ML13234A442

(VCSNS) - Request for Additional Information

ML13234A442
Person / Time
Site:	Summer
Issue date:	08/28/2013
From:	Martin R Plant Licensing Branch II
To:	Gatlin T South Carolina Electric & Gas Co
Martin Robert, NRR/DORL 415-1493
References
TAC ME7586
Download: ML13234A442 (12)

Text

UNITED STATES NUCLEAR REGULATORY COMMISSION WASHINGTON, D.C. 20555-0001 August 28, 2013 Mr. Thomas D. Gatlin Vice President, Nuclear Operations South Carolina Electric & Gas Company Virgil C. Summer Nuclear Station Post Office Box 88, Mail Code 800 Jenkinsville, SC 29065

SUBJECT:

VIRGIL C. SUMMER NUCLEAR STATION, UNIT NO.1 (VCSNS) - REQUEST FOR ADDITIONAL INFORMATION (TAC NO. ME7586)

Dear Mr. Gatlin:

By letters dated November 15, 2011, January 26 and October 10, 2012, the South Carolina Electric & Gas Company (SCE&G) submitted a license amendment request (LAR) to revise Facility Operating License Number NPF-12 for the Virgil C. Summer Nuclear Station, Unit No.1.

The LAR would permit transition of the fire protection licensing basis from Title 10 of the Code of Federal Regulations, Section 50.48(b), to 10 CFR 50.48(c), "National Fire Protection Association Standard NFPA 805."

The Nuclear Regulatory Commission staff Probabilistic Risk Assessment Licensing Branch has reviewed the information provided by SCE&G and has determined that additional information is needed as discussed in the Enclosure. As discussed with your staff on August 21, 2013, we request that SCE&G respond within ninety (90) calendar days from the date of this letter.

Please note that the staff's review is continuing and further requests for information may be developed.

Sincerely,

~~n~~ect Plant Licensing Branch 11-1 Manager Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-395

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv

REQUESTS FOR ADDITIONAL INFORMATION LICENSE AMENDMENT REQUEST TO ADOPT PERFORMANCE-BASED NATIONAL FIRE PROTECTION ASSOCIATION STANDARD 805 FOR FIRE PROTECTION FOR VIRGIL C. SUMMER NUCLEAR STATION, UNIT NO.1 DOCKET NO. 50-395 By letters dated November 15, 2011, January 26 and October 10, 2012, the South Carolina Electric & Gas Company (SCE&G, the licensee) submitted a license amendment request (LAR) to revise Facility Operating License Number NPF-12 for the Virgil C. Summer Nuclear Station, Unit No.1 (VCSNS). The LAR would permit transition of the fire protection licensing basis from Title 10 of the Code of Federal Regulations (10 CFR), Section 50.48(b), to 10 CFR 50.48(c),

"National Fire Protection Association Standard NFPA 805" (NFPA 805). The staff has determined that additional information is needed to complete the review as discussed below.

Probabilistic Risk Assessment (PRA) RAI 01.01 In the letter dated October 10, 2012, (Agencywide Documents Access and Management System (ADAMS) Accession No. ML12297A218) South Carolina Electric and Gas (SCE&G) specified the treatment of hot work induced cable fires (PRA RAI 1). The response states that as a practical approach, the incipient state for this ignition source (welding) is assumed to be 20 minutes and that at this point in time, a full cable tray, the one with the highest conditional core damage probability (CCDP) in the transient zone, is assumed damaged.

However, credit for suppression before damage to the cables in the tray in the case of these fires is incorrect since some damage occurs instantly upon the start of a hot work induced cable fire. As a result, remove the credit for suppression in the analysis of your hot work induced cable fires and provide the following:

a. The updated core damage frequency (CDF), large early release frequency (LERF), Delta

(~)CDF and ~LERF for the appropriate fire areas for hot work induced cable fires without the credit for suppression.

b. The CDF, LERF, ~CDF and ~LERF for the plant.

PRA RAI 10.01 The National Fire Protection Association Standard 805 (NFPA-805), "Performance-Based Standard for Fire Protection for Light Water Reactor Electric Generating Plants", 2001 Edition, incorporated by reference into 50.48(c), states that the Probabilistic Risk Assessment (PRA)

-2 approach, methods, and data shall be acceptable to the NRC. NFPA-805 also requires that the change in public health risk arising from transition from the current 'fire protection program to an NFPA-805 based program, and all future changes to the program be acceptable to the NRC.

Regulatory Guide (RG) 1.174, "An Approach for Using Probabilistic Risk Assessment in Risk Informed Decisions on Plant-Specific Changes to the Licensing Basis," provides quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

Describe the criteria for defining Epsilon as it pertains to L1 CDF and L1 LERF in LAR Attachment C, "NEI 04-02 Table B-3 Fire Area Transition."

PRA RAI 12.01 In the October 10, 2012 letter, SCE&G stated that electrical raceway fire barrier systems (ERFBS) were credited at their full hourly rating for the installed configuration per Generic Letter (GL) 86-10, Supplement 1, "Fire Endurance Test Acceptance Criteria for Fire Barrier Systems Used to Separate Safe Shutdown Trains Within the Same Fire Area" (PRA RAI 12). SCE&G also stated that in the nuclear safety capability assessment (NSCA), the associated circuits were not affected in the Fire PRA (FPRA) scenarios. Provide the following:

a. A description of the treatment in the FPRA of ERFBS. Are targets that are protected by the barrier assumed to be fully protected until the hourly rating is reached, after which the targets are exposed to the fire? If not, provide justification for the alternative assumption. Discuss your response with respect to the ASME/ANS PRA Standard RA-Sa-2009, Part 4.

b. An evaluation of the impact of any alternative assumption on CDF, LERF, L1CDF and L1LERF.

PRA RAI 15.01 In the October 10, 2012 letter, SCE&G stated that, "It was judged that a fire burning for 20 to 40 minutes could reasonably be expected to cause damage across a fire zone boundary that is based on spatial separation" (PRA RAI 15 on FSS-A4-01). The response also indicated that a sensitivity study is done on the time to damage for multicompartment fire scenarios where a time of only 10 minutes is allowed, and the fire CDF increases by a factor of 2. The response does not provide a justification for 20 minutes, although the original RAI asks for justification.

Provide the following:

a. Justification for 20 minutes, as well as for the alternate assumption in the sensitivity study.

b. Identify and examine a representative or bounding configuration.

i. Provide a justification for the timing through examining that configuration ii. Provide justification for the configuration as being representative or bounding.

iii. Identify the time arrived at for that bounding or representative configuration in the PRA analysis

c. Update to the PRA as necessary, and provide new fire CDF/LERF/L1 CDF/L1 LERF.

-3 PRA RAI 17.01 In the October 10, 2012 letter, SCE&G discussed the dependency between automatic and manual suppression systems. In particular, there is discussion on the relationship between the water supply and the fire brigade hose stream and sprinkler systems qualitatively (PRA RAI 17 on FSS-C7 -01). However, it is not stated whether failures of the firewater pumps are included in the FPRA model. However, the dependency between as a result of the fire water supply from the fire water pumps and the fire brigade does not appear to be addressed qualitatively.

Provide the following:

a. A discussion of whether there are any failures of the firewater pumps explicitly included in the PRA.

b. If this dependency is not addressed quantitatively in the PRA, provide a sensitivity study on CDF, LERF, ~CDF and ~LERF which includes this dependency for the affected fire areas.

PRA RAI 21.01 In the October 10, 2012 letter, SCE&G stated that damage criterion for sensitive electronics is applied in the CB06 relay room (PRA RAI 21 on FSS-G2-01). In the disposition of the original peer review finding, it states that this damage criterion is applied in the main control room (MCR). SCE&G also indicated that it is not applied in the switchgear rooms since a hot gas layer (HGL) was postulated. Provide the following:

a. An evaluation of the switchgear rooms for damage to sensitive electronics relays due to exposure to a fire in another panel, if a HGL does not form.

b. A determination of whether the relays in the switchgear rooms are considered to be sensitive electronics and if so, an evaluation to determine if they fail.

c. An update to the PRA as applicable, and also an update to the fire CDF, LERF, ~CDF and ~LERF provided for the affected fire areas.

PRA RAI 22.01 In the October 10, 2012 letter, SCE&G responded to PRA RAI 22 on FSS-HS-01 and stated that uncertainty and sensitivity analysis were performed for a few zone models such as SWPH01 and CB04. However, these analyses with respect to this Supporting Requirement (SR) could not be identified for SWPH01 and CB04. Provide an example where FSS-HS-01 is addressed and summarize the treatment with regards to FSS-HS-01.

PRA RAI 34.01 In the October 10, 2012 letter, SCE&G stated that, "For HEPs being performed outside the Main Control Room, an additional 5 minutes (total of 10 additional minutes) was added to the T1/2 (Median Response Time) to account for environmental, travel path, emergency lighting, etc."

(RAI 34).

SCE&G also stated that, "However, a factor of 2 was only added for actions outside the MCR where numerous rooms need to be accessed to perform the operator manual action." NUREG

- 4 where numerous rooms need to be accessed to perform the operator manual action." NUREG 1921, "EPRI/NRC-RES Fire Human Reliability Analysis Guidelines," Section 4.11, Reviews with Plant Operations; Section 4.3, Feasibility Assessment; and Section 4.6.2, Timing (under "Performance Shaping Factors"), provides guidance on considering what fire-specific factors might change the estimate of timing information and how to modify it appropriately for use in the fire human reliability assessment (HRA). Provide the following:

a. Confirmation that a verification walk-through or an equivalent will be performed for these operator actions.

b. Confirmation that the factor of 2 is appropriate given the guidance in NUREG 1921.

c. Definition of "numerous" and justify why that number of rooms is appropriate.

PRA RAI54 In response to PRA RAI 54, the licensee referenced calc notes CN-RRA-02-42, "Documentation of LERF for V. C. Summer Nuclear Station Probabilistic Safety Assessment," CN-RRA-02-51, "V. C. Summer Nuclear Station Severe Accident Phenomena," and CN-RRA-02-80, "V. C.

Summer Nuclear Station Level 2 Upgrade. These calc notes indicate that the LERF model was upgraded. In general, the American Society of Mechanical Engineers (ASME) standard recommends that such an upgrade should be subject to peer review. Has this revised model been subject to peer review, if not, when will the upgraded LERF model be peer reviewed?"

PRA RAI 66.01 In the October 10, 2012 letter, SCE&G indicated that the MCB fire scenarios were corrected to address incorrect CCDPs from the PRA study (PRA RAI 66 on FSS-B2-01). Provide the CDF, LERF, ~CDF and ~LERF for fire area CB17.

PRA RAI 72.01 In the October 10, 2012 letter, SCE&G indicated that an independent validation is planned to identify whether any fast acting components exist in the cabinets in which incipient detection is installed (PRA RAI 72). Provide the following:

a. Indicate if validation has been done, and if so describe the effect on the CDF, LERF,

~CDF and ~LERF.

b. If not yet completed, provide the schedule for completion and applicable PRA update.

PRA RAI 73.01 In the October 10, 2012 letter, SCE&G stated that "A 3.5 min value is applied to all scenarios for damage to cables above the cabinet" (PRA RAI 73).

a. Clarify that 3.5 is the number of minutes allowed for suppression prior to damage of those cables, and not the minimum damage height above the cabinet for those cabinets where incipient detection is applied.

-5

b. If the 3.5 does not represent the minimum height for which target cables are damaged above cabinets containing incipient detection, indicate the minimum height used in the calculations.

c. Confirm that this minimum height represents or bounds conditions present in the field.

d. Should the timing to damage change after this evaluation, provide a sensitivity analysis on CDF, LERF, ACDF and ALERF for the fire areas containing incipient detection.

PRA RAI 76.01 In a letter dated July 26, 2012, (ADAMS Accession No. ML12202A027) the NRC asked PRA RAI 76 and requested a description of how the fire brigade arrival time of 10 minutes (for a MCR fire that was used in the Control Room Risk Calculation) compares to the time identified in pre fire plans for fire brigade arrival to the MCR during a fire or during a fire brigade drill. This information was not provided in the RAI response. The October 10, 2012 letter stated that 10 minutes was realistic (PRA RAI 76).

a. Provide justification for the 10 minutes assumed in the non-suppression probability for MCR abandonment. Please discuss drill data and pre-fire plans as requested in the original RAI.

b. If the 10 minutes cannot be supported, provide an alternate time that is supportable and indicate the effect on CDF, LERF, ACDF and ALERF.

PRA RAI 85.01 The NFPA-805 standard incorporated by reference into 50.48(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-805 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-805 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provides quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

Table 2 in the FPRA Sensitivity and Uncertainty Report regarding "Sensitivity Analyses for VCS Fire PRA Quantification" provides the impact on CDF and LERF for several alternative assumptions and issues.

a. Evaluate ACDF and ALERF and their sensitivity to the assumptions from Table 2, and supplement the assumptions evaluated to account for the Fire Scenario Selection (FSS)

SRs from UNC-A2.

b. For UNC-A2 it was noted that sensitivity analysis was done in lieu of uncertainty analysis (Le., propagation of parameter uncertainty). Describe whether the results of the sensitivity study on the total CDF and LERF and on ACDF and ALERF support the conclusions that the estimated CDF, LERF, ACDF and ALERF used in the analysis are not significantly affected by state-of-knowledge correlations (SOKC); and, thus they can be compared to the acceptance guidelines on the mean values in RG 1.174.

c. If any of the sensitivity analysis results exceed the acceptable change in risk guidelines due in part to the use of bounding assumptions, confirm that a reasonable alternative assumption would result in an acceptable impact

- 6 PRA RAI86 The NFPA-B05 standard incorporated by reference into 50.4B(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-B05 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-B05 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provide quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

When the requested increase in CDF is greater than 10.6 per year or the requested increase in LERF is greater than 10-7 per year, the total CDF and LERF are required in order to determine the acceptability of the requested increase as described in RG 1.174. LAR Attachment W states that the total increase in CDF is 3.6X 10.6 per year.

a. Provide an estimate of the total CDF and LERF that includes all internal and external initiating events.

b. If your estimate of the total CDF or LERF exceeds 10-4 per year or 10-5 per year respectively, summarize how the acceptance guidelines in Section 2.4 of RG 1.174 are satisfied.

PRA RAI87

a. Provide confirmation that Item S-2.1B of LAR Attachment S, Table S-2, "Implementation Items," will include a confirmatory demonstration of the feasibility of the recovery actions (RAs) credited, including a field verification walk-through of transit times and that execution times will be performed and documented.

b. Confirm that documentation will be developed indicating that the RAs are reliable and the FPRA HRA will be updated following the field verification to ensure the risk metrics, which includes the additional risk of RAs, reported in the LAR, as supplemented, have not increased.

c. If this action will not be included under Implementation Item S-2.1B, then specify where this activity is covered in LAR Attachment S.

PRA RAI88 In the October 10, 2012 letter, SCE&G indicated that the PRA will be updated for the installation of a different power source (SSD RAI 11). Discuss the effect on the PRA qualitatively, and indicate the effect on CDF, LERF, L\CDF and L\LERF.

PRA RAI89 The NFPA-B05 standard incorporated by reference into 50.4B(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-B05 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-B05 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provide quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a

-7 general framework for determining the acceptability of risk-informed changes.

Table V-16 in the LAR indicates that ignition frequency support requirement A4 (IGN-A4) is a capability category (CC) II. However, the report "Fire Ignition Frequency Analysis (Task 5.6)",

TR07800-007, states that a "review of fire events suggest no unusual pattern that can be attributed to a specific ignition source. Therefore, the generic frequencies do not need plant specific update." The lack of an "unusual pattern" is not consistent with ASME and American Nuclear Society (ANS) standard RA-Sa-2009, "Addenda to ASME/ANS RA-S-2008, Standard for Level1/Large Early Release Frequency Probabilistic Risk Assessment for Nuclear Power Plant Applications," (ASME/ANS PRA Standard) which, for CC II, directs that fire frequencies should be updated if "outliers are found." Note 1 in the Standard subsequently defines outliers as "where the plant has experienced more fires of any given type than would be expected given the generic industry experience, or where the plant has experienced a type of fire that is potentially risk relevant but is not reflected in the generic event database." Clarify this apparent discrepancy.

PRA RAI90 The NFPA-805 standard incorporated by reference into 50.48(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-805 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-805 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provide quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

An HRA evaluation was performed to credit administrative limits on combustibles in certain areas of the plant. This analysis was based on the plant having clear demarcations of where transient combustibles are prohibited. Two HRA approaches, primarily Cognitive Reliability Error Analysis Method (CREAM) and Technique for Human Error Rate Prediction (THERP) as support, were applied and a probability of 0.004 for the placement of transient combustibles in the marked areas of the plant was derived.

According to discussions during the audit, contrary to the analysis, the purpose of the administrative limit is not to prevent the placement of transient combustibles in a marked area of the plant. Instead, the marked area is a location to prevent transient combustibles beyond a certain physical size. Thus, the HRA did not evaluate the correct implementation of the control at the plant. The NRC staff evaluated the 0.004 probability for the correct plant configuration, where certain transient combustibles are limited in the administratively controlled area of the plant, and determined that that the primary analysis tool, CREAM, the basis for the 0.004 prQbability, is a poor match for the human failure event in this application. CREAM is best suited to modeling decision-making, especially that performed by control room operators in responding to an accident requiring a reactor trip, rather than maintenance or testing technicians performing actions in the field.

The NRC staffs view is that this type of 'fire protection administrative control which prohibits combustibles of a certain size is much more difficult to follow than controls which simply prohibit transient combustibles in a zone. The staff also views marking an area where combustibles are

- 8 allowed to be counter to the fire protection culture as seen by plant personnel.

Assigning a value of 0.004 to the probability of failing the administrative control appears to be too low and will require justification. Provide the following:

a. Confirmation that this administrative limit is still planned for your plant.

b. A sensitivity study where the credit for this administrative limit is removed from the PRA.

c. An analysis of the impact on CDF, LERF, n.CDF and n.LERF for the affected fire areas.

d. If the PRA is sensitive to the removal of credit for administrative limits, provide an analysis of the administrative limit using methodes) alternate to CREAM.

e. Justification of the heat release rate for the modeled violation of the administrative limit with consideration given for the transient combustibles which may exist in the room, considering the equipment and required maintenance, storage, and occupancy; as well as any actual violations of administrative combustible controls which have occurred in the room or comparable locations of the plant.

PRA RAI92 The NFPA-805 standard incorporated by reference into 50.48(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-805 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-805 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provide quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

According to Section 6.1.3.3 of the Fire Modeling Generic Methodology, DC0780B-001, prompt suppression and detection can be credited when a continuous or hot work fire watch is present.

Describe how prompt detection and suppression is modeled in your PRA, for a continuous watch. Provide the following discussion and justification for applying a continuous watch for fires other than hot work fires.

a. Provide the fire ignition sources for which this applies.

b. Provide a discussion which assesses the characteristics which would delay prompt detection, and indicate how these issues for the particular fire initiators are addressed.

For example, if prompt detection was applied for a transient ignition source, indicate how it would be ensured that the transient fire area is surveilled and how that would lead to prompt detection.

c. Confirm that one of the continuous watch's purposes is to extinguish the fire. Also confirm that an extinguisher will be readily available (including being located in the vicinity being surveilled), that there will be no impediments to applying the extinguisher, and that the fire watch will have undergone adequate training in the use of extinguishers.

If a more capable suppressant system (i.e. fire hose) can be used in place of an extinguisher to qualify for this credit, provide a discussion regarding the staging and rapidity with which the suppressant can be applied.

d. Indicate how prompt detection and suppression are credited in the PRA for each of the ignition sources being credited. Describe the credit given in the PRA.

-9 PRA RAI93 The NFPA-805 standard incorporated by reference into 50.48(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-805 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-805 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provide quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

In the October 10, 2012 letter, SCE&G indicated that junction box fires are limited to a single cable tray, utilizing the cable tray or conduit with the largest CCDP in the transient zone (PRA RAI 01). However, cables from more than a single tray or conduit can enter a junction box.

As a result, perform an analysis that takes into account failure of all cables entering the junction box. Provide the effect on CDF, LERF, LlCDF and LlLERF from the analysis of the risk from junction box fires on an area and plant-wide basis.

PRA RAI94 The NFPA-805 standard incorporated by reference into 50.48(c) states that the PRA approach, methods, and data shall be acceptable to the NRC. NFPA-805 also requires that the change in public health risk arising from transition from the current fire protection program to an NFPA-805 based program, and all future changes to the program be acceptable to the NRC. RG 1.174 provide quantitative guidelines on CDF and LERF, and identifies acceptable changes to these frequencies that result from proposed changes to the plants licensing basis and describes a general framework for determining the acceptability of risk-informed changes.

According to more recent discussions with the staff as documented in the public meeting on June 20, 2013 (presentation entitled "NFPA 805 Transient Combustible Controls, ADAMS Accession No. ML13170A130), SCE&G is considering changing the administrative limit discussed in PRA RAI 90 such that each fire area in question will be treated as a restricted area, rather than an administrative limit placed on a vicinity within the fire area. It should be noted that completed FAQ 12-0064 provides one acceptable way to evaluate administrative limits placed on a location in the plant. Provide the following:

a. Confirmation that you are making this change to your administrative limits in your plant.

b. A summary of the updated analysis that evaluates the impact of this change of the PRA on CDF, LERF, LlCDF and LlLERF

c. A discussion of how this administrative limit is credited in the PRA update.

PRA RAI95 In the October 10, 2012 letter, SCE&G responded to PRA RAI 08 and stated that two instances for MCR abandonment received a detailed HRA. Those two cases were the failure to abandon upon loss of control (LOC), and the failure to successfully shutdown upon successful abandonment. In the case of failure to abandon upon LOC, it is stated that this circumstance leads directly to core damage and large early release.

- 10 However, failure to successfully shutdown for LOC upon successful abandonment is not addressed in the RAI response. Summarize how successful shutdown upon LOC upon successful abandonment is addressed in the risk evaluation. Note that successful shutdown upon LOC may be very complex. If the PRA postulates the potential for successful shutdown following abandonment due to LOC, provide a discussion of this analysis and a justification.

Also, perform a sensitivity where CCDP = 1 for failure to successfully shutdown for successful abandonment upon LOC and indicate the impact upon CDF, LERF, ~CDF and ~LERF.

August28,2013 Mr. Thomas D. Gatlin Vice President, Nuclear Operations South Carolina Electric & Gas Company Virgil C. Summer Nuclear Station Post Office Box 88, Mail Code 800 Jenkinsville, SC 29065

SUBJECT:

VIRGIL C. SUMMER NUCLEAR STATION, UNIT NO.1 (VCSNS) - REQUEST FOR ADDITIONAL INFORMATION (TAC NO. ME7586)

Dear Mr. Gatlin:

By letters dated November 15,2011, January 26 and October 10,2012, the South Carolina Electric & Gas Company (SCE&G) submitted a license amendment request (LAR) to revise Facility Operating License Number NPF-12 for the Virgil C. Summer Nuclear Station, Unit No.1.

The LAR would permit transition of the fire protection licensing basis from Title 10 of the Code of Federal Regulations, Section 50.48(b), to 10 CFR 50.48(c), "National Fire Protection Association Standard NFPA 805."

The Nuclear Regulatory Commission staff Probabilistic Risk Assessment Licensing Branch has reviewed the information provided by SCE&G and has determined that additional information is needed as discussed in the Enclosure. As discussed with your staff on August 21,2013, we request that SCE&G respond within ninety (90) calendar days from the date of this letter.

Please note that the staff's review is continuing and further requests for information may be developed.

Sincerely, IRA!

Robert E. Martin, Senior Project Manager Plant Licensing Branch 11-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket No. 50-395

Enclosure:

Request for Additional Information cc w/encl: Distribution via Listserv DISTRIBUTION PUBLIC LPL2-1 RJF RidsAcrsAcnw_MailCTR Resource RidsNrrDorlDpr Resource RidsNrrDorlLpl2-1 Resource RidsRgn2MailCenter Resource RidsNrrLASFigueroa Resource RidsNrrDe Resource RidsNrrPMSummer Resource AKlein, NRR JRobinson, NRR JS Hyslop, NRR SDinsmore, NRR MSnodderly, NRR MBarillas,NRR ADAMSAccesslon N0.: ML13234A442 *Bsyemal'1 OFFICE LPL2-1/PM LPL2-1/LA NRRJAPLA LPL2-1/BC LPL2-1/PM NAME RMartin SFigueroa HHamzehee* RPascarelli RMartin DATE 08/28/13 08/28/13 08/22/13 08/28/13 08/28/13 OFFICIAL RECORD COPY