ML040480089

Plants, Units 1 and 2, Issuance of Amendments Reactor Trip System Instrumentation

ML040480089
Person / Time
Site:	Vogtle
Issue date:	04/01/2004
From:	Gratton C NRC/NRR/DLPM/LPD2
To:	Gasser J Southern Nuclear Operating Co
BloomSD/NRR/DE/EMCB/415-1313
Shared Package
ML040960002	List: ML040480089
References
TAC MC1551, TAC MC1552
Download: ML040480089 (12)

Text

April 1, 2004 Mr. J. T. Gasser, Vice President Southern Nuclear Operating Company, Inc.

Post Office Box 1295 Birmingham, Alabama 35201-1295

SUBJECT:

VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 RE: ISSUANCE OF AMENDMENTS RE: REACTOR TRIP SYSTEM INSTRUMENTATION (TAC NOS. MC1551 AND MC1552)

Dear Mr. Gasser:

The Nuclear Regulatory Commission (Commission) has issued the enclosed Amendment No. 131 to Facility Operating License NPF-68 and Amendment No. 110 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 December 15, 2003.

The amendments revise Surveillance Requirements (SR) 3.3.1.2 and SR 3.3.1.3 of the TSs on the reactor trip system instrumentation. The proposed changes to SR 3.3.1.2 deletes Note 1, adds an instruction for adjusting power range channel output only when the calorimetric heat balance calculation results exceed the power range channel output by more than 2 percent of rated thermal power. The format of SR 3.3.1.3 is being changed to be consistent with SR 3.3.1.2.

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/

Christopher Gratton, Sr. Project Manager, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation Docket Nos. 50-424 and 50-425

Enclosures:

1. Amendment No. 131 to NPF-68

2. Amendment No. 110 to NPF-81

3. Safety Evaluation cc w/encls: See next page

ML040480089 Package No.: ML040960002 NRR-058 Encl 1: ML040960285 OFFICE PDII-1/PM PDII-1/LA EEIB/SC IROB/SC SRXB/SC OGC** PDII-1/SC NAME CGratton CHawes EMarinos* TBoyce* JWermiel* LZaccari* JNakoski DATE 3/19/04 3/19/04 3/3/04 2/27/04 3/2/04 3/8/04 3/26/04 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. 131 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 December 15, 2003, 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. 131, 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/

John A. Nakoski, Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Technical Specification Changes Date of Issuance: April 1, 2004

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. 110 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 December 15, 2003, 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. 110, 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/

John A. Nakoski, Chief, Section 1 Project Directorate II Division of Licensing Project Management Office of Nuclear Reactor Regulation

Attachment:

Technical Specification Changes Date of Issuance: April 1, 2004

ATTACHMENT TO LICENSE AMENDMENT NO. 131 FACILITY OPERATING LICENSE NO. NPF-68 DOCKET NO. 50-424 AND TO LICENSE AMENDMENT NO. 110 FACILITY OPERATING LICENSE NO. NPF-81 DOCKET NO. 50-425 Replace the following pages of the Appendix A Technical Specifications and associated Bases with the attached revised pages. The revised pages are identified by amendment number and contain marginal lines indicating the areas of change.

Remove Insert 3.3.1-9 3.3.1-9 B 3.3.1-55 B 3.3.1-55 B 3.3.1-56 B 3.3.1-56 B 3.3.1-57 B 3.3.1-57 B 3.3.1-57a --

B 3.3.1-57b --

B 3.3.1-58 B 3.3.1-58 B 3.3.1-59 B 3.3.1-59 B 3.3.1-60 B 3.3.1-60 B 3.3.1-61 B 3.3.1-61 B 3.3.1-62 B 3.3.1-62 B 3.3.1-63 B 3.3.1-63 B 3.3.1-64 B 3.3.1-64 B 3.3.1-65 B 3.3.1-65 B 3.3.1-66 B 3.3.1-66

-- B 3.3.1-67

SAFETY EVALUATION BY THE OFFICE OF NUCLEAR REACTOR REGULATION RELATED TO AMENDMENT NO. 131 TO FACILITY OPERATING LICENSE NPF-68 AND AMENDMENT NO. 110 TO FACILITY OPERATING LICENSE NPF-81 SOUTHERN NUCLEAR OPERATING COMPANY, INC., ET AL.

VOGTLE ELECTRIC GENERATING PLANT, UNITS 1 AND 2 DOCKET NOS. 50-424 AND 50-425

1.0 INTRODUCTION

By letter dated December 15, 2003, Southern Nuclear Operating Company, Inc., et al. (the licensee) proposed license amendments to change the Technical Specifications (TS) for the Vogtle Electric Generating Plant (Vogtle), Units 1 and 2. The proposed changes would revise Surveillance Requirements (SR) 3.3.1.2 and SR 3.3.1.3 on reactor trip system (RTS) instrumentation. The proposed changes to SR 3.3.1.2 would move Note 1 to the body of the SR, replace the reference to nuclear instrumentation system (NIS) channel output by a reference to power range channel output, and delete the reference to the absolute difference.

The format of SR 3.3.1.3 is being changed to be consistent with the proposed changes to SR 3.3.1.2. The licensee also provided the associated changes to the Bases of the TSs.

2.0 REGULATORY EVALUATION

In accordance with Standard Review Plan (SRP) (NUREG-0800) Sections 7.1, "Instrumentation and Controls - Introduction," and 7.2, "Reactor Trip System," the acceptance criteria for the review of RTS instrumentation are the relevant requirements of the following regulations:

! Title 10 of the Code of Federal Regulations (10 CFR) Section 50.55a(h) that requires IEEE Standard 279-1971, "Criteria for Protection Systems for Nuclear Power Generating Stations."

! General Design Criterion (GDC) 2, "Design Basis for Protection Against Natural Phenomena," of Appendix A to 10 CFR Part 50.

! GDC 4, "Environmental and Missile Design Basis."

! GDC 13, "Instrumentation and Control."

! GDC 20, "Protection Systems Functions."

! GDC 21, "Protection System Reliability and Testability."

! GDC 22, "Protective System Independence."

! GDC 23, "Protection System Failure Modes."

! GDC 24, "Separation of Protection and Control Systems."

! GDC 25, "Protection System Requirements for Reactivity Control Malfunctions."

! GDC 29, "Protection Against Anticipated Occurrences."

SRP 7.2 also gives the following major design considerations: (1) system redundancy requirements to assure that at least two redundant logic trains (i.e., a minimum degree of redundancy of one) are provided to initiate reactor trip, and (2) electrical and physical independence, and single failure criterion requirements.

3.0 BACKGROUND

The licensee adopted the Improved Technical Specifications (ITS) in License Amendment No. 96 for Unit 1 and License Amendment No. 74 for Unit 2 (issued September 25, 1996) based on NUREG-1431, "Standard Technical Specifications for Westinghouse Plants,"

Revision 1, dated April 1995. Since then, industry and the NRC staff have been working to improve the ITS, in NUREG-1430 through NUREG-1434 for the different plant vendors, and as a result, generic changes have been developed for the standard ITS in NUREG-1431.

Changes to NUREG-1431 would be applicable to Vogtle because the TSs for Vogtle are based on NUREG-1431.

The proposed changes adopt NRC-approved generic changes in the industry TSTF-371, Revision 1, "NIS Power Range Channel Daily SR TS Change to Address Low Power Decalibration," that was approved by the NRC staff in a letter dated April 2, 2002. As stated by the NRC staff in its discussion of TSTF-371, the TSTF revises SR 3.3.1.2 to resolve the undesirable condition that compliance with the current SR 3.3.1.2 may result in a non-conservative channel calibration during reduced power operations. The proposed SR 3.3.1.2 would only require adjustment of the NIS power range channels when the calorimetric heat balance calculated power is greater than the power range indicated power by +2 percent. The changes to SR 3.3.1.3 are editorial because of the changes to SR 3.3.1.2.

The NIS power range channels provide indications of reactor power to the RTS. These indications are, as shown in TS Table 3.3.1-1, for the RTS trip function on the power range neutron flux high. The daily surveillance of the NIS power range channels for the power range neutron flux high trip function (SR 3.3.1.2) ensures the channels accurately reflect the reactor power based on the calorimetric heat balance calculation. A low power indication in the NIS power range channels would non-conservatively affect the RTS, and thus, the protection of the reactor.

In its application, the licensee stated that the proposed changes address the potential effects of decalibrating the NIS power range channels at less than 100 percent power operation as discussed in Westinghouse Technical Bulletin (TB) ESBU-TB-92-14-R1, "Decalibration Effects of Calorimetric Power Measurements on the NIS High Power Reactor Trip at Power Levels Less than 70% RTP [Rated Thermal Power]," dated February 6, 1996. The TB identified potential effects for such decalibration, that can occur due to the increased uncertainty of the secondary side power calorimetric when performed at reduced-power operation. The

plant-specific reduced power level where this occurs can be determined following the guidance in the TB. The Vogtle calculation of the power level below which NIS power range channel adjustments in a decreasing power direction become a concern are at 50 percent RTP. The calculation was not reviewed by the NRC staff.

As stated in the application, this power level for Vogtle is less than 50 percent RTP (i.e., the nominal 109 percent RTP high flux trip setpoint, in TS Table 3.3.1-1, is considered adequately conservative for NIS calibrations performed at or above 50 percent RTP). The calculation has a table that shows that calibrating the NIS channels at calorimetric power levels less than 50 percent RTP would require the allowable NIS trip setpoint to be set to less than or equal to 90 percent RTP and calibrating at less than 20 percent RTP, adjust the setpoint to less than or equal to 75 percent RTP.

The licensee stated that the Westinghouse TB recommends that caution should be exercised if the NIS power range channels are adjusted in the decreasing power direction when the power channels indicate a higher power than the secondary side power calorimetric measurement at power levels below a plant-specific value (i.e., 50 percent RTP for Vogtle, as discussed above).

This recommendation is in conflict with SR 3.3.1.2, which requires channel adjustment when the absolute difference is greater than 2 percent RTP and the plant is greater than or equal to 15 percent RTP. In its application, the licensee stated that it had implemented administrative controls soon after it had discovered this issue involving SR 3.3.1.2.

The proposed amendment removes the requirement to adjust the NIS power range channels in the decreasing power direction when the indicated power is greater than the calorimetric heat balance calculation by more than 2 percent RTP. The licensee stated that compliance with existing SR 3.3.1.2 may result in a non-conservative channel calibration during reduced power operation. The licensee's presentation of the changes to TS Bases for SR 3.3.1.2 provides a description of the potential decalibration of the NIS power range channels at reduced-power operation.

4.0 TECHNICAL EVALUATION

The licensee's proposed changes to SR 3.3.1.2 would (1) move the requirement in Note 1 to the body of the SR, replace the reference to NIS channel by a reference to power range channel, and delete the reference to the absolute difference, and (2) editorially revise the SR to state the following:

Compare results of calorimetric heat balance calculation to power range channel output.

Adjust power range channel output if calorimetric heat balance calculation results exceed power range channel output by more than +2% RTP.

The NIS channel for SR 3.3.1.2, as shown in item 2.a of TS Table 3.3.1-1, is the power range channel. The current SR 3.3.1.2 requires the power range channel output to be adjusted when the absolute difference between the channel output and the calorimetric heat balance calculation is greater than 2 percent RTP. With the content of Note 1 moved to the SR and the reference to the absolute difference removed, the revised SR 3.3.1.2 is the same as the current SR 3.3.1.2 except that the revised SR would require the power range channel to be adjusted only when the calorimetric heat balance calculation results exceed the power range channel output by 2 percent RTP. Therefore, if the power range channels are underestimating reactor power by more than 2 percent RTP, the channels are required to be adjusted to indicate power

more accurately. The 2 percent RTP limit and the 24-hour surveillance frequency are intended to ensure that the power range high neutron flux high setpoint reactor trip signal will be generated prior to the safety analysis limit. The calorimetric heat balance calculation is considered the more accurate determination of reactor power. This change does not affect the design of any NIS channel.

As stated above, the Westinghouse TB addresses potential effects of decalibrating the NIS power range channels at reduced power operation. The licensee has proposed to require the readjustment of the power range channel output only if the channel output is less than the calorimetric heat balance calculation result when the channel input to the RTS for reactor power could be too low for a reactor trip. The revised SR 3.3.1.2 would act to have the channel outputs overestimate the reactor power, which would be a conservative input to the RTS, and compensate for the potential decalibration addressed in the TB.

The licensee further stated in its application that it also considered the effect of the potential decalibration of the NIS power range channels addressed in the TB on the following RTS design functions: power range indications, power range RTS trip functions (other than the high neutron flux), power range RTS permissive functions, power range control functions, and miscellaneous alarm functions. The licensee stated that none of these RTS design functions were adversely impacted by the potential decalibration addressed in the TB.

There is the potential that the decalibration may cause the reset of the P-10 interlock to occur at a power level that is lower than the allowable value in TS Table 3.3.1-1 (i.e., the NIS channel indication is higher than the actual RTP). The function of the automatic P-10 interlock reset is to enable reactor trips from the power range neutron flux-low and the intermediate and source range neutron flux functions. These reactor trips provide reactor protection for uncontrolled reactivity excursions from subcritical to low power (i.e., less than 8 percent RTP). The licensee addressed this in its application and stated that, for this case, the NIS power range channel would reach the reactor trip at the power range neutron flux-high trip setting well before the actual power reached the trip setting of 118 percent RTP and this event would remain bounded by the accident analyses in the Vogtle Final Safety Analysis Report (FSAR) Update. As shown in Section 15.4.1 of the FSAR Update, for the analysis of the uncontrolled rod cluster control assembly bank withdrawal from a subcritical condition, the reactor trip is assumed to be initiated by the power range high neutron flux and not by any of the reactor trips enabled by the reset of the P-10 interlock. Therefore, the impact of the potential decalibration on the reset of the P-10 interlock does not change the accident analyses in the FSAR Update.

For SR 3.3.1.3, the licensee has proposed to move Note 1 to the body of SR 3.3.1.3 for consistency with the proposed change to SR 3.3.1.2. The proposed change to SR 3.3.1.3 is editorial in nature because the requirements of SR 3.3.1.3 are not being changed. The proposed change moves the requirement in Note 1 of SR 3.3.1.3 into the body of the SR and the acronym NIS is spelled out because it no longer appears in SR 3.3.1.2. The surveillance requirement in SR 3.3.1.3 remains unchanged; excore NIS channels are adjusted every

31 effective full power days if the absolute difference between the incore and excore axial flux difference is greater than or equal to 3 percent RTP.

Based on the above evaluation, the NRC staff concludes that proposed change to SR 3.3.1.2 is conservative, accounts for potential effects of decalibrating the NIS power range channels during reduced-power operation, will ensure that the power range high neutron flux high setpoint reactor trip signal will be generated prior to the safety analysis limit, and does not change the design of any NIS channel or its conformance with the regulatory requirements stated in Section 2.0 of this Safety Evaluation. The NRC staff finds that the NIS power range channels continue to meet GDC 13 because appropriate controls are provided to maintain reactor power within prescribed operating ranges for normal operation, anticipated operational occurrences, and accidents to ensure adequate safety. For the proposed change to SR 3.3.1.3, the NRC staff concludes that the change is editorial in nature and does not change the requirement of SR 3.3.1.3. Based on these conclusions, the NRC staff further concludes that the proposed amendments are acceptable.

In its application, the licensee presented the changes to be made to the TS Bases that address the potential decalibration of the NIS power range channels at reduced power operation. Since the Bases are not part of the TS, the NRC staff reviewed the Bases only to assure consistency with the proposed changes. The NRC staff is not approving the Bases changes, but is including the revised bases pages for completeness.

5.0 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.

6.0 ENVIRONMENTAL CONSIDERATION

The amendments 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 (69 FR 2747). 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.

7.0 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 Contributor: Steven Bloom Date: April 1, 2004

Vogtle Electric Generating Plant cc:

Mr. N.J. Stringfellow, Manager Harold Reheis, Director Licensing Department of Natural Resources Southern Nuclear Operating 205 Butler Street, SE. Suite 1252 Company, Inc. Atlanta, Georgia 30334 P. O. Box 1295 Birmingham, Alabama 35201-1295 Attorney General Law Department Mr. Skip Kitchens, General Manager 132 Judicial Building Vogtle Electric Generating Plant Atlanta, Georgia 30334 Southern Nuclear Operating Company, Inc. Mr. Laurence Bergen P. O. Box 1600 Oglethorpe Power Corporation Waynesboro, Georgia 30830 2100 East Exchange Place P. O. Box 1349 Mr. J. B. Beasley, Jr. Tucker, Georgia 30085-1349 Executive Vice President Southern Nuclear Operating Arthur H. Domby, Esquire Company, Inc. Troutman Sanders P. O. Box 1295 NationsBank Plaza Birmingham, Alabama 35201-1295 600 Peachtree Street, NE.

Suite 5200 Steven M. Jackson Atlanta, Georgia 30308-2216 Senior Engineer - Power Supply Municipal Electric Authority Resident Inspector of Georgia Vogtle Plant 1470 Riveredge Parkway, NW. 8805 River Road Atlanta, Georgia 30328-4684 Waynesboro, Georgia 30830 Mr. Reece McAlister Office of the County Commissioner Executive Secretary Burke County Commission Georgia Public Service Commission Waynesboro, Georgia 30830 244 Washington St., S. W.

Atlanta, Georgia 30334