ML20248G349

Proposed Tech Specs,Consisting of Tech Spec Change 89-40, Clarifying Requirements for RCS Head Vents

ML20248G349
Person / Time
Site:	Sequoyah
Issue date:	10/05/1989
From:	TENNESSEE VALLEY AUTHORITY
To:
Shared Package
ML20248G336	List: ML20248G334 ML20248G349
References
NUDOCS 8910100209
Download: ML20248G349 (15)

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. ENCLOSURE li- $

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af a. '. PROPOSED TECHNICAL' SPECIFICATION CHANGE'

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SEQUOYAH NUCLEAR PLANT UNITS:1 AND 2a f

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' DOCKET NOS.;50-327'AND'50-328J

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-j; LIST OF AFFECTED PAGES

. Unit 1 VI.

.3/4 4-28 B.3/4 4'-2

.B 3/4'4-14 Unit 2

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'If)DEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS a

> :SECTION' PAGE' i:,. 3/4.4' REACTOR COOLANT SYSTEM-3/4.4)1) REACTOR C00'LA'NT LOOPS AND' COOLANT CIRCULATION-

'Startup-and' Power Operation............................... 'i 3/4.4-1 e'

Hot Standby............................................. ..: 3/4 4-la Shutdown.................................................. , '/4'4-2 3 I 3/4.4.N LSAFETY-VALVES -' SHUTDOWN..................................

3/4 4-3

3/4.4.36 SAFETY'AND RELIEF VALVES - OPERATING Safety Valves:- Operating.................................

3/4 4-4 Relief Valves 1 .0perating......... .............'.......... 3/4'4-4a 3/4.4.4 PRESSURIZER............................................... 3/4 4-S.

3/4.415 STEAM'GENERAT0RS.......................................... ,

. 3/4 4-6 i3/4.4.6 REACTOR COOLANT' SYSTEM LEAKAGE I

. Leakage: Detection Systems................................. 3/4 4 Op e rati onal . Le a kage . . . . . . . . . . '. . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3/4 4-14 3/4.4.7 c CHEMISTRY................................................. 3/4 4-16

3/4.4.8. SPECIFIC ACTIVITY......................................... 3/4 4-19 3/4.4.9 PRESSURE / TEMPERATURE LIMITS 1sL' .

Reactor Coolant System.................................... 3/4 4-23 .

Pressurizer............................................... ,

3/4 4-26 3/4.4.10 STRUCTURAL INTEGRITY

.,. ASME Code Class 1, 2 and 3 Components..................... 3/4 4-27

3/4.4.11 R120 VENTS..............................

REACTOR COOLANT SYSTEM, 3/4 4-28

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' LSEQUDYAH - UNIT 1 VI Amendment No. 116 June 1, 1989

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LREACTOR COOLANT SYSTEM HEAD.

3/4.4.11 REACTOR COOLANT SYSTEM VENTS

LIMITING CONDITION FOR OPERATION iful A 7 c3HV

3.4.11 T e Reactor Coolant System Vent (RG6V) path / shall be OPERABLE. *

~ APPLICABILITY: MODES 1, 2, and 3.

ACTION:

2. 'With only ene'RCSV path OPERA.BLE, STADTUP~:nd/cr DOMER OPER^. TION ::y centinue previded the incperable path i; ::tatsined cle;cd with pewer remcVed 'rcr the valve actuater ; restore the incperable psth to OPE"^.SLE statu; within 30 dcy;; cr be in HOT ST^90BY with h 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />; and HOT SM' J T00WM within the felicwing C heur3.

Ac.5MV 3o cly i

o- A )(. With no M SV path OPERA , restore at least one path to OPERABLE ,

status within 72 heur; or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />,

b. The proviskoni of Spec 31'ca% 3.0.4 we. not aff l icals.

SU VEILLANCE REQUIREMENTS g

ScSHV 4.4.11 Each RG5Y path shall be demonstrated OPERABLE at.least once per 18

. months by:

a.# Verifying.that the upstream manual isolation valves are locked in.the open position,fer tho heart yent, l..

b. .0perating each remotely controlled valve through at least one cycle from the control room, and Ac58V

c. Verifying flow throughethe ".CS" path /* der % venting, eac4 AlnperaNeltesab b"' N8 vse s, ,. 1 ows4 be maidahed 9 m nuw & 4 4/4 hordh #IO5ed~4d di Po*C'

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• Lsc cf "cwcr Operated Relief Valve; (POPV' ) "ith :::cciated block valve:

i: cen;idered onc cy;ter Clocure of one er both-Mock-valves does not make

- the vent path-isoperable-provided-the-valve (+)-can4c Opened.

1. The requirement to verify that the upstream manual isolation valves are locked in the open position is waived until the Cycle 4 refueling outage. This waiver is granted on a one-time basis. At the first Mode 5 outage following issuance of the above waiver, a flow verification test will be performed to verify that the manual isolation valves are open.

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SEQUOYAH - UNIT 1 3/4 4-28 Amendment No. 116 , 123

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' REACTOR COOLANT SYSTEM J

I BASES ,

safety valves are OPERABLE, an operating RHR loop, connected to the RCS, provides overpressure relief capability and will prevent RCS overpressurization.

During operation, all pressurizer code safety valves must be OPERABLE to prevent the RCS from being pressurized above its safety limit of 2735 psig.

The combined relief capacity of all of these valves is greater than the maximum surge rate resulting from a complete loss of load assuming no reactor trip until the first Reactor Protective System trip set point is reached (i.e., no credit is taken for a direct reactor trip on the loss of load) and also assuming no operation of the power operated relief valves or steam dump valves.

Demonstration of the safety valves' lift settings will occur only during shutdown and will be performed in accordance with the provisions of Section XI of the ASME Boiler and Pressure Code.

, The power operated relief valves (PORVs) and steam bubble function to relieve RCS pressure during all design transients up to and including the design step load decrease with steam dump. Operation of the PORVs minimizes the undesirable opening of the spring-loaded pressurizer code safety valves.

Each PORV has a remotely operated block valve to provide positive shutoff capability should a relief valve become inoperable.

Tke, P0RM% also 4vachm 40 remwe non-condensible5 e' SYe** I'** SAC f"'5"'E3 'f*

3/4.4.4 PRESSURIZER The limit on the maximum water volume in the pressurizer assures that the parameter is maintained within the normal steady state envelope of operation assumed in the SAR. The limit is consistent with the initial SAR assumptions.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> periodic surveillance is s'ufficient to ensure that the parameter is restored to within its limit following expected transient operation. The -

maximum water volume also ensures that a steam bubble is formed and thus the RCS is not a hydraulically solid system. The requirement that 150 kw of pressurizer heaters and their associated controls be capable of being supplied electrical power from an emergency bus provides assurance that the plant will be able to control reactor coolant pressure and establish natural circulation R16 conditions.

3/4.4.5 STEAM GENERATORS The Surveillance Requirements for inspection of the steam generator tubes ensure that the structural integrity of this portion of the RCS will be maintained. The program for inservice inspection of steam generator tubes is based on a modification of Regulatory Guide 1.83, Revision 1. Inservice inspection of steam generator tubing is essential in order to maintain surveillance of the conditions of the tubes in the event that there is evidence of mechanical damage or progressive degradation due to design, manufacturing errors, or inservice conditions that lead to corrosion. Inservice inspection of steam generator tubing also provides a means of characterizing the nature and cause of any tube degradation so that corrective measures can be taken.

MAR 251982 SEQL'OYAH - UNIT 1 8 3/4 4-2 Amendment No. 12 I

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3/4.4.10 STRUCTURAL INTEGRITY.

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The inservice inspection and testing programs for ASME Code Class 1, 2

.and 3 components ensure that the structural integrity and operational readiness {

l .oflife these components of the plant. will be maintained at an acceptable level throughout the These programs are in accordance with Section XI of the ASME 10 CFR Part Boiler and Pressure Vessel Code and applicable Addenda as required by' 50.55a the Commission purs(g) except where specific written relief has been' granted by uant to 10 CFR Part 50.55a (g)(6)(i).

Components of the reactor coolant' system were designed prior to' issuance.

of Section XI.of the ASME Boiler and Pressure Vessel Code. These components wf_ll be. tested to the~ extent pra~ctical within the limitations of the original y plant design, geometry, and materials of construction of the components.

HERD i 3/4.4.11 REACTOR COOLANT SYSTEM VENTS The function of the RC the reactor vessel-head,and/or pre;;uriz;r.ts is to remove noncondensables or steam from or inability to depressurize the RHR System initiate ,

the accumulation of noncondensable gases in the Reactor Coolant System. The Heving either cy;te: 0PEPASLE cr brain;; On: reactor safety ecch ;y;t= "e eppetite grade vent paths. )

p;th in vessel Of Spetific tion 3.4.11. ) train; OPERf3LE is sufficient to = :t the prc'si;iens L ls -

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f SEQUOYAH ' UNIT 1 B 3/4 4-14

_ Amendment No. 116 June 1, 1989

INDEX LIMITING CONDITIONS FOR OPERATION AND SURVEILLANCE REQUIREMENTS .

SECTION PAGE 3/4.4 REACTOR COOLANT SYSTEM 3/4.4.1 REACTOR COOLANT LOOPS AND COOLANT CIRCULATION Startup and Power Operation............................... 3/4 4-1 Hot Standby............................................... 3/4 4-2 Hot Shutdown.............................................. 3/4 4-3 Cold Shutdown............................................. 3/4 4-5 3/4.4.2- SAFETY VALVES - SHUTD0VN.................................. 3/4 4-6 3/4.4.3 SAFETY AND RELIEF VALVES - OPERATING Safety Valves 0perating................................... 3/4 4-7 Relief Valves 0perating.................................. 3/4 4-8 3/4.4.4 PRESSURIZER............................................... 3/4 4-9 3/4.4.5 1

STEAM GENERATORS..........................................

3/4 4-10 3/4.4.6 REACTOR COOLANT SYSTEM LEAKAGE Leakage Detection Systems................................. 3/4 4-17 Operational Leakage....................................... 3/4 4-18 3/4.4.7 CHEMISTRY................................................. 3/4 4-21 3/4.4.8 SPECIFIC ACTIVITY......................................... 3/4 4-24  ;

3/4.4.9 PRESSURE / TEMPERATURE LIMITS Reacto r Coo l ant Sys tem. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3/4 4-28 Pressurizer............................................... 3/4 4-32 3/4.4.10 STRUCTURAL INTEGRITY ASME Code Class 1, 2 and 3 Components..................... 3/4 4-33 R106 3/4.4.11 REACTOR COOLANT SYSTEM VENTS.............................. 3/4 4-34 t HE69 f

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SEQUOYAH - UNIT 2 VI Amendment No. 106 l June 1, 1989 j j

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REACTOR COOLANT SYSTEM l

3/4.4.11 REACTOR COOLANT SYSTEM VENTS LIMITING CONDITION FOR OPERATION uHadJ Res W -

3.4.11 -Twe. Reactor Coolant System' Vent (RGW) paths shall be OPERABLE.

• APPLICABILITY: MODES 1; 2, and 3.

ACTION:

a. With :nly One RCSV path OPEP.ABLE, STARTUP and/or-POWER-OPERAHON may

-cont 4 cue previded the ineperable path it maintained c!cced "ith - -

power removed 're.-' the valve actuaters; restere the inoperable-path-

-to OPERABLE ctate e ithin 30 daysi-or-be-in-HOT--ST.^NDBY within-6--

-hour:

and HOT SHUTDOWN within$ the-fem cwing 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br />.

RtsHV 30

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a f. With no N path OPE LE7restoreatleastonepathtoOPERABLE status within 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />; or be in HOT STANDBY within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

b. The provisons of Speelhca% 3.0 4 are nd afpOcble.

SU VEILLANCE REQUIREMENTS RC6HV 4.4.11 Each RGSV path shall be demonstrated OPERABLE at least once per 18 months by:

a .' # Verifying that the upstream manual isolation valves are locked in l the open position,fer the head vent >

\ b.

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Operating each remotely controlled valve through at least one cycle

'from the control room, and Rc5HV

c. Verifying flow throughath RCSVpath/durngventing.

4 cad

• Tnopeneble90h invd le maidaitsecl cined wHh foser removeE Eo ss $s Val@ obvah/S.IA4*9 liCJ'IV Pdb I~' A'I*& N'P"' AI' *b'I' "" "ff "N ll'

/7100E, powr. h// As w d & d e v' b' ** N

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• U56 ef Pcwer Uperated Relicf Valve (PORV' ) with as cciated b!cck valver

-is-cons 4dered-onc cycte-' Clocure of One er bot 41-tdeck valve; dec: not ;ake-the vent path incperable provided the vche(+)-ean be cpened-

1. The requirement to verify that the upstream manual isolation valves are locked in the open position is waived until the Cycle 4 refueling outage.

This waiver is granted on a one-time basis. At the first Mode 5 outage following issuance of the above waiver, a flow verification test will be performed to verify that the manual isolation valves are open.

SEQUOYAH - UNIT 2 3/4 4-34 Amendment No. 106,112 l i

a REkCTORCOOLANT, SYSTEM '

i BASES 3/4.4.'2 and 3/4.4.3 SAFETY AND RELIEF VALVES

The pressurizer code safety valves operate to prevent the RCS from being pressurized above its Safety Limit of 2735 psig. .Each safety valve is designed to relieve 420,000 lbs per hour of saturated steam at the valve set point.

r The. relief capacity of a single safety valve is adequate to relieve any over-pressure condition which could occur during shutdown. In the event that no safety valves are OPERABLE, an operating RHR loop, connected to the RCS, provides overpressure relief capability and will prevent RCS overpressurization.

During operation, all pressurizer code safety valves must be OPERABLE to prevent the RCS from being pressurized above its safety limit of 2735 psig.

The combined relief capacity of all of these valves is greater than the maximum

' surge rate resulting from a complete loss of load assuming no reactor trip until the first Reactor Protective System trip set point is reached (i.e., no credit is taken for a direct reactor trip on the loss of load) and also assuming no operation of the power operated relief valves or steam dump valves.

Demonstration of the safety valves' lift settings will occur only during shutdown and will be performed in accordance with the provisions of Section XI of the ASME Boiler and Pressure Code.

The power operated relief valves (PORVs) and steam bubble function to relieve RCS pressure during all design transients up to and including the I design step load decrease with steam dump. Operation of.the PORVs minimizes the undesirable opening of the spring-loaded pressurizer code safety valves.

Each PORV has a remotely operated block valve to provide positive shutoff capability should a relief valve become inoperable.

The POR\/tg aho Qah % move, non.pjedje,s o, sQ km & puwd $M 3/4.4.4 PRESSURIZER The limit on the maximum water volume in the pressurizer assures that the parameter .is maintained within the normal steady state envelope of operation i assumed in the SAR. The limit is consistent with the initial SAR assumptions.

The 12 hour1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br /> periodic surveillance is sufficient to ensure that the parameter

.is restored to within its limit following expected transient operation. The maximum water volume also ensures that a steam bubble is formed and thus the RCS is not a hydraulically solid system. The requirement that 150 kw of I pressurizer heaters and their associated controls be capable of being supplied electrical power from an emergency bus provides assurance that the plant will be able to control reactor coolant pressure and establish natural circulation conditions.

I SEQUOYAH - UNIT 2 B 3/4 4-2 l

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REACTOR COOLANT SYSTEM

' BASES 3/4.4.11 -REACTOR COOLANT SYST NTS R106 h

The function of the RCNead nts is to remove noncondensables or steam from

-the' reactor vessel head,end/cr pressurizer. This system is designed to mitigate' a possible condition of inadequate core cooling, inadequate natural circulation, or inability to depressurize the RHR System initiated conditions resulting

-from the accumulation of noncondensable gases in the Reactor Coolant System.

The reactor vessel head vent 9d tb pe="" char vent cr: ::;h designed with redundant safety grade vent pa s. hv ng either y te; OPERACLE cr hav'n; i

cae p;th 4- each syste= frer oppcs 4e tiain:, GFERACLE is 5sfficient t: :::t th previrien: cf Specificetiei. 3 4-14--

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SEQUOYAH - UNIT 2 B 3/4 4-15 Amendment No.106 June 1, 1989

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.h/ ENCLOSURE 2 PROPOSEDTECHNICALSPECIFICATIbNCHANGE' (SEQUOYAH NUCLEAR' PLANT UNITS 1-AND 2' a,

DOCKET NOS. 50-327.AND 50-328 TVA-SQN-TS-89-40 4 ' ,

DESCRIPTION AND JUSTIFICATION FORT REVISING.TS 3/4 4'.11-a 6

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l ENCLOSURE 2  !

l~ 1 Description of Change Tennessee Valley Authority proposes to modify the Sequoyah Nuclear Plant (SQN) Units 1 and 2 technical specifications (TSs) to revise the reactor coolant system (RCS) vent TS and make corresponding changes to the index and affected bases.

Reason for Change The present ROC vent TS contains inconsistencies between the requirements in the limiting condition for operation (LCO) (with footnote) and the bases with respect to the required vent paths. The RCS vent TS contains inconsistent language in the LCO, the footnote, and the bases regarding

" paths" and " systems"; inconsistent action requirements with respect to removing power from the valve actuators on inoperable vent paths; and duplicate and inconsistent requirements for the pressurizer power-operated relief valve.(PORV) vent paths. For example, a pressurizer PORV may be inoperable for TS 3.4.3.2, satisfy the conditions of Action a for

'TS 3.4.3.2, and be considered oper2ble as an RCS vent path for TS 3.4.11.

Justification for Change The requirements for pressurizer PORV operability are deleted from the LCO 1for TS 3.4.11 to eliminate redundancy with TS 3.4.3.2. The requirements of TS 3.4.3.2 ensure that two pressurizer PORV vent paths are available, one of which may be used to satisfy RCS vent requirements. With one PORV inoperable as a vent path (incapable of RCS pressure control), 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is allowed to restore the PORV vent paths, or plant shutdown is required.

With both PORVs inoperable as vent paths, I hour is allowed to restore the PORV vent paths, or plant shutdown is required. The out-of-service times allowed by TS 3.4.3.2 are also more restrictive than the out-of-service time allowed by TS 3.4.11. The proposed change to the LCO for TS 3.4.11 eliminates duplication between specifications without any relaxation in requirements. The proposed change focuses the requirements cf TS 3.4.11 on the RCS vent. The potential for misinterpreting the requirements for pressurizer PORV vent paths and RCS head vent paths will be eliminated by this change.

The action statements have been changed to reflect the revised LCO for TS 3.4.11. The current action requirements allow 30 days for repairs when either the RCS head vent path or the pressurizer PORV vent path are out of service. The action requirements also allow 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> for repair when both the RCS head vent path and the pressurizer PORV vent path are out of service. The revised action statement for TS 3.4.11 allows 30 days for repair when the RCS head vent path is out of service. The action requirements (Statements b, c, and d) for TS 3.4.3.2 allow 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> or less for repairs when the pressurizer PORV vent path (s) is out of service. With only the RCS head vent paths out of service, the i

proposed TS 3.4.11 will allow 30 days for repair (consistent with current

! requirements). With only the pressurizer PORV vent paths out of service, TS 3.4.3.2 allows one hour for repair (considerably more restrictive than current requirements). With both the RCS head vent paths and the pressurizer PORV vent path out of service, TS 3.4.3.2 still controls and is more restrictive than the current requirements.

The allowance for startup and power operation with the RCS head vent

! system inoperable permitted by the current &ction statement has been incorporated by stating that the provisions of TS 3.0.4 are not applicable. The requirement to have power removed from the valve actuators on inoperable RCS head vent paths has been changed to a footnote for the LCO for TS 3.4.11. This will ensure that power is removed from

! the valve actuators on an inoperable head vent path even when the provisions of the LCO are being satisfied. In addition, a one-hour time limit is added to the power removal requirement. Similar requirements for power removal for the pressurizer PORV vent paths are contained in TS 3.4.3.2.

Redundant wording from the surveillance requirements is deleted to improve clarity.

Corresponding changes to the index and bases are made to be consistent with the proposed changes to TS 3.4.11.

Environmental Impact Evaluation The proposed change request does not involve an unreviewed environmental question because operation of SQN Units 1 and 2 in accordance with this change would not:

1. Result in a significant increase in any adverse environmental impact previously evaluated in the Final Environmental Statement (FES) as modified by the Staff's testimony to the Atomic Safety and Licensing Board, supplements to the FES, environmental impact appraisals, or in any decisions of the Atomic Safety and Licensing Board.

2. Result in a significant change in effluents or power levels.

3. Result in matters not previously reviewed in the licensing basis for SQN that may have a significant environmental impact.

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• ENCLOSURE 3 PROPOSED TECHNICAL SPECIFICATION CHANGE.

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SEQUOYAH NUCLEAR PLANT UNITS l AND 2 DOCKET NOS. 50-327 AND 50-328 TVA-SQN-TS-89-40 DETERMINATION OF NO SIGNIFICANT HAZARDS CONSIDERATIONS

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ENCLOSURE 34 l

Significant Hazards Evaluation l

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TVA has evaluated the proposed TS change and has determined that it does d not represent a significant hazards consideration based on criteria 4 established in 10 CFR 50.92(c). Operation of SQN in accordance with_the-proposed amendment will not:

(1) Involve a significant increase in the probability or consequences of I an' accident previously evaluated.

SQN Final Safety Analysis Report (FSAR) Section 5.5.15 describes the RCS head vent. The head vent system is designed to remove noncondensible gases or steam from the reactor vessel head through the remote manual operations from the control room. The head vent system is connected above the reactor vessel to one of the upper head injecticn system discharge pipes (FSAR Figure 6.3.2-16). The head vent system discharges to the pressurizer relief tank (FSAR Figure 5.1-1). Similarly, the pressurizer PORVs provide a vent path i from the RCS through the pressurizer. The PORVs also discharge to the pressurizer relief tank (FSAR Figure 5.1-1).

i The-proposed changes to TS 3.4.11 are made to clarify the RCS head I vent requirements. The deletion of the PORV vent path requirements from TS 3.4.11 will not increase the probability or consequences of any previously evaluated accidents because the requirements of TS 3.4.3.2 for PORV operability are more restrictive than those imposed by the current TS 3.4.11. The revised bases for TS 3.4.3.2 clearly identify that the PORVs provide a vent path from the pressurizer. The remaining changes to TS 3.4.11 and its bases section make the wording of the TS specific to the RCS head vent.

The requirements for system operability in the revised TS are consistent with the current wording. As such, the balance of the changes to TS 3.4.11 will not increase the probability or consequences of any previously evaluated accident.

(2) Create the possibility of a new or different kind of accident frcm any previously analyzed.

The proposed changes to TS 3.4.11, its bases, and the bases of TS 3.4.3.2 are made to clarify the requirements for the RCS head vent. The proposed changes do not conflict with or relax the current requirements for the PORVs or the RCS head vent. The changes are administrative in nature by removing ambiguous wording and duplicate requirements. The function and operation of the PORVs and the RCS head vent system remain unchanged. Therefore, the proposed changes will not create the possibility of a new or different kind of accident from any previously analyzed.

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'(3). Involve a significant reduction in a margin of safety.

As described above, the_ proposed revisions to TS 3.4.11 and the associated bases changes are.made to clarify the-requirements for the

~RCS head vent. .The requirements of TS 3.4.3.2.for PORV operability are more restrictive than the current requirements of TS 3.4.11.

Additionally, the revised bases for TS 3.4.3.2 clearly identify that the PORVs provide a vent path through the pressurizer. .The other changes to TS 3.4.11 and its bases make TS 3.4.11 specifically address.the requirements for.the RCS head vent.- This serves to remove ambiguity and duplication from the TS requirements.. The revised TS:3.4.11 is consistent with.the current requirements for,the RCS head vent. The' function and operation of both the head vents and,

-the PORVs remain. unchanged.. Therefore, the proposed changes do not reduce the margin of safety..

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