ML20141A854

Proposed Tech Specs Revising LCO 3.4.10 to Reduce Nominal Set Pressure by 1% to 2460 & Increase Tolerance to +2%

ML20141A854
Person / Time
Site:	Vogtle
Issue date:	06/13/1997
From:	SOUTHERN NUCLEAR OPERATING CO.
To:
Shared Package
ML20141A817	List: ML20141A812 ML20141A854
References
NUDOCS 9706230186
Download: ML20141A854 (5)

Text

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ENCLOSURE 3 VOGTLE ELECTRIC GENERATING PLANT REQUEST TO REVISE TECIINICAL SPECIFICATIONS PRESSURIZER SAFETY VALVE AND SETPOINT TOLERANCE l

MARKED-UP TECIINICAL SPECIFICATION AND BASES PAGES 1

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l The following pages from VEGP Unit I and Unit 2 TS LCO 3.4.10 and the associated Bases have been marked to show the proposed change.

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l 9706230186 970613 PDR ADOCK 05000424 P PDR E3-1 l'

t Pressurizer Safety Valves 3.4.10 0'

3.4 REACTOR COOLANT SYSTEM (RCS) 3.4.10 Pressurizer Safety Valves LCO 3.4.10 Three pressurizer safety valves shall be OPERABLE with lift settings 2 9460 psig and s 2510 psig. l 2450 APPLICABILITY: MODES 1, 2, and 3.

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NOTE-----------------------------

l The lift settings are not required to be within the LCO limits during MODE 3 for the purpose of setting the pressurizer safety valves under ambient (hot) conditions.

This exception is allowed for 54 hours6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br /> following entry into MODE 3 provided a preliminary cold setting was made prior to heatup.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One pressurizer safety A.1 Restore valve to 15 minutes valve inoperable. OPERABLE status.

B. Required Action and B.1 Be in MODE 3. 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> associated Completion Time not met. AND OR B.2 Be in MODE 4. 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> Two or more i pressurizer safety valves inoperable.

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Vogtle Units 1 and 2 3.4-20 Amendment No. 96 (Unit 1)

Amendment No. 74 (Unit 2)

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- Pressurizer Safety Valves B 3.4.10 B 3.4 REACT 0P. COOLANT SYSTEM (RCS) I B 3.4.10 Pressurizer Safety Valves BASES BACKGROUND The pressurizer safety valves provide, in conjunction with the Reactor Protection System, overpressure protection for the RCS. The pressurizer safety valves are of the pop type. ,

The valves are spring loaded and self actuated by direct 1 fluid pressure with backpressure compensation. The safety l P

valves are designed to prevent the system pressure from '

' 4/ 4[/lfIF/W exceeding the system Safety Limit (SL), 2735 psig, which is nuM g 110% of the design pressure.

< JS40ff/p Because the safety valves are self actuating, they are I considered independent c ponents. The relief capacity for each valve, 420,000 lb/h , is based on postulated 8 N g.# f g overpressure transient conditions resulting from a complete l loss of steam flow to the turbine with the reactor operating '

{ /S $/#/td 4/ A [ at 102 percent of engineered safeguards design power.4This ef r event results in the maximum surge rate into the

[### ,

i pressurizer, which specifies the minimum relief capacity for 764# /Js4 Whid the safety valves aThe discharge flow from the pressurizer

[ safety valves is s ected to the pressurizer relief tank.

M7 M [#/#dr Sg/

L This discharge ow is indicated by an increase in temperature d stra am of the pressurizer safety valves or I increase in 1e pre: surizer relief tank temperature or

/ # M U/8 0// # $ k level js4vfe4.r 3 % 4r l

MO Overpr sure protection is required in MODES 1, 2, 3, 4, 5, 5fff # ##f6 M 4K4 and S DE 6 with the reactor vessel head on; however, in 4, 5, and 6 with the reactor. vessel head on, L( g ypfg appjg-)i erpressure protection is provided by operating procedures and by meeting the requirements of LCO 3.4.12. " Cold

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(Nd dictefft /4 Temperature Overpressure Protection System (COPS)."

Mff88/* b The upper and lower pressure limits are based on the tolerance requirement Z:1. ') L. '-:f:-:.; ;rx xrn 2:::

1%

g /g/j g la^^ , ;3 The lift etting is for the ambient conditions

//)(rtsJt //t /s/ttgcg associated with MOD 1, 2,.and 3. This requires either that the valves be t hot or that a correlation between hot den 4dse/wp@ and cold settings established. L Y The pressurizer s fety valves are part of the primary 0///ptJ4 success path and itigate the effects of postulated Qo(Hs. Q Oseumedi lhe.

sale fu ona

/ (continued)

Vogtle Units 1 and 2 B 3.4-50 Revision No. 0

Pressurizer Safety Valves B 3.4.10 i

4

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(

l I BASES (continued) { 2NO[Sh f l

LCO The three pressuriztr safi ty valves are set to open at 4he M RCS d::i;n pressure '0 00 ;;i ), and within the m

g specified tolerance, to avoid exceeding the maximum design

pressure SL,4to maintain accident analyses assumptions, end-t

:: ;'y ith Z Z . 6 ...... .. The upper and lower J

! pressure tolerance limits are based on the $ tolerance i requirements #;f. f:r 'iftir.; - n.c ; ci . ; 2000 g .3 L ) din 4he.3Nt.}sy endhp.se.s gsfuepe The limit protected by this Specificati6n is the reactor i coolant pressure boundary (RCPB) SL of 110% of design i pressure.

APPLICABILITY In MODES 1, 2, and 3, OPERABILITY of three valves is l'

required because the combined capacity is J red to keep reactor coolant pressure below 110%.of its dezign value during certain accidents. MODE _3 is conservatively

' included, although the listed accidents may not require the j safety valves for protection.

The LCO is not applicable in MODE 4, MODE 5, or MODE 6 (with the reactor vessel head on) because the cold overpressure ~

protection system is in service. Overpressure protection is not required in MODE 6 with reactor vessel head removed.

The Note allows entry into MODE 3 with the lift settings.

outside the LCO limits. This permits testing and examination of the safety valves at high pressure and temperature near their normal operating range, but only i after the valves have had a preliminary cold setting. The cold setting gives assurance that the valves are OPERABLE near their design condition. Only one valve at a time will be removed from service for testing. The 54 hour6.25e-4 days <br />0.015 hours <br />8.928571e-5 weeks <br />2.0547e-5 months <br /> exception is based on 18 hour2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> outage time for each of the three valves. The 18 hour2.083333e-4 days <br />0.005 hours <br />2.97619e-5 weeks <br />6.849e-6 months <br /> period is derived from operating experience that hot testing can be performed in this timeframe. .

ACTIONS A.d With one pressurizer safety valve inoperable, restoration must take place within 15 minutes. The Completion Time of (continued)

B 3.4-52 Revision No. O Vogtle Units 1 and 2

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- Pressurizer Safety Valves i B 3.4.10 BASES i ACTIONS A.1 (continued) i

25 minutes reflects the importance of maintaining the RCS l overpressure protection system. An inoperable safety valve

coincident with an RCS overpressure event could challenge the integrity of the pressure boundary.

, B.1 and B.2 If the Required Action of A.1 cannot be met within the j required Completion Time or if two or more pressurizer l safety valves are inoperable, the plant must be brought to a MODE in which the requirement does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 4 within 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />. The allowed l Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without l challenging plant systems. In MODE 4, overpressure protection is provided by the cold overpressure protection j system. The change from MODE 1, 2, or 3 to MODE 4 reduces l l the RCS energy (core power and pressure), lowers the i potential for large pressurizer insurges, and thereby removes the need for overpressure protection by three pressurizer safety valves.

SURVEILLANCE SR 3.4.10.1 REQUIREMENTS SRs are specified in the Inservice. Testing Program.

Pressurizer safety valves are to be tested in accordance with the requirements of Section XI of the ASME Code y jo (Ref. 4), which provides the activities and Frequenc' necessary to satisfy the SRs. No additional requ' ments l are specified. The lift settings shall be 2 psig and

s; 2510 psig. The lift setting pressures shall correspond to ambient conditions of the valves at nomal operating temperature and pressure.

The penuaw ufe9 uln sefpold fo/wonee is s 2 % fo r 0 M M 6 I L i f f) I k **' 4 5 voNn sk// pt asef k i 1% cicalg fif a Sverillom h ol/w for dn*/y.

(continued)

Vogtle Units 1 and 2 B 3.4-53 Revision No. O