ML20058H997

Application for Amends to Licenses NPF-68 & NPF-81, Relocating Requirements of TS 3/4.3.4, Turbine Overspeed Protection to Section 16.3 of Fsar.Ge Proprietary Rept GET-8039 Encl.Proprietary Rept Withheld,Per 10CFR2.790

ML20058H997
Person / Time
Site:	Vogtle
Issue date:	11/19/1993
From:	Mccoy C GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19311B229	List: ML20058H997 ML20058J006 ML20058J010
References
LCV-0125, LCV-125, NUDOCS 9312130328
Download: ML20058H997 (6)

Text

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Georga Power conwy 40 inwners Center F e ww

• , o Pcd 0% Box 1295 BmmWn Aubama 3W.'1 Tekume 205 877J122 m

C. K. McCoy Georgia Power hwPe# t W ar voc ar November 19, 1993

+ eem eb u se em LCV-0125 Docket Nos. 50-424 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATIONS RELATED TO TURBINE OVERSPEED PROTECTION In accordance with the provisions of 10 CFR 50.90, Georgia Power Company (GPC) proposes to amend the Vogtle Electric Generating Plant (VEGP) Unit I and Unit 2 Technical Specifications (TS), Appendix A to Operating Licenses NPF-68 and NPF-81. The proposed change would relocate the requirements of TS 3/4.3.4, Turbine Overspeed Protection, to section 16.3 of the VEGP Final Safety Analysis Report (FSAR). In addition, when the requirements are relocated to the FSAR, GPC plans to modify the surveillance intervals for exercising the high pressure turbine stop valves, the low pressure turbine intermediate stop valves and intercept valves, and the high pressure turbine control valves. The proposed modification would increase the surveillance intervals for exercising the valves through a complete cycle to a maximum of three months based on the unit-specific turbine wheel missile analysis results and wheel inspection requirements. The methodology for determining the surveillance intervals for these valves was developed by the General Electric Company (GE), and applies GE's proprietary wheel missile analysis which was approved by the NRC in 1986 (reference NUREG-1048, Appendix U). Recent updates to and application of the analysis for evaluating steam valve surveillance test intervals were performed by GE in cooperation with an initiative of the Boiling Water Reactor (BWR) Owners Group. The methodology is applicable to all GE nuclear turbines with built-up low pressure rotors, both in BWR and pressurized water reactor (PWR) plants. Georgia Power Company is proposing that VEGP serve as the lead plant for obtaining regulatory approval of this methodology.

The proposed changes to the TS and their bases are provided in enclosure 1. An evaluation pursuant to 10 CFR 50.92 showing that the proposed changes to the TS do not involve significant  ;

hazards considerations is provided as enclosure 2, and the marked-up pages are provided as  ;

enclosure 3. In accordance with 10 CFR 50.91, the designated state official will be sent a copy of l this letter and all enclosures. )

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U. S. Nuclear Regulatory Commission LCV-0125 Page 2 In addition, the proposed change to the FSAR and its basis is included as enclosure 4. Enclosure r 4 includes a report that serves as a supplement to the January 1984 General Electric report to the l NRC entitled " Probability of Missile Generation in General Electric Nuclear Turbines." This supplementary report (Steam Valve Surveillance Test Interval Extension, GET-8039, September 1993) describes a general methodology for selecting turbine steam valve surveillance test intervals -

for GE nuclear turbines with low pressure rotors employing shrunk-on wheels and contains information that is proprietary to the General Electric Company. Therefore, this submittal is ,

supported by an affidavit signed by GE, the owner of the information, which sets forth the basis on which the information may be withheld from public disclosure by the Commission and addresses with specificity the considerations listed in paragraph (b)(4) of section 2.790 of the Commission's regulations. Accordingly, it is respectfully requested that the information which is proprietary to GE be withheld from public disclosure in accordance with 10 CFR 2.790 of the Commission's regulations. A nonproprietary version of the supplementary report (GET-8039.1) is also included as part of enclosure 4.

Georgia Power requests appro val of this proposed amendment by September 1994, which corresponds to the next scheauled refueling outage for Unit 1.

Mr. C. K. McCoy states that he is a Vice President of Georgia Power Company and is authorized to execute this oath on behalf of Georgia Power Company and that, to the best of his knowledge and belief, the facts set forth in this letter and enclosures are true.

• GEORGIA POWER COMPANY BY: -

C. K. McCoy Sworn to and subscribed before me this day of

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Not'ary Public CKM/NJS 1

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LCV-0125 '

Page 3 1

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I Enclosures-i

1. Basis for Proposed Change 2.10 CFR 50.92 Evaluation

3. Proposed Change to the Technical Specifications

4. Proposed Change to the FSAR xc: Decrgia Power Company Mr. J. B. Beasley, Jr.

Mr. M. Sheibani NORMS U. S. Nuclear Regulatory Commission ,

Mr. S. D. Ebneter, Regional Administrator Mr. D. S. Hood, Licensing Project Manager, NRR Mr. B. R. Bonser, Senior Resident Inspector, Vogtle State of Georgia Mr. J. D. Tanner, Commissioner, Department of Natural Resources l

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- ENCLOSURE 1 VOGTLE ELECTRIC GENERATING PLANT  :

REQUEST TO REVISE TECIINICAL SPECIFICATIONS RELATED TO TURBINE OVERSPEED PROTECTION BASIS FOR PROPOSED CIIANGE  ;

Proposed Change The proposed change to the Vogtle Electric Generating Plant (VEGP) Unit I and Unit 2 Technical Specifications (TS) would relocate the requirements of TS 3/4.3.4, Turbine Overspeed  ;

Protection, to section 16.3 of the VEGP Final Safety Analysis Report (FSAR). As part of section 16.3 ofthe FSAR, the relocated requirements would be subject to TS 6.7.1.i which requires that <

written ,,.ocedures be established, implemented, and maintained covering the activities of the Technical Specification Improvement Program implementation.

i Basis On July 22,1993, the Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors became effective. According to the Policy Statement, the purpose of the TS is to impose those conditions or limitations upon reactor operation necessary to obviate the ,

possibility of an abnormal situation or event giving rise to an immediate threat to the public health and safety by identifying those features that are of controlling importance to safety and ,

establishing on them certain conditions of operation which cannot be changed without prior Commission approval. Furthermore, the Policy Statement establishes an objective set of criteria which delineate those constraints on design and operation of nuclear power plants that are derived from the FSAR and that belong in the TS in accordance with 10 CFR 50.36 and the purpose of the TS. Specifically, these criteria are as follows:

• Installed instmmentation that is used to detect, and indicate in the control room, a ,

significant uormal degradation of the reactor coolant pressure boundary.  ;

e A process variable, design feature, or operating restriction that is an initial condition of a design basis accident or transient analysis that either assumes the failure of or presents a challenge to the integrity of a fission product barner.

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. A structure, system, or component that is part of the primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.  ;

. A structure, system, or component which operating experience or probabilistic safety assessment has shown to be significant to public health and safety.  !

The turbine overspeed protection system is provided to prevent the generation of potentially ,

damaging missiles due to a failure or transient that could result in an overspeed condition. I Ilowever, a turbine overspeed event does not represent a significant abnormal degradation of the El-1

ENCLOSURE I (CONTINUED)

REQUEST TO REVISE TECIINICAL SPECIFICATIONS RELATED TO TURBINE OVERSPEED PROTECTION I

~ BASIS FOR PROPOSED CIIANGE reactor coolant pressure boundary, and it is not a design basis accident or transient. Therefore, i

the turbine overspeed protection system is not installed instmmentation that is used to detect, and indicate in the control room, a significant abnormal degradation of the reactor coolant pressure boundary. Similarly, the turbine overspeed protection system is not a process variable that is an initial condition of a design basis accident or transient that either assumes the failure of or presents .

a challenge to the integrity of a fission product barrier. Furthermore, the turbine overspeed protection system is not a system, structure or component that is part of a primary success path and which functions or actuates to mitigate a design basis accident or transient that either assumes the failure of or presents a challenge to the integrity of a fission product barrier.

Finally, with respect to probabilistic risk significance, the frequency of turbine missile damage to a safety-related stmeture can be expressed as the product of the probability of missile genes's, the probability of missile strike, and the probability of damage to the target structure. (See the VEGP FSAR, section 3.5.1.3.) Based on Regulatory Guide 1.115, Revision 1, the probability cf missile genesis is conservatively assumed to be lx10-4. The probability of missile strike and the probability of damage to a target structure are discussed in sections 3.5.1.3.4.3 and 3.5.1.3.4.4 of the VEGP FSAR. Table 3.5.1-4 of the FSAR lists turbine missile strike and damage probabilities per missile fragment for individual target structures from the Unit I turbine. (Similar values would be obtained for Unit 2.) The summation of all these probabilities is 0.897x10-7, which would be the value for the plant. Therefore, a failure of the turbine overspeed protection system is not a significant contributor to overall risk.

In conclusion, the existing TS requirements for the turbine overspeed protection system do not meet any of the criteria of the Final Policy Statement and can safely be relocated to the VEGP FSAR. This conclusion is consistent with the results of the NRC review of the application of the Interim Policy Statement criteria to the Westinghouse Standard Technical Specifications as documented in NRC letter, T. E. Murley to W. S. Wilgus, "NRC Staff Review of Nuclear Steam  ;

I Supply System Vendor Owners Groups' Application of the Commission's Interim Policy Statement Criteria to Standard Technical Specifications," May 1988.

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ENCLOSURE 2!  ;

1 VOGTLE ELECTRIC GENERATING PLANT l REQUEST TO REVISE TECHNICAL SPECIFICATIONS l RELATED TO TURBINE OVERSPEED PROTECTION 1

1 10 CFR 50.92 EVALUATION  !

i Georgia Power Company has reviewed the requirements of 10 CFR 50.92 as they relate to the  !

proposed change and has made the following determination:

l. The proposed change does not involve a significant increase in the probability or -  ;

consequences of an accident previously evaluated. The proposed change involves the I relocation of the TS requirements for the turbine overspeed protection system to the VEGP FSAR. The requirements that will reside in the FSAR will continue to ensure that the -  ;

probability of turbine missile generation is maintained below NRC limits as defined in - l NUREG-1048, Appendix U. Since the tuibine overspeed protection system will remain capable of protecting the turbine from excessive overspeed, the proposed change will have no effect on the consequences of an accident previously evaluated. j

2. The a. posed change will not create the possibility of a new or different kind of accident than any previously evaluated. The proposed change does not involve any change to the configuration or mahod of operation of any plant equipment, and no new failure modes have .

been defined for any plant system or component. In addition, no new limiting failures have  ;

s  ; been identified as a result of the proposed change. The requirements for the turbine j g overspeed protection system that will reside in the FSAR will ensure that the system remains j capable of protecting the turbine from excessive overspeed. Therefore, the proposed change  ;

will not create the possibility of a new or different kind of accident than any previously  ;

evaluated. ]

3. The proposed change does not involve a significant reduction in a margin of safety. The ,

proposed change would allow the requirements for the turbine overspeed protection system to j be relocated to the FSAR on the basis that the turbine overspeed protection system does not  ;

meet the criteria of the NRC Final Policy Statement on Technical Specifications Improvements for Nuclear Reactors. The requirements that will reside in the FSAR for the turbine overspeed protection system will ensure that the system remains capable of protecting '

the turbine from excessive overspeed. Therefore, the proposed change will not involve a significant reduction in a margin of safety.

Conclusion Based on the preceding analysis, Georgia Power Company has determined that the proposed change to the TS will not significantly increase the probability or consequences of an accident ,

previously evaluated, create the possibility of a new or different kind of accident than any -j previously evaluated, or involve a significant reduction in a margin of safety. Therefore, the proposed change meets the requirements of 10 CFR 50.92 (c) and does not involve a significant hazards consideration.

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