ML11238A072
| ML11238A072 | |
| Person / Time | |
|---|---|
| Site: | South Texas  |
| Issue date: | 08/23/2011 |
| From: | Gerry Powell South Texas |
| To: | Document Control Desk, Office of Nuclear Reactor Regulation |
| References | |
| NOC-AE-11002714 | |
| Download: ML11238A072 (9) | |
Text
Nuclear Operating Company South Texas Prolect Electric Generating' Station P.. Box 289 Wadsworth, Texas 77483 A
August 23, 2011 NOC-AE-1 1002714 10CFR54 STI: 32913936 File: G25 U. S. Nuclear Regulatory Commission Attention: Document Control Desk One White Flint North 11555 Rockville Pike Rockville, MD 20852-2746 South Texas Project Units 1 and 2 Docket Nos. STN 50-498, STN 50-499 Response to Requests for Additional Information for the South Texas Proiect License Renewal Application (TAC Nos. ME4936 and ME4937)
References:
- 1. STPNOC Letter dated October 25, 2010, from G. T. Powell to NRC Document Control Desk, "License Renewal Application" (NOC-AE-10002607) (ML103010257)
- 2. NRC letter dated July 28, 2011, "Requests for Additional Information for the Review of the South Texas Project, License Renewal Application - Scoping and Screening Audit" (ML11201A055)
By Reference 1, STP Nuclear Operating Company (STPNOC) submitted a License Renewal Application (LRA) for South Texas Project (STP) Units 1 and 2. By Reference 2, the NRC staff requested additional information for review of the STP LRA. STPNOC's response to the request for additional information is provided in the Enclosure to this letter.
There are no regulatory commitments in this letter.
Should you have any questions regarding this letter, please contact either Arden Aldridge, STP License Renewal Project Lead, at (361) 972-8243 or Ken Taplett, STP License Renewal Project regulatory point-of-contact, at (361) 972-8416.
I declare under penalty of perjury that the foregoing is true and correct.
Executed on
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Date G. T. Powell Vice President, Technical Support & Oversight KJT
Enclosure:
STPNOC Response to Requests for Additional Information A
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NOC-AE-1 1002714 Page 2 cc:
(paper copy)
(electronic copy)
Regional Administrator, Region IV U. S. Nuclear Regulatory Commission 612 East Lamar Blvd, Suite 400 Arlington, Texas 76011-4125 Balwant K. Singal Senior Project Manager U.S. Nuclear Regulatory Commission One White Flint North (MS 8B1) 11555 Rockville Pike Rockville, MD 20852 Senior Resident Inspector U. S. Nuclear Regulatory Commission P. 0. Box 289, Mail Code: MN1 16 Wadsworth, TX 77483 C. M. Canady City of Austin Electric Utility Department 721 Barton Springs Road Austin, TX 78704 John W. Daily License Renewal Project Manager (Safety)
U.S. Nuclear Regulatory Commission One White Flint North (MS 011-Fl)
Washington, DC 20555-0001 Tam Tran License Renewal Project Manager (Environmental)
U. S. Nuclear Regulatory Commission One White Flint North (MS O11F01)
Washington, DC 20555-0001 A. H. Gutterman, Esquire Kathryn M. Sutton, Esquire Morgan, Lewis & Bockius, LLP John Ragan Catherine Callaway Jim von Suskil NRG South Texas LP Ed Alarcon Kevin Polio Richard Pena City Public Service Peter Nemeth Crain Caton & James, P.C.
C. Mele City of Austin Richard A. Ratliff Alice Rogers Texas Department of State Health Services Balwant K. Singal John W. Daily Tam Tran U. S. Nuclear Regulatory Commission
Enclosure NOC-AE-1 1002714 Page 1 of 7 STPNOC Response to Requests for Additional Information SOUTH TEXAS PROJECT LICENSE RENEWAL APPLICATION REQUESTS FOR ADDITIONAL INFORMATION RAI 2.1-1
Background:
Title 10 of the Code of Federal Regulations (10 CFR) 54.4, "Scope," states, in part, (a) Plant systems, structures and components within the scope of this part are:
(1) Safety-related systems, structures, and components which are those relied upon to remain functional during and following design-basis events (as defined in 10 CFR 50.49 (b)(1)) to ensure the following functions:
(i) The integrity of the reactor coolant pressure boundary; (ii) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (iii) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to those referred to in 10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.
Issue:
During the scoping and screening methodology audit, performed on-site May 16-19, 2011, the U.S. Nuclear Regulatory Commission (NRC or the staff) determined, through a review of the license renewal implementing documents and discussions with STP Nuclear Operating Company (STPNOC or the applicant), that a quality class, "QC-4," had been used in identifying structures, systems, and components (SSCs) to be included within the scopeof license renewal in accordance with 10 CFR 54.4(a)(1) that was not addressed in the license renewal application.
Request:
The staff requests that the applicant provide a description of the process used to evaluate components identified as QC-4 in the plant equipment database or other documents, to identify SSCs to be included within the scope of license renewal in accordance with 10 CFR 54.4(a)(1).
The staff requests that the applicant perform a review of this issue and indicate if the review concludes that use of the scoping methodology precluded the identification of SSCs which should have been included within the scope of license renewal in accordance with 10 CFR 54.4{a).. Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a) criteria. List any additional SSCs included within the scope as a result of your efforts, and list those structures and components for which aging management reviews were conducted or any additional information related to material and environment combinations. For each structure and
Enclosure NOC-AE-1 1002714 Page 2 of 7 component, describe the aging management programs, as applicable, to be credited for managing the identified aging effects.
STPNOC Response:
South Texas Project (STP) systems, structures and components (SSCs) classified as Quality Class 4 (QC-4) are identified as safety-related and are included within the scope of license renewal under the requirements of 10 CFR 54.4(a)(1). In accordance with the requirements of 10 CFR 54.4(a)(2), nonsafety-related SSCs whose failure could impact any of the functions identified for 10 CFR 54.4(a)(1) SSCs including SSCs classified as QC-4, are included within the scope of license renewal. Therefore, this review concludes that use of this scoping methodology does not preclude the identification of SSCs which should have been included within the scope of license renewal in accordance with 10 CFR 54.4(a). No additional scoping evaluations regarding this issue are required to be performed to address the 10 CFR 54.4(a) criteria.
Section 2.1.2.1, 10 CFR54.4(a)(1) Safety Related, of the STP License Renewal Application (LRA) will be revised to include Quality Class 4 (QC-4) SSCs and will state that Quality Class 4 SSCs are within the scope of license renewal for 10 CFR 50.54(a)(1).
RAI 2.1-2 Backgqround:
Title 10 of the Code of Federal Regulations (10 CFR) 54.4, "Scope," states, in part, (a) Plant systems, structures and components within the scope of this part are:
(1) Safety-related systems, structures, and components which are those relied upon to remain functional during and following design-basis events (as defined in 10 CFR 50.49 (b)(1)) to ensure the following functions:
(i) The integrity of the reactor coolant pressure boundary; (ii) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (iii) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to those referred to in 10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.
(2) All nonsafety-related systems, structures and components whose failure could prevent satisfactory accomplishment of any of the functions identified in (a)(1)(i), (ii), or (iii) of this section.
Issue:
During the scoping and screening methodology audit, performed on-site May 16-19, 2011, the staff reviewed the license renewal application, license renewal implementing documents and had discussions with the applicant, to determine the applicant's approach for identifying nonsafety-related SSCs, with the potential to impact safety-related SSCs, and to include the nonsafety-related SSCs within the scope of license renewal in accordance with 10 CFR 54.4
Enclosure NOC-AE-1 1002714 Page 3 of 7 (a)(2). The staff determined that the method used to address the potential for nonsafety-related SSCs to impact safety-related SSCs located in the turbine building as provided during discussions with the applicant, was different than the method provided in the license renewal application (LRA) and the applicant's implementing documents. The staff performed a plant walkdown of the safety-related SSCs located in the turbine building (feedwater regulating control valves' associated air solenoid valves and limit switches) and determined that there were nonsafety-related SSCs located within the vicinity of the safety-related SSCs. The LRA and the applicant's implementing documents stated that nonsafety-related piping and structures that could potentially interact with the safety-related solenoid valves and limit switches were included within the scope of license renewal in accordance with 10 CFR 54.4 (a)(2). However, during audit discussions with the staff, the applicant stated that the safety-related solenoid valves and limit switches were qualified to withstand the effects of the failure of nonsafety-related SSCs within the vicinity of the safety-related SSCs and, therefore, the nonsafety-related SSCs were not included within the scope of license renewal in accordance with 10 CFR 54.4 (a){2).
Request:
The staff requests that the applicant perform a review of this issue and provide a discussion and basis for the position, as stated by the applicant during the scoping and screening methodology audit, that nonsafety-related SSCs within the vicinity of the safety-related solenoid valves and limit switches located in the turbine building are not required to be included within the scope of license renewal in accordance with 10 CFR 54.4(a)(2). Indicate if the review concludes that use of the scoping methodology precluded the identification of systems, structures, and components (SSCs) which should have been included within the scope of license renewal in accordance with 10 CFR 54.4(a)(2). Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a)(2) criteria. List any additional SSCs included within the scope as a result of your efforts, and list those structures and components for which aging management reviews were conducted or any additional information related to material and environment combinations. For each structure and component, describe the aging management programs, as applicable, to be credited for managing the identified aging effects.
STPNOC Response:
Prior to submittal of the STP LRA, the feedwater regulating valves and associated safety-related solenoid valves and limit switches were walked down to identify nonsafety-related components whose failure could affect these safety-related components. Components in immediate vicinity of the solenoid valves and limit switches that were judged to have the potential for spatial interaction with the solenoid valves and limit switches to prevent satisfactory performance of their Intended function were included in the scope of license renewal under the requirements of 10 CFR 54.4(a)(2). The feedwater regulating valves and lines are within the scope of license renewal and subject to periodic external surfaces monitoring per LRA Section B2.1.20; thereby, ensuring that any external aging effects will be managed.
The solenoid valves, limit switches and associated circuits are environmentally qualified for steam line break, water spray and harsh temperature environments. High energy nonsafety-related components not in immediate vicinity that can not impact the safety-related components are not included within the scope of license renewal because the safety-related components are qualified for the environment resulting from failure of those nonsafety-related components. This is consistent with Section 5.2.3.2 of NEI 95-10, Rev. 6, Appendix F which states that "If a component is qualified/designed to maintain its function in an environment that could be caused by failure of a nearby non-safety SSC, that non-safety SSC would NOT need to be within the scope of 54.4(a)(2)."
Enclosure NOC-AE-1 1002714 Page 4 of 7 As a result of this review, no previously unidentified components are brought into the scope of license renewal.
RAI 2.1-3 Backgqround:
Title 10 of the Code of Federal Regulations (10 CFR) 54.4, "Scope," states, in part, (a) Plant systems, structures and components within the scope of this part are:
(1) Safety-related systems, structures, and components which are those relied upon to remain functional during and following design-basis events (as defined in 10 CFR 50.49 (b)(1))to ensure the following functions:
(i) The integrity of the reactor coolant pressure boundary; (ii) The capability to shut down the reactor and maintain it in a safe shutdown condition; or (iii) The capability to prevent or mitigate the consequences of accidents which could result in potential offsite exposures comparable to those referred to in 10 CFR 50.34(a)(1), 10 CFR 50.67(b)(2), or 10 CFR 100.11, as applicable.
(2) All nonsafety-related systems, structures and components whose failure could prevent satisfactory accomplishment of any of the functions identified in (a)(1)(i), (ii), or (iii) of this section.
Issue:
During the scoping and screening methodology audit performed on-site May 16-19, 2011, the staff determined that the applicant had performed a plant walkdown in April 2011, subsequent to the submittal of the license renewal application, during which the applicant identified additional SSCs to be included within the scope of license of renewal in accordance with 10 CFR 54.4(a)(2). The applicant had not submitted this information to the NRC, which identified additional non safety-related SSCs to be included within the scope of license renewal.
Request:
The staff requests that the applicant perform a review of this issue and indicate if the review concludes that use of the scoping methodology precluded the identification of SSCs which should have been included within the scope of license renewal in accordance with 10 CFR 54.4(a). Describe any additional scoping evaluations performed to address the 10 CFR 54.4(a) criteria. List any additional SSCs included within the scope as a result of your efforts, and list those structures and components for which aging management reviews were conducted or any additional information related to material and environment combinations. For each structure and component, describe the aging management programs, as applicable, to be credited for managing the identified aging effects.
Enclosure NOC-AE-1 1002714 Page 5 of 7 STPNOC Response:
Section 2.1.2.2 of the LRA states that non-safety related SSCs containing fluid or steam, and located in the same room or area containing safety-related SSCs are included in scope for potential leakage boundary (spatial) interaction under criterion 10 CFR 54.4(a)(2) (regardless of the system pressure). Identification of the rooms and areas of concern for potential spatial interaction is based on a review of the Current Licensing Basis and design drawings and considered for potential communication with other rooms that may contain 10 CFR 54.4(a)(1) components. The methodology used for the Reactor Containment Building (RCB), Isolation Valve Cubicle (IVC), Fuel Handling Building (FHB), and Mechanical Auxiliary Building (MAB) is to include all non safety-related fluid-filled SSCs in scope of license renewal for spatial interaction unless the components are in a closed area that does not allow spatial interaction with SSCs in an adjacent area.
Some SSCs in the MAB and FHB were not included within the scope of license renewal in the submitted LRA because of an incorrect usage of the information contained on a set of drawings showing seismic Il/I conditions. If the drawing indicated that the room did not contain seismic Il/I conditions (non Il/I area), then the approach was to exclude the room from 10 CFR 54.4(a)(2) evaluation for spatial interaction. The approach incorrectly concluded that the non-seismic Il/I area did not contain safety-related components although the room could have included safety-related components above non safety-related components.
Further evaluation determined that the approach for excluding non-seismic Il/I areas from 10 CFR 54.4(a)(2) evaluation for spatial interaction was not a valid approach. Walkdowns were performed for these previously excluded areas. The walkdowns identified that potential spatial interaction exists between seismic Il/I and non-seismic Il/I areas, and that some non-seismic Il/I areas contain safety-related components above non safety-related components.
Each room that was excluded from a 10 CFR 54.4(a)(2) evaluation based on the approach described above was reviewed to determine if the room contained safety-related components.
Table 1 shows the components that were identified within previously excluded rooms that could spatially interact with SR components and are in-scope per 10 CFR 54.4(a)(2). These components will be placed in-scope and managed by the aging management program (AMP) listed in Table 1.
LRA Sections 2.3.3, 2.3.4, 3.3 and 3.4 will be revised to include the components contained in Table 1. Boundary drawings will be revised to show the components listed in Table 1 are within the scope of license renewal.
Enclosure NOC-AE-1 1002714 Page 6 of 7 Table I Components within previously excluded rooms that could spatially interact with SR components and are in-scope per 10 CFR 54.4(a)(2).
Note: Components are designated by South Texas Project Total Plant Numbering System (TPNS) nomenclature.
AMP B.1.22, "Inspection of Internal Surfaces in AMP B.1.2, "Water Miscellaneous Chemistry" and AMP B.1.20, Piping and AMP B.1.16, "One-Time Comp "External Surfaces Comp Ducting Comp Inspection" Type Monitoring Program" Type Components" Type 7Q061TED0332 Valve 7S201MSP001 Filter 7Q061TED0096 Valve 7Q061TED0361 Valve 7S201TSB0230 Valve 7Q061TED0097 Valve 7Q061TED0362 Valve 7S201TSB0305 Valve 7Q061TED0098 Valve 7Q061 TED0363 Valve 7S201TSBO316 Valve 7Q061TED0170 Valve 7Q061TED0375 Valve 7S201TSB0380 Valve 7Q061TED0265 Valve 7Q061TED0378 Valve 7S201TSB0381 Valve 7Q061TED0268 Valve 7Q062TED0332 Valve 7S202MSP001 Filter 7Q061TED0281 Valve 7Q062TED0361 Valve 7S202TSB0305 Valve 7Q062TED0096 Valve 7Q062TED0362 Valve 7S202TSB0316 Valve 7Q062TED0097 Valve 7Q062TED0363 Valve 7S202TSB0380 Valve 7Q062TED0098 Valve 7Q062TED0375 Valve 7S202TSB0381 Valve 7Q062TED0170 Valve 7Q062TED0378 Valve N1SBFV5019 AOV-3 7Q062TED0265 Valve 7R181NDM102A Vessel N2SBFV5019 AOV-3 7Q062TED0268 Valve 7R181TBR0055 Valve 7Q062TED0281 Valve 7R181TBR0168 Valve 7R301TWL1086 Valve 7R181TBR0169 Valve 7R302TWL1 086 Valve 7R181TBR0218 Valve 7R321XPA1902 Pump 7R182NDM202A Vessel 7R321XWS0076 Valve 7R182TBR0055 Valve 7R321XWS0077 Valve 7R182TBR0168 Valve 7R321XWS0078 Valve 7R182TBR0169 Valve 7R321XWS0079 Valve 7R321 TWS0035 Valve 7R321XWS0080 Valve 7R322TWS0035 Valve 7R321XWS0081 Valve 7R322TWS0068 Valve 7R321XWS0083 Valve 7S201MDM001 Vessel 7R322TWS0036 Valve 7S201 MDM002 Vessel 7R322TWS0041 Valve 7S201 MSP001 Filter 7R322XPA1 902 Pump 7S201 TSB0230 Valve 7R322XWS0076 Valve 7S201TSB0305 Valve 7R322XWS0077 Valve 7S201TSB0316 Valve 7R322XWS0078 Valve 7S201TSB0319 Valve 7R322XWS0079 Valve 7S201 TSB0380 Valve 7R322XWS0080 Valve 7S201 TSB0381 Valve 7R322XWS0081 Valve 7S202MSP001 Filter 7R322XWS0082 Valve 7S202TSB0305 Valve 7R322XWS0083 Valve
Enclosure NOC-AE-1 1002714 Page 7 of 7 AMP B.1.22, "Inspection of Internal Surfaces in AMP B.1.2, "Water Miscellaneous Chemistry" and AMP B.1.20, Piping and AMP B.1.16, "One-Time Comp "External Surfaces Comp Ducting Comp Inspection" Type Monitoring Program" Type Components" Type 7S202TSB0316 Valve 9QO61NPA112A Pump 7S202TSB0319 Valve 9QO61NPA112B Pump 7S202TSB0380 Valve 9QO61NPA112C Pump 7S202TSB0381 Valve 9QO61NPA112E Pump 9S191TDW0609 Valve 9QO61NPA112F Pump 9S192TDW0609 Valve 9QO61NPA112G Pump NiFHLCV0027B Valve 9QO61NPA112H Pump N1FHPSV0028A PSV 9QO62NPAl 12A Pump N 1FHPSV0028B PSV 9QO62NPA112B Pump N1SBFV5019 AOV-3 9QO62NPA112C Pump N2SBFV5019 AOV-3 9QO62NPA 112E Pump OCM01FHVLVO026B Valve 9QO62NPA112F Pump 9QO62NPA112G Pump 9QO62NPA112H Pump 9R301NPA0103A Pump 9R301NPA0103B Pump Notes:
AOV - air-operated valve PSV - pressure relief valve