ELV-03576, Application for Amends to Licenses NPF-68 & NPF-81 to Revise TS 4.3.4.2.d Re Periodic Disassembly & Exam of Valves Associated W/Turbine Overspeed Protection Sys

Application for Amends to Licenses NPF-68 & NPF-81 to Revise TS 4.3.4.2.d Re Periodic Disassembly & Exam of Valves Associated W/Turbine Overspeed Protection Sys

ML20095F816
Person / Time
Site:	Vogtle
Issue date:	04/28/1992
From:	Mccoy C GEORGIA POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20095F820	List: ELV-03576, Application for Amends to Licenses NPF-68 & NPF-81 to Revise TS 4.3.4.2.d Re Periodic Disassembly & Exam of Valves Associated W/Turbine Overspeed Protection Sys ML20095F892
References
ELV-03576, ELV-3576, NUDOCS 9204280305
Download: ML20095F816 (6)

Text

_ -

Gmvg a rout Cww,-

40 Imenen Cen M Pahay Post Utce D> 1295

. B.rm n@w, NaNum 3R701

, Test Fone 20$ 87/ 7122 u$

C. K. McCoy Gt>orgia Power-1% sx:ern e:a ; c tcfem ELV-03576 q c f/ fl--

.g 001353 Docket Nos. 50-424 50-425 U. S. Nuclear Regulatory Commission ATTN: Document Control Desk Washington, D. C. 20555 Gentlemen:

V0GTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATION 4.3.4.2.d TURBINE OVERSPFED PP.0TECTION SYSTEM In accordance with the provisions of 10 CFR 50.90 and 10 CFR 50.59, Georgia Power Company (GPC) hereby proposes to amend the Vogtle Electric Generating Plant (VEGP) Unit 1 and Unit 2 Technical Specifications, Appendix A to Operating Licenses NPF 68 and NPF-81. The prcoosed amendment would revise Technical Specification (TS) surveillance requirement 4.3.4.2.d regarding the periodic disassembly and inspection of the valves associated with the turbine overspeed protection system.

The proposed change and its basis are described in enclosure 1, Our evaluation pursuant to 10 CFR 50.92 showing that the proposed change does not involve significant hazards considerations is provided as enclosure 2. A markup of the affected page from the TS is provided as enclosure 3.

Georgia Power Company requests approval of the proposed amendment by December 31, 1992, so that the chedule for the March 1993 Unit I refueling outage can be established as appropriate. In accordance with 10 CFR 50.91, the designated state official will be sent a copy of this letter and all enclosures.

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 c .ove'o 0 f/l '

m :t v u By: U I //

C. K. McCoy Sworn to and subscribed before me this 20R day of O , 1992.

hm Notary Public

~

CKM/N.lS,;mb M'"" t 9204280305 920428 ADOCK 05000424

\

PDR P PDR

Georgia Power A U. S. Nuclear Regulatory Commission ELV-03576 Page 2

Enclosures:

1. Basis for Proposed Change

2. 10 CFR 50.92 Evaluation

3. Instructions for Incorporation xc: Georaia Power Company Mr. W. B. Shipman Mr. M. Sheibani NORMS U. S. Nuclear Reaulatory Commission Mr. S. D. Ebneter, Regional Administrator Mr. D. S. Hood, Licensing Project Manager, NRR Mr. B. R. Bonser, Senior Resident inspector, Vogtle Slate of Georaia Mr. J. D. Tanner, Commissioner, Department of Natural Resources 700775

ENCLOSURE 1 V0GTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATION 4.3.4.2.d TURBINE OVERSPEED PROTECTION SYSTEM BASIS FOR PROPOSED CHANGE Proposed Chance Existing surveillance requireirent 4.3.4.2.d requiras at lost one each of the four high pressure turbine stop valves, four high pressure turbine control valves, six low-pressure turbine intcrmediate stop valves, and six low pressure turbine intercept valves to he disassembled and inspected at least once per 40 months. The proposed change would revise this requirement so that all of these valves are disassembled and inspected at least once por 60 months.

Basis Vogtle Electric Generating Plant is equip)ed with Gener.; Electric turbine-generators. Steam from each of tie four s b .a generators enters the I high pressure turbine through four 28-inch stop valves and governing control I valves; one stop valve and one control valve form a single assembly. After j extanding through the high-pressure turbine, the steam is reheated to superheat j conditions. Af ter reheating, the steam flows through the 34-inch combined l intermediate stop and intercept valves in each of the six steam lines leading to '

the inlas of the three low pressure turbines. Similar to the main stop and control ulves, the intermediate stop and intercept valves form six single assemblies. Valve opening actuation is provided by a 1600-psig hydraulic l- system; valve closing actuation is provided by springs and steam forces upon the l reduction or relief of fluid pressure. Actuation of the emergency trip system l

will release the hydraulic fluid pressure in the valve actuators, allowing i springt to ciose the valves.

Under the existing surveillance requirement, assuming an IB month fuel cycle, one each of the stop valves, control valves, and the interm diate stop and intercept valves are disassembled and inspected during every other refueling outage. Under the proposed surveillance requirement, all four stor. valves would be disassembled and inspected during one oatage, the four control valves during the next outage and the intermediate stop and intercept valves during the next outage. While the stop and control valves in a s13am line are considered to form a single assembly, they. can be disassembled separately.. However, the intermediate stop and intercept valves are integrel units which must-be disassembled and inspected at one time. Therefore, under the proposed change, all of the subiact valves would be disassembled and inspected at least once per 60 months (recos n izing potential variations in fuel cycle length, but not to .

result in the surveillance interval exceeding the 25-purcent extension allowed by TS 4.0.2).

Under the existing surveillance requirement, all of the subject valves would b6 inspected after approximately 12 fuel cycles. Under the proposed requirement, l- El-1

ENCLOSURE 1 (00tiTINUED)

REQUEST TO REVISE TECH!ilCAL SPEctflCAT10!i 4.3.4.2.d TURBINE OVERSPEED PROTECTION SYSTEM MSJS FOR PROPOSED CHANGE all of the valves would be inspec:ed every three fuel cycles. The net effect is that the va les are inspected more frequently. In addition, it is advantageous to inspect til of the valves of a given type during one outage, rather than one of each, from th standpoint of training maintenance personnel, obtaining spare parts and supplies, and the experience gained by ins)ecting all valves of each type at ona time, the proposed requirement is preferaale to the existing one. A problem generic to a given type of valve can be corrected at one time. The effect of more frequent inspections plus inspecting all valves of a given type at the same tima should result in increased reliability of the turbine overspeed protection system.

t

/I El-2 1

ENCLOSURE 2 V0GTLE ELECTRIC GENERATING PLANT REQUEST 10 REVISE TECHNICAL SPECIFICATION 4.3.4.2.d TURBINE OVERSPEED PROTECTION SYSTEM 1QlfR 50.92 EVALUATION Pursuant to 10 CFR 50.9E, CPC has evaluated the proposed amendment and has determined that operation of the facility in accordance with the proposed amendment w9uld not involve a significant hazards consideration. The basis for this determination is as follows:

1

1. The proposed amendment does not involve a significant increase in ths J 3robabi1My or consequences of an accident previously evaluated. The vendcr .

1as confirmed that the proposed inspection frequency has no effect on the '

turbine-generator missile analysis, since the ana?ysis does not have a component which includes valve inspection frequency The 60 month inspection interval is consistent with the vendor's recommendations for valves in this type of service. The net effect of the pro)osed change will be more frequent inspections for each valve. This should .1 ave a positive effect on the reliability of these valves.

2. The proposed amendment does not create the possibility of a new or different kind of accident from any accident previously evaluated. The proposed amendment does not involve any changes in design or operating parameters for these valves. They will continue to perform their function as intended and as assuraad in the accident analyses. The proposed amendment only affects the frequency at which these valves will be disassembled and inspected, the net effect of which should be improved reliability.

3. The proposed amendment dNs not involve a significant reduction in a margin of safety. As_ stated above, the vendor has confirmed that the proposed amendment has no effect on the turbine-generator missile analysis.

Furthermore, with an increased inspection frequency, the valves should be able to perform their intended-function with increased reliability.

Conclusion Based on the preceding analysis, GPC has determined that the proposed amendment to the TS will not significantly increase the probability or consequences of an accident previously evaluated, creatu the possibility of a new or different kind of accident previously evaluated, or involve a significant ' eduction in a margin.

of safety. Georgia _ Power Company therefore concludes that the proposed amendment meets the requirements of 10 CFR 50.92(c) and does not involve a significant hazards consideration.

l l E2-1 o

a re-.. a - - .-u - - . - ruw -...sa_r-+s w a-e 4

=

I ENCLOSURE 3 l V0GTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECHNICAL SPECIFICATION 4.3.4.2.d TURBINE OVERSPEED PROTECTION SYSTEM MARKED-UP PAGE i

i L

kr l- E3-1 l

!