ML20070E269

Proposed Tech Specs 3.4.A Incorporating Action Statement for Inoperability of One Steam Generator PORV & Revise Bases for Tech Spec Section 3.4

ML20070E269
Person / Time
Site:	Prairie Island
Issue date:	02/26/1991
From:	NORTHERN STATES POWER CO.
To:
Shared Package
ML20070E264	List: ML20070E261 ML20070E266 ML20070E269
References
NUDOCS 9103050315
Download: ML20070E269 (6)

Text

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TS.3.6 1 1:" ?! 40/27/09 3.4 STEAM AND POWER CONVERSION SYSTEM enlicabiliev Applies to the operating status of the steam and power conversion system, f

Obiective To'specify minimum conditions of steam relievin6 espacity and auxiliary feed.

. watet supply necessary to assure the capability of removing decay heat from the reactor, and to limit the concentration of activity that might be released

- by steam relief to the atmosphere.

'4 _ _ m l

(except as specified in 3.4.A.2 below):

Soecification

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A.

13,eam Generator Safety and Pnv Ooerated Relief Vt.1vas i

- /.

A reactor shall not be made or maintained critical nor shall reactor coolant system average te erature exceed 350*F unless the following conditions are satisfied.

If :h :: ::nditiens nnet be satisfied within-

-ene-hour-i-n4.:ia:: th: ::ti:n neeeeeary :: p1;;; :h: uni: in "0T Cl"JT007",

ni he in :: 1 ee-HGT-SHUTMW richin th:- nex: 5-heur: :nd ::du : ::;;;;r

y:::: cverag: :empeteewe-4e-1 r 3 50* F viehh-ehe-fel-bewby 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />se J.

Ten steam generator safety valves shall be OPERABLE with lif t settings of 1077,1093,1110,1120 and 1131 psig gli except during testing.

I f.

Both steam-generator power operated relief valves for that reactor are OPEPABLE.

B, tuxilic v Faedvater Svstem 1.

A reactor shall not. be made or maintained critical nor shall reactor coolant system averaSe temperature. exceed 350*F unless

-the followin6 conditions are satisfied (except as specified in

3. 4.- B. 2 below) :

a.

For single unit operation, the turbine driven pump associated with that reactor plus one motor driven pump j'

are OPERABLE.

.- b.. For-two unit operation, all four auxiliary feedvater pumps are OPERABLE.

c.

Valves.and piping associated with the above components l

are OPERABLE except that during STARTUP.OPERATICN I

necesse.ry changes _ may be made in motor-operated valve position. All such changes shall be under direct admini-

.strative control.

2.

During STARTUP OPERATION or POWER OPERATION, the foll.owing condition of inoperability may exist provided STARTUP-OPERATION is discontinued

- until OPERABILITY is restored. If OPERABILITY is not restored within the time specified,- be in at least HOT SHUTDOWN within the next 6 l

hours'and reduce reactor coolant system average temperature below 350* F within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, One steam generator power operated relief valve may be inoperable a.

l-for 48-hours.

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-m m-i 3,4 STEAM AND POWER CONVERSION SYSTEMS

-f Bases A reactor' shutdown from power requires removal of decay heat.

Decty

heat removal requirements are normally satisfied by the steam bypass to the-condenser and by continued feedwater flow to the steam generators, Normal feedwater flow to the' steam generators is provided by operation of the turbine. cycle feedwater-system.

The ten steam generator safety valver have a tot I combined rated capability of 7,745,000 lbs/hr, The total full power steam flow is

'7,094,000_ lbs/hr; therefore,.the. teri steam generator safety valves will

. be able to relieve the total steam flow if necessary (Reference 1).

In the unlikely event of complete loss of offsite electrical power to either or both reactors, continued removal of decay heat would be assured ~by availability of either the steam. driven auxiliary feedwater

_ pump or the motor driven auxiliary feedwater pump associated with each reactor,'and by steam discharge-to the atmosphere through the steam

_ generator safety valves.

One auxiliary feedwater pump can supply sufficient feedwater for removal-of decay heat from one reactor. The

motor driven auxiliary.feedwater pump for each reactor can be made-available to the other reactor.

During STARTUP OPERATIONS, the Auxiliary Feedwater motor operated injection valves maybe less than full

.open as necessary to faciliate plant startup, m

g N. J The minimum amount:of water specified 'for the condensate storage tanks is sufficient'to remove the decay heat generated by one reactor in the

~

first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of-shutdown.

Essentially unlimited replenishment of the condensate storage supply is available from the intake structures t

through the_ cooling water system.

.The'two steam generator power operated relief valves located upstream of the main steam isolation valves are required to. remove decay._ heat and pyt cool the reactor downffollowing a'high energy line rupture outside containment -(Reference 2),+ Isolation dampers are required in ventilation ducts thacL penetrate : chose rooms containing equipment needed for *h* A -

l kSn'ergy'lise ' rupture outs'ide' containmen

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The limit.ations on sacondary system-specific activity. ensure that the resultant off. site radiation dose.will be limited to a small fraction F

of 10.CFR Parc_100 limitsiin the event of a steam line rupture. This-1 dose also" includes the effects of a coincident 1,0 gpm primary to j

secondary tube leak in the' steam. generator of the affected steam line.

-.These values are consistent with the assumptions'used in the accident.

analyses.

gollowingasteamgenerat'or'cuberu'ptureevent (Reference 3) and

~

Reference M) 5,4 1 USAR, Secti 4

3 USAR, Section 1

2. Y,SAR, Appendix I

9 3ect b p a s e.

B.3 4- /

The steam generator power operated relief valves are provided with manual upstream block valves to permit testing at power and to provide a means of isolation.

In order to assure timely response to a steam generator tube rupture event, a

steam generator power operated relief valve is considered operable when it is capable of being remotely operated and when its associated block valve is open.

A

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Exhibit C Prairio Island Nuc1 car Cencrating Plant License' Amendment Request Dated' February 26, 1991 Revised Technical Specification Pages Exhibit C consists of the revised pages for the Prairie Island Nuc1 car Generating-Plant Technical Specification with the proposed: changes

= incorporated.

The revised pages are listed below:

TS.3.4 1 B.3.4 1 r

1 l

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j' TS.3.4 1 3.4 STEAM AND. POWER CONVERSION SYSTEM.

Anolicability Applies to the operating status:of the steam and power conversion system, Obiective

- To specify minimum conditions of steam relieving capacity and auxiliary feed.

water supply necessary to assure the capability of removing decay heat from the reactor, and to limte the concentration of activity that might be released by steam relief to the atmosphere.

Specification A.

Steam Generator Safety and Power Operated Rollef Valves 1.- A' reactor shall not be made or maintained critical nor shall reactor l

coolant system average temperature exceed 350'F unless the following conditions are satisfied (except as specified in 3.4. A,2 below):

-a.

Ten steam generator safety valves shall be OPERABLE with lift settings of 1077, 1093,'1110, 1120 and 1131 psig 11% except during

testing,

b..Both steam generator power operated relief valves for that l

reactor are OPERABLE.

2.

During STARTUP OPERATION or POWER OPERATION, the following condition of inoperability may exist provided STARTUP OPERATION is discontinued until-OPERABILITY is restored. If OPERABILITY is not restored within the time specified, be in at leact HOT SHUTDOWN within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and -reduce reactor coolant: system average temperature below

'350'F within the-following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />;

-a.

One steam' generator power operated relief valve may.be inoperable

.for 48. hours.

B.

Auxiliary Feedwater System

-1.

A reactor shall not be made or maintained critical nor shall reactor coolant system average temperature exceed-350*F unless the1following conditions are satisfied (except as specified in 3.4.B.2 below):

U a.

For single unit-operation, the turbine driven pump associated with that reactor-plus one' motor driven pump aro OPERABLE.

i b.

For two unit operation, all four auxiliary feedwater pumps are OPERABLE.

c.

Valves and piping associated with the above components are OPERABLE except that during STARTUP OPERATION necessary changes may be made in motor operated valvo position. All such changes shall be under direct admini-strative control.

B.3.4 1 3.4 STEAM AND POWER CONVERSION SYSTEMS Enses-LA reactor shutdown from power requires removal of decay heat.

Decay heat

' removal requirements are normally. satisfied by the steam bypass to the condenser and by. continued feedwater flow to the steam generators.

Normal feedwater-flow to the steam generators is provided by operation of the turbine cycle.feedwater system.

The ten steam generator safety valves have a total combined rated capability of 7,745,000 lbs/hr.

The total full power steam flow is 7,094,000 lbs/hr; therefore, the-ten steam generator safety valves will be abic to rollove the

-total' steam flow if necessary (Reference 1).

.In the unlikely event of complete loss of offsite electrical power to olther or both reactors, continued re;.aval of decay heat would be assured by availability of either the_' steam driven auxiliary feedwater pump or the motor driven auxiliary feodwater pump associated with each reactor, and by

(

steam discharge to the atmosphere through the steam generator safety valves.

One auxiliary feedwater pump can supply sufficient feedwater for removal of E

decay _ heat from one reactor. The motor driven auxiliary feedwater pump for each reactor can be made available to the other reactor.

During STARTUP OPERATIONS, the : Auxiliary Feedwater motor operated injection valves maybe less than full open as necessary to facilitate plant startup.

The minimum amount of~ water specified for the condensate' storage tanks is sufficient to remove the decry heat generated by one reactor in the first 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> of shutdown - Essentially unlimited replenishment of the condensato storage' supply is available from the intake structures through the cooling L

water system.

The two-steam generator power operated relief valves located upstream of the main steam-isolation valves are required to remove decay heat and cool the

! reactor down following'a steam generator tube rupture event (Reference 3) and

(

following a high energy line rupture outside containment (Reference 2).

The

. steam generator power' operated relief valves are provided with manual upstream g

block valves to permit testing at power and to provide a means of isolation.

In order to assure timely response to a steam generator tube rupture event, n

. steam generator power operated relief valve is considered operable when it is capable of being remotely operated and when its associated block valvo is

open, a c,1ation dampers are required in ventilation ducts that penetrate those rooms containing. equipment needed for a high energy line rupture outside p

containment.

The limitations on secondary system specific activity ensure that the-i resultant off site radiation dose will be limited to a small fraction of 10 CFR Part 100'11mits in the event of a-steam line rupture.

This dose also includes the-effects of a coincident 1.0 gpm primary to secondary tube leak in L

the steam generator of the affected steam line.

These values are consistent with the assumptions used in the accident analyses.

Reference 1

J

1. USAR, Scction 11.9.4

2. USAR, Appendix I

3. USAR, Section 14.5.4

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