ML080880180
ML080880180 | |
Person / Time | |
---|---|
Site: | Vogtle ![]() |
Issue date: | 07/07/2008 |
From: | Richard Jervey NRC/NRR/ADRO/DORL/LPLII-1 |
To: | Tynan T Southern Nuclear Operating Co |
Lingam, Siva NRR/DORL 415-1564 | |
Shared Package | |
ML080880179 | List: |
References | |
TAC MD7772, TAC MD7773 | |
Download: ML080880180 (8) | |
Text
July 7, 2008 Mr. Tom E. Tynan Vice President - Vogtle Vogtle Electric Generating Plant 7821 River Road Waynesboro, GA 30830
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2, ISSUANCE OF AMENDMENTS REGARDING REVISION TO TECHNICAL SPECIFICATION TO LOWER THE NOMINAL TRIP SETPOINT OF THE REFUELING WATER STORAGE TANK (TAC NOS. MD7772 AND MD7773)
Dear Mr.Tynan:
The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment No. 151 to Facility Operating License NPF-68 and Amendment No. 132 to Facility Operating License NPF-81 for the Vogtle Electric Generating Plant, Units 1 and 2. The amendments consist of changes to the Technical Specifications (TSs) in response to your application dated January 9, 2008, as supplemented by letters dated February 6, 2008, March 5, 2008 and May 22, 2008.
The amendments revise TS 3.3.2, Engineered Safety Feature Actuation System (ESFAS)
Instrumentation, Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation, Function 7.b, and TS 3.5.4, Refueling Water Storage Tank (RWST), Surveillance Requirement (SR) 3.5.4.2. The proposed change to TS 3.3.2 lowers the nominal trip setpoint and corresponding allowable value of the refueling water storage tank (RWST) Level - Low Low at which the semi-automatic switchover from the RWST to the containment emergency sump occurs.
A copy of the related Safety Evaluation is also enclosed. A Notice of Issuance will be included in the Commission's biweekly Federal Register notice.
Sincerely,
/RA/
R. A. Jervey, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425
Enclosures:
- 1. Amendment No. to NPF-68
- 2. Amendment No. to NPF-81
- 3. Safety Evaluation cc w/encls: See next page
July 7, 2008 Mr. Tom E. Tynan Vice President - Vogtle Vogtle Electric Generating Plant 7821 River Road Waynesboro, GA 30830
SUBJECT:
VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2, ISSUANCE OF AMENDMENTS REGARDING REVISION TO TECHNICAL SPECIFICATION TO LOWER THE NOMINAL TRIP SETPOINT OF THE REFUELING WATER STORAGE TANK (TAC NOS. MD7772 AND MD7773)
Dear Mr.Tynan:
The U.S. Nuclear Regulatory Commission has issued the enclosed Amendment No. to Facility Operating License NPF-68 and Amendment No. to Facility Operating License NPF-81 for the Vogtle Electric Generating Plant, Units 1 and 2. The amendments consist of changes to the Technical Specifications (TSs) in response to your application dated January 9, 2008, as supplemented by letters dated February 6, 2008, March 5, 2008 and May 22, 2008.
The amendments revise TS 3.3.2, Engineered Safety Feature Actuation System (ESFAS)
Instrumentation, Table 3.3.2-1, Engineered Safety Feature Actuation System Instrumentation, Function 7.b, and TS 3.5.4, Refueling Water Storage Tank (RWST), Surveillance Requirement (SR) 3.5.4.2. The proposed change to TS 3.3.2 lowers the nominal trip setpoint and corresponding allowable value of the refueling water storage tank (RWST) Level - Low Low at which the semi-automatic switchover from the RWST to the containment emergency sump occurs.
A copy of the related Safety Evaluation is also enclosed. A Notice of Issuance will be included in the Commission's biweekly Federal Register notice.
Sincerely,
/RA/
R. A. Jervey, Project Manager Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425
Enclosures:
- 1. Amendment No. 151 to NPF-68
- 2. Amendment No. 132 to NPF-81
- 3. Safety Evaluation cc w/encls: See next page DISTRIBUTION:
Public RidsNrrDorlLpl2-1 RidsNrrDeEicb RidsNrrDssSsibEicb LPL2-1 R/F RidsNrrDssSrxb RidsNrrLAGLappert RidsAcrsAcnw&mMailCenter GHill (4) RidsNrrPMRJervey RidsOgcRp RidsNrrDirsItsb RidsRgn2MailCenter RidsNrrDeEicb RidsNrrDorlDpr Package No.: ML080880179; Amendment No.: ML080880180; Tech Spec No.: ML080880198 *memo transmitted SE dated OFFICE NRR/LPL2-1/PM NRR/LPL2-1/LA SRXB/BC EICB/BC ITSB/BC SSIB/BC OGC NLO NRR/LPL2-1/BC NAME RJervey GLappert GCranston WKemper RElliott MScott DRoth MWong 6/6/08 6/6/08 6/16/08 6/9/08 6/25/08 7/1/08 DATE 3/7/08* 3/25/08*
OFFICIAL RECORD COPY
SOUTHERN NUCLEAR OPERATING COMPANY, INC.
GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA VOGTLE ELECTRIC GENERATING PLANT, UNIT 1 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 151 License No. NPF-68
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment to the Vogtle Electric Generating Plant, Unit 1 (the facility) Facility Operating License No. NPF-68 filed by the Southern Nuclear Operating Company, Inc. (the licensee), acting for itself, Georgia Power Company, Oglethorpe Power Corporation, Municipal Electric Authority of Georgia, and City of Dalton, Georgia (the owners), dated January 9, 2008, as supplemented by letters dated February 6, 2008, March 5, 2008 and May 22, 2008, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations as set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations set forth in 10 CFR Chapter I; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
- 2. Accordingly, the license is hereby amended by page changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. NPF-68 is hereby amended to read as follows:
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 151, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. Southern Nuclear shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3. This license amendment is effective as of its date of issuance and shall be implemented within 30 days of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Melanie C. Wong, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to License No. NPF-68 and the Technical Specifications Date of Issuance: July 7, 2008
SOUTHERN NUCLEAR OPERATING COMPANY, INC.
GEORGIA POWER COMPANY OGLETHORPE POWER CORPORATION MUNICIPAL ELECTRIC AUTHORITY OF GEORGIA CITY OF DALTON, GEORGIA VOGTLE ELECTRIC GENERATING PLANT, UNIT 2 AMENDMENT TO FACILITY OPERATING LICENSE Amendment No. 132 License No. NPF-81
- 1. The Nuclear Regulatory Commission (the Commission) has found that:
A. The application for amendment to the Vogtle Electric Generating Plant, Unit 2 (the facility) Facility Operating License No. NPF-81 filed by the Southern Nuclear Operating Company, Inc. (the licensee), acting for itself, Georgia Power Company Oglethorpe Power Corporation, Municipal Electric Authority of Georgia, and City of Dalton, Georgia (the owners), dated January 9, 2008, as supplemented by letters dated February 6, 2008, March 5, 2008 and May 22, 2008, complies with the standards and requirements of the Atomic Energy Act of 1954, as amended (the Act), and the Commission's rules and regulations as set forth in 10 CFR Chapter I; B. The facility will operate in conformity with the application, the provisions of the Act, and the rules and regulations of the Commission; C. There is reasonable assurance (i) that the activities authorized by this amendment can be conducted without endangering the health and safety of the public, and (ii) that such activities will be conducted in compliance with the Commission's regulations set forth in 10 CFR Chapter I; D. The issuance of this amendment will not be inimical to the common defense and security or to the health and safety of the public; and E. The issuance of this amendment is in accordance with 10 CFR Part 51 of the Commission's regulations and all applicable requirements have been satisfied.
- 2. Accordingly, the license is hereby amended by page changes to the Technical Specifications as indicated in the attachment to this license amendment, and paragraph 2.C.(2) of Facility Operating License No. NPF-81 is hereby amended to read as follows:
Technical Specifications and Environmental Protection Plan The Technical Specifications contained in Appendix A, as revised through Amendment No. 132, and the Environmental Protection Plan contained in Appendix B, both of which are attached hereto, are hereby incorporated into this license. Southern Nuclear shall operate the facility in accordance with the Technical Specifications and the Environmental Protection Plan.
- 3. This license amendment is effective as of its date of issuance and shall be implemented within 30 days of issuance.
FOR THE NUCLEAR REGULATORY COMMISSION
/RA/
Melanie C. Wong, Chief Plant Licensing Branch II-1 Division of Operating Reactor Licensing Office of Nuclear Reactor Regulation
Attachment:
Changes to License No. NPF-81 and the Technical Specifications Date of Issuance: July 7, 2008
ATTACHMENT TO LICENSE AMENDMENT NO. 151 FACILITY OPERATING LICENSE NO. NPF-68 DOCKET NO. 50-424 AND TO LICENSE AMENDMENT NO. 132 FACILITY OPERATING LICENSE NO. NPF-81 DOCKET NO. 50-425 Replace the following pages of the Licenses and the Appendix A Technical Specifications (TSs) with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.
Remove Pages Insert Pages License License License No. NPF-68, page 4 License No. NPF-68, page 4 License No. NPF-81, page 4 License No. NPF-81, page 4 TSs TSs 3.3.2-14 3.3.2-14 3.5.4-2 3.5.4-2
SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 151 TO FACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 132 TO FACILITY OPERATING LICENSE NPF-81 SOUTHERN NUCLEAR OPERATING COMPANY, INC.
VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425
1.0 INTRODUCTION
By application dated January 9, 2008 (Agencywide Documents Access and Management System (ADAMS) Accession No. ML080150161), as supplemented by letters dated February 6, 2008 (ADAMS Accession No. ML080370342), March 5, 2008 (ADAMS Accession No. ML080660527) and May 22, 2008 (ADAMS Accession No. ML081440204), Southern Nuclear Operating Company, Inc. (SNC, the licensee), requested changes to the Technical Specifications (TSs) for the Vogtle Electric Generating Plant, Units 1 and 2 (Vogtle 1 and 2 or VEGP). The supplements dated February 6, 2008, March 5, 2008 and May 22, 2008, provided additional information that clarified the application, did not expand the scope of the application as originally noticed, and did not change the U.S. Nuclear Regulatory Commission (NRC) staff original proposed no significant hazards consideration determination as published the Federal Register on January 29, 2008 (73 FR 5230).
Changes to the TS are proposed as follows:
- 1. TS Table 3.3.2.1, AEngineered Safety Feature Actuation System [ESFAS]
Instrumentation,@ Function 7.b, Refueling Water Storage Tank (RWST) Level-Low Low, The Allowable Value of Function 7.b, would be changed from 264.9 inches to a span from 210.4 to 216.6 inches. The Nominal Trip Setpoint (NTS), would be changed from 275.3 inches to 213.5 inches. There is a footnote added to TS Table 3.3.2.1 regarding the one-time implementation of the setpoint and allowable values.
- 2. The TS Surveillance Requirement (SR) 3.5.4.2 required RWST borated water volume would be changed from 631,478 gallons to 686,000 gallons.
TS Change 1 will lower the NTS and corresponding allowable value of the RWST Level - Low Low signal at which the semi-automatic switchover from the RWST to the containment sump will occur.
TS Change 2 will increase the minimum required borated water volume. The 686,000 gallons represent actual contained borated water volume in the RWST. The RWST minimum inventory and semi-automatic switchover to containment sump setpoint will ensure that the emergency core cooling system (ECCS) and containment spray system (CSS) sump screens will be fully submerged at the time of the initiation of switchover to ECCS recirculation from the containment emergency sump pumps. The proposed TS changes are in response to NRC Generic Letter 2004-02, APotential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors.@
The VEGP Final Safety Analysis Report (FSAR), Section 6.3.2.2.9, Refueling Water Storage Tank, states that the RWST provides a source of water for the safety injection (SI), containment spray, centrifugal charging, and residual heat removal (RHR) pumps following an accident. The SI mode of the ECCS operation consists of the ECCS pumps (charging pumps, SI pumps, and RHR pumps) and the containment spray pumps taking suction from the RWST and delivering to the reactor coolant system (RCS) and containment, respectively. During the injection mode of the ECCS operation, the operator monitors the RWST level and containment emergency sump level in anticipation of switchover. Upon receipt of the RWST Level-Low Low level alarm, the operator is required to initiate the manual operations to complete switchover in a timely manner. The switchover from the injection to cold leg recirculation is initiated automatically upon receipt of the RWST Level-Low Low trip signal and is completed by timely operator action at the main control room board. The switchover is initiated by the automatic opening of the containment emergency sump isolation valves. This automatic action aligns the suction of the RHR pumps to the containment emergency sump to ensure continued availability of suction source. Manual actions according to FSAR Table 6.3.2-7, Sequence of Switchover Operations, must be performed following switchover initiation to ensure that all pumps are protected with suction flow available from the containment emergency sump.
2.0 REGULATORY EVALUATION
2.1 The Commission=s regulatory requirements related to the contents of the TSs are set forth in Title 10 of the Code of Federal Regulations (10 CFR), Part 50, Section 50.36, Technical specifications, that assures the TS specified limiting conditions for operations are consistent with the assumed values of the initial conditions in the licensee=s safety analyses. In accordance with 10 CFR 50.36, the NRC staff and the nuclear steam supply system (NSSS) Owner=s groups developed improved standard technical specifications (ISTSs) that meet 10 CFR 50.36(d)(2), limiting conditions for operation, criteria. The ECCS must be designed so that its calculated cooling performance following postulated loss-of-coolant-accidents (LOCAs) conforms to the 10 CFR 50.46(b)(5), Long-term cooling, requirements. The objectives of NRC Generic Letter (GL) 2004-02, APotential Impact of Debris Blockage on Emergency Recirculation during Design Basis Accidents at Pressurized-Water Reactors,@ and Generic Safety Issue (GSI) 191, AAssessment of Debris Accumulation on PWR Sump Performance,@ are to ensure that post-accident debris blockage will not impede or prevent the operation of the ECCS and CSS in recirculation mode at pressurized-water reactors (PWRs) during LOCAs or other high-energy line break (HELB) accidents for which sump recirculation is required. Section 50.36(d)(1)(ii)(A) states, Where a limiting safety system setting is specified for a variable on which a safety
limit has been placed, the setting must be so chosen that automatic protective action will correct the abnormal situation before a safety limit is exceeded. Furthermore, section 50.36(d)(3) states, Surveillance requirements are requirements relating to test, calibration, or inspection to assure that the necessary quality of systems and components is maintained, that facility operation will be within safety limits, and that the limiting conditions for operation will be met.
2.2 Regulatory Guide (RG) 1.105, Revision 3, Setpoints for Safety-Related Instrumentation, describes a method acceptable to the NRC staff for complying with the NRCs regulations for ensuring that setpoints for safety-related instrumentation are initially within and remain within the TS limits. The RG endorses Part I of ISA-S67.04-1994, Setpoints for Nuclear Safety-Related Instrumentation, subject to the NRC staff clarifications.
2.3 NRC Regulatory Issue Summary (RIS) 2006-17, NRC Staff Position on the Requirements of 10 CFR 50.36, Technical Specifications, Regarding Limiting Safety System Settings During Periodic Testing and Calibration of Instrument Channels, dated August 24, 2006 (ADAMS Accession No. ML051810077), addresses the NRCs requirements on limiting safety system settings (LSSSs) assessed during periodic testing and calibration of instrumentation. This RIS discusses issues that could occur during testing of LSSSs and which, therefore, may have an adverse effect on equipment operability.
2.4 Letter from Patrick L. Hiland, NRC, to the Nuclear Energy Institute (NEI) Setpoint Methods Task Force, "Technical Specification for Addressing Issues Related to Setpoint Allowable Values," dated September 7, 2005 (ADAMS Accession No. ML052500004). This letter addresses the footnotes that should be added to SRs related to setpoint verification surveillance for instrument functions on which a safety limit has been placed and the information to be included to ensure operability of the instruments following surveillance tests related to instrument setpoints.
2.7 Letter from Bruce A. Boger, NRC, to Alexander Marion, NEI, "Instrumentation, Systems, and Automation Society (ISA) S67.04 Methods for Determining Trip Setpoints and Allowable Values for Safety-Related Instrumentation," dated August 23, 2005 (ADAMS Accession No. ML051660447).
2.8 Letter from James A. Lyons, NRC, to Alexander Marion, NEI, "Instrumentation, Systems, and Automation Society S67.04 Methods for Determining Trip Setpoints and Allowable Values for Safety-Related Instrumentation," dated March 31, 2005 (ADAMS Accession No. ML050870008).
3.0 TECHNICAL EVALUATION
=
Background===
The following background information is obtained from the licensees submittals and referenced sources.
The RWST supplies borated water to both trains of the ECCS and the CSS during the injection phase of a LOCA recovery. The RWST Level - Low Low signal automatically initiates opening of the residual heat removal (RHR) containment emergency sump isolation valves. Upon receipt of the RWST Level - Low Low signal, the operator is required to perform manual switchover steps to complete the switchover in an orderly and timely manner and in proper sequence. The containment emergency sump isolation valves are automatically opened on the RWST Level-Low-Low concurrently with a safety injection signal so as to provide a source of water to the RHR pumps. The operator manually shuts the suction valves to the RWST. The operator also aligns the suction of the charging and SI pumps to the discharge of the RHR pumps, thereby assuring an available suction source for all ECCS pumps. The revised RWST Level - Low Low nominal setpoint will continue to assure that the ECCS switchover is completed prior to the receipt of the RWST empty alarm. Following ECCS realignment from injection to recirculation and upon receipt of an RWST empty level alarm, the containment spray pumps= suctions are remote-manually transferred to the containment emergency sumps. Both CSS pumps take suction from the containment emergency sumps and deliver flow to the containment spray ring headers.
The proposed TS changes are required to meet commitments related to the resolution of issues identified in NRC GL 2004-02, APotential Impact of Debris Blockage on Emergency Recirculation During Design Basis Accidents at Pressurized-Water Reactors,@ dated September 13, 2004. Also these changes were necessitated by the recent identification of a design deficiency that the RHR containment sump screens could uncover at the initiation of switchover of the ECCS suction from the RWST to the containment sumps following a LOCA.
New containment emergency sump screens were installed in Vogtle 1 during the fall of 2006, and Vogtle 2 during the spring of 2007 that increased the available screen area from approximately 54 square feet to 765 square feet for each of the RHR screens, and approximately 54 square feet to 590 square feet for each CSS screen. These screens have a smaller mesh size, 3/32-inch diameter versus 1/8-inch square opening in the old screens. Current modeling shows that the water level in the containment building will be at 175 feet-8 inches at the initiation of sump recirculation. The design of the containment sump screens requires that the containment sump water level be maintained at 177 feet or greater to assure screen performance with the assumed debris loading. This water level ensures that there is a minimum of 3 inches of water over the top of the screens (elevation 176 feet-9 inches).
The proposed TS changes to lower the semi-automatic switchover setpoint and increase the minimum RWST borated water volume are required because of the design of the new sump screens which are required to be fully submerged.
The increase in the RWST minimum inventory and semi-automatic switchover to the containment sump setpoint will ensure that ECCS and CSS sump screens will be fully submerged at the time of the initiation of switchover to ECCS recirculation from the containment emergency sump pumps.
The change in delivered water volume between the current RWST minimum inventory and the RWST semi-automatic switchover to the containment sump setpoint will increase the amount of water available in the containment sumps at the beginning of the ECCS switchover. The containment sump setpoint revision will result in an increase of approximately 69,000 gallons in delivered RWST water, and the RWST volume revision will result in an increase of approximately 54,500 gallons. Thus, the total increase in delivered RWST water prior to semi-automatic
switchover to the containment sump is approximately 123,500 gallons which will increase the available net positive suction head (NPSH). It will delay the start of switchover from approximately 8 minutes to several hours depending on LOCA break size.
The revised RWST Level - Low Low nominal setpoint will continue to ensure that ECCS switchover is completed prior to receipt of RWST Empty alarm. The revised RWST Empty setpoint alarm provides sufficient margin to ensure that CSS switchover is completed and suction to the RWST is isolated. The licensee has stated in their letter of May 22, 2008, that once switchover begins, the operator has 11.1 minutes to complete the switchover, and that existing criteria requires a minimum of 10 minutes for this phase of ECCS operation. Additionally the time before switchover is required increases from 21.6 minutes to 27.9 minutes, thus providing the operators additional time in advance to plan for switchover. The NRC staff evaluated the change in setpoint from a human factors perspective and noted the time to switchover, while shorter than before, still exceeds the basis of the current sizing and alarm setpoints (a minimum of 10 minutes for the switchover). Thus, the NRC staff has concluded that the operator has sufficient time to successfully perform manual operations and switchover from RWST to the containment sumps.
In the licensees May 22, 2008, letter, the implementation plan for changing to the new Table 3.3.2.1, Function 7.b setpoint and allowable values is discussed. The implementation requires a one-time footnote to the table to be added to allow the orderly change for all 4 instrumentation channels each for Unit 1 and 2. The footnote allows 2 channels to be inoperable simultaneously for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> during the period of implementation, whereas the Table 3.3.2.1 requirement normally allows only one channel to be inoperable for up to 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The licensee has discussed the instrumentation function during the period of implementation for this change and has identified that for the period of time the Function 7.b setpoint and allowable values are transitioning between the current (old) setpoint and the proposed (new) setpoint that the response of the system would be either controlled by the old setpoint or the new. The staff has reviewed the footnote and found it to be a reasonable means to transition to the desired new setpoint.
In the licensees January 9, 2008 application, a description of the impact of the proposed TS changes was included for non-LOCA analyses, a small break LOCA analysis, a LOCA long-term cooling evaluation, a LOCA containment response analysis and a boration capability evaluation.
The licensee concluded that there will be no impact on these analyses. The NRC staff finds these evaluations to be acceptable because the evaluations showed that the change in RWST setpoint level and the resulting water volume would be available to satisfy ECCS and CSS functions in the long term recirculation period, or the RWST level and volume was not credited in the LBLOCA analyses, such that the proposed TS changes would have no impact on these analyses.
In response to the NRC staff request for additional information (RAI), the licensees letter dated February 6, 2008, evaluated and demonstrated that adequate NPSH margin in excess of 45 feet will be available for all ECCS and CSS pumps during the recirculation mode of operation. The licensee also stated in the application of January 9, 2008, that the calculation of the maximum containment water levels is based on the full contained volume of the RWST, maximum inventory from the LOCA, and conservative modeling of the containment to maximize the flood level for the design and environmental qualification of equipment. The existing analysis is unchanged by the change in the semi-automatic switchover RWST setpoint, because it is based on the physical characteristics of the RWST (maximum contained volume) and does not use the switchover setpoint. Thus the proposed increased water volume delivered to containment was already
considered and does not cause a flooding or environmental effect. The NRC staff concluded that the calculated NPSH of the proposed change is beneficial in comparison to the current NPSH.
The current VEGP TS 2.1.1 for the reactor core safety limits (SLs) states: In MODES 1 and 2, the combination of THERMAL POWER, Reactor Coolant System (RCS) highest loop average temperature, and pressurizer pressure shall not exceed the SLs specified in Figure 2.1.1-1. And the current VEGP TS 2.1.2 for the RCS pressure safety limit states: In MODES 1, 2, 3, 4, and 5, the RCS pressure shall be maintained 2735 psig. Automatic protection for these SLs is provided by:
- a. high pressurizer pressure trip;
- b. low pressurizer pressure trip;
- c. overtemperature T trip;
- d. overpower T trip;
- e. power range neutron flux trip;
- f. reactor coolant flow trips (including undervoltage and underfrequency of the reactor coolant pump buses); and
The semi-automatic switchover to the containment sump by the RWST Level-Low Low instrumentation does not play any part in the operations of the above listed protective functions.
Therefore, the NRC staff finds that the semi-automatic switchover to the containment sump by RWST Level-Low Low instrumentation is not SL-related in accordance with 10 CFR 5.36(d)(1)(ii)(A).
By letter dated March 5, 2008, the licensee provided relevant parameters used in calculating the nominal trip setpoint, allowable value, Acceptable As-Left, and Acceptable As-Found values, as discussed in the enclosure to the letter, Vogtle Electric Generating Plant Response to NRC Request for Additional Information Regarding License Amendment Request to Revise Technical Specifications (TS) 3.3.2, ESFAS Instrumentation, and TS 3.5.4, Refueling Water Storage Tank (RWST), (Westinghouse proprietary). The methodology referenced by the licensee used the square-root-of-the-sum-of-the-squares for the independent uncertainties and arithmetic summation for the uncertainties that are not independent. The licensee used the same value for the AV, Acceptable As-Found value, and the Acceptable As-Left value. The NRC staff reviewed Westinghouses proprietary calculation on the methodology used to calculate the total channel statistical allowance and the rack calibration accuracy and finds them acceptable. However, since the information provided is proprietary, the NRC staff is not reporting any setpoint numbers in this report. The NRC staff finds that the setpoint calculation methodology is consistent with the guidance in NRC RG 1.105, Revision 3, and is acceptable.
The NRC staff reviewed the licensees processes to address instrumentation found out of calibration, as discussed in the March 5, 2008, letter and finds that with the AV, Acceptable As-Found value, and the Acceptable As-Left value all being the same, during the calibrations tests whenever the As-Found value is observed to be beyond the Acceptable As-Left value, the licensee will declare the channel inoperable, recalibrate the instruments within the Acceptable As-Left value and enter this event into the corrective action program for evaluation of the instruments acceptable operation. The NRC staff finds this practice to be consistent with the guidance in RG 1.105 and RIS 2006-17, and therefore acceptable.
The NRC staff finds that because the RWST Level-Low Low setpoint instrumentation does not play any part in initiation of the protective functions that protect the reactor core SLs and RCS pressure SL specified in TS SLs 2.1.1 and 2.1.2, respectively, this function is not SL-related.
Furthermore, because the licensee has used the same value for AV, Acceptable As-Found value, and Acceptable As-Left value the applicable plant processes are consistent with RG 1.105 and RIS 2006-17. The NRC staff finds that the setpoint calculation methodology complies with RG 1.105. Based on above considerations, the NRC staff concludes that the proposed TS changes discussed in Section 1.0 comply with 10 CFR 50.36, and are, therefore, acceptable.
The licensee included revised TS Bases in its application to be implemented with the TS change.
The NRC staff approval was based on the information provided by the licensee, including the TS Bases. After incorporation of the amendment, the licensee may follow TS 5.5.14 should it desire to make additional changes to the bases.
4.0 STATE CONSULTATION
In accordance with the Commission's regulations, the Georgia State official was notified of the proposed issuance of the amendments. The State official had no comments.
5.0 ENVIRONMENTAL CONSIDERATION
The amendments change a requirement with respect to the installation or use of facility components located within the restricted area as defined in 10 CFR Part 20 and change surveillance requirements. The NRC staff has determined that the amendments involve no significant increase in the amounts and no significant change in the types of any effluents that may be released offsite and that there is no significant increase in individual or cumulative occupational radiation exposure. The Commission has previously issued a proposed finding that the amendments involve no significant hazards consideration, and there has been no public comment on such finding (73 FR 5230). Accordingly, the amendments meet the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22(c)(9). Pursuant to 10 CFR 51.22(b) no environmental impact statement or environmental assessment need be prepared in connection with the issuance of the amendments.
6.0 CONCLUSION
The Commission has concluded, based on the considerations discussed above, that: (1) there is reasonable assurance that the health and safety of the public will not be endangered by operation in the proposed manner, (2) such activities will be conducted in compliance with the Commission's regulations, and (3) the issuance of the amendments will not be inimical to the common defense and security or to the health and safety of the public.
Principal Contributors: K. Desai, S. Mazumdar Date: July 7, 2008
Vogtle Electric Generating Plant, Units 1 & 2 cc:
Mr. Tom E. Tynan Tucker, GA 30085-1349 Vice President - Vogtle Arthur H. Domby, Esquire Vogtle Electric Generating Plant Troutman Sanders 7821 River Road Nations Bank Plaza Waynesboro, GA 30830 600 Peachtree Street, NE Suite 5200 Mr. N. J. Stringfellow Atlanta, GA 30308-2216 Manager, Licensing Southern Nuclear Operating Company, Inc. Resident Inspector P.O. Box 1295 Vogtle Plant Birmingham, AL 35201-1295 8805 River Road Waynesboro, GA 30830 Mr. Jeffrey T. Gasser Executive Vice President Office of the County Commissioner Southern Nuclear Operating Company, Inc. Burke County Commission P.O. Box 1295 Waynesboro, GA 30830 Birmingham, AL 35201-1295 Mr. Bob Masse Mr. Steven M. Jackson Resident Manager Senior Engineer - Power Supply Oglethorpe Power Corporation Municipal Electric Authority of Georgia Vogtle Electric Generating Plant 1470 Riveredge Parkway, NW 7821 River Road Atlanta, GA 30328-4684 Waynesboro, GA 30830 Mr. Reece McAlister Executive Secretary Georgia Public Service Commission 244 Washington St., SW Atlanta, GA 30334 Mr. Harold Reheis, Director Department of Natural Resources 205 Butler Street, SE, Suite 1252 Atlanta, GA 30334 Attorney General Law Department 132 Judicial Building Atlanta, GA 30334 Mr. Laurence Bergen Oglethorpe Power Corporation 2100 East Exchange Place P.O. Box 1349