF REGULATORY COMMITMENTS

The following table identifies those actions committed to by SCE&G, Virgil C. Summer NuclearStation in this document. Any other statements in this submittal are provided for informationpurposes and are not considered to be commitments. Please direct questions regarding thesecommitments to Mr. Bruce L Thompson, Manager, Nuclear Licensing, (803) 931-5042.

TDUE DATE [ EVENT

Increase the scope of circuit protection modifications 2015Update Generic Methodology Calculation, DC0780B-001 July 1, 2013

thomas d. gatlin vice president, nuclear …803.345.4342 a scana company april 1, 2013 rc-13-0054...

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