Text

Proposed Tech Specs,Submitting Suppl Info to STP Proposed Improved TS
	ML20138K971
Person / Time
Site:	South Texas
Issue date:	02/11/1997
From:	; HOUSTON LIGHTING & POWER CO.
To:	;
Shared Package
ML20138K969	List: ML20138K971; ST-HL-AE-5571, Submits Suppl Info Re STP Proposed Improved TS;
References
	NUDOCS 9702190269
	Download: ML20138K971 (206)
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Accumulators

3.5.1 L

3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS).

3.5.1.-Accumulators i

., LCO 3.5.1 Three ECCS accumulators shall.be OPERABLE.

APPLICABILITY: MODES 1 and 2.

j MODE 3 with pressurizer pressure > 1000 psig.

l ACTIONS i CONDITION REQUIRED ACTION COMPLETION TIME i

l A. One accumulator A.1 Restore boron 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months j inoperable due to concentration to

' boron concentration within hmits.

i not within limits.

B. One accumulator B.1 Restore accumulator 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months inoperable for reasons to OPERABLE status, i other than Condition A.

C.__ Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months ,

1. associated Completion !

Time of Condition A

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AND j or B not met.

, C.2 Reduce pressurizer 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 3 pressure to j s 1000 psig.

f D. Two or more D.1 Enter LC0 3.0.3. Immediately i

accumulators

inoperable.

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t j 9702190269 970211 1

PDR ADOCK 05000498 1 P PM i

! South Texas Units 1 and 2 3.5-1 Rev. O. 02/05/97 1

Accumulators 3.5.1 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.1.1 Verify each accumulator isolation valve is 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

fully open. l i

i SR 3.5.1.2 Verify borated water volume in each 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months accumulator is a 8800 gallons and s 9100 gallons.

1 SR 3.5.1.3 Verify nitrogen cover pressure in each 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months accumulator is a 590 psig and s 670 psig.

SR 3.5.1.4 Verify boron concentration in each 31 days accumulator is a 2700 ppm and 5 3000 ppm.

AND

NOTE------

Only required !

to be performed i for affected '

accumulators Once within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after each solution volume increase of a 88 gallons of indicated level that is not the result of addition from the Refueling Water Storage Tank (continued)

South Texas Units 1 and 2 3.5-2 Rev. O, 02/05/97

Accumulators 3.5.1 I

i SURVEILLANCE. REQUIREMENTS (continued)

SURVEILLANCE- FREQUENCY

! SR 3.5.1.5 Verify power is removed from each 31 days .

accumulator. isolation valve operator wheri ,

pressurizer pressure is ' 100. = 2000 psig. I i

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l j South Texas Units 1 and 2 3.5-3 Rev. O. 02/05/97 t

ECCS -Operating 3.5.2 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.2 ECCS-Operating LC0 3.5.2 Three ECCS trains shall be OPERABLE.

APPLICABILITY: MODES 1. 2. and 3.

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

Entry into and operation in MODE 3 with ECCS pumps declared l inoperable pursuant to LC0 3.4.12. " Low Temperature Overpressure Protection (LTOP) System - MODE 4." is allowed l for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or until the temperature of one or more ,

RCS cold legs exceeds 375 F. whichever comes first.

{

................__....................................____ j ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One RHR subsystem A.1 Restore RHR subsystem 14 days inoperable. to OPERABLE status.

AND 21 days from discovery of failure to meet the LC0 B. One SI subsystem B.1 Restore SI subsystem 7 days inoperable. to OPERABLE status.

AND 21 days from discovery of failure to meet the LCO (continued) 1 i

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i South Texas Units 1 and 2 3.5-4 Rev. O. 02/05/97 l

l ECCS-Operating l

l 3.5.2 :

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l ACTIONS (continued) !

i CONDITION REQUIRED ACTION COMPLETION TIME !

l C. Two RHR subsystems C.1 Restore one RHR 7 days 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months I i inoperable. subsystem to OPERABLE !

status. '

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D. Two SI subsystems D.1 Restore one SI 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months inoperable. subsystem to OPERABLE status.

E. Required Action and E.' Be in MODE 3. Entee 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion LCO 3.0.3. Immediately Times for Conditions A B, gr C. Or D not AND met.

E2 Be in MODE 4. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 9B "0TE Condition not a :licable when three n-,-,,u-,,-+--- ,--

'!..y~'m'm::.

.. " i. :'. ""

Three SI subsystems incperable.

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South Texas Units 1 and 2 3.5-5 Rev. 0, 02/05/97

ECCS-Operating 3.5.2 ACTIONS (continued)

CONDITION REQUIRED ACTION COMPLETION TIME E gggpired Action and E1 Enter LC0 3.0.3. Immediately associated Comoletion '

Time for Condition D not met.

08

NOTE---------- '

Condition not aDolicable when three RHR subsystems are inoDerable.

Three SI subsystems ;

inoDerable.

G Three RHR subsystems Gml Initiate action to Immediately Fr inoperable. Fr1 restore RHR subsystems ,

to OPERABLE status. l l

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i South Texas Units 1 and 2 3.5-6 Rev. 0, 02/05/97

ECCS-Operating 3.5.2

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-SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY-SR 3.5.2.1 Verify each ECCS manual. power operated, 31 days and automatic valve in the flow path, that l is not: locked, sealed, or otherwise secured l in position, is in the correct position. ;

1 SR 3.5.2.2 Verify ECCS piping is full of water. 93 31 days I j 1

SR 3.5.2.3 Verify each HHSI, LHSI, and RHR pump's In accordance developed head at the test flow point-is with the !

greater than or-equal to the required Inservice !

developed head. Testing Program !

i SR 3.5.2.4 Verify each ECCS automatic valve in the 18 months i flow path that is not locked, sealed or {

otherwise secured in position, actuates to '

the correct position on an actual or simulated actuation signal.

SR 3.5.2.5 Verify each HHSI and LHSI pump starts 18 months automatically on an actual or simulated actuation signal.

SR 3.5.2.6 Verify by visual inspection, each ECCS 18 months train containment sump suction inlet is not restricted by debris and the suction inlet trash racks and screens show no evidence of structural distress or abnormal corrosion.

i South Texas Units 1 and 2 3.5-7 Rev. O. 02/05/97 !

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' ECCS-Shutdown r

3.5.3

3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)

, 3.5.3 ECCS Shutdown LCO 3.5.3: -Two ECCS Trains shall be OPERABLE with one 0"2RABLE High-

Head Safety Injection (HHSI) subsystem with the pump breaker n racked in.

......N0TES---------------------------

1. After entering MODE 4 from MODE 3. more than one HHSI F pump breaker may be racked in until one or more RCS cold )

leg temperature s s 325' F. .I )

1 -

2. More than one HHSI pump breaker may be energized for testing or filling accumulators provided the discharge j of the pump is isolated from the RCS.

! 3. After entering MODE 4 from MODE 5.-all HHSI pump breakers may be racked out until one or more RCS cold

i. leg temperature > 225 F.

~

4. RHR subsystem OPERABILITY in MODE 4 shall be in accordance with LCO 3.4.6. "RCS Loops - MODE 4.

APPLICABILITY: MODE 4.

ACTIONS ~

CONDITION ! REQUIRED ACTION COMPLETION TIME A. One required ECCS- A.1 Verify one OPERABLE 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months train inoperable. HHSI subsystem with the pump breaker racked in.

G A.2 Restore required ECCS 14 days train to OPERABLE

-status.

(continued)

South. Texas Units 1 and 2 3.5-8 Rev. O. 02/05/97

ECCS-Shutdown 3.5.3 ACTIONS (continued)-

CONDITION REQUIRED ACTION COMPLETION TIME

, i B. -Two required ECCS B.1. Restore one required l' hour

trains inoperable. ECCS train to J

OPERABLE status.

4

C. Required Action and C.1 Be in MODE 5. 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months associated Completion Time not met.

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SURVEILLANCE REQUIREMENTS SURVEILLANCE FRE0VENCY :

SR--3.5.3.1 NOTE

.^ P99 cubsyste =y be ccncidered OPEP^3LE.

durinc clicn=nt. and cccration for decay heat re Oval if capable Of being =nually rc ligned tc the ECCS cdc cf Operation.

In accordance The following SRs are applicable for all with applicable-equipment required to be OPERABLEi SRs SR 3.5.2.2 SR 3.5.2.6 SR 3.5.2.3 ,

l (continued) i l

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South Texas Units 1 and 2 3.5-9 Rev. O. 02/05/97 l

e ECCS-Shutdown l

, 3.5.3 t l l l

' SURVEILLANCE REQUIREMENTS (continued) :

SURVEILLANCE I I FREQUENCY ;

SR 3.5.3.2 ------------------NOTES-------------------

1. Not required to be met when entering i MODE 4 from MODE 3 until any RCS cold .

leg temperature s s 325'F. I

2. Not required to be met when entering l t MODE 4 from MODE 5 until any RCS cold !

leg temperature > 225 F. l Verify HHSI pump breaker alignment. Once after ;

entry into MODE 4

AND e ,

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31 days l thereafter ;

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South Texas Units 1 and 2 3.5-10 Rev 0, 02/05/97 L -

!- f RWST 3.5.4 ;

i i 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) ;

3.5.4 Refueling Water Storage Tank.(RWST)

LC0 3.5.4 The RWST shall be OPERABLE.

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APPLICABILITY: MODES 1, 2. 3. and 4. I l

ACTIONS i

CONDITION REQUIRED ACTION COMPLETION TIME l A. RWST boron A.1 Restore RWST boron 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months concentration not concentration to within limits. within limits.

i B. RWST inoperable for B.1 Restore RWST to ' hour reasons other than OPERABLE status.

Condition A.

C. Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time not met. AND C.2 Be in MODE 5, 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months t

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l South Texas Units 1 and 2 3.5-11 Rev. O. 02/05/97 i l l

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RWST 3.5.4 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.4.1 Verify RWST borated water volume is 7 days a 458,000 gallons.

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SR 3.5.4.2 Verify RWST boron concentration is 7 days a 2800_ ppm and s 3000 ppm.

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l South Texas Units 1 and 2 3.5-12 Rev. O, 02/05/97 l

I Accumulators ,

B 3.5.1 j

! B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l 1

l B 3.5.1 Accumulators BASES l i

BACKGROUND The functions of the ECCS accumulators are to supply water {

to the reactor vessel during the blowdown phase of a loss of I coolant accident (LOCA), to provide inventory to help accomplish the refill phase that follows thereafter, and to

3rovide Reactor Coolant System (RCS) makeup for a small

)reak LOCA.

The blowdown phase of a large break LOCA is the initial period of the transient during which the RCS departs from equilibrium conditions, and heat from fission product decay, hot internals, and the vessel continues to be transferred to the reactor coolant. The blowdown phase of the transient ends when the RCS pressure falls to a value approaching that of the containment atmosphere.

In the refill phase of a LOCA, which immediately follows the blowdown phase, reactor coolant inventory has vacated the core through steam flashing and ejection out through the break. The core is essentially in adiabatic heatup. The balance of accumulator inventory is then available to help fill voids in the lower plenum and reactor vessel downcomer so as to establish a recovery level at the bottom of the core and ongoing reflood of the core with the addition of safety injection (SI) water. 1 The accumulators are pressure vessels partially filled with borated water and pressurized with nitrogen gas. The accumulators are passive components, since no operator or l control actions are required in order for them to perform their function. Internal accumulator tank pressure is sufficient to discharge the accumulator contents to the RCS.

if RCS pressure decreases below the accumulator pressure. l Three accumulators are piped into the RCS loops A. B. and C I cold legs via separate accumulator lines and each is !

isolated from the RCS by a motor o)erated isolation valve '

and two check valves in series. T1e motor o)erated isolation valves are interlocked by P-11 wit 1 the pressurizer pressure measurement channels to ensure that the valves will automatically open as pressurizer pressure increases to above the permissive circuit P-11 setpoint.

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i South Texas Units 1 & 2 B 3.5-1 Rev. O. 02/05/97 l

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l l Accumulators i B 3.5.1 BASES '

BACKGROUND This interlock also prevents inadvertent closure of the !

! (continued) valves during normal operation prior to an accident. The !

L valves will automatically open, however, as a result of an l l SI signal. These features ensure that the valves meet the i

requirements of the Institute of Electrical and Electronic Engineers (IEEE) Standard 279-1971 (Ref. 1) for "o)erating r bypasses" and that the accumulators will be availa]le for !

injection without reliance on operator action. Above 1000 ;

psig in the pressurizer. the accumulator's discharge valve ;

is open and the valve's oosition indication is monitored by !

an indeoendent mechanism.with cElectrical power is then i

(

removed from the MOV at 2000 osia. =d the v&c': pccition ind1 cation 1: =nitcr d by :n independcnt =cch:nis:

The accumulator size water volume, and nitrogen cover l pressure are selected so that two of the three accumulators !

are sufficient to partially fill the reactor vessel to aid

safety injection in covering the core before significant !

l clad melting or zirconium water reaction can occur following i a LOCA. The need to ensure that two accumulators are available for this function is consistent with the LOCA assumption that the entire contents of one accumulator will l l be lost via the RCS pipe break during the blowdown phase of the LOCA. l i

l APPLICABLE The accumulators are assumed OPERABLE in both the large and j SAFETY ANALYSES small break LOCA analyses at full power (Ref. 2). These are ;

the Design Basis Accidents (DBAs) that establish the -

! acceptance limits for the accumulators. Reference to the '

analyses for these DBAs is used to assess changes in the l accumulators as they relate to the acceptance-limits. !

In performing the LOCA calculations, conservative assumptions are made concerning the availability of ECCS flow. In the early stages of a LOCA. with or without a loss of offsite power, the accumulators provide the sole source of makeup water to the RCS. The assumption of loss of l offsite power is required by regulations and conservatively t

imposes a delay wherein the ECCS pumps cannot deliver flow until the emergency diesel generators start, come to rated speed, and go through their timed loading sequence. In cold leg break scenarios, the entire contents of one accumulator are assumed to be lost through the break.

l The limiting large break LOCA is a double ended guillotine i break at the discharge of the reactor coolant pump. During (continued) .

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South Texas Units 1 & 2 B 3.5-2 Rev. O. 02/05/97

Accumulators B 3.5.1 !

1 BASES ;

, APPLICABLE this event..the accumulators discharge to the RCS as soon as i

. SAFETY ANALYSES, RCS pressure decreases to below accumulator pressure. l (continued)

As a conservative estimate. no credit is taken for ECCS pump flow until an effective delay has elapsed. This delay accounts for the diesels starting and the pumps being loaded and delivering full flow. The delay time is conservatively i set with an additional 2 seconds to account for SI signal generation. During this time, the accumulators are analyzed

as providing the sole source of emergency core cooling. No operator action is assumed during the blowdown stage of a large break LOCA.

1 The worst case small break LOCA analyses also assume a time delay before pumped flow reaches the core. For the larger range of small breaks, the rate of blowdown is such that the increase in fuel clad temperature is terminated solely by the accumulators, with pum)ed flow then providing continued cooling. As the range of areak size decreases, the ;

accumulators and SI pumps both play a -) art in terminating the rise in clad temperature. As breat size continues to decrease the role of the accumulators continues to decrease until they are not required and the SI pumps become solely responsible for terminating the temperature increase.

This LC0 helps to ensure that the following acceptance criteria established for the ECCS by 10 CFR 50.46 (Ref. 3) l will be met following a LOCA: !

a. Maximum fuel element cladding temperature is s 2200*F:

b. Maximum cladding oxidation is s 0.17 times the total cladding thickness before oxidation;

c. Maximum hydrogen generation from a zirconium water reaction is s 0.01 times the hypothetical amount that l would be generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding surrounding the plenum volume, were to react: and

d. Core is maintained in a coolable geometry.

Since the accumulators discharge during the blowdown phase of a LOCA they do not contribute to the long term cooling requirements of 10 CFR 50.46.

(continued)

South Texas Units 1 & 2 B 3.5-3 Rev. O. 02/05/97

Accumulators I B 3.5.1 l BASES APPLICABLE For both the large and small break LOCA analyses, a nominal SAFETY ANALYSES contained accumulator water volume is used. The contained 1 (continued) water volume is the same as the deliverable volume for the !

accumulators, since the accumulators are emptied, once discharged. For small breaks, an increase in water volume is a peak clad temperature penalty. For large breaks, an i

increase in water volume can be either a peak clad I temperature penalty or benefit, depending on downcomer )

filling and subsequent spill through the break during the core reflooding portion of the transient. The analysis makes a conservative assumption with respect to ignoring or taking credit for line water volume from the accumulator to !

the check 3valve. The safety analysis assumes nominal values l of 1200 ft or 8977 gallons. To allow for instrument '

inaccuracy. values of 8800 gallons and 9100 gallons are specified for the lower and upper limits. -

The minimum boron concentration setpoint is used in the, post LOCA boron coggentration calculation. The calculation is performed to assure reactor subcriticality in a post LOCA environment. Of particular interest is the large break LOCA since no credit is taken for control rod assembly insertion. A reduction in the accumulator minimum boron concentration would produce a subsequent reduction in the l available containment sump concentration for post LOCA '

shutdown and an increase in the maximum sump pH. The maximum boron concentration is used in determining the cold leg to hot leg recirculation injection switchover time and minimum sump pH.

The large and small break LOCA analyses are performed at the minimum nitrogen cover )ressure, since sensitivity analyses have demonstrated that ligher nitrogen cover pressure results in a computed peak clad temperature benefit. The maximum nitrogen cover pressure limit prevents accumulator relief valve actuation, and ultimately preserves accumulator integrity.

The effects on containment mass and energy releases from the accumulators are accounted for in .the appropriate analyses (Refs. 2). I The accumulators satisfy Criterion 3 of the NRC Policy Statement (Ref. 4).

l (continued) l South Texas Units 1 & 2 8 3.5-4 Rev.. O. 02/05/97

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i Accumulators l B 3.5.1

-BASES' (continued) i i

LC0 The LC0 establishes the minimum conditions required to !

ensure that the accumulators are available to accomplish their core cooling safety function following a LOCA. Three accumulators are required to ensure that 100% of the i contents of two of the accumulators will reach the core !

during a LOCA. This is consistent with the assumption that ;

, the contents of one accumulator spill through the break. If '

E less than two accumulators are injected during the blowdown i phase of a LOCA. the ECCS acceptance criteria of '

10 CFR 50.46 (Ref. 3) could be violated. !

For an accumulator to be considered OPERABLE. the isolation valve must be fully open, power removed when a 2000 asig :

abcvc 1000 ~ig containedvEdume,,andthelimitsestfalishedintheSRsfor boron concentration. and nitrogen cover ;

pressure must be met. ;

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. APPLICABILITY In MODES 1 and 2. and in MODE 3 with pressurizer pressure ,

> 1000 psig the accumulator OPERABILITY requirements are j based on full power operation. Although cooling '

requirements decrease as power decreases, the accumulators are still required to provide core cooling as long as elevated RCS pressures and temperatures exist.

This LC0 is only applicable at pressures > 1000 psig. At pressures s 1000 psig. the rate of RCS blowdown is such that the ECCS pumps can provide adequate injection to ensure that peak clad temperature remains below the 10 CFR 50.46 (Ref. 3) lim't of 2200*F.

In MODE 3. with pressurizer pressure s 1000 psig, and in MODES 4. 5. and 6. the accumulator motor operated isolation valves are closed to isolate the accumulators from the RCS. i This allows RCS cooldown and depressurization without discharging the accumulators into the RCS or requiring :

depressurization of the accumulators.

(continued) l l

South Texas Units 1 & 2- B 3.5-5 Rev. O 02/05/97

Accumulators B 3.5.1 i BASES (continued)

ACTIONS M If the boron concentration of one accumulator 'is not within limits, it must be returned to the limits within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months .

In this Condition, ability to maintain subcriticality or i minimum boron precipitation time may be reduced. In the reflood phase of the calculated response to LOCA, the boron content of an accumulator is not specifically evaluated since it is not of concern during this phase of the accident. During the recirculation phase, when the ECCS is taking suction from the containment sump, the boron content of the accumulators is considered but its contribution is small when compared with the total volume of the RCS and the Refueling Water Storage Tank (RWST). Boiling of ECCS water in the core during reflood corc;3ntrates boron in the saturated liquid that remains in the core. In addition, current analysis techniques demonstrate that the accumulators may not discharge following a large main steam line break. If they do discharg3 their impact is minor and not a design limiting event. Thus. 77 hours8.912037e-4 days 0.0214 hours 1.273148e-4 weeks 2.92985e-5 months is allowed to return the boron concentration to within limits.

M If one accumulator is inoperable for a reason other than boron concentration. the accumulator must be returned to OPERABLE status within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . In this Condition, the required contents of two accumulators cannot be assumed to reach the core during a LOCA. The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion Time to open the valve, remove power to the valve, or restore the proper water volume or nitrogen cover pressure ensures that prompt action will be taken to return the inoperable accumulator to OPERABLE status. The Completion Time minimizes the potential for exposure of the plant to a LOCA i under these conditions.

1 C.1 and C.2 I If the accumulator cannot be eturned to OPERABLE status _ l within the associated Com)letion Time, the plant must be brought to a MODE in whic1 the LCO does not apply. To achieve this status, the plant must be brought to MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and pressurizer 3ressure reduced to s 1000 psig within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . T1e allowed Completion Times are reasonable, based on operating experience, to reach the (continued) l South Texas Units 1 & 2 B 3.5-6 Rev. O. 02/05/97 1

i

. Accumulators B 3.5.1 BASES ACTIONS C.1 and C.2 (continued) recuired plant conditions from full power conditions in an orcerly manner and without challenging plant systems.

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If more than one accumulator is inoperable, the plant is in a condition outside the requirements of the LCO: and LCO 3.0.3 must be er.tered immediately.

SURVEILLANCE SR 3.5.1.1 L REQUIREMENTS i Each accumulator valve should be verified to be fully open.

i every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . This verification ensures that the accumulators are available for injection and ensures timely-

, discovery if a valve is less than fully open. If an isolation valve is not fully o]en, the rate of i. 6 ction to the RCS would be reduced. Altlough a motor operated valve position should not change with power removed, a closed valve could result in not meeting accident analyses assumptions. This Frequency is considered reasonable in view of other administrative controls that ensure a mispositioned isolation valm is unlikely.

SR 3.5.1.2 and SR 3.5.1.3 l

L Every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months , borated water volume and nitrogen cover pressure are verified for each accumulator. Methods of verification include the absence of alarms. This Frequency is sufficient to ensure adequate injection during a LGCA.

Because of the static design of the accumulator, a 24 hour-Frequency usually allows the operator to identify changes before limits are reached. Operating experience has shown l this Frequency to be appropriate for early detection and correction of off normal trends.

SR 3.5.1.4 The boron concentration should be verified to be within required limits for each accumulator every 31 days since the static design of the accumulators limits the ways in which (continued)

South Texas Units 1 & 2 B 3.5-7 Rev. O 02/05/97

t

' Accumulators B 3.5.1 :

BASES i

SURVEILLANCE SR 3.5.1.4 ' (continued) l REQUIREMENTS the concentration can be changed. The 31 day Frequency is :

adequate to identify changes that could occur from mechanisms such as inleakage. A second conditional Frequency is modified by a Note that limits the additional '

sampling to only the affected accumulator 4s-). Sampling the I ;

affected acamulator within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after an 88 gallon ,

increase will identify whether inleakage or make up from a !

source, other than the RWST. which may cause a change in boron concentration from the required limits. It is not necessary to verify boron-concentration if the added water ,

inventory is from the RWST, because the water contained in the RWST is within the accumulator boron concentration requirements. This is consistent with the recommendation of NUREG-1366 (Ref. 5).

t SR 3.5.1.5 !

Verification every 31 days that power is removed from each accumulator isolation valve operator when the pressurizer ,

pressure is ' 1000 = 2000 psig ensures that an active ,

failure could not result in the undetected closure of an accumulator motor operated isolation valve. If this were to occur, only one accumulator would be available for injection given a single failure coincident with a LOCA. Since power

.is removed under administrative control, the 31 day Frequency will provide adequate assurance that power is removed.

This SR allows power to be supplied to toe motor operated isolation valves when pressurizer pressure is r 1000

< 2000 psig, thus allowing operational flexibility by avoiding unnecessary delays to manipulate the breakers during plant startups or shutdowns. Even with power supplied to the valves, inadvertent closure is prevented by the pressurizer pressure interlock associated with the valves.

Should closure of a valve occur in spite of the interlock.

the SI signal provided to the valves would open a closed valve in the event of a LOCA.

(continued)

South Texas Units 1 & 2 B 3.5-8 Rev. 0, 02/05/97

Accumulators B 3.3.1 BASES (continued)

REFERENCES 1. IEEE Standard 279-1971.

2. UFSAR. Chapter 6.

3. 10 CFR 50.46.

4 Final Policy Statement on Technical Specification Improvements for Nuclear Power Reactors. 58 FR 39132.

July 22, 1993.

5. NUREG-1366. December. 1992.

i 1

South Texas Units 1 & 2 B 3.5-9 Rev. O. 02/05/97 i

ECCS -Operating B 3.5.2 B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l l

B 3.5.2 ECCS -Operating i BASES' i

l BACKGROUND The function of the ECCS is to )rovide core cooling and i l negative reactivity to ensure tlat the reactor core is i prote. Led after any of the following accidents l

a. Loss of coolant accident (LOCA), coolant leakage '

greater than the capability of the normal charging system:

b. Rod ejection accident:

c.

Loss of secondary coolant accident, including uncontrolled steam release or loss of feedwater: and i

d. Steam generator tube rupture (SGTR).

i The addition of negative reactivity is designed primarily for the loss of secondary coolant accident where primary cooldown could add enough positive reactivity to achieve criticality and return to significant power.

There are three phases of ECCS safety injection operation:

injection, cold leg recirculation, and hot leg recirculation. In the injection phase, water is taken from the refueling water storage tank (RWST) and injected into the Reactor Coolant System (RCS) through three cold legs.

When sufficient water is removed from the RWST to ensure that enough boron has been added to maintain the reactor subcritical and the containment sumps have enough water to supply the required net positive suction head to the ECCS pumps, suction is switched to the containment sump for cold leg recirculation. After a) proximately 6.5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months , at least one train of ECCS flow is slifted to the hot leg recirculation phase to 3rovide a backflush, which would reduce the boiling in tie top of the core and any resulting boron precipitation.

Residual Heat Removal (RHR) system operation may be used after certain DBAs which occur from a sequence of events that result in a substantially intact RCS system (e.g. Main Steam Line Break (MSLB)). This mode of operation is after the RCS coolant temperature has been reduced to less than (continued) i i

i South Texas Units 1 & 2 8 3.5-10 Rev. 0, 02/05/97

ECCS-Operating B 3.5.2 BASES BACKGROUND- 350'F after the DBA. Steam Generators are used to (continued) reduce the RCS coolant temperature to less than 350*F for these DBAs. This specification assures the availability of an RHR subsystem to be manually aligned if a DBA occurs.

Alternate methods of heat removal exist for this function, such as feed and bleed, however the RHR is the preferred heat removal method.

The ECCS consists of two subsystems: A Safety Injection (SI) subsystem and a RHR subsystem. Each subsystem consists of three redundant 100% capacity trains. The SI subsystem includes the High Head Safety Injection (HHSI) pumps. Low Head Safety Injection (LHSI) Jumps. RHR heat exchangers, and-the associated valves. The RiR subsystem includes the RHR pump and RHR heat exchangers and valves which are manually aligned to provide long term cooling after a DBA transient which may result in operation of the RHR (e.g. MSLB).

The ECCS accumulators and the RWST are also part of the ECCS, but are not considered part of an ECCS flow path as described by this LCO.

The SI subsystem flow paths consist of piping valves.-heat exchangers and pumps such that water from the RWST can be injected into the RCS following the accidents described in the Applicable Safety Analysis (ASA) section. The major components of each train are the HHSI pumps, the LHSI pumps, and the RHR heat exchangers.

Each ECCS train consists of a 100% capacity system that is independent and redundant such that any train is capable of supplying 100% of the flow required to mitigate the accident. This independent and redundant train design provides the operators with the ability to achieve the recuired 100% flow to the core with a loss of offsite power anc single active failure at the time an accident occurs.

The RHR subsystem flow paths consist of piping, valves. heat exchangers and pumps such that suction can be taken from the RCS hot legs. cooled in the RHR heat exchangers, and returned to the RCS following certain accidents described in the ASA section below (e.g. MSLB). The major com)onents of each train are the RHR pumps and the RHR heat exc1 angers.

Each train consists cf .100t caprit" syste- that is I redundant such that any train is capable of sup) lying 100%

of the flow required to support mitigation of tie applicable accident.

(continued)

South Texas Units 1 & 2 B 3.5-11 Rev. O. 02/05/97 1

l 1

l' ,

ECCS-Operating ,

B 3.5.2 BASES I BACKGROUND During the injection phase of LOCA recovery. a suction !

(continued) header supplies water from the RWST to the ECCS pumps. The- !

discharge from the HHSI pumps feeds the injection lines to i three of the RCS cold legs, with one pump sup)1ying a line '

to one RCS cold leg. The discharge from the _HSI ;

the injection lines to three of the RCS cold legs, pumps a feed j with one pump supplying a line to one RCS cold leg.This gain arrangement ensures sufficient flow to the core to meet the ,

analysis assumptions following a LOCA in one of the RCS cold legs with a single active failure.

For LOCAs that are too small to depressurize the RCS below !

the shutoff head of the HHSI pumps, the charging pumps !

supply water until the RCS pressure decreases below the HHSI E pump shutoff head. During this period, the steam generators i are used to provide the majority of the core cooling function.

1 During the recirculation phase of LOCA recovery, pump suction is transferred to the containment sump. Initially. :

recirculation is through the same paths as the injection i phase. Subsequently, recirculation altermte: includes ;

injection between combinations of the hot and cold legs.

For some non-LOCA events, the RCS remains intact and the RHR )

subsystems provide a means of removing the decay heat from the primary system when the RCS average temperature is less than 350*F.

l i

The HHSI portion of the ECCS also functions to supply borated water to the reactor core following increased heat ,

removal events. such as MSLB. The limiting design !

conditions occur when the negative moderator temperature :

coefficient is highly negative, such as at the end of each I cycle.

During low temperature conditions in the RCS, limitations are placed on the maximum number of pumps that may be OPERABLE. Refer to the Bases for LC0 3.4.12. " Low Temperature Overpressure Protection (LTOP) System -

MODE 4".and LC0 3.4.13. "LTOP - MODE 5 and MODE 6 With Head On". for the basis of these requirements.

The SI subsystems are actuated upon receipt of an SI signal.

The actuation of safeguard loads is accomplished in a programmed time sequence. If offsite power is available, the safeguard loads start immmediately in the programmed (continued)

South Texas Units 1 & 2 B 3.5-12 Rev. O. 02/05/97 l

4

1 l

ECCS-Operating l B 3.5.2 i BASES l

BACKGROUND sequence. If offsite power is not available. the Engineered I (continued) Safety Feature (ESF) buses shed nor el Operating selected i I loads and are connected to the standby diesel generators ,

(SDGs). Safeguard loads are then actuated in the programmed time sequence. The time delay associated with diesel starting, sequenced loading, and pump starting determines the time required before pumped flow is available to the core following ,a LOCA.

The RHR subsystem is manually aligned and actuated when the RCS coolant temperature is reduced to less than 350*F. If offsite power is not available, the RHR pumps would be manually connected to the SDGs follcwing completion of the automatic ESF bus strip and load sequencing.

The PSA success criteria are as follows (Ref.1):

The system success criteria utilized in the Probabilistic Safety Assessment is one High Head train for small-break, and two High Head Safety Injection trains for medium and large-break Loss of Coolant Accidents.

Small break Loss of Coolant Accidents will require only one Low Head Safety Injection pump; however, medium break and large break Loss of Coolant Accidents will require two Low Head Safety Injection pump trains. One, two or three Low Head Safety Injection pumps start from standby, manually or automatically on a Safety Injection signal, take suction from the common suction line, and discharge into the injection line, continuing operation for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

At least one of the three Residual Heat Removal trains is !

put into service during normal and accident conditions to remove decay heat from the Reactor Coolant System. Also, a flow path through the Residual Heat Removal heat exchanger is available for one operating Low Head Safety Injection pump train during recirculation following injection in response to a Loss of Coolant Accident.

The PSA potential for an initiating event is as follows (Ref. 1):

A pipe brcok dovectrc= cf the check valves in the Safety Inacction line: viill result in b rge Los: cf Coc h nt Accident. Thi; event 10 cubcumed in the Large Les: cf :

Ccchnt Accident initiating event. Inadvertent actuation of two of the four Safety Injection signals will result in a (continued)

South Texas Units 1 & 2 B 3.5-13 Rev. O. 02/05/97

ECCS-Operating ,

B 3.5.2

~ BASES l t BACKGROUND reactor trip but injection into the Reactor Coolant System l (cont ~ ued) will not occur since normal reactor operating pressures are

. higher than safety injection system design.

Normal operation of the Residual Heat Removal System occurs after the plant has been shut down. Inadvertent ooeration of the Residual Heat Removal Syste : p_qm_a during plut I :

03eration will not impact the Reactor Coolant System since t1e Reactor Coolant System pressure during plant operation is much higher than the Residual Heat Removal pump head.

Inadvertent opening of both isolation Motor-Operated Valves in any of the inlet lines would overpressurize the Residual-Heat Removal piping, possibly resulting in a medium or large break Loss of Coolant Accident. -

The active'ECCS components, along with the passive accumulators and the RWST covered in LCO 3.5.1,

" Accumulators," and LCO 3.5.4, " Refueling Water Storage Tank (RWST) " provide the cooling water necessary to meet General Design Criteria (GDC) 35 (Ref. 2). i APPLICABLE The LC0 helps to ensure that the following acceptance SAFETY ANALYSIS criteria for the ECCS, established by 10 CFR 50.46 (Ref. 3),

will be met following a LOCA:

a. Maximum fuel element cladding temperature is s 2200*F:

b. Maximum cladding oxidation is s 0.17 times the total cladding thickness before oxidation:

c. Maximum hydrogen generation from a zirconium water reaction is s 0.L1 times the hypothetical amount generated if all o' the metal in the cladding cylinders surroundi1g the fuel, excluding the cladding surrounding the plenum volume, were to react:

d. Core is maintained in a coolable geometry: and

e. Adequate long term core cooling capability is maintained.

The LC0 also limits the potential for a post trip return to power following an MSLB event and ensures that containment temperature limits are met.

(continued)

South Texas Units 1 & 2 B 3.5-14 Rev. 0, 02/05/97 e -

l ECCS-Operating B 3.5.2 BASES APPLICABLE Credit is taken for each ECCS train in a large break LOCA SAFETY ANALYSES event at full power (Refs. 4 and 5). This event establishes (continued) the requirement for runout flow for the ECCS pumps. as well -

as the maximum response time for their actuation. The HHSI pumps are credited in some small break LOCA events. These ,

events establish the flow and discharge head at the design point for the HHSI pumps. The SGTR and MSLB events also credit the HHSI pumas. The OPERABILITY requirements for the ECCS are based on tie following LOCA analysis assumptions:

i

a. A large break LOCA event, with loss of offsite power and a single failure disabling one SDG in combination -

with a break location which results in loss of all injection flow from one train; and

b. A small break LOCA event.'with a loss of offsite power and a single failure disabling one ECCS train in ,

combination with a break location which results in loss of injection flow from one train.

During the blowdown stage of a LOCA. the RCS depressurizes as primary coolant is ejected through the break into the containment. The nuclear reaction is terminated either by moderator voiding during large breaks or control rod insertion for small breaks. Following depressurization, emergency cooling water is injected into the cold legs, flows into the downcomer, fills the lower plenum, and refloods the core.

\

The LC0 ensures that an ECCS train will deliver sufficient water to match boiloff rates soon enough to minimize the i consequences of the core being uncovered following a large !

break LOCA. It also ensures that the HHSI pumps will i deliver sufficient water and boron during a small break LOCA to maintain core subcriticality. .For a small break LOCA, the steam generators continue to serve as the heat sink, providing part of the required core cooling.

The PSA risk significance is as follows (Ref.1):

Because of the potentially large effect of the High Head I l Safety Injection system on accident consequences, this system has a high risk significance. i Based on the assumed reliability, and relative importance of the Safety Injection systerr. the Probabilistic Safety (continued) l South Texas Units 1 & 2 B 3.5-15 Rev. 0, 02/05/97 l l

ECCS-Operating B 3.5.2 BASES.

i APPLICABLE Assessment can be used in MODES 1, 2. 3. and 4 to justify SAFETY ANALYSES one train of Safety Injection out-of-service for 7 days, and (continued) two trains of Safety Injection out-of-service if one of them

", is restored to service within 1 day.

The Probabilistic Safety Assessment analysis of the effect of the Residual Heat Removal system on accident consequences determined that this system has a medium risk significance.

Based on the assumed reliability availability, and relative importance of the Residual Heat Removal system, the Probabilistic Safety Assessment can be used to justify one Residual Heat Removal train out-of-service for 14 days and two Residual Heat Removal trains arc inoperable. cither the i SI train er the Rc':idual H00t Re c"al train can be out-of-l service for 7 days.

The ECCS trains satisfy Criterion 3 of the NRC Policy statement (Ref. 6).

4

~

Z LC0 In MODES 1. 2. and 3. three independent (and redundant) ECCS trains are required to ensure that sufficient ECCS flow is available, assuming a single failure affecting one train and loss of all injection flow from another train through the RCS break location. Additionally. individual components within the ECCS trains may be called upon to mitigate the consequences of other transients and accidents. The RHR subsystems are required to 3rovide the preferred cooling

capability to remove decay leat following certain DBAs.

1 In MODES 1. 2. and 3. an SI subsystem consists of a HHSI pump, a LHSI pump, and a RHR heat exchanger. Each SI subsystem includes the piping. instruments. and controls to ensure an OPERABLE flow path capable of taking suction from the RWST upon an SI signal and automatically transferring suction to the containment sump.

s In MODES 1. 2. and 3. an RHR subsystem consists of a RHR pump and a RHR heat exchanger. Each subsystem includes the piping, instruments, and controls to ensure an OPERABLE flow 3ath capable of being aligned to take suction from the RCS lot legs and pumping the water through a RHR heat exchanger and returning it to the RCS.

(continued)

South Texas Units 1 & 2 B 3.5-16 Rev. O, 02/05/97 r

i ECCS-Operating l B 3.5.2 BASES LC0 .

During an event requiring ECCS actuation, a flow path is (continued) required to 3rovide an abundant supply of water from the RWST to the RCS via the ECCS pumps and their respective supply headers to each of three cold leg injection nozzles.

In the long term, this flow path may be switched to take its supply from the containment sump and to supply its flow to the RCS hot and cold legs.

The flow path for each train (except for the RHR subsystems) is designed to be independent to ensure that no single failure can disable another ECCS train.

APPLICABILITY In MODES 1. 2. and 3. the ECCS OPERABILITY requirements for the limiting Design Basis Accident, a large break LOCA. are based on full power operation. Although reduced power would not require the same level of performance, the accident analysis does not provide for reduced cooling requirements in the lower MODES. The HHSI pump performance requirements are based on a small break LOCA. MODE 2 and MODE 3 requirements are bounded by the MODE 1 analysis.

This LC0 is only applicable in MODE 3 and above. Below MODE 3. when )ressurizer pressure has decreased below the P-11 interloct setpoint, the SI actuation due to low pressurizer pressure is manually bypassed by operator control. In MODE 4. system functional requirements are relaxed as described in LC0 3.5.3. "ECCS-Shutdown."

i As indicated in a Note, entry into and operation in MODE 3 with ECCS trains declared inoperable pursuant to LC0 3.4.12. ;

" Low Temperature Overpressure Protection (LTOP) System - 1 MODE 4." is necessary due to an LTOP arming temperature near ;

the MODE 3 boundary temperature of 350'F. LCO's 3.4.12 and 3.4.13. " Low Temperature Overpressure Protection (LTOP) ;

System - MODE 5 and MODE 6 with Head On." require certain pumps be rendered inoperable at and below the LTOP arming temperature. When this temperature is at or near the MODE 3 boundary temperature, time is needed to restore the inoperable pumps to OPERABLE status.

MODE 4 OPERABILITY requirements are described in LC0 3.5.3.

"ECCS - Shutdown."

In MODES 5 and 6. plant conditions are such that the probability of an event requiring ECCS injection is (continued)

South Texas Units 1 & 2 B 3.5-17 Rev. O 02/05/97

. _ _ _ _ . - _ . ~ _ _ _ ... _ _ _ __. _ . _ _ . _

! i ECCS-Operating l B 3.5.2 i t

BASES

t l

APPLICABILITY extremely low. Core cooling requirements in MODE 5 are !

(continued) addressed by LCO 3.4.7. "RCS Loops-MODE 5. Loops Filled."

! and LCO 3.4.8. "RCS Loops-MODE 5. Loops Not Filled." MODE 6 l core cooling requirements are addressed by LC0 3.9.5. ;

l "Rt.sidual Heat Removal (RHR) and Coolant Circulation-High !

. Water Level." and LC0 3.9.6. " Residual Heat Removal (RHR) i l and Coolant Circulation-Low Water Level." ;

. ACTIONS .A_,1 With one RHR subsystem ino)erable, the inoperable components must be returned to OPERAB_E status within 14 days. The 14 l

. day Completion Time is based on the availability of two redundant and independent 100% capacity RHR subsystems, and alternative means of removing decay heat below 350*F. An ;

STP analysis (Ref. 1) has shown that the impact of.having an i RHR subsystem inoperable is sufficiently small to justify continued operation for 14 days.

l The 21 day portion of the Completion Time for Required ;

Action A.1 is based upon engineering judgment. It takes i into account the low probability of coincident-entry into '

two Conditions in this Specification coupled with the low

]robability of an accident occurring during this time. :

Refer to Section 1.3 for a more detailed discussion of the :

purpose of the "from discovery of failure to meet the LC0" portion of the Completion Time. !

i l A RHR subsystem is inoperable if it is not capable of being I aligned to provide flow through the RHR heat exchanger for the removal of decay heat from the primary system following a reduction of RCS temperature to less than 350*F.

Due to the redundancy and independence of the subsystems, the inoperability of one RHR subsystem does not render the other two subsystems or alternative -athods (e.a. feed and bleed) of heat removal incapable of performing the required function.

l l

I (continued)

South Texas Units 1 & 2 B 3.5-18 Rev. O. 02/05/97 l

i

t

" ECCS-Operating i B 3.5.2 l r .

BASES ACTIONS M (continued) !

With one SI subsystem ino)erable, the inoperable components must be returned to OPERA 3LE status within 7 days. The 7 ;

, day Completion Time is based on the continued availability ;

of two 100% capacity SI subsystems, either capable of l

providing the required cooling, if a LOCA were to occur. j l The only restriction on continued operation is the aossible ;

inability of the subsystems to respond to a DBA wit 1 certain unlikely combinations of- RCS break locations and a single '

active failure of an additional SI subsystem. An STP '

analysis (Ref. 1) has shown that the impact of having an SI subsystem inoperable is sufficiently small to justify ;

. continued operation for 7 days. The time is also reasonable '

for repair and testing of inoperable components.

The 21 day portion of the Completion Time for Required i Action B.1 is based upon engineering judgement. It takes into account the low probability of coincident entry into two Conditions in this Specification coupled with the low arobability of an accident occurring during this time. ;

Refer to Section 1.3 for a more detailed discussion of the 4

purpose of the "from discovery of failure to meet the LC0" portion of the Completion Time.

l An SI subsystem is inoperable if it is not capable of 4

delivering design flow to the RCS. Individual components are inoperable if they_ are not capable of performing their design function or supporting systems are not available.

'; Due to the redundancy and independence of subsystems, the inoperability of one component in a subsystem does not render the ECCS incapable of performing its function.

Neither does the inoperability of multiple different components, in different subsystems, necessarily result in a loss of function for the ECCS. The intent of this Condition is to maintain two subsystems of 100% ECCS available.

U With two RHR subsystems inoperable, one RHR subsystem must be restored to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7 tys. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7-day Completion Time is based on the availability of a separate redundant and independent 100% capacity RHR subsystem and alternative means of removing decay heat (contirued)

South Texas Units 1 & 2 B 3.5-19 Rev. 0, 02/05/97 .

ECCS-Operating i B 3.5.2 i BASES ;

i ACTIONS L 1 (continued) l below 350*F. An STP analysis (Ref. 1) has shown.that the I impact of having two RHR subsystems inoperable is i sufficiently small to justify continued operation for 24 ;

hours 7 dy . !

i A RHR subsystem is inoperable if it is not capable of being l l

aligned to provide flow through the RHR heat exchanger for t the removal of decay heat from the primary system following ,

! a reduction of RCS temperature to less than 350*F. l l

, This Action is not intended to be used to voluntarily remove l l two subsystems from service. It is intended, however, to !

allow time to restore one subsystem to OPERABLE status when !

l one subsystem has been intentionally removed from' service '

for testing or maintenance and another subsystem becomes inoperable for unplanned reasons. ,

Due to the redundancy of subsystems and the diversity of potential heat removal methods, the inoperability of two RHR pumas does not render the other subsystem or alternative ;

metlods of heat removal incapable of performing the required i function. '

l 0.J.

l With two SI subsystems ino)erable, one inoperable subsystem l

must be returned to OPERAB_E status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . In this Condition the )lant maintains 100% of a single OPERABLE SI subsystem availa)le: however some OBAs. such as a break j in a location which diverts all flow, preventing it from {

reaching the RCS, could prevent one SI subsystem from 1 providing the required function. The 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion i Time is based on an NRC reliability evaluation (Ref. 6), and is a reasonable time for re) air of many ECCS components. An STP analysis (Ref.1) has slown that the impact of having two SI subsystems inoperable is sufficiently small to justify continued operation for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . An SI subsystem is inoperable if it is not capable of delivering design flow to the RCS. Individual components are inoperable if they

, are not capable of performing their design function or l supporting systems are not available.

(continued) i South Texas Units 1 & 2 B 3.5-20 Rev. 0, 02/05/97 4 l l

.m . - .,. _ _ ._ )

1 ECCS-Operating j B 3.5.2 r I

BASES i

ACTIONS DJ. (continued) j This Action is not intended to be used to voluntarily remove I two subsystems from service. It is intended. however, to allow time to restore one subsystem to OPERABLE status when one subsystem has been intentionally removed from service for testing or maintenance and another subsystem becomes inoperable for unplanned reasons. !

E.1 and E.2 -

If the Reauired Action and Comoletion Times of conditions A.B or C are not met. the olant must be brouaht to a MODE in which the LCO does not acolv. To achieve this status. the olant must be brouaht to MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months anc to MODE 4 within 12 hoJrs. The allowed Comoletion Times are l reasonable. Jased on ooeratina exoerience. to reach the recuired olant conditions from full oower conditions in an orcerly manner and without challenaina olant systems.

EJ. Ezl:

If the Required Action and Com)letion Times of Condition: .^.. ;

B. C. Or D w e j.1 not met, rist assessment has shown that the plant is in a condition which jeopardizcs continued plant safety, and a shutdown is appropriate. Therefore. .

immediate entry into LC0 3.0.3 is appropriate. !

Similarly, when three SI subsystems are inoperable exclusively for reasons other than inoperabilities ,

associated with the RHR heat exchanger, the plant is in a !

condition outside the accident analyses: therefore LC0 3.0.3 must be entered immediately. A Note has been included _

which indicates that this Condition is not applicable if three subsystems of RHR are inoperable. Condition F G requires immediate action to restore one subsystem of RHR to OPERABLE status, and when completed. this Condition will apply. With three subsystems of RHR inoperable, the plant !

cannot shutdown in a normal controlled manner.

(continued)

South Texas Units 1 & 2 B 3.5-21 Rev. O, 02/05/97

-. . .. . - .- - . ~ - - . - - - - - - - - --. .--

I ECCS-Operating f B 3.5.2 BASES ACTIONS L1 Ed- l

}

+

(continued) '

With three RHR subsystems inoperable, the plant is not ,

capable of providing decay heat removal via the preferred i j and required method. This Condition is a i all three RHR subsystems are inoperable. pplicable must beonly if Action ;

immediately initiated and continued until one subsystem is restored to OPERABLE status. The Required Action for inoperable RHR subsystems does not require a shutdown '

because the RHR subsystems are used to perform thc shutdown. '

A forced shutdown would direct the plant to take actions which required systems could not support and could result in !

challenging safety systems. The immediate Comaletion Time t reflects the importance of returning an RHR su) system to I ,

OPERABLE status. Other methods of post accident decay heat i removal exist below 350*F. The immediate Com)letion Time i also reflects the importance of maintaining tie availability ;

of the balance of the RHR subsystem to support the !

availability of this method of heat removal. :

SURVEILLANCE SR 3.5.2.1 l; REQUIREMENTS Verifying the correct alignment for manual, power operated, i and automatic valves in the ECCS flow paths provides l assurance that the proper flow paths will exist for ECCS l operation. This SR does not apply to valves that are l locked, sealed, or otherwise secured in position, since.

these were verified to be in the correct position prior to locking, sealing, or securing. A valve'that receives an actuation signal is allowed to be in a non-accident Josition provided the valve will automatically reposition wit 11n the proper stroke time. This Surveillance does not require any testing or valve manipulation. Rather, it involves verification that those valves capable of being mispositioned are in the correct position. The 31 day Frequency is appropriate because the valves are operated under administrative control, and an improper valve position would only affect a single train. This Frequency has been ;

shown to be acceptable through operating experience.

I l

(continued)

South Texas Units 1 & 2 B 3.5-22 Rev. O. 02/05/97

ECCS-Operating B 3.5.2 BASES SURVEILLANCE SR 3.5.2.2 REQUIREMENTS .

(continued) The ECCS pumps are normally in a standby. nonoperating mode.

As such, flow path piping has the potential to develop voids and )ockets of entrained gases. Maintaining the aiping from i the ECCS pumps to the RCS full of water ensures tlat the system will perform properly, injecting its full capacity into the RCS upon demand. This is accomolished by ventina the ECCS oumo casinas and accessible discharae Dioina hiah ooints. This will also prevent water hammer, pump cavitation, and pumping of noncondensible gas (e.g. , air.

nitrogen, or hydrogen) into the reactor vessel following an SI signal or during shutdown cooling. The 93 .31 day Frequency takes into consideration the gradual nature of the pctential-fee gas accumulation in the ECCS piping, the STP cperating experience with venting cperations, the system des!;n. cperater fifR^ considerations. and generation of unneccc ary radicactive liquid waste. and orocedural controls covernina system ooeration.

SR 3.5.2.3 Periodic surveillance testing of SI and RHR pumps to detect I gross degradation caused by impeller structural damage or I other hydraulic component problems is required by Section XI ,

of the ASME Code. This type of testing may be accomplished l by measuring the pump developed head at only one Joint of the pump characteristic curve. This verifies bot 1 that the measured performance is within an acceptable tolerance of the original pum) baseline performance and that the performance at tie test flow is greater than or equal to the performance assumed in the plant safety analysis. SRs are specified in the Inservice Testing Program, which encompassesSection XI of the ASME Code.Section XI of the ASME Code provides the activities and Frequencies necessary to satisfy the requirements.

SR 3.5.2.4 and SR 3.5.2.5 These Surveillances demonstrate that each automatic ECCS ,

valve actuates to the required position on an actual or !

simulated SI signal and that each SI of an actual or simulated SI signal. pump starts The 18 monthon receipt Frecuency is based on the need to perform these Surveillances uncer (continued)

South Texas Units 1 & 2 B 3.5-23 Rev. O. 02/05/97

l ECCS -Operating B 3.5.2 BASES 4

SURVEILLANCE SR 3.5.2.4 and SR 3.5.2.5 :

REQUIREMENTS (continued) the conditions that apply during a plant outage and the potential for unplanned plant transients if the Surveillances were performed with the reactor at power. The 18 month Frequency is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment. The actuation logic is tested I as part of ESF Actuation System testing, and equipment performance is monitored as part of the Inservice Testing Program.

SR 3.5.2.6 Periodic inspections of the containment sump suction inlet ensure that it is unrestricted and stays in proper operating 4

condition. The 18 month Frecuency is based on the need to perform this Surveillance uncer the conditions that ap)1y during a plant outage, on the need to have access to tie location with consideration for ALARA practices, and because of the potential effect of equi) ment OPERABILITY if the l Surveillance were performed wit 1 the reactor at power. This Frequency has been found to be sufficient to detect abnormal degradation and is confirmed by operating experience.

REFERENCES 1. A) plication of the Probabilistic Safety Assessment to '

t1e South Texas Project Improved Technical Specifications.

2. 10 CFR 50. Appendix A. GDC 35.

3. 10 CFR 50.46.

4. UFSAR Section 6.3.

5. UFSAR, Chapter 15.

6. NRC Final Policy Statement on Technical Specifications Improvements for Nuclear Power Reactors, 58 FR 39132.

July 22, 1993.

South Texas Units 1 & 2 B 3.5-24 Rev. 0, 02/05/97

j ECCS-Shutdown l B 3.5.3 !

B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) i

-B 3.5.3 ECCS-Shutdown BASES l

BACxGROUND The Background section for Bases 3.5.2. "ECCS-Operating,"

is applicable to these Bases, with the following modifications.

In MODE 4 the required ECCS trains consist of two separate i cubsystem: trains of High Head Safety Injection (HHSI) and I j Low Head Safety Injection (LHSI) Jumps. In MODE 4 the OPERABILITY requirements for the (HR pumps are described in LCO 3.4.6 "RCS Loops - MODE 4" and are not a part of this specification.

The ECCS flow paths consist of piping, valves.. heat l exchangers, and pumps such that water from the refueling l water storage tank (RWST) can be injected'into the Reactor 1 Coolant System (RCS) following the accidents described in I Bases 3.5.2. j

-l l

APPLICABLE The Applicable Safety Analyses section of Bases 3.5.2 also SAFETY ANALYSES applies to this Bases section.

Due to the stable conditions associated with operation in MODE 4 and the reduced 3robability of occurrence of a Design Basis Accident (DBA), t1e ECCS operational requirements are reduced. It is understood in these reductions that automatic safety injection (SI) actuation, due to low pressurizer pressure, is not available'. In this MODE, sufficient time exists for manual actuation of the required ECCS to mitigate the consequences of a DBA.

Only two trains of ECCS are required for MODE 4. This requirement dictates that single failures are not considered during this MODE of operation. The ECCS trains satisfy Criterion 3 of the NRC Policy Statement.

LC0 In MODE 4. two of the three inde)endent and redundant ECCS trains are required to be OPERAB_E to ensure that sufficient ,

ECCS flow is available to the core following a DBA. !

(continued)

South Texas Units 1 & 2 B 3.5-25 Rev. O. 02/05/97

t .

ECCS-Shutdown B 3.5.3 li i !

BASES !

LC0 In MODE 4. an ECCS train consists of a HHSI pump, a LHSI !

(continued) pum , and an RHR heat exchanger. Each train includes the- ;

pip ng, instruments, and controls to ensure an OPERABLE flow !

pat capable of taking suction from the RWST and l

transferring suction to the containment sump. The MODE 4 OPERABILITY requirements for the RHR pumps are described in i LC0 3.4.6, and are not a part of this specification. ,

During an event requiring ECCS actuation, a flow path is !

required to provide an abundant supply of water from the !

-RWST to the RCS via the ECCS pumps to the associated cold ;

, leg injection nozzles. In the long term, this flow path may l be switched to take its sup)ly from the' containment sump and to deliver its flow to the RCS hot and cold legs. ;

i The LC0 is modified by four Notes. The first Note provides !

an allowance for entry into MODE 4 from MODE 3 with more l than one HHSI Jump breaker racked in. This Note nurmits i entry into MODE 4. followed by a system alignment which is consistent with the assum)tions of Low Temperature !

Overpressure Protection (_ TOP) analyses assumptions. The '

temperature limit is based on the Pressure - Temperature curve in the LTOP analyses (Ref. 1.) :

The second Note is provided to permit the filling of I accumulators or performance of system testing. Before an additional HHSI pump breaker may be racked in, the discharge of the associated pump must be isolated from the RCS to prevent a mass addition excursion beyond the capability of l the LTOP system. To assure that the RCS is protected, an isolation valve is closed with the power iemoved or a manual isolation valve is secured in the closed oosition.

The third Note is provided to permit entry into MODE 4 from MODE 5 with no HHSI pump breaker racked in. S)ecification 3.4.13. "LTOP System - MODE 5 and MODE 6 with lead On" requires all three HHSI pump breakers to be racked out.

This Note provides operational margin to enter MODE 4 and

! then place a nump in service with its breaker racked in.

The temperatuce limit is low enough that an event which requires HHSI pump actuation will not occur too quickly for operator intervention to restore a pum) to service. Belew l At 225*F and below. after being in MODE 5. the RCS remains near cold shutdown conditions, and HHSI ECCS respnse will not typically be required. l l

1 (continued)

I South Texas Units 1 & 2 B 3.5-26 Rev. 0, 02/05/97 '

ECCS -Shutdown i B 3.5.3

=

BASES f

LCO (continued) ThefourthNoteiskROPERABILITYinMODE4.rovided specification for R This Notetoisclarify the app !

necessary because the RHR provides an ECCS support function for some DBAs when the plant is operating in MODES 1. 2 and !

3. as described in LC0 3.5.2 and associated Bases. However i in MODE 4, the RHR OPERABILITY requirements are specified in {

the Reactor Coolant System chapter of the Technical l Specifications since the RHR subsystem becomes one of the l primary methods of heat removal. The Note assures that the ,

user properly refers to LC0 3.4.6. "RCS Loops - MODE 4." for <

the use and requirements of the RHR subsystem. j

)

APPLICABILITY In MODES 1. 2. and 3. the OPERABILITY requirements for SI i and RHR subsystems are covered by LC0 3.5.2.

l In MODE 4 with RCS temperature below 350'F. two OPERABLE ECCS trains are acceptable without single failure consideration, on the basis of the stable reactivity of the reactor and the limited core cooling requirements. Two r

trains are required because the system must be capable of i responding to a DBA pi3e break which could occur at a cold j leg such that one of tie injection flows would be diverted I away from the core cooling function.

In MODES 5 and 6. plant conditions are such that the probabilit'y of an event requiring ECCS injection is extremelylow. Core cooling requirements in MODE 5 are addressed by LCO 3.4.7. "RCS Loops-MODE 5. Loops Filled."

and LCO 3.4.8. "RCS Loops-MODE 5. Loops Not Filled."

MODE 6 core cooling requirements are addressed by LCO 3.9.5.

" Residual Heat Removal (RHR) and Coolant Circulation-High Water Level." and LC0 3.9.6. " Residual Heat Removal (RHR) i and Coolant Circulation-Low Water Level."

I ACTIONS A.1 and A.2 l With one required ECCS train irioperable, the plant is not prepared to respond to the relatively unlikely event of a loss of coolant accident which occurs at a location which !

diverts the flow of the remaining OPERABLE ECCS train.

Required Actions for this condition include verification that the OPERABLE HHSI subsystem pump brehker is racked in l (continued) I South Texas Units 1 & 2 B 3.5-27 Rev. O. 02/05/97 l

L. . _ _ -- -

l ECCS-Shutdown B 3.5.3 1 !

l BASES l

ACTIONS A.1 and A.2 (continued) !

to support immediate operation and to restore the second l ECCS train within 14 days.

l The Com)letion Time of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months to verify a HHSI subsystem is OPERABLE with the Jump's breaker pro >erly aligned ensures that the required ECCS train is capa)le of performing its function if manuall actuated. Verification of an OPERABLE HHSI pump with its breaker closed racked in is not intended I to require the pump be associated with the OPERABLE ECCS <

train. This specification requires many components within !

the ECCS to be OPERABLE. Inoperability of one component may not affect the OPERABILITY of another. For example, an .

l inoperable LHSI pump may not prevent a HHSI pum) from '!

performing its function. For this Condition, tie HHSI pump, ;

in the same train as an inoperable LHSI pump, may continue !

to serve as an OPERABLE HHSI pump. The intent of this l Condition is to ensure that 100% capacity of a single train t

i of ECCS remains OPERABLE.

The Completion Time of 14 days to restore the second ECCS !

train is ap3roariate based on the low probability of a LOCA in MODE 4 w11c1 results in a loss of injection flow from the -

i OPERABLE train.

( .

fL1 !

With two required ECCS trains inoperable, the plant is not '

prepared to respond to Design Basis Events requiring SI.

The 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Com)letion Time to restore at least one ECCS l train to OPERA 3LE status ensures that prompt action is taken i to provide the required cooling capacity or to initiate actions to place the plant in MODE 5, where an ECCS train is not required.

This Action is not intended to be used to voluntarily remove two required trains from service. It is intended, however.

l to allow time to restore one required train to OPERABLE status when one train has been intentionally removed from service for testing or maintenance and another required train becomes inoperable for unplanned reasons. l i

(continued) i l South Texas Units 1 & 2 B 3.5-28 Rev. O, 02/05/97 l

l-

I i t I

f ECCS-Shutdown i B 3.5.3 BASES ACTIONS [l (continued) .

When the Required Actions of Condition A or B cannot be i completed within the required Completion Time, a controlled i shutdown should be initiated. Twenty-four hours is a ;

reasonable time, based on operating experience, to reach l MODE 5 in an orderly manner and without challenging plant I systems or operators. I t

SURVEILLANCE SR 3.5.3.1 I REQUIREMENTS I

The applicable Surveillance descriptions from Bases 3.5.2 i ap)1y. This SR 1: modified by a Note that allow: an R9R su::ystem to bc considered OPEPfSLE during slig=cnt and l Operation for decay heat r=0 val. if capable of being l nnually realigned (r=0tc or local) to the ECCS =de of Operation =d not otherwisc inoperabic. Thi allow;

, Operation in the R9R mode during MODE d . if neccc:ary.

l SR 3.5.3.2 l

This SR is provided to assure that the assumptions of the LTOP analyses for the plant are maintained. The analyses assumed that for the mass and pressure transients in MODE 4 the potentially OPERABLE pumps were limited to one centrifugal charging pump and one HHSI pump. The SR is

, modified by two Notes which require the SR to be met at a temperature of > 225 F. when entering from MODE 5 and s '

5 325*F. if entering from MODE 3. The Frequency provides I verification that the HHSI aump breakers are appropriately aligned upon entry into MODE 4 and once per 31 days. This frequency is adequate to assure the ap)ropriate alignment is l

maintained when considered with the otler administrative controls over plant equipment. j REFERENCES 1. WCAP-13782. "Setpoint Program Determination for the Westinghouse Cold Overpressure Mitigation System in ,

the Houston Lighting & Power South Texas Units 1 & 2. l (Rev.2)". February 1994.

The applicable referentes from Bases 3.5.2 also apply.

l 1

l. South Texas Units 1 & 2 B 3.5-29 Rev. O. 02/05/97 I

a

RWST !

B 3.5.4

i B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l B 3.5.4 Refueling Water Storage Tank (RWST) ,

BASES BACKGROUND- The RWST supplies borated water to the Chemical and Volume .

Control System (CVCS) during abnormal operating conditions. l to the refueling cavity during refueling, and to the ECCS :

l and the Containment Spray System during accident conditions. .!

( !

The RWST supplies each train of the ECCS and the Containment i S) ray System through a supply header during the injection i plase of a loss of coolant accident-(LOCA) recovery. A ,

i motor operated isolation valve is provided in each header to i isolate the RWST from the ECCS once the system has been :

transferred to the recirculation mode. No automatic signal !

is provided to close these valves and they are operated i manually. The recirculation mode is entered when pump ,

, sucticn is transferred to the containment sump following receipt of the RWST-Low Low (Level 1) signal. Use of a i single RWST to supply all trains of the ECCS and Containment

) Spray System is acceptable since the RWST is a passive j component, and passive failures are not required to be !

assumed to occur coincidentally with Design Basis Events. l During normal operation in MODES 1, 2, 3, and 4, the ECCS I and Containment Spray pumps are aligned to take suction from the RWST. l The ECCS and Ccntair ent S: ray Syst= pumps are provided I with recirculation lines tlat ensure each pump can maintain j minimum flow requirements when operating at or near shutoff head conditions.

When the suction for the ECCS and Containment S) ray System pumas is transferred to the containment sump, t1e RWST flow patis are isolated to prevent a release of the containment sump contents to the RWST, which could result in a release of contaminants to the atmosphere.

This LC0 ensures that:

a, The RWST contains sufficient borated water to support the ECCS during the injection phase: and I (continued)

South Texas Units 1 & 2 B 3.5-30 Rev. 0, 02/05/97

l RWST !

B 3.5.4 i BASES I l

l i

BACKGROUND - b. Sufficient water volume will exist in the containment !

(continued) sump to support continued operation of the ECCS and j Containment Spray System pumps at the time of transfer ;

j to the recirculation mode of cooling: and I j i

c. The reactor remains subtritical following a LOCA. !

Insufficient water in the RWST could result in insufficient cooling capacity when the transfer to the recirculation mode ;

occurs. Impro)er boron concentrations could result in a j

, reduction of S)H or excessive boric acid precipitation in >

the core following the LOCA. !

i APPLICABLE During accident conditions, the RWST provides a source of l SAFETY ANALYSES borated water to the ECCS and Containment Spray System i pumps. As such it provides containment cooling and :

depressurization, core cooling and replacement inventory !

and is a smrce of negative reactivity for reactor shutdown t (Ref. 1). The design basis transients and applicable safety !

analyses concerning each of these systems are discussed in the Applicable Safety Analyses section of B 3.5.2. "ECCS-Operating": B 3.5.3. "ECCS-Shutdown": and B 3.6.6.

" Containment Spray and Cooling Systems." These analyses are i used to assess changes to ths RWST in order to evaluate their effects in relation to the acceptance limits in the ;

analyses. .

i The RWST must also meet volume and boron concentration for i non-LOCA events. The volume is not an explicit assumption !

in non-LOCA events since the required volume is a small ;

fraction of the available volume. The deliverable volume !

limit is set by the LOCA and containment analyses. For the i RWST the deliverable volume is different from the total 1 volume contained since, due to the design of the tank. more water can be contained than can be delivered. The minimum boron concentration is an explicit assumption in the main steam line break (MSLB) analysis to ensure the required shutdown capability. The minimum boron concentration limit is an important assumption in ensur49 the required shutdown capability.

For a large break LOCA analysis the minimum RWST water volume limit of 458.000 gallons (of which 359.000 gallons l are considered deliverable) and the lower boron (continued) l South Texas Units 1 & 2 B 3.5-31 Rev. O. 02/05/97 i i

RWST B 3.5.4 BASES APPLICABLE -

SAFETY ANALYSES concentration limit of 2800 ppm are used to compute the post (continued) LOCA sump boron concentration necessary to assure subcriticality. The large break LOCA is the limiting case since the safety analysis assumes that all control rods are out of the core.

The upper limit on boron concentration of 3000 p)m is used to determine the maximum allowable time to switc1 to hot leg recirculation following a LOCA. The purpose of switching from cold leg to hot leg injection is to avoid boron precipitation in the core following the accident.

The RWST satisfies Criterion 3 of the NRC Policy Statement (Ref. 2).

LC0 The RWST ensures that an adequate su) ply of borated water is available to cool and depressurize tie containment in the event of a Design Basis Accident (DBA), to cool and cover the core in the event of a LOCA to maintain the reactor subcritical following a DBA and to ensure adequate level in the containment sump to su) port ECCS and Containment Spray System pump operation in tie recirculation mode.

To be considered OPERABLE the RWST must meet the water volume and boron concentration limits established in the SRs.

APPLICABILITY In MODES 1. 2, 3 and 4. RWST OPERABILITY requirements are dictated by ECCS and Containment Spray System OPERABILITY requirements. Since both the ECCS and the Containment Spray System must be OPERABLE in MODES 1. 2. 3 and 4. the RWST must also be OPERABLE to su) port their operation. Core cooling requirements in MODE 5 are addressed by LC0 3.4.7.

"RCS Loops-MODE 5. Loops Filled." and LCO 3.4.8. "RCS Loops-MODE 5. Loops Not Filled." MODE 6 core cooling requirements are addressed by LC0 3.9.5. " Residual Heat Removal (RHR) and Coolant Circulation-High Water Level."

and LCO 3.9.6. " Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level."

(continued)

South Texas Units 1 & 2 B 3.5-32 Rev. O. 02/05/97

- - .. - - . - - - - . ~ _ . - - - - - . - -.. - . - . - - .

t RWST B 3.5.4

! BASES (continued) l i' ACTIONS L1 ;

i With RWST boron concentration not within limits, it must be !

returned to within limits within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Under this i condition the ECCS can not fully perform its design :

functions. Therefore. 3romat action must be taken to '

4.

restore the tank to OPEMBLE condition. The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months limit to ;

' restore the RWST boron concentration to within limits was >

developed considering the time required to change the boron concentration and the fact that the contents of the tank are ;

4 still available for injection. !

I fL1 :

With the RWST inoperable for reasons other than Condition A.

it must be restored to OPERABLE status within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months .

! In this Condition, neither the ECCS nor the Containment !

Spray System can perform their design function. Therefore, prompt action must be taken to restore the tank to OPERABLE j

status or to place the plant in a MODE in which the RWST is 4 not required. The short time limit of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months to restore the >

RWST to OPERABLE status is based on this condition simultaneously affecting redundant trains.

C.1 and C.2 If the RWST cannot be returned to OPERABLE status within the associated Completion Time, tN plant must be bro @t to a ,

MODE in which the LC0 does not apply. To achieve this 1 status, the plant must be brought to at least MODE 3 within '

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed Completion Times are reasonable. based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

SURVEILLANCE SR 3.5.4.1 REQUIREMENTS The RWST water volume should be verified every 7 days to be above the required plnimum level in order to ensure that a (continued)

South Texas Units 1 & 2 B 3.5-33 Rev. O. 02/05/97

RWST B 3.5.4 BASES l

SURVEILLANCE SR 3.5.4.1 (continued) l REQUIREMENTS ~

sufficient initial supply is available for injection and to l support continued ECCS and Containment Spray System pump operation on recirculation. Since the RWST volume is ;

! normally stable and is protected by an alarm a 7 day Frequency is appropriate and has been shown to be acceptable through operating experience.

SR 3.5.4.2 l

l The boron concentration of the RWST should be verified every

[ 7 days to be within the required limits. This SR ensures l that the reactor will remain subcritical following a LOCA.

I Further, it assures that the resulting sum) pH will be l maintained in an acceptable range so that )oron

precipitation in the core will not occur and the effect of chloride and caustic stress corrosion on mechanical systems and components will be minimized. Since the RWST volume is l normally stable, a 7 day sampling Frequency to verify boron concentration is appropriate and has been shown to be acceptable through operating expericnce.

1

! REFERENCES 1. UFSAR, Chapters 6 and 15.

l 2. Final Policy Statement on Technical Specification Improvements for Nuclear Power Reactors 58 FR 39132.

July 22,1993.

i South' Texas Units 1 & 2 B 3.5-34 Rev. O. 02/05/97 1 , .

i cpW b.9. \

8.l 5

I 3 5 EMERGENCY CORE COOLING SYSTEMS (Ect.b 3 .5.1 AfCUMULAT v - A.l I

% l

. 11MITING CONDffiON FOR OPERATTON / / / / f

/

- - 1 s s W 3.5.1 G ach sat w in ur m a syuangccumulatoMsha11_ be OPE BL wi : j

^

Theisolationvalveopenandpowerremoved,] h 5Etc 5 gygi g u.5.if a.

, b. A contained borated water volume of between 8800 and 9100 gallons, g , , ,,, ,4 c. A boron concentration of between 2700 ppm and 3000 ppm. A 1,. qp g 3,5,i.3 A nitrogen cover-pressure of between 590 and 670 psig.

(d.

APPLICABILITY: H0 DES 1, 2, and 39. Tat. www<< pet % > icoo fM ACTION: A.I '

Wikhl/ne accumulator,inoperables}c,. eu. epi as a resun .m ow_a M %closed t Ju A

%"(

40 jlcfang (a.

11 s 0 ' ation valve >or_ Ae boron cpficentration outside tb6 reautyb_4/ . I Llim' W.frestore\tYe inocerabitjaccumulator to OPERABLE status within I da 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months or be iri at least HOT STANDBY within the next 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and l :

Avneo c. 3,i reduce pressurizer giressure to less than 1000 psig within the

following 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months . i A .3

\ sk *' b. With one umulator inope le due to th soladort valve eing closed ither open the solation valv ithin 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months be in at l 1eas OT STANDBY wi n the next 6 rs and reduce p ssurizer 4,g p sure to less t n 1000 psig wi n the followino hours

c. Wi the bgp6n_ conrJHftrati<fn of))ne accumulator 5utsidejt'he requ$pe8 ) F*

AmodA Mb t restoretthnboron concentrationTto witMn the fecuired IMitJs ,

i with n 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months pe m at BY within Ahe next o *"7'" h ' i ressurizerbistHul51 ss th=a 14nn n<in w essure i M780N C fnours jna icuus our s Ayon 0 O Y b (the f611owing Mr wJr{ pe,pova C AA b b e e=f.

A,q SURVEILLANCE RE0VIREMENTS ff. .5.151 (Each accafnulator stM1 be demofistr_atedstrtKAutt.m

_. AL,leeM unce , ,

', @ Verif water vo ume, IV"absencMT alams,)the contained borated nitrogen cover-pressure in %he tanks, an@

[g S g

B,,3 A.t d$re*s-n < --A s<wovam L gb e g g,, 3,5,u Qp Verify {n,gArit)e accumulator isolation valve is A .s DTeapon

b. At least once per 31 days and within 6 houb after each_ ifLn , gyg7 f 4 A LS.I.'4 v_olume incrones nf nrrater than'or caual id3 O efA ans voluar o m _

pertrvino Ahe boMn concentraMon of 2he astumulator somioM

~ M -

Pressurizer pressure above 1000 psig_ .- N - - - @

1 50'JTH TEXAS - UNilS 1 & 2 hQ -

3/4 5-1 ter r+eMe adeded aesa sMrs.

Unit 1 - Amendment Ho'. 64,54. 59 Unit 2 - Amendment No. 40,43,47 A .6 l ti,efre not de result ~et 4/./,' v,*,n #s.y for BA/S7~

4

<A~ M,(

Section 3.5 Markup inserts insert 1 1

O. Two or more D.1 Enter LC0 3.0.3 Imediately accumulators A,4 inoperable.

a 4

s 4 ;

J i

1

=?

l'

\

i i

bpd4 ' TAN % 3.5 il l #

EMERGENCY CORE COOLING SYSTEMS Cz toco3 SURVEILLANCE REOUIREMENTS (Continuedi [

,R u .t.g c. At least once per 31 days when the RCS pressure is psig by verifying that power to the isolation valve operator is removed.

(d. At least cnce pe/18 months by verif ng that each accumulat isola-tion valve ope,4 automatically und each of the following onditions:

6.l1

1) When n actual or a simul ed RCS pressure signal ceeds the t P- (PressurizerPressu Block of Safety Injec on) Setpoint, r

Uponreegptofa fety Injection test sig 1. ,

4. 5.1. 2 ch accumulat" water level and pr ,sure channel sh be demon-strated ERABLE:

a. At lea once per 31 days by e performance of an ANALOG C 'EL OPE ONAL TEST, and

b. ' least once per 18 me s by the perform ,ce of a CHA EL ALIBRATION.

' S 4,/$ l i

1 1

/

SOUTH TEXAS - UNITS 1 & 2 3/4 5-2 G yeL. 3 o

hechc5dh3.7~2.

l EMERGENCY CORE COOLING SYSTEMS [f'c4b 0

N.T 34.5.2 ECCS 9 0Z = b} 'T m C P M " '"

On EOUrt TO ?E0 @ ppe,4Q l

A.( IMITING CONDITION FOR OPERATION g

~

tco 3.5.2 Three { independent Emeyyeficy Corefoolinosyftem hyteni shall be OPERABLE with each ubsystem compr ed of:

a. One OPERAB E High Head Sa ty Injection p p, i

b. One OPE BLE Low Head S ety Injection mp, i

- LA.Y

c. One O RABLE RHR heat xchanger, and % ep l !

r ,'

, d. An PERABLE flodat capable of taki g suction f m the r ueling t,nsh w'.er storage tapik a Safety Injec ion signal nd automa ically ansferring sucti to the contain ent sump du ing the recirculation phas of operation t ough a His Head Saf y Injection pump an into the React Coolant S tem and rough a low Head Safety Inje ion pump and it respectiv RHR heat xchanger /,/6 j into the Reacto Coolant System. ,

APPLICABILITY: I HODES I, 2, and 3 [NJr 2 'Pr.p wJ Mo1E ACTION: M

@ Wiigh Head less tna ne aoovgssubsystemppPERABLE, ut with at le S ety Injection ppmps in an OPE E status, tw two ow Head *f" A g l Safety I ction pumps an / associated RHR eat exchanger in an **5 OPE _RAJL statup, and s cient flow pa s to accommod e thes (M A cM B W LOPERABlf Safety inje on pumps and heat exchano s.** re"nra ,

the inoperable subsystembf to OPERABLE status withinz7 daydof be b' pn at leajg HOT ST/)fDBY wit)fh the nexV6 hours afin. HOT Shl0TDOWN}1 MWE Lwithin tKe fo11ow)6g 6 hogfs.f g ggy,,/ 2

b. In the event-he ECCS is actuated an injects water into the eactor) u d -s' k Coolant Sys m, a Special Report s 11 be prepared and sub tied to / A+ MA I ItheCommis on pursuant to Specif ation 6.9.2 within 90 ys describin the circumstances of e actuation and the t al

&.*J accumul ed jetuation cycles t date. The current val of the ,

ctor for each affecte Safety Injection nozzi shall be usage (provi d in this Special Rep t whenever its value ceeds 0.70.,i .I )

-m

The proviions of spect cations 3.0. and 4.0.4 a ot applica e for j L5 1.2.

entry to MODE 3 for e Safety In etion pumps lared inope ble i fJME purs ant to Specift ion 4.5.3.1. provided th the Safety j

% ttA i'*D u s are restored. o_0PERABLE s tus withig 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months orleri t he p ~ Iab temperature of one'or more of the RC5 cold legs exceeding 375*F, di whichever comes first.

rf 1 red pumps, nrpt en.nangers and flow / paths vetxAuty every) l SOUTH TEXAS - UNITS 1 & 2 3/4 5-3 Unit 1 - Amendment No. 4,59 Unit 2 - Amendment No. 47 hae lfb

I 1

6,0wkcadwrl 3S2 Section 3.5 Markup inserts insert 2

. (incorporates former footnote '*')

___..__________..______.___.-________ NOTE-------------------------------------

Entry into, and operation in MODE 3 with ECCS pumps declared inoperable pursuant to LCO 3.4.12. " Low Temperature Over prc: urc Overoressure Protection z,&

(LTOP) System - MODE 4." is allowed for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or until the temperature of one or more RCS cold legs exceeds 375'_F whichever comes first.

insert 3 .

(replaces cts ACTION)

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME l D. Two SI subsystems inoperable.

D.1 Restore one SJ.

subsystem to OPERABLE status.

24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

@ l E. Required Action and E.1 Be in MODE 3. Este 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion LC0 3.0.3. !=cdistely Time for Conditions A.

B, or C er-9 not met. AND QB L2 Be in MODE 4. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Three SI subsystc=

incperable

?aqc .2 & O $

Sp a bcche'v, 3.6.2

, Section 3.5 Markup inserts F _ Reauired Action and M Enter LCO 3.0.3. Immediately-associated Comoletion Time for Condition D not met.

DE

........N0TE----------

Condition not 3031icable when three RHi su]sustemj_J_re t

inocerable.

........_ =,....___.

Three 31 cubsylt.gms inocerable.

4 I

l l

43C 1h b

5pechab 3.7, L

+

' ~

EMERGENCY CORE COOLING SYSTEMS SURVEILLANCE REOUIREMENTS 652 Each ECCJ,,eetrkystem shall be Jamenstratea urtmLt:

. At least once per 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months by verifyi that the.following v ves are in the indi ted positions with wer to the valve oper tors removed:

4 Valve Numb Valve Functi Valve Posi on XSI0008 ,B,C High Head ot Leg- Closed L*

Recircul ion Isolation XR 019 A,B, Low H d Hot Leg Clo d i 84 ^

q Reci ulation Isolation W 4

b. ,Af.leastfonceper3bd 7

I ferify that the ECCS piping is ful,1 of waterJby ve og the L. A .I 9, g ,,; points mp casings anprtcesswie oisway, piping AJ

) Verifying that each anual, power-operated, or automatik 4 st L 5.nt in the flow path tha is not locked, sealed, or otherwise secured in position, is in its correct position.

By a visual ins'pect n which veri"u tha no loose debris (r (c. 3 trash, s.

clothing, c.) is present in th containment which Id be transported to e contaanment sump a cause restriction the pump suction uring 10CA conditions This visual inspe ion shall Li6 be perform .

1) Fo all accessible areas o the containment pri to establish-g CONTAINMENT INTEGRIT , and 2 Of the areas affected ithin conta;r .er.t at e completion of each containment en when CONTAINMENT I GRITY is established.

(Wonce

- ment per sump 18and mon...ar-viruri.. ;j( visual inspection @in1etC2D#containT

_ _ --c; m suction. /

S t. 3.f.2.c, restricted debris and th omer6nertti ft'/ ash racks,f M screen show no~ evidence o structural distress or abnomal

' Corrosi .

6 AM O

SOUTH TEXAS - UNITS 1 & 2 3/4 5-4 Gy

k fCli C AN% b8, *1.

EMERGENCY CORE COOLING SYSTEMS leh Aw.c una G. l 111RVEILLANCE REOUIREMENTS (Continued) " I

.gleasy once per 18 mon s(duringshutd Q k.S Verif @neac ha u omatic valve in the flow path actuates to h .445 correct position on at(Automatic Swucnover to t,ontainmenu

. '1

% 1. T,"& . 4 6""* ' ' ' ' S "' ' ' ' ' 'P ""'**^**d-Verifying that eachror stardautomatically 3 A l [ Jon r-cmot orca Saf#v Iniectionles _

oiIowirW n3 g 3,g,g ,$ a) High Head Safety Injection , nd b) LoIHe y Infection pump. --

j M% Lthe a e.ne.1 , ' A. t *4 44, k+k b pd '

$ 3 7,2J f. verif that eac pi me- alowlDa pumps develo e In ateoj w y a 6 A i Terentia ,/ pressure on r rculation flow W Kn tested py antJ n1 cv.f. b4 Specifica on4.0.5:{- e-AJaw1p

%E in

1) gh Head Sa njectionpump > 1480 p d, and gype penn j

Low SafetyInjection p > 28 psid.

g. By perfo 'ing a flow st, during s tdown, follo ng completi n of ,

modifi tions to the CCS subsyste that alter se subsyste flow l char teristics and erifying tha 1 For High He SafetyInjec on pump line , with the gh Hea Safety Inj tion pump run ng, the pump low rate i greate than 1470 gpm and less t n 1620 gpm.

2) For Lo Head Safety In ection pump 1 nes, with e Low ad Safet Injectionpum running, the ump flow r te is eater tha 550 gpm and 1 s than 2800 m.

t. 7 t'

/

SOUTH TEXAS - UNITS 1 & 2 3/4 5-5

< /

00) l c

$ cekew 3,T,2, EMERGENCY CORE COOLING SYSTEMS b3/4 6 RES186AL HEAT REMOVAL MHR) SYSlEH 4,\

kLIMITNGCONDITIONFORRATION / y 3* "

6 M inde nt Residual Heat val (RHR) p[shallbeOPERABLE with each loip compr d of:

a. One OP BLE RHR pump,

b. 0 OPERABLE RHR h exchanger, and I '4*

t c One OPERABLE f wpath capable of ing suction mitsassociated)

RCS hot leg d discharging to s associated R cold leg.*f APPLICABILITY: HODES.1,.t and 3.

4_ee ,o g ACTION: "

el Ca W one RHR no le, restore the T OPERABLE Acnc o A J status within avs/or ce inA t least HOT A ANDB n the 4 rt

, ggg g g 6nna Inr4 1, unT ronTnnun virhin the fol' w ou f (b A @two R r Rif AfW C. OPFRABlE status wit _14totFJf6r begat least STANDBYpftnin ggg (6 hourf and in UOf SHUTDOW1Within Xe followin hours. /

three RH rable, immediately initiate corrective ac_ tion to restoreCat lsast one)RHR,leee to OPERABLE status AceN /

Gt S DeTTDjad % 60 URVEILLANCE REOUIREMENTS

,,,,u.i,J m

4.'$.6_.fEach RHR loo [ hall be demopdrated OPERABLE Jia STAGGERED TEST)

M S* AS17 pursuant to Jhe requirementsAf Specificationg.0.5p 4.5.6.2 At least once per 18 months by ver.ifying automatic interlock actio@ p ,a of the RHR system from the Reactor Coolant System to ensure that: ,

Q,u.de-str 4 *-

. With a simulated or actual Reactor Coolant System pressure signal g+a. 34 greater than or equal to 350 psig, the interlocks grevent the valve yn a from being opened, c ,

ves HOV-0060 A and C and H0V- 1 A, B, may have pow emoved to support R (Fire Hazard lysis Re ) assumptions.

SOUTH TEXAS - UNITS 1 & 2 .

3/4 5-11 Unit 1 - Amendment No. 4,41,59 Unit 2 - Amendment No. M ,47 hdy

I i

. hckb 3&3 i l

l TSI - 105 '

EMERGENCY CORE COOLING SYSTEMS ( ELCS) Itd 3/4. 5. 3 ECCS [5USSMf1TMS)-{T,y L M AN 350*F) Q j A.1% )

LIMITING CONDITION FOR OPERATION s.co 3.55 ECCS o #

3.5.3$ mjo-ne~ ~ T ow nerts (shall be OPERABLEf $.c.

fa. Two 0l'ERABLE gh Head Safety .jection pumps,* in,

b. Two OPER E Low Head Safe Injectionpumps nd their associ ed l RHR h exchangers, and

c. T OPERABLE flow pa s capable of taki suction from t refueling ater storage tan pon being manuall realigned and tr sferring suction to the tainment sump duri the recirculat n phase of operation thre h a High Head Safe Injection pump d into the t System and throu a Low Head Safe Injectionpu (Reactor Cooand its rp ective RHR heat ex anger into the Re otor Coolant .

APPLICABILITY: H0DE 4. Th4 pwtwA nexn 4.,. ~+ e . y. L- w yi ACTION:

4, gg Lq l

a. With less than the abov required ECCS components OPERAB Lio 1 ecauseof\ 1 the inoperability of ther the High Head Safety Injec n pu:ps or 1 l the flow paths fro he refueling water storage tank estore at '

i least the requir ECCS components to OPERABLE sta s within I hour '

or be in COLO JT00WN within the next 20 hours2.314815e-4 days 0.00556 hours 3.306878e-5 weeks 7.61e-6 months . ; (lwi uc. l

b. With less an the above-required ECCS compo nts OPERABLE because of '

w & hvM .

the ino rability of either the residual h gg l removal heat exchangers or t Low Head Safety Injection pumps, store at least the required C"/ i EC components to OPERABLE status or ntain the Reactor Coolant !

stem T,yg less than 350'F by use Iternate heat removal methods. j

{c. In the event the ECCS is actuated and injects water into the ReactorD [

Coolant System,.a Special Report shall be prepared and submitted to 3 the Commission pursuant to Specification 6.9.2 within 90 days describ jl .

ing the circumstances of the actuation and the total accumulated I actuation cycles to date. The current value of the usage factor for ,

each affected Safety Injection nozzle shall be provided in this M, l gcial Report whenever its value exceeds 0.70,, __

RED

& x w i *A maxim of one High He afety Injecti ump shall be OPE .and a second High ad' Safety Inje pump shall ERABLE except'tha s breaker shall ptive i e .

} e arked nut (the th d HHsi pnmp cha hav. 4+c breaka--r_ fad nut) within:

(1)Q:4HHes)fter entering MODE 4 from H0DE 3 prior to the tamneratur_e of _

b 'Lo3.sa one or i f the RCS cold legs decreasing be o 5'@o ci swa Greid (2 ' b ars fter entering MODE 4 from H00 5 prior to the temperature o nii.h a si ma f k+t-oefrhoreoftheRCScoldlegsexceeding2

! Al 50 TEXAS ' UNITS I & 2 3/4 5-6 M

A L.'1 .

by Ih4

i 6pec b cada N 3 5 5 Section 3.5 Markup inserts )

insert 4 ;

(NOTES to follow LCO 3.5.3) 1

.;..................................... NOTES------------------------..---.....

l 1. After entering MODE 4 from MODE 3. more than one HHSI pump breaker may be racked in until one or more RCS cold leg temperature s 5 325" F. !

2. More than one HHSI pump breaker may be energized for testing or filling ,

accumulators provided the discharge of the pump is isolated from the RCS. d !

3. After entering MODE 4 from MODE 5. all HHSI pump breakers may be racked out until one or more RCS cold leg temperature > 225 F. @ ,

4. RHR subsystem OPERABILITY in MODE 4 shall be in accordance with LC0 3.4.6. Q "RCS Loops - MODE 4."

l Insert 5 (replaces existing ACTION section)

CONDITION REQUIRED ACTION COMPLETION TIME i

A. One required ECCS A.1 Verify one OPERABLE 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months i train inoperable HHSI subsystem with the pump breaker racked in. i AND M Restore required ECCS 14 days I train to OPERABLE '

status.

B. Two required ECCS B.1 Restore one required I hour trains inoperable. ECCS train to OPERABLE status.

C. Required Action and C.1 Be in MODE 5. 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months associated Completion Time of Condition A or B not met, i

l C 38

84'( c sh 3,5.3 l

i l

EMERGENCYCORECOOLINGSYSTEMS[6(LSb AI 6AA.m A' ECCS @85YSTEif9- (&LE&S SURVEf Lt ANCE RE001REMENTS A THANm 35D29

' ' ~ '

- rs (1 3

1. A

% _d + / bib.-. % ..e VA.G 4_.5.3.1 Th nents s be demonstfated OPESABLE per th'elapplicable *") g D'SI'I teo"I rements pecift ation .2 4A 944 me., A + , n,c o?EtAEf '.

fe. 5.M 5.3fD2 5fA11 Hf h ffead Safe njection 5s, except tWabove a136ed

TOPERABL um shall be vnstrated i ra31e* by verffvino thafthe moto SM'T13 f H4AA circui rea er e s' ed in the o

~

posittert/tiithln 4 burskfter entering $t,3,ar g.c l

%qxA, 1100t 4 rom H00 3 prior to the temperature of one or/more of~theRCSccTQ g ens ecreasino low 325'E whic gr comes nrst;)ana at seast once per 31 days thereaf te i

(419t& b ' '

Ast L0 e

8 1

6 l(p#r. .W. !"A ere I % las.

Y hN *g $ */ C et 0 $~

do LCog g,c q ggg ogg I_ I SA f J.v.7275*F h $.

e, ..,9 g

O 53 e,, w> n.st F

An inoperable pump may be energized for testing or for filling accumulators)

\ _ Drovir'ed t ha Mteharne _nf the nte hn been (enlated frnm the RC ac ed isola iso tiononvafvewipfpow vjfive sptured remo/ed fror/the va)se operfor, of b man n the/closedgositief. f f SOUTH TEXAS - UNITS 1 & 2 3/4 5-7 E.

Magc3 hY

Spec.icalto n 3. 5. 3 t

Section 3.5 Markup inserts ir Insert 6 .

u F

k.lA.T.. E l

,A.n. . D. .U. ..D. c e ih e o c + nm, m,1,vg ss, hn an v v,n,,e 4, An,rnA A,DE.D.A,w w w.

DI E i ou,--je.w1 -- wu ww w Ai re4 nn sl 4, nn-Ant ww, '*M M 1 Mi4 Tvh *rW snA anne wT*w VW%v s& 4 nn #ne Ana s si WE.

i

VWT 1 T UwwwI

{

w n, n

l

.n."_%

m h, P.n.e..n,s.f

~ - s, i , a.snsy--,n v v ww , n,n 7

18 m....s. .e. . l I.s . j s I

e,won s l, i, n nA +n +bn~ COIC m..nMn a f, ann e.s t. 4 nn. .

ynww ov ...w ovvs . vww v vyo, v, i t

L I

E i

5 1

f 1

s 4

I I

a 4

I l

0 4(, k0 1

i I

bgCc's cs W 6, $. &

EMERGENCY CORE COOLING SYSTEMS CCCC. A.. k)

I R FUELING VATER STORAGE TA [ROS T) 4.\

{11HTTINGAMDITf0NrodERATION) t_co 3,5.d 3.5 7The g water ge WST$shall be OPERABLE y 4,1 a [ A minimum ained borated wa volumeIf[458,000 gallons, and

b. A on concentration b eenhg0 ppm and 3000 ppm.

l APPLICABILTTY: H0 DES 2 , 3, and 4. gg,c o A.l cr7 6 Il TD 5R5 h, usw eM 4La ca:n 5) '

g .n g g ruwh ==RVsT inererab1Leestore-a---to Ortett status within I hour @

Actica C- be in et leist-trJT Q11cwimr30 hoursjSTANDBQlthin 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and in(COLD DKTTDOWN)within g "d j

stmvfittANCE REOUTREMENTS

/ +

4.5/VThe RWST shall be demonstrated OPEPABLEQt leist)once per 7 days by:

g g,9 g,g7

. ,Verifyhtherr s) berated water volume C - _ t'.m te. k. e.. Q >,4 5 g,o ,o 3 6 , ]

b. Verif the r

g, g cron concentration Sf 19 =t:r.{'is y 2 foe pm A ggo,oppQ s.<

.t A.I SOUTH TEXAS - UNITS I & 2 3/4 5-10 Unit 1 - Amendment No. H, 54 Unit 2 - Amendment No. 40, 43 3,7 i L

l 1

Speedaesdron 3.6. $

Section 3.5 Markup Inserts l

1 Insert 7 l CONDITION REQUIRED ACTION COMPLETION TIME A. RWST boron A.1 Restore RWST boron 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months concentration not concentration to Qg,f, within limits. within limits te OPEPABLE status.

i

(

f a

l f

)

l I

i l

l l

3

/qc 2 / 1 l

t cts 3/4 .s.3 1 l I

i l

, EMERGENCY CORE COOLING SYSTEMS ECCS SUBSYSTEMS - T,y LESS THAN OR EQUAL TO 200*F h LIMITING CONDITION FOR OPERATION 3.5.3.2 All High Head Safety Injection pumps'shall be inoperable. 'l APPLICABILITY: MODE 5 and MODE 6 with the reactor vessel head on. ,

Ase ACTION-

,h_rnssJ h'D 3 *b b3 With a Safety Injection pump OPERABLE, t-estore all High Head Safety Injection !

pumps to an inoperable status within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months . '

1 i

SURVEILtANCE REOUIREMENTS l 4.5.3.2 All High Head Safety Injection pumps shall be demonstrated inoperable

by verifying that the motor circuit breakers are secured in the open position at least once per 31 days.

I j

1 I

l l

An inoperable pump may be energized for testing or for filling accumulators l

provided the discharge at the pump has been isolated from the RCS by a closed isolation valve with power removed from the valve operator, or by a manual isolation valve secured in the closed position.

i

l. I i

L J

)

SOUTH TEXAS - UNITS 1 & 2 3/4 5-8 Unit 1 - Amendment No. 4 l

l

{ g.se I .t l l

. l i

dT.53/4.5',4 ;

1 ,

i l

EMERGENCY CORE COOLING 3/4.5.4 (Thi ication number is not 4. h

^j /

I 4,

I i

l 1

4 A.14 SOUTH T - UNITS 1 & 2 4 5-9 p.y 4 1 I

STP ITS Ccnversion -

Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS)

ADMINISTRATIVE CHANGES A.1 - All reformatting and renumbering are in accordance with ;

NUREG-1431. As a result, the Technical Specifications (TS) l i should be more readily readable, and therefore :

understandable, by plant operators as well as other users.

i The reformatting, renumbering, and rewording process

~lnvolves no technical changes to existing Technical ,

Specifications.

l

Editorial rewording (either adding or deleting) is made i consistent with NUREG-1431. During Improved Technical Specifications (ITS) development certain wording preferences j or English language conventions were adopted which resulted ,

in no technical changes (either actual or interpretational) to 1 i' the Technical Specifications. Additional information has also been added to more fully describe each subsection. This 1 wording is consistent with NUREG-1431. Since the design is j already approved by the NRC, adding more detail does not

result in a technical change.

i A.2 Details regarding the acceptance criteria limits for continued j OPERABILITY of the RWST ECCS accumulators are moved 1-

from CTS LCO 3.5.1 a, b, c, and d to the Surveillance

! Requirements associated with this LCO (ITS SRs 3.5.1.1 !'

l through 3.5.1.5). Since the requirements remain unchanged

+~

and only their location is different, this is considered an editerial administrative change and is consistent with' NUREG-1431.

A.3 Current TS 3.5.1 contains a separate Action b for an accumulator inoperable due to a closed isolation valve. The existing Action requires the valve to be opened within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months , or a shutdown be initiated. This i: th: : me :::ica dirce cd by CTS 11,1 Action a reouires an accumulator be !

restored to OPERABLE status within the same time when few

n :cuma!::ct inoperable due to other reasons (i.e. other than a closed isolation valve or boron concentration outside the reauired limits). The proposed ITS 3.5.1 Action B 1 combines these requirements. In this channe, ooenine a ;

closed isolation valve is eauivalent to restoring the accumulator to OPERABLE status. Since no change in Required Action or Completion Time is made, this chan;;c i:

South Texas Units 1 & 2 Page A - 1 Rev. O, 02\05\97

STP ITS Ccnversi:n Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) 1 mercly an editorial preference is considered an administrative change. This change is ccasi::en: .vith NUREC 1431, and does not present any change from the current TS !

requirements.

A.4 A proposed ITS 3.5.1 Condition D is added to CTS 3.5.1 l requiring immediate entry into LCO 3.0.3 when the system conditions are such that the plant has 2 or more inoperable accumulators. and This change is considered administrative because it does not represent a technical change from the current TS which also requires immediate entry into LCO i 3.0.3 for the condition of more than one accumulator i inoperable. Furthermore, the actions reauired by CTS 3.0.3 and ITS 3.0.3 are the same. The addition of this proposed l l

Condition D is administrative and consistent with the edi:cria! preferences of NUREG-1431. l l

4 i

A.5 A oortion of C! rification has been added 10 bciter describe the STP in crprc:: tion of :he CTS Surveillance Requirement 4.5.1.1 d h to verify th:: cach accumu!: tor ise!: tion valve is ,

open, and the boron concentration for each accumulator j within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after "each solution volume increase" with-a 4 makeup of greater than or equal to 1% has occurred. Fct the l l

va!ve pc !!!cn, the propc:cd !TS SR 3.S.1.5 c! rific the tequirement ic indica:c that they must be fu!!y cpen ver;us the existing TS .vhich cn!y require them c be open. Fcr the accumu!:tcr !cvc!, the conditiena! sureci!!ance of bcron concentra !ca,2 A Note is included in orooosed ITS SR 3.5.1.4 frequency which clearly states that only affected 4

accumulator (s) need to be surveilled. This chance is considered administrative because the CTS and ITS statements are eauivalent. This administrative change does not modifv ;

any technical reauirements and is consistent with the '

NUREG.

A.6 Not used. The fccinc'c denoted by an "*" in the Applicability of CTS 3.5.2 has been incorporated as a Note to 4

the Applicability of the propc cd !TS. The fccincic has been 1 revised consistent .cith the ::y!c cf NUREC 1131, .cithout cny ;ub;tentive chen;;c to the OS requirements.

1 1

i South Texas Units 1 & 2 Page A - 2 Rev. O, 02\05\97

l S1? ITS Convmion Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) ;

i A.7 ITS Condition E E has been added to CTS 3.S.2 Actions which clarifies what Required Action is necessary when twq l trains cernin ccmbin tion; of inoperable Safety injection (SI) l

nd Rc;idun! Heat Remc/2! (RHR) :eb;y; tem; exist for a ;

period beyond that specified in the associated Completion Times { addressed in DOC L2), and for three trains of SI I l inoperable. Condition E E directs immediate compliance l with LCO 3.0.3, consistent with the CTS requirement. CIS l 3.5.6 Action c addresses the condition for three RHR trains

! inoperable reauiring immediate corrective action to restore at j least one RHR train. This CTS reauirement is caotured in ITS '

, 3.5.2 Action G. However. ITS 3.5.2 Action F covers the j situation where all three Si trains are inocerable which could be a result of three RHR trains inocerable due to the relationshio between the Si trains and the RHR trains. A

, Note is included in ITS Action F that addresses this condition I

by stating that the condition is not aoolicable when three RHR subsystems are inoperable (i.e.. the three 51 trains are inoperable due to three RHR subsystems inonerable). This note is reauired as a result of the two CTS specifications l (3.5.2 and 3.5.6) beine combined into ITS 3.5.2. This condition merely provides clarification of the Action reqJired when the Emergency Core Cooling System (ECCS) is not in compliance with the listed Conditions and Completion Times. As such, this change is editorial and does not change l existing requirements or practices. This i; consistent ;/ith the phi!c;cphy of NUREG-li31.

A.8 CTS Surveillance Requirement 4.5.2.e.1, requires each l automatic valve in the flow path to actuate to its correct position upon receipt of an Automatic switchover to Containment Sump test signal. The proposed change is incorporated in19.wkh ITS SR 3.5.2.4 and modifies the I wording of the Surveillance to exclude the valves that are locked, sealed or otherwise secured in position. This change is considered administrative since any valve that is secured in its required safety position is meeting the intent of the CTS requirement. This change is consistent with NUREG-1431.

I i

South Texas Units 1 & 2 Page A - 3 Rev. O, 02\05\97

I STP ITS Ccnversion l Attachment 3 - Discussion of Changes

! Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) 1 l

A.9 CTS Surveillance Requirements 4.5.2.e.1 & 2 utilize an actuation test signal during testing. The proposed change will allow an actual signal, as well as a simulated test signal, to meet the Surveillance Requirement in ITS SRs 3.5.2.4 and

3.5.2.5. This change allows taking credit for unplanned actuations if sufficient information is collected to satisfy the surveillance test requirements. Because an actual initiation is as good or better for testing of the function than a simulated l initiation, the proposed requirement does not change the technical content or validity of the test. Therefore, this change is considered administrative and is consistent with NUREG-1431.

A.10 A Note has been added to CTS LCO 3.5.3 to clarify where <

the requirements for the RHR subsystems are located when operating in MODE 4. This Note is provided to clarify that i although the RHR is a subsystem of the ECCS when operating in MODES 1,2,3, and 4, the system also performs the functions required by LCO 3.4.6, which are more restrictive than those in the ECCS requirements. Therefore, for clarity and ease of application, all RHR OPERABILITY requirements while operating in MODE 4 are incorporated into LCO 3.4.6 specification. This Note is an editorial preference and does not by itself represent a technical change in the specifications. Thi; chani;c i; con;i;;cnt '...a NUREC 1431. I A.11 The CTS note to SR 4.5.3.1.2, which permits operation of a l High Head Safety injection (HHSI) pump for testing or to fill '

er-test an accumulator, has been moved to a Note to ITS LCO 3.5.3. The proposed location better reflects the appropriate implementation of the exception to the LCO which specifies only one HHSI pump breaker may be racked in when operating in MODE 4. This change is editorial in nature, does not change technical reauirements and is considered an administrative channe. and cen;istent wii NUREC l'31. !

A.12 The CTS footnote to LCO 3.5.3.1 contains a restriction on the number of HHSI pump breakers which may be racked in.

i This restriction is moved to proposed ITS LCO 3.5.3, which i better reflects the appropriate implementation of the I requirement. This change is editorial in nature in that information maintained in a note to the CTS LCO is now South Texas Units 1 & 2 Page A - 4 Rev. O, 02\05\97 1

i STP ITS Ccnv:rsi:n Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) directiv included in the ITS LCO. This channe does not alter l

any technical information and is considered administrative.

and i; cen;i; ten: v/?:h the ph!!c,cphy of NUREC 1131.

A.13 Not used. A Nc: c h ; been included for C'S SR i.5.3.1.1 to

! c!=i'y the-current pactice and in:crpret;'ica cf allevving i ___;: _

, . . . . ... ._. u. ....i _..r. ._ _ _.y........ _. : _ , _ r. ., _.. ecce _ . ~ .. . . u . .,..... _ . ..,.

OPERAP,LE sub;y :cm :! hough they have been manua!!y c!!;ned ic func'icn ;; p:f. cf an RHR sy;;cm in Ope = tion.

l Thi; i; cen;i; tent ve!!h th: !!creance to : ke manu;! action in

.m. . _n e a. .. ._. . . . .. . ... ~ .. . .. .... . .- _. e cc e .,.,.. . _. ~ . . ._; . . .: , . . . ~ . . ,

cen;isten veith exi; ting plant interpretation; and precedures.

The add!!!cn of th!; c!=! fica !cn 1c !TS SR 3.5.3.1 = .: Ncic, l i; thereferc :n editoria! change ;;ith nc effect en th:

e

....r

_ _ i. _ ._. ~_. .. ,. . :. _. _. _. r. . ..u. . _ v. __ _ u. .._. . _.. i. w_ _ :. . . r. ~: _...

T. L. :. ,., :. ,., _._._.

. . _,,:.., .. _. . .. ..,! .. L.

. .A .l l ~I D. _rt"* 1. A. .S,1. .

l A.14 This CTS number is not used in the CTS. It is labeled, "(This l specification number is not used)," therefore, this page is being deleted from the ITS. This change is consistent with NUREG-1431.

A.15 Details regarding the acceptance criteria limits contained in

CTS Surveillance Requirement 4.5.5 for continued OPERABILITY of the Refueling Water Storage Tank (RWST) are moved to the ITS Surveillance Requirements 4TS 3.5.4.1. l.

l and 3.5.4.2. Since the requirements remain unchanged and only their location is different, this is an editorial change.

This change is consistent with NUREG-1431.

1 I

A.16 Requirement contained in CTS surveillance 4.5.3.1.2 is transformed to a Note for the ITS SR 3.5.3.2 and a Note for the ITS LCO 3.5.3. The Notes provide an allowance, when entering MODE 4 from MODE 3, that more than one HHSI pump breaker may be racked in. This allowance is maintained until any RCS cold leg temperature reache; decreases below 325 F. At that temperature, only one HHSI pump breaker may be racked in. The insertion of the Notes does not modify the technical requirements of the CTS and

! the change is considered administrative in nature. This change is cen;i; ent v/ith the ph!!c,cphy of NUREC 1431.

4 South Texas Units 1 & 2 Page A - 5 Rev. O, 02\05\97 l

STP ITS Conversion Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS)

TECHNICAL CHANGES - MORE RESTRICTIVE M.1 CTS 3.5.3.1 Action; a and b for one or two inoperabie, I required Low Head Safety injection (LHSI) pumps or RHR heat exchangers is to maintain the RCS average coolant temperature below 350 F, or restore the inoperable components. The proposed changes to the Actions table will limit the time,in which continued operation with one train inoperable is permitted, to only 14 days in ITS 3.5.3 Action A +. The proposed specification will require the plant to be in MODE 5 within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months if both ECCS trains of arg inooerable due to the required LHSI pumps and gr RHR are heat exchanger beine inoperable in ITS Action C. These are additional restrictions on plant operations and were incoroorated to orovide consistence with other ITS specifications that reauire the olant to be olaced in a MODE outside the aoolicability of the LCO. and are cen;i; tent ve!!h the philc;cphy of NUREC 1131.

M.2 Not used. CTS LCO 3.S.2, Action and LCO 3.5.5, Action and b require;;he p! ant be in Het Standby //ithin the next 5 hcur; and Mc Shuideven vei$in Se fc!!cvving 5 hcur; for exceeding the time !!=it for incperability of cnc ECCS cr one er tv/c RHR ;ubsystem;. !TS Action: A, B, and C provide for the inoperabi!!:y of the:c ;ubsystem; but ;!;c require in !TS Action E th : LCO 3.0.3 be entered. !TS LCO 3.0.3 require;

, the plan: be p! ced in cc!d shutdev/n <<hich cen;;ituic;;

more restrictive operating requirement. This i; cen;istent

.viS me phi!c;cphy of NUREC H31.

M.3 CTS surveillance requirement 4.5.1.1.b requires verification of the boron concentration of the accumulator solution after each vabe volume increase of greater than or equal to 1% of tank volume. The proposed TS SR 3.5.1.4 requires performance of the surveillance after an increase of greater than or equal to 88 gallons. This is a more restrictive change because the current TS limit of 1% of the tank volume is equivalent to approximately 187 gallons, while the proposed South Texas Units 1 & 2 Page M - 1 Rev. O, 02\05\97

i l

STP ITS GInversion Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) ,

limit of 88 gallons corresponds to 1% of the minimum contained borated water volume of 8800 gallons established ,

in CTS LCO 3.5.1.b and orooosed SR 3.5.1.2. This channe was made to more aoorooriatelv aoolv any ootential dilution '

by 1% to the actual borated water volume. not the tank I volume.

M.4 Limits on the total combined duration of operation in the Actions for one RHR subsystem inoperab!e and one SI subsystem inoperable have been established. This limit of 21 days is based on the combination of operation for the ;

maximum permitted time with one RHR subsystem '

inoperable (14 days), combined with one SI subsystem ;

inoperable (7 days) in ITS Actions A.1 and B.1. The limit ;

prevents the continuous operation of the plant with a :

degraded emergency core cooling system by maneuvenng j between the two Actions repeatedly. Current TS Actions do not contain such a limitation, and this is an additional restriction on plant operations. This change is consistent with NUREG-1431 guidance regarding total combined duration of operations in these Actions. ;

i l

l

)

South Texas Units 1 & 2 Page M - 2 Rev. O, 02\05\97

.- . - . . . - . . . . - . . - - - . . ~ . - . .. - . - . .- -- -

7

!. [

s STP ITS Cenversion i Attachment 3 - Discussion of Changes -

Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) 1 l TECHNICAL CHANGES - LESS RESTRICTIVE l

L.1 The current TS requirement of Surveillance 4.5.1.1.b requires the verification of the accumulator's boron concentration 'i whenever makeup to the tank exceeds 1% of the tank's !

volume. This verification is modified to be consistent with NUREG-1431 version of ITS SR 3.5.1.4. The proposed ,

change requires verification of the accumulator's boron l concentration after makeup to the tank exceeds H 88 l

!!=

, ' from any source other than the Refueling Water -l t

Storage Tank (RWST). The RWST is a TS surveilled source of borated water, monitored for OPERABILITY every 7 days for boron concentration.' Makeup. from the RWST is a fully 3

acceptable source of water for the accumulators. The RWST is also u"xl for other ECCS functions for the mitigation of i DBA. The proposed change is less restrictive in that the accumulators are presently monitored for boron concentration l change for makeups of n SS ;;;!!=: or more from the 'l ' l l RWST. Makeups from sources other than the RWST will !

continue to require boron concentration verification within 6 j hours of exceeding the makeup limit. This channe is acceptable because makeuo from the RWST can not reduce the accumulator boron concentration below the minimum limit since the water contained in the RWST is within the 2 accumulator boron concentration reauirements.

- L.2 CTS 3.5.2 orovides specifications for the Enweencv Core Cooline Srtem which includes the Si subsystems and a cortion of the RHR comoonents. CTS 3.5.6 orovides soecifications for the entire RHR trains. These two soecifications have been combined into ITS 3.5.2 to fully address the relationshio between the Si and RHR systems.

liowever. CTS 3.5.2 only directiv orovides for a condition where one Si train is inooerable, even though there are three trains reauired. The CTS reauires LCO 3.0.3 to be entered if two or three Si trains are inoperable. Proposed ITS 3.5.2 '

allows 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for two Si trains to be inoperable or LCO 3.0.3 must be entered and specifically reauires LCO 3.0.3 be i entered if three Si trains are inooerable. The fact that 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months are allowed for two Si trains to be inocerable in the orooosed ITS where LCO 3.0.3 had been reauired in the CTS is considered a less restrictive chanee. Additionally the )

allowed outane times for one RHR train inocerable has been l l l l' l South Texas Units . & 2 Page L - 1 Rev. O, 02\05\97 l l

. _ _ ____ _ - . __ , _ _ __._s _. _.-.

STP ITS Conversion Attachment 3 - Discussion of Changes Section 3.S - EMERGENCY CORE COOLING SYSTEMS (ECCS) increased from 7 days to 14 days. ITS Actions A through F G I have been proposed for combinations of one or more RHR or i SI subsystem (s) inoperability now contained in CTS LCO 3.5.2 and 3.5.6. The proposed Actions are designed to I permit continued operations when possible due to the unique .

STP ECCS three train design. The Actions also acknowledge i the relationship between 51 and RHR subsystems and the l dependence of the SI subsystem on the availability of the i RHR subsystem as the primary success path for removal of !

decay heat for certain design basis accidents. The followine ;

matrix shows any orooosed chance to allowed outane times. l The new Comoletion Times associated with two of three I trains inoDerable is Consistent with the STP desien and the J aoolication of NUREG-1431 to a three train desien as described in STP's letter of Februarv 6.1997 (ST-HL-AE-5571). The Comp!ction Time hcve genc=!!y been extended for the vericu: ccmbinctica: cf inopemb!c equipment.

Current Tech. ProposM Tech. j Spec. Allowed Spec. Allowed i Condition Outage Time Outage Time ,

1 One SI Subsystem inoperable 7 days 7 days !

d Two SI Subsystems inoperable None - 3.0.3 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

_One RHR Subsystem inoperable 7 days 14 days Two RHR Subsystems inoperable 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 24 hour:7 dcy: I j Three SI Subsystems inoperable None - 3.03 None - 3.03 ;

with at least one RHR subsytem l'

. OPERABLE.

i 3

Three RHR Subsystems inoperable immediate immediate l Action to Action to Restore Restore l

South Texas Units 1 & 2 Page L 2 Rev. O, 02\06\97

._ - - ~ - . - - . - ~ . - . . - - _ - - - - - . - . . - - - - . _ _ . -

i STP ITS Conversion Attachment 3 - Discussion of Changes :

[ Section 3.5 s EMERGENCY CORE COOLING SYSTEMS (ECCS) ~ !

. .i

' The proposed changes have been subjected to a risk informed evaluation and the results demonstrate that the proposed changes have !!'t! cr no sienificant impact on the

, . overall Core Damage Frequency or Larne Early Release Freauency for the duration of the allowed outane times Hsle associated with the STP units plants.

L.3 -The CTS requirement of LCO 3.5.2 to perform additional !

! verifications of the OPERABILITY of the ECCS pumps, RHR j heat exchangers and flow paths when a single train is inoperable, has been deleted. The actions required by the -!

CTS note were vague and operating experience indicates that !

the additional testing does not provide any additional margin

of safety. Existing surveillance tests demonstrate the availability of the required equipment. This is consistent with l

NUREG-1431.

l i

E L.4 The CTS requirement of 4.5.2.a for a daily verification that

power is rernoved from the Hot Leg recirculation isolation valve operators has been deleted. This change is made -

consistent with the design of the South Texas Project (STP) j ECCS in which each valve can orly affect the operation of a ;

single train. The basis for the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months frequency of the CTS :

was that in the more common Westinghouse ECCS design, ,

mis-alignment of a single valve can cause the defeat of :

multiple trains of equipment. . The STP design uses individual :

train specific Hot Leg recirculation lines without a common ;

header. As such, the mis-positioning of a valve could, at i worst, affect a single train. Therefore, this surveillance has L been removed and the valves will be treated in'a manner 1 similar to others with the same potential for disabling a single train of equipment. This change represents a less restrictive change which recognizes and credits the STP design. -TMs ch=;;; is consi; ten with the ph!!c;cphy of NU"EC 1431.

L.5 The requirement of CTS 4.5.2.c for visual inspection of the containment, to assure that no loose debris is present which could cause restrictions to the containment sump suction lines, has been deleted. The normal administrative controls for plant cleanliness and control of materials are adequate to provide assurance that no challenge to the ability of the ,

sumps to perform their required functions will occur. Any I changes to the administrative controls are subject to the South Texas Units 1 & 2 Page L - 3 Rev. O, 02\05\97 i

.,- -_ _~~ . - . . .. . - . . . - - - .- - - . . .- - . . ~

r o :

i STP ITS CCnversion i Attachment 3 - Discussion of Changes - ;

Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) i

control and reviews required by 10 CFR 50.59 which j l provides an adequate margin of safety. This change is j consistent with NUREG-1431. '

i L.6 CTS 4.5.2.e reauires actuation of automatic valves and safety ;

iniection oumos be oerformed once oer 18 months durine

! shutdown. .This e limitation on performance of automatic ;

actuation testing during shutdown of CTS 4.5.2.e has been

removed in orooosed specifications SR 3.5.2.4 and SR i 3.5.2.5. .The is proposed change is required and appropriate !

i - because the specification a) has also been modified by-a i

Ncte v/hich per .!!: to allow credit for actual actuations, and l b) the proposed allowed outage times provides adequate time -l to perform testing, or portions thereof, while operating. This :

channe is acceotable because it does not imoact the health ;

and safety of the oublic. This change is consitent with j NUREG-1431.

4 1 t L.7 The requirements of CTS 4.5.2.g for post-modification !

. performance testing of the ECCS subsystems is being )

j removed. These requirements are adequately addressed by plant administrative controls on plant design modifications.

j. _ Furthermore. ITS suveillances are orovided to ensure the j ooerability of the systems. . This change is consistent with NUREG-1431.

9

'. . L.8 Not used. The 77:quency fc verif,ing th: the ECCS pipin;; i:

l fu!! cf v/:te: h:: been changed f:c . 31 day; : 92 day; fc:

cs r. e a. . .e .,. . .t,. ,. . r t. ~_ _ t. ...._. ._ ._. .: ..,. _. ..;. _ .a.~. ..._ .. _ . . .r :..m

. . _ : _... i .;..-... .

. . ~

J._r___.....__.__!__.r

. ... . ~ . ~ ~ ... .. .e T. u. D L. :~_. .t. . _. .J.

. _.-. _, ..L....

~m., . .

..,.__.n..,.___-.,...__.__;...t.~_..:..:__c._._._,..___.

. y m. . . . . . , , . . . , . . . .

...... . . . ~ , . .

,i. i _ . t _

. . ~ , . . ~

, perfer .ance Of the ECCS ventin;; p:ccedure resu!!: :n the l ;;cnt :ica cf unnece:2 y !! quid ::dic '!ve v/ ::c, and i

pc;c: Oper ::::'c unneeded d ,e cent ::y : ^.L^.R^.

r. m ~. . .r:._ .n. .. .,., . .t _.e~r. -o .;._.,:

__..__1.r_i_ . _ _. . .. ., .:.t. . __

.~_ r _ _.. _~e cc _.e, .._. ~; !

a..u. n . . _ _ _r . ..t.

.. . .r.,,

. _._.~

. :._.,2.__

r..

__. a._.. . . : _ .,, .,_~a

. . . . . . . . . . . .a~ _....

... . . .t. :~_t. .

i _

.. H L _ _ _ t. . . ..l l H , . .

~ t. ..,J__., J. : _ _ _ _ . t _ D. U. D, r_ ._ a. !. ._ _. . ,., ._. g. . .t _

_r .....r.r.....~... . ~

y::cm2, pecvide ::= nce that ga: veid: .v!!! .ct fc m and

~ n.,. 2. .~,_ ..:.,..,a___..

i

.t.

. . . , , ~ . r. .t. .:. .., ._ t. .._. ._ _. ..: ., __ _. _. .: .,.

. ~_. _ . ..

.... .. .. t. . L ~ - _ r.t. r. l ~

_ _t.r..,, _f. k l .~.l I D, et.".*. 1. A. .'.3 1. .

I 1

1 L

h 4

4 i

[ South Texas Units 1 & 2 Page L - 4 Rev. O, 02\05\97 l

i q

i STP ITS CInversion :

Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) ,

~

L.9 The ::::::'! n: en op = ting w!!h on :bnorm:! pump

! gnment fe!! wing : MODE chang: int MODE 4 ft =

MODE 5, h:ve been =cdif!:d :nd th: i hour !!m! h:: been

=cved. Thb ch:ng: CTS 3.5.3.1 LCO Note M restricts only one of the two OPERABLE HHSI oumo to have its breaker racked in for low Temo Overoressure Protection considerations. The CTS reauires this to be done within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after enterine MODE 4 from MODE 3 or orior to an RCS cold les temoerature decreasine below 325 "F. This restriction is also imoosed within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after enterine '

MODE 4 from MODE 5 or orior to an RCS cold lee temperature exceeding 225 F. The orooosed change in ITS LCO 3.5.3 is to delete the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months reauirement and oniv allows abnormal alignments based purely on the temperature of the RCS cold legs. The :!!:=:ne provide; fc nc HHS:

pump: bre:ke ::: bc =cked in frem 200 F :: 225 F when

n::: ng MODE i f := ".005 _5. - The orowsed channe ;

reauires all but one HHSI oumo breaker be. racked out durine (1) after enterine MODE 4 from MODE 3 ririor to the temoerature of one or more of the PQcold lens decreasine j below 325 F or (2) after enterine MODE 4 from MODE 5 '

l orior to the temoerature of one or more of the RCS cold lens exceeding 225 F. The proposed ITS LCO still requires 2 ,

OPERABLE HHSI subsystems before entering MODE 4. This j change is also reflected in the performance of the conditional surveillance requirements of proposed SR 3.5.3.2. The change is justified since the temoerature limit assures that the RCS oressure boundary stress limits will not be exceeded at any or6ssure uo to the normal oressurizer relief valve setooints. The olant soecific analysis for the oressure and temoerature limits of the RCS indicate sufficient margin is available between the soecified 325* F limit for ooeration j with more than one HHSI oumo breaker racked in, and the l limitine temoerature for maximum desien oressure of the j vessel. Additional margin is orovided since the limitina j location for stress is within the vessel walls, and durine a j

. cooldown from MODE 3 to MODE 4i the vessel wall internal temoerature will exceed the RCS cold les temperatures for all but extremelv slow cooldown rates. The allowance for movine the olant from MODE 5 to MODE 4 and not reauirine a HHSI oumo's breaker to be racked in still reauires 2 OPERABLE HHSI subsystems. The allowance oermits a ;

mar cf temoerature limit of 2^0 F :: 225 F to perform the South Texas Units 1 & 2 Page L - 5 Rev. O, 02\05\97

a STP ITS CenvGrsion Attachment 3 . Discussion of Changes

Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) i I rackine in of one HHSl oumo breaker. The time during -

which the additional HHSI oumos will be alinned is further 1 limited by olant concerns with ooeratine for extended oeriods e in what is normally a transition MODE. and tvoical operations will be limited to enouah time to alien the

[ reauired systems and oroceed with a cooldown'or heatuo.

The four hour limit did little to contribute to minimization of risk, rather it imoosed an additional unnecessary restriction p on Dlant operators requiring diversion of their attention from l- oroceeding with the reauired ooerations to track a time limit of little sienificance. b:: d en the STP p!:n: :pecif: P :=ure nd T:=p :::ur: !!= :: ::hich p::':!d: :==::n:: th:: th:

~

p!: : :n adequ:::!y ::: pend :: the ! =':ini; OPL fc :h ::

ecad:::cn:.

L.10 CTS 3.5.3 Actions a and b for an inoperable required HHSI

pump or flow path and inooerable RHR heat exchanner or 'I LHSI oumo are modified to reflect the STP three train design and the separate RHR subsystem. The proposed ITS Action

. A.2 will allow continued operation for up to 14 days with one HHS1 pump or flowpath inoperable. The proposed j specification, ITS Action A.1, requires that one OPERABLE l HHS1 pump breaker be verified racked in within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months ,

which provides immediate assurance that one tra!.i of ECCS is j available to function if actuated. In addific: ,, a specification I which allows one hour to restore one required ECCS train if both required trains are inoperable, has been added in ITS Action B. This provides opportunity for restoration of the

required function if it is determined that both trains are inoperable. The one hour time is adequate to perform

?' immediate actions to restore a train to OPERABLE status,

while minimizing the potential for an event which requires the system's availability. If one train cannot be restored, or if one train is inoperable for more than 14 days, the

! specification requires the plant be placed in a condition where the specification no longer applies, MODE 5, within

!' 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months in ITS Action C. The new ITS Actions are designed to include consideration of the unioue STP three train desian. ;

indeoendent RHR subsystems which are utilized for normal !

shutdown cooline in this condition, and LTOP considerations. l j The Comoletion Time for an inocerable ECCS train is I

! extended to 14 days for the HHSI oumo and system flow oath (and a slieht extension in the time to reach MODE 5 if i

l South Texas Units 1 & 2 Page L - 6 Rev. O, 02\05\97

i

.i

)

STP ITS Conv:;rsi:n Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) i I

the Action is not comolied with) because of the continued availability of a fully canable indeoendent ECCS tr.aip.tg perform the reauired safety function as well as confirmation within one hour of the reauired breaker alienment of an i OPERABLE HHSI oumo. In addition, the availability of RHR !

subsystems to remove heat from the crimarv system in this j mode of ooeration suooorts the extended comoletion Time. !

The extremelv low risk of a limitine desian basis accident in the reduced oressure and temoerature conditions of MODE 4 oermit credit for manual alienment and actuation of ECCS-systems during accident conditions. One train of ECCS and j!

the reauired RCS / RHR looos orovide assurance that the i reauired safety functions can be oerformed to mitimate the - l consecuences of any accident which occurs. !

4 L.11 CTS 3.5.5 Action allows 1-hour for the RWST to be restored to OPERABLE due to the boron concentration beine out of :

limit. ITS LCO 3.5.4, Action A has been proposed which l allows up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to restore the RWST to OPERABLE due to the boron concentration not within limits. This Action is !

added to CTS LCO 3.5.5 and is designed to permit restoration of the RWST without forcing an immediate '

shutdown, and is consistent with the amount of time which would be required to restore the boron conccetration. A .

forced shutdown would further jeopardize the plant due to j the importance of RWST availability, while an eight hour i delay to restore the parameter would have little effect on the !

probability that a DBA could not be properly mitigated. Ih.e )

orooosed channe is reasonable considerine that the RWST l volume is still intact and is larne enough to assure that any I channes in boron concentration will be slow and if the limits are exceeded, it will orobably not be by a significant amount.

The orooosed channe also orovides a more reasonable time in which to restore boron concentration than the orevious time of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . This change is consistent with NUREG-1431.

L12 CTS SR 4.5.1.1.d. which reauires an 18 month test to verify that the accumulator isolation valves automatically ooen when a simulated or actual P-11 interlock setooint is exceeded or when an Si sienal is received is beine deleted.

The CTS alreadv reauires the valves to be verified ooen everv 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and the valve's electrical oower be verified removed once oer 31 days. These reauirements ensure the South Texas Units 1 & 2 Page L - 7 Rev. O, 02\05\97 l

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STP ITS Conversion Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) <

l i

accumulator isolation valves do not orevent the accumulators ,

from oerforming their safety function. The safety analysis does not reauire the valves to move durine oower coeration or in a cost accident situation. Since no automatic action is i Igauired for the safety function, oerformine this test is unnecessary and can be deleted. Th;s less restrictive change is acceotable because it does not imoact the oublic health and safety. This change is consistent with NUREG-14312 !

L.11 CTS SR 4.5.1.2 specifies reauirements for testing the

{

accumulator oressure and level instruments. These l

,. reauirements are deleted since thev are not necessary to meet the reauirements of ooerability for the accumulators.

Ooerability of the accumulators is deoendent on the auantity l and concentration of borated water and the oressure of the i cover eas. The method of determinine the volume of the borated water and the oressure of the cover nas is not an I assumotion or initial condition for any safety analysis. This '

change is considered less restrictive because it deletes a test .

oreviousiv reauired in the CTS and is acceotable because its I removal does not alter the safety analysis. This chance is !

consistent with NUREG-1431 and is similar to the CTS for the !

RWST where the temoerature and level limits. not the instrumentation are specified.

L.14 CTS 4.5.1.1.c reauires verifvine everv 31 days that the power to the accumulator isolation valves is removed when the oressurizer oressure is above 1000 osie. The orooosed channe in SR 3.5.1.5 is to oerform the same surveillance at the same freauency but oniv when the oressurizer oressure is greater than or caual to 2000 osin. This change allows ooerational flexibility by avoidine unnecessary delavs to manioulate the breakers durine olant startuos or shutdowns.

This change is acceotable because alternate orotection is orovided during the oeriod of time the oressurizer oressure is )

> 1000 osie and < 2000 osie. Alternate orotection is orovided by verification that the valves are open every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months (SR 3.5.1.1), the oressurizer oressure interlock associated with the valves to orevent their closure above 1000 osie in the oressurizer, and an 51 signal orovided to the valves would ooen a closed valve in the event of a LOCA.

j This change is considered less restrictive because coerators have more time to initially remove oower from accumulator South Texas Units 1 & 2 Page L - 8 Rev. O, 02\05\97

. __ _.._ _ . . _ _ _ _ . _ _ . _ _ . _ _ . . _ _ _ _ . _ . . _ _ . _ _ .m--__.

STP ITS Conversi: n i

Attachment 3 - Discussion of Changes

Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) l i-isolation valves durine olant startuos and shutdowns. This-channe is consistent with NUREG-1431.

1 j L.M CTS Action a includes, in oart. to reduce oressunzer oressure - l to less than 1000 osie within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months of reachine HOT I

- STANDBY once an accumulator cannot be restored to I

operable status. ITS 3.5.1 Reauired Action C.2 reauires the j l oressurizer pressure to be reduced to less than or eaual to i j 1000 osie under the same conditions and time constraints. I

This channe is considered less restrictive because operators l

! have the additional flexibility of reducine oressurizer oressure i

to 1000 osin and below where oreviousiv thev had to droo - )

i the pressure below 1000 osin. Placine the olant in MODE 3 - l (HOT STANDBY) with the oressurizer oressure at 1000 osie :

olaces the olant in a mode below the mode of aoolicabilitv. '!

The channe is acceotable because this ensures the olant is in j a safe condition. This channe is consistent with NUREG-- J j 1431. .!

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L.1.1 CTS 3.5.2 Action Note (*) orovides for the orovisions for {

excludine Soecifications 3.0.4 (Prohibits entry into a MODE :

)

when the LCO for that MODE can not be met) and 4.0.4 l (Prohibits entrv into a MODE when the SR for that MODE

has not been oerformed) for entry into MODE 3 for the Si

]

j oumos declared inooerable. The inocerability in this case is I

{' due to the motor circuit breakers secured in the open )

oosition and the Note only anolies if the Sl oumos are !

restored within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or orior to the temoerature of one or I

!- more of the RCS cold lees exceedine 375'F. This information i is caotured in an Aoolicability Note in ITS 3.5.2 that states n that entrv into, and operation in MODE 3 with ECCS oumos declared inooerable oursuant to LCO 3.4.12 is allowed for uD to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or until the temperature of one or more RCS i cold lees exceeds 375 F. LCO 3.4.12 renders the HHSl i oumos inooerable by removine the oower from the oumos by rackine the breakers out under administrative controls. -It also allows (within the Bases) an alternate method of rendering the HHSl pumos inoperable by using two indeoendent means to orevent a oumo start such that a single failure or single action will not result in an iniection into the RCS (e.e.. oumo )

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South Texas Units 1 & 2 Page L - 9 Rev. O, 02\05\97 4

-j

STP ITS Cenversi::n Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) 4 control switch beine olaced in oull to lock and at least one valve in the discharge closed). This change is considered less restrictive because the alternate method of renderine the HHSI oumo is not available in the CTS. The alternate means of renderine the HHSI vemo inocerable considers single failure or single action cases and is a oroven method of oreventine Si flow to the RCS. The change is acceotable !

because allowine a satisfactory alternate method of oreventine Si flow to the RCS does not imoact oublic health ,

and safety. !

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South Texas Units 1 & 2 Page L - 10 Rev. O, 02\05\97 a ..

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STP ITS Cenversinn l Attachment 3 - Discussion of Changes !

i Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) ,

. i TECHNICAL CHANGES - REMOVAL OF DETAll >

l J

I LA.1 The detail of the CTS SR 4.5.1.1.a.1 which stipulates how to

]

assure that the accumulator borated water volume and e

nitrogen cover pressure is within limits (i.e.. "bv the absence

of alarms") is being moved to the Bases.- This detail is not e necessary to be included in the technical soecifications to ensure the limits are satisfied and moving this detail to the bases is acceotable because it does not alter any technical reauirements. This channe does not imoact the health and

safety of the oublic. Channes to the ITS Bases are subiect to the controls described in Chaoter 5 " Administrative i l

Controls "of the orooosed soecification. : !!:en:ce '

.....__n.m._ a_a__. _.

. .L.... a. .n.. _._,_, . . .. .a. . i. n., e c o. . e, .

n. e, n, ev:!uctica : ch=.ge. This will ensure that any change is properIy reviewed. T. '.:. .'. ..-. ..- . . :. ., -... ...:. .,*.- .. ..* .. :'.' '. ." 'a..ce.

i 44 %

LA.2 Not usede c . . .#'. . .c, = '. . '5 e " p .. '.:5 b. h53.5'--":.-... ' " ...-u'.'g

. . . '.-#..s, uu a . .. .

. . b ,. '. s s ! n ._,

n._ _I[* s... L.. .%.. .s.. a.w.e _ . .i..

.e-uni. a l m.

..._sev . !, _ !. .s...!. ._.s

.e . . . . .%.s.m._.w.s.... .... ..7 . I ._.=. l l . s I

..7 .

5. .. .w.. . . .. .. . . . s y ... J

____;_; ._,u

. %% h..s. g

. . .L.w_...u _, _ cv.g..

e., a i :__ ,i. :, ____:.

.d . ..hi . %%s p

.a .t,._ i. ._.g__. h y

_i__

. _a.

_ f. ._.. ._ .__

l__,. en e -l

.. y y._sr..w

_2. . .v.a

. _ _,..s. L.g. ...u . A l. i . w 3 .; .__ . .. i. n. t. c D vT v sr . ., n, w . l.i.

. ,. .1. ._ _. . - _ L..s _ _ TL 1, u d l l __ , . . ._ .L s. %_., _L ,_ __ t,

"O ' ' '"'* ' ' ' ' ' ' * '

'T

.____f.,__.A...._;

y %,p .p7 5%. . . . . TL..-__s_g..f._'._'_'._..,.._,..L.._,._t._'O'_""_',

Uu s. %s .a g.. .. .w J. .. v s . . w . v ., d

.............r...._,_._c,.L.._,.:_____..r._m_;.

_ _i:_:

.r... .. . . , . . . . . . . . . t,.,.

specification: 3.3.2, "ESFAS !n;t.umentation." This w!!!

........L...,.,_.,,_L..,._.__:._.___.i.,,..a._..._a.

. . . . . .. .. . . . v. r. . . ... . . . . . T. L. . :, _ L. . .,.._. ,. _ r ,

!. . . , . J. .L. . L.11 1 D. .et. ~ . A. 1 .S,1. .

m,. . . .. ... .. . , -

LA.3 N ot u sed . . c c ". .. .. ^ . ". . .. . _-- ". ,". .:. . - .. .

. . .- . '. '. . .c . '. . .'.m--. ,". . .:. - . ..

i i

monthly and an 18 month test te verify that the accumu! tor !

pre;;u.c and !cre! in:t.ument: at: OPERABLE is being =cved

. , _....._..~....__n.m._

a a.._ m_ ..... ...

.L. ...... . a. n. . _m_ _,

. . . a. _ _ .. i. n. c r ,o, .

- ...,n,_ ....f...

en e

._ ,.L...._.__.

T. L. ... . . .

, . l. . . ~.. f ._ .

......r.. . . ! I l . . .!. J. .,.

......,___.L...,..._..,,_L...-_.._._...:n.L_,_____.:,._L.,,..:_..,_a..

. . . . . . . . ~ . . . . . . . . . . - rr. r.. .. ......m T. L.

. .!..,,.. .L. ., . _ !. .. . .,1. ,.,.

. ._ .. .. A.

.. ..L. . tw i l I D. et,'.,

.m. 1. A. .S,1. .

LA.4 The detail of what constitutes an OPERABLE ECCS / RHR subsystem, contained in CTS LCOs 3.5.2. 3.5.3.1 and 3.5.6 I and action 3.5.2.a, is being moved to the Bases. This includes the status of individual components and their support requirements. It is not necessarv to include this i South Texas Units Page LA - 1 Rev. O, 02\05\97

l i i

I STP ITS Ccnvarsi:n !

i

Attachment 3 - Discussion of Changes <

Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) l I

l information in the Technical Soecifications to ensure the l ECCS trains operabilitv. The reauirements of the ITS l

specifications, the associated Surveillance Reauirements, and l

the reauirement of SR 3.0.1 (SRs shall be met during the i MODES or other soecified conditions in the Aoolicability for I individual LCOs) are adeauate for maintaining the subsystems OPERABLE. As such, the relocated information is not l reauired to be included in the Technical Soecifications to orovide adeauate orotection of the oublic health and safety.

Changes to the ITS Bases are subject to the controls described in Chapter 5, " Administrative Controls," of the proposed specifications. Any channes to the Bases is reauired to be evaluated usine the 10 CFR 50.59 criteria. This evaluation will ensure that any change will be orooerly reviewed. This change is consistent with NUREG-1431.

LA.5 The details of the method used to assure that the ECCS piping is full of water, contained in CTS Surveillance Requirement 4.5.2.b.1, have been moved to the Bases.!!cen=c contrc!!cd dccument:. The !!cenze contrc!!=f document: which now de:cribe the:c detait: are subject ic the centrc! and review:

required by 10 CFR 50.59, providing ::urance that any chen;;c: w!!! bc cpproprictc!y revicwcd pric: !O )

imp!cmentation. The Bases are subject to the controls described in Chapter 5. "Adminstrative Controls" of the crocosed soecifications. Any chances to the Bases is reauired to be evaluated usine the 10 CFR 50.59 criteria. I This evaluation will ensure that any change will be oronerly reviewed.

LA.6 Details of limits and performance methodology of CTS Surveillance Requirement 4.5.2.f are being moved to plant l controlled documents for Inservice Testing Program requirements applicable to the HHSI, LHSI, and RHR pumps.

Thc= p! nt centro!!cd dccument: arc =bject tc the contro!

and review required by 10 CFR 50.59, previding adequate i c;=rance that any propc cd change The Inservice Testine Program is controlled by 10 CFR 50.55a. orovidine adeauate assurance that any oroposed chance to the relocated l

reauirements will be adequately reviewed prior to

! implementation.

f South Texas Units Page LA - 2 Rev. O, 02\05\97

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l STP ITS C:nversion Attachment 3 - Discussion of Changes -

Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS) l LA.7 The details of steps required to isolate a HHSI pump from the

! RCS are provided by a Note C1 associated with the current I t

TS Surveillance Requirement 4.5.3.1.2. These details are not required for clarification of the specification and are moved -

to the ITS Bases. The Bases are subject to the controls described in Chapter 5 :" Administrative Controls" of the proposed specifications. Any chinge to Bases is required to be evaluated using the 10 CFR 50.59 criteria. This evaluation will ensure that any change will be properly reviewed. This change is consistent with NUREG-1431.

l LA.8 The requirement in CTS 3.5.2 action b to provide a Special Report in the event the ECCS i,s actuated and injects water ,

into the Reactor Coolant System has been deleted. This requirement is adequately captured by th: : pc- !ng requirement: in 10 CFR 50.73 (a)(2)(iv). reauirine a reoort in

.the event of an ECCS actuation within 30 days. The existine l

regulatory reauirements orovide sufficient control over this reoortine reauirement without oroviding unnecessarv l dy. plication within the TS. This channe is consistent with l NUREG-1431 as revised by eeneric channe BWOG-09-C.23 !

(removal of ECCS special report from Section 5.0). and-is imp!:m:nted in p!;nt pectedure:. O !::!ca cf this !cvc! cf dup!!:::!ve det !! i; cen !; tent with NUREC 1131. Change

;!:n! p:Oct ; :: ::: Cont:0"Od in 20:0:&nce "/:$ 10 CFR 50.50. Th::: ecnt:0!: ::: adequ;;c 0c :::ure the !:vc! cf

afety provided by the ex!::ing :pecif! ::!cn: wi!! be maint:!ned.

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South Texas Units Page LA - 3 Rev. O, 02\05\97 l

STP iTS Conversi:n Attachment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS)

RELOCATION There are no specifications relocated frorn this section. ;

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South Texas Units Page R - 1 Rev. O, 02\05\97

7 STP ITS Conv:rsitn Att chment 3 - Discussion of Changes Section 3.5 - EMERGENCY CORE COOLING SYSTEMS (ECCS)

BASES CHANGES The Bases of the current Technical Specifications for Section 3.5 have been completely replaced by revised Bases that reflect the format and applicable content of the proposed STP Technical Specification Section 3.5, consistent with the NUREG-1431. The revised Bases are shown in the proposed STP Technical Specification Bases.

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i South Texas Units 1 & 2 Page B - 1 Rev.0, 02/05/97

STP ITS CONVERSION i ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOUNG SYSTEMS l

ADMINISTRATIVE CHANGES l

l South Texas Project Units 1 and 2 are converting to the improved Technical l

! Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." Some of the proposed changes involve !

reformatting, renumbering, and rewording of Technical Specifications. These !

changes, since they do not involve technical changes to the Technical Specifications, are administrative.

This type of change is connected with the movement of requirements within the current requirements, or with the modification of wording which does not affect the technical content of the curient Technical Specifications. These changes will also include nontechnical modifications of requirements to conform to the Writer's Guide or provide consistency with the improved Standard Technical Specifications in NUREG-1431. Administrative changes are not intended to add, I delete, or relocate any technical requirements of the current Technical Specifications.

l l in accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated these proposed Technical Specification changes and determined j they do not represent a significant hazards consideration. The following is j provided in support of this coaclusion.

l

1. Does the change involve a significant increase in the probability or l consequences of an accident previously evaluated?

The proposed changes involve reformatting, renumbering, and rewording of the existing Technical Specification. These modifications involve no technical changes to the existing Technical Specifications. The majority of changes were done in order to be consistent with NUREG-1431. During the development of NUREG-1431, certain wording preferences or English language conventions were adopted. The changes are administrative in nature and do not impact initiators of analyzed events. They also do not impact the assumed mitigation of accidents or transient events. Therefore, the changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated? ,

l The proposed changes involve reformatting, renumbering, and rewording of :

the existing Technical Specifications. The changes do not involve a physical alteration of the plant (no new or different type of equipment will i

I South Texas Units 1 & 2 Page 1 of 42 Rev. O, 02/05/97 1

STP ITS CONVERSION l ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l t

l be installed) or changes in methods governing normal plant operation. The

I changes will not impose any new or different requirements or eliminate i

any existing requirements. Therefore, the changes do not create the l possibility of a new or different kind of accident from any accident l previously evaluated. i l

l 3. Does this change involve a significant reduction in margin of safetyt l

The proposed changes involve reformatting, renumbering, and rewording of the existing Technical Specifications. The changes are administrative in nature and will not involve any technical changes. The changes will not reduce a margin of safety because it has no impact on any safety analysis assumptions. Also, since these changes are administrative in nature, no question of safety is involved. Therefore, the changes do not involve a significant reduction in a margin of safety.

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l South Texas Units 1 & 2 Page 2 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS RELOCATED SPECIFICATIONS No specifications in this section were Relocated.

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l South Texas Units 1 & 2 Page 3 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION l SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l

1 i

MORE RESTRICTIVE CHANGES

, South Texas Project Units 1 and 2 are converting to the improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." Some of the proposed changes involve adding more restrictive requirements to the existing Technical Specifications by l either making current requirements more stringent or by adding new requirements l which currently do not exist. !

These changes may include additional commitments that decrease allowed outage l time, increase frequency of surveillance, impose additional surveillance, increase l

the scope of a specification to include additional plant equipment, increase the '

applicability of a specification, or provide additional actions. These changes are generally made to conform with the NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated these proposed Technical Specification changes and determined !

they do not represent a significant hazards consideration. The following is j provided in support of this conclusion. l

1. Does the change involve a significant increase in the probability or consequences of an accident previously evaluated!

The proposed changes provide more stringent requirements than previously existed in the Technical Specifications. These more stringent requirements do not result in operation that will increase the probability of initiating an analyzed event. If anything the new requirements may decrease the probability or consequences of an analyzed event by incorporating the more restrictive changes. The changes do not alter assumptions relative to !

mitigation of an accident or transient event. The more restrictive requirements continue to ensure process variables, structures, systems, and components are maintained consistent with the safety analyses and licensing basis. Therefore, the changes do not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

The proposed changes provide more stringent requirements than previously existed in the Technical Specifications. The changes do not alter the plant l configuration (no new or different type of equipment will be installed) or f

l South Texas Units 1 & 2 Page 4 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION

, SECTION 3.5 - EMERGENCY CORE COOL.ING SYSTEMS make changes in the methods governing normal plant operation. The changes do impose different requirements. However, these changes are consistent with the assumptions in the safety analyses and licensing basis.

Therefore, the changes do not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in margin of safety?

The proposed changes provide more stringent requirements than previously existed in the Technical Specifications. Adding more restrictive requirements either increases or has no impact on the maryn of safety. !

The changes, by definition, provide additional restrictions to enhance plant rafety. The changes maintain requirements within the rafety analyses and licensing basis. As such, no question of safety is involved. Therefore, the changes do not involve a significant reduction in a margin of safety. '

i South Texas Units 1 & 2 Page 5 of 42 Rev. O, 02/05/97

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!_ STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS 1

[

s LESS RESTRICTIVE CHANGE L.1 !

1 South Texas Project Units 1 and 2 are converting to the Improved Technical i

,. Specifications (ITS) as outlin'ed in NUREG-1431, " Standard Technical

)

_ Specifications, Westinghouse Plants." The proposed change involves making the i current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for

. conversion to NUREG-1431.

t The current TS requirement of Surveillance 4.S.1.1.b requires the i verification of the accumulator's boron concentration whenever makeup to the tank exceeds 1% of the tank's volume.. This verification is modified to i be consistent with NUREG-1431 version of ITS SR 3.5.1.4. The proposed i change requires verification of the accumulator's boron concentration after

makeup to the tank exceeds J.$ SS ;;;!! =, from any source other than I

! the Refuelirg Water Storage Tank (RWST). The RWST is a TS surveilled 8 f source of borated water, monitored for OPERABILITY every 7 days for

} boron concentration. Makeup from the RWST is a ful:y acceptable source

['

of water for the accumulators. The RWST is also used for other ECCS functions for the mitigation of DBA. The proposed change is less restrictive

!: in that the accumulators are presently monitored for boron concentration i change for makeups of 1% SS ;;;!! as or more from the RWST. Makeups i from sources other than the RWST will continue to require boron

! concentration verification within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months of exceeding the makeup limit.

. This channe is acceptable because makeuo from the RWST can not reduce j the accumulator boron concentration below the miniraum limit since the i water contained in the RWST is within the accumulator boron 4

concentration reauirements.

.I in accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project !

l has evaluated this proposed Technical Specifications change and determined it J does not represent a significant hazards consideration. The following is provided in support of this conclusion.

3

1. Does the change involve a significant increase in the probability or j consequence of an accident previously evaluatedi t

4 The proposed change permits makeup to the accumulators from the _i

Refueling Water Storage Tank (RWST) for an unlimited volume without the ;

requirement of monitoring boron concentration of the accumulators.

Neither the RWST or the accumulator boron concentration is an assumed

, initiator of an evaluated accident and therefore a makeup from the RWST

to the accumulators cannot affect the probability of an accident. The L

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South Texas Units 1 & 2 Page 6 of 42 Rev. O, 02/05/97 I .. . .

j STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l 4

change is proposed to allow unlimited makeups to the accumulators from

)

the RWST without the requirement to monitor the accumulator's boron I

concentratic . The RWST boron concentration is required to be monitored l every 7 days by TS to be considered OPERABLE. Boron concentration in the RWST is primarily of importance during the unlikely event of a secondary side rupture and potential for a return to criticality during the cooldown. The makeup to the accumulators from any source, other than ,

the RWST, will continue to require the boron concentration verification. l Therefore, the change does not involve a significant increase in the l probability or consequences of an accident previously evaluated. i

, 2. Does the change create the possibility of a new or different kind of l accident from any accident previously evaluated?

The proposed change does not involve the installation or use of any new i or different equipment. Nor does it involve any new or different mode of

. operation of the plant. The proposed change allows makeups to the accumulators from the RWST without sampling for boron concentration. !

The RWST will be sampled for boron concentration on a weekly basis. If :

makeups to the accumulators are made from other sources, samples will I continue to be required to ensure boron concentration remains within ,

specified limits. Based on this, the change does not create the possibility l of a new or different kind of accident from any accident previously

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evaluated.

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3. Does this change involve a significant reduction in a margin of safety?

The allowance to makeup to the accumulatorr. from a monitored boron source, the RWST, will continue to ensure the boron concentration of the !

accumulators will remain within assumptions of the safety analyses. If 1 makeups to the accumulators, exceeding 1% are made from any other sources, the requirements to verify boron concentration of the accumulators, will continue.to be required. Thus, the boron concentration of the accumulators will remain within required limits and will provide the ;

required borated water in the event of a DBA. Therefore, this change does not involve a significant reduction in a margin of safety.

South Texas Units 1 & 2 Page 7 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.2 South Texas Project Units 1 and 2 are converting to the improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

CTS 3.5.2 orovides soecifications for the Emergency Core Cooline System which includes the SI subsystems and a cortion of the RHR components.

CTS 3.5.6 orovides soecifications for the entire RHR trains. These two soecifications have been combined into ITS 3.5.2 to fully address the relationshio between the Si and RHR systems. However. CTS 3.5.2 only directiv orovides for a condition where one Si train is inocerable. even though there are three trains reauired. The CTS reauires LCO 3.0.3 to be entered if two or three Si trains are inocerable. Prooosed ITS 3.5.2 allows 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months for two Si trains to be inooerable or LCO 3.0.3 must be entered and soecifically reauires LCO 3.0.3 be entered if three Si trains are inonerable. The fact that 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months are allowed for two Si trains to be inocerable in the orocosed ITS where LCO 3.0.3 had been reauired in the CTS is considered a less restrictive change. Additionally the allowed outane times for one RHR train inooerable has been increased from 7 davs l to 14 days. ITS Actions A through F G have been proposed for j combinations of one or more RHR or SI subsystem (s) inoperability now '

contained in CTS LCO 3.5.2 and 3.5.6. The proposed Actions are i designed to permit continued operations when possible due to the unique STP ECCS three train design. The Actions also acknowledge the relationship between Si and RHR subsystems and the dependence of the si subsystem on the availability of the RHR subsystem as the primary success path for removal of decay heat for certain design basis accidents. The followine matrix shows any orooosed chance to allowed outane times.

The new Comoletion Times associated with two of three trains inooerable is consistent with the STP design and the aoolication of NUREG-1431 to a three train design as described in STP's letter of February I1.1997 (ST-HL-AE-f 1). The Comp!ction Time: hcve genere!!y been extended for the vericus comb:nctions of incpereb!c equipment.

South Texas Units 1 & 2 Page 8 of 42 Rev. O, 02/05/97

STP ITS CONVERSION l

ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS Current Tech. Proposed Tech.

Spec. Allowed l Spec. Allowed Condition Outage Time Outage Time One SI Subsystem inoperable . 7 days 7 days !

Two SI Subsystems Inoperable None - 3.0.3 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months One RHR Subsystem inoperable 7 days 14 days l Two RHR Subsystems Inoperable 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7 days l l 3 l Three SI Subsystems Inoperable with None - 3.03 None - 3.03 ;

at least one RHR subsytem OPERABLE. i Three RHR Subsystems inoperable immediate Action immediate Action ;

to Restore to Restore !

The proposed changes have been subjected to a risk informed evaluation !

and the results demonstrate that the proposed changes have !!".!c cr no sienificant impact on the overall Core Damage Frequency or Laree Early Release Freauency for the duration of the allowed outane times esk associated with the STP units plaMs.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this proposed Technical Specifications change and determined it i does not represent a significant hazards consideration. The following is provided in support of this conclusion.

I

1. Does the change involve a significent increase in the probability or !

consequence of an accident previously evaluatedt !

The proposed change does not significantly increase the probability or consequences of an accident previously evaluated as demonstrated by the plant specific probabilistic safety evaluation performed to compare the changes with the current TS limits. The South Texas Project (STP) utilizes a unique combination of three independent and redundant ECCS trains with three separate and distinct RHR subsystems, sharing only certain piping, valves and the RHR heat exchangers. The evaluation demonstrates that combinatorial changes and the increased Completion Times for the proposed modifications within the proposed Action table have little or no

effect on the overall predicted Core Damage Frequency (CDF) or Lareg l

South Texas Units 1 & 2 Page 9 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS Early Release Freauqncy for the STP plants. The changes provide I assurance that the interdependence of the ECCS with the availability of the RHR for certain combinations of conditions are adequately addressed, ,

while recognizing that alternative methods of low pressure and temperature heat removal may be utilized in place of the RHR. Based on the plant specific evaluation of the proposed Action table, and the unique STP design, this change does not involve a significant increase in the probability or consequence of an accident previously evaluated.

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

The proposed change does not involve the installation or operation of any new or different kinds of equipment. Nor does it involve a new or different mode of operation. The change provides a table of required actions which must be taken if certain combinations of equipment are unavailable to perform their safety function. The proposed changes do not '

result in systems operating in a manner different from existing procedures i and practices, they merely permit operations with certain combinations of !

f>wer available OPERABLE trains for limited periods of time. Therefore the pioposed change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in a margin of safety!

As described above, an evaluation has been performed which demonstrates that combined changes and the increased Completion Times for the ,

proposed modifications within the proposed Action table have little or no l effect on the predicted overall CDF for the STP plants. Furthermore, the l proposed changes permit continued operations when appropriate, !

minimizing the risk associated with unnecessary plant transients such as l forced shutdowns when adequate safety function capability continues to l exist. In addition, the changes provide assurance that the interdependence of the FCCS with the availability of the RHR for certain combinations of conditions are adequately addressed. Finally, the changes recognize that the functions of the RHR can be performed using alternative plant systems and operations. The effect of the proposed change is therefore to unify the overall assessment and response to unavailability of ECCS systems, while providing appropriate margin for continued operations. Based on this, the change does not involve a significant reduction in a margin of safety. l I

l South Texas Units 1 & 2 Page 10 of 42 Rev. O, 02/05/97

l STP ITS CONVERSION i ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION ;

SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.3 i

South Texas Project Units 1 and 2 are converting to the improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the 1

current Technical Specifications (CTS) less restrictive. Below is the description of '

this less restrictive change and the No Significant Hazards Consideration for I conversion to NUREG-1431. l The CTS requirement of LCO 3.5.2 to perform additional verifications of the OPERABILITY of the ECCS pumps, RHR heat exchangers and flow paths l when a single tram is inoperable, has been deleted. The actions required l by the CTS note were vague and operating experience indicates that the l additional testing does not provide any additional margin of safety.

Existing surveillance tests demonstrate the availability of the required equipment. This is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project ,

has evaluated this proposed Technical Specifications change and determined it !

does not represent a significant hazards consideration. The following is provided in support of this conclusion. '

1. Does the change involve a significant increase in the probability or consequence of an accident previously evaluatedt i

The proposed change removes a footnote which required verification of ;

available systems when inoperabilities occur in one train of ECCS. The l actions required by the footnote are adequately addressed by the normal '

surveillance requirements which assure the availability of the required systems, and by the administrative controls over these systems to assure their continued availability between surveillance tests. Experience has demonstrated that increased surveillance of other trains when an independent train is inoperable does not provide any additional assurance of the availability or reliability of the OPERABLE train (s). The only exception would be for postulated recognized common mode failures, which are adequately addressed by plant administrative controls which would immediately result in the appropriate Actions being taken for all affected systems. Since the proposed change does not affect the way the plant systems are operated, nor does it significantly reduce the assurance of availability of the required systems, the change does not involve a significant increase in the probability or consequence of an accident previously evaluated.

South Texas Units 1 & 2 Page 11 of 42 Rev. O, 02/05/97 I

STP ITS CONVERSION i ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS

2. Does the change create the possibility of a new or different kind of l accident from any accident previously evaluated?

\

The proposed change does not involve the installation or operation of any i new or different kinds of equipment. Nor does it involve any new or '

different mode of operation of the plant. The proposed change merely removes a conditional surveillance requirement which other requirements, administrative controls and experience demonstrates, provides little or no additional assurance of the availability of plant systems. Therefore, the change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in a margin of safety!

The proposed change removes a footnote which required verification of available systems when inoperabilities occur in one train. The actions I required by the existing footnote are addressed by the surveillance requirements, and by other administrative controls to assure their continued availability between required tests. Experience has demonstrated that increasing surveillance testing of redundant trains when an independent train is inoperable provides little additional assurance of availability or reliability. With the exception of a postulated, recognized common mode failure, normal testing would adequately identify the condition. If the condition is recognized, the failure would be addressed by plant I administrative controls that would immediately result in the appropriate )

Actions being taken for all affected systems. Based on the existence of other measures which adequately address the reason for the current i requirement, this change does not involve a significant reduction in a !

margin of safety.

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South Texas Units 1 & 2 Page 12 of 42 Rev. O, 02/05/97 l

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION ,

SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.4 South Texas Project Units 1 and 2 are converting to the improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the current Technical Specifications (CTS) less restrictive. Below is the description of 3 this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

The CTS requirement of 4.S.2.a for a daily verification that power is removed from the Hot Leg recirculation isolation valve operators has been deleted. This change is made consistent with the design of the South Texas Project (STP) ECCS in wiiich each valve can only affect the operation of a single train. The basis for the 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months frequency of the CTS was that in the i more common Westinghouse ECCS design, mis-alignment of a single valve 4

can cause the defeat of multiple trains of equipment. The STP design uses individual train specific Hot Leg recirculation lines without a common header. As such, the mis-positioning of a valve could, at worst, affect a single train. Therefore, this surveillance has been removed and the valves will be treated in a manner similar to others with the same potential for disabling a single train of equipment. This change represents a less restrictive change which recognizes and credits the STP design. -TMs I change is consistent with the ph!!c cphy of NUREC 1131.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this proposed Technical Specifications change and determined it :

does not represent a significant hazards consideration. The following is provided ]

in support of this conclusion. j

1. Does the change involve a significant increase in the probability or consequence of an accident previously evaluated?

This change removes the current requirement to perform a daily verification i that power is removed from the Hot Leg recirculation isolation valve l operators. This change is proposed to make the application of I administrative controls over valve positions consistent with other system valves and their respective functions. In the design of the STP ECCS, mis-positioning of the listed valves can at worst jeopardize the operation of a single train. The basis for the current 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months frequency was that potential mis-alignment of a single valve could cause the defeat of multiple trains of equipment. The STP design uses individual, train specific Hot leg recirculation lines without a common header. B :cd on the STP design, the Hot Leg recircu! tion !!nc i;c!: tion va!vec cre no different from South Texas Units 1 & 2 Page 13 of 42 Rev. O, 02/05/97

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STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION l SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS c rid per:pective San other va!ve: vehich could i;c! ate er divert ;y; tem f!cv. if mi;pcsitioned. Therefore, this surveillance has been removed and the valves will be treated consistent with the administrative controls and l requirements applicable to all ECCS valves. The proposed change does not :

affect any initiating assumptions of the safety analysis and therefore, the change does not involve a significant increase in the probability or consequence of an accident previously evaluated ,

2. Does the change create the possibility of a new or different kind of i accident from any accident previously evaluated? '

The change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of operation of the plant. The proposed change merely removes a surveillance requirement which was inconsistent with the STP design, and which other requirements and administrative controls adequately describe. Therefore, the change does not create the possibility of a new or different kind of i accident from any accident previously evaluated. I

3. Does this change involve a significant reduction in a margin of safety?

As described above, the proposed change makes the surveillances applicable to the affected ECCS Hot Leg injection valves consistent with - !

the STP design and administrative controls applicable to other valves with a similar potential to affect plant operations. Since the change will make the controls over the valve positions consistent with existing controls, the change does not involve a significant reduction in a margin of safety. l 1

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South Texas Units 1 & 2 Page 14 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.5 South Texas Project Units 1 and 2 are converting to the Improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for ;

conversion to NUREG-1431. l The requirement of CTS 4.5.2.c for visual inspection of the containment, to assure that no loose debris is present which could cause restrictions to the l containment sump suction lines, has been deleted. The normal administrative controls for plant cleanliness and control of materials are adequate to provide assurance that no challenge to the ability of the sumps to perform their required functions will occur. Any changes to the administrative controls are subject to the control and reviews required by 10 CFR 50.59 which provides an adequate margin of safety. This change is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Ter Project has evaluated this proposed Technical Specifications change and determined it does not represent a significant hazards consideration. The following is provided in support of this conclusion.

1. Does the change involve a significant increase in the probability or l consequence of an accident previously evaluated? !

The proposed change removes the requirement for a visual inspection of the containment to assure that no loose debris is present. Administrative controls for plant cleanliness and control of materials are adequate to provide assurance that no challenge to the ability of the sumps to perform their required functions will occur. The administrative controls and the retained requirement for a periodic surveillance of the sumps provides appropriate assurance that the systems will function as designed and assumed in the safety analyses. Therefore, the change does not significantly increase the probability or consequence of an accident previously evaluated.

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

The change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of operation of South Texas Units 1 & 2 Page 15 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l the plant. The proposed change merely removes a surveillance requirement that is adequately addressed through retained requirements and normal plant administrative controls. Based on this, the change does not create the possibility of a new or different kind of accident from any accident previously evaluated. ,

3. Does this change involve a significant reduction in a margin of safety?

As described above, the proposed change merely removes the requirement for a visual inspection of the containment to assure that no loose debris is present. Administrative controls for plant cleanliness and control of materials assure that no challenge to the ability of the sumps to perform !

their design functions will occur. The normal administrative controls and '

the retained requirements for periodic surveillance of the sumps provides 4

adequate assurance that the systems will function as designed and assumed in the safety analyses. Since controls are retained which assure the basis for the deleted surveillance is addressed, this change does not involve a significant reduction in a margin of safety, i

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i South Texas Units 1 & 2 Page 16 of 42 Rev. O, 02/05/97

i STP ITS CONVERSION ;

ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION

! SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l

LESS RESTRICTIVE CHANGE L.6 l South Texas Project Units 1 and 2 are converting to the improved Technical l Specifications (ITS) as outlined in NUREG-1431, " Standard Technical l Specifications, Westinghouse Plants." The proposed change involves making the current Technical Specifications (CTS) less restrictive. Below is the description of l this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

CTS 4.5.2.e reauires actuation of automatic valves and safety iniection oumos be oerformed once oer 18 months, durine shutdown. This e i orooosed limitation on performance of automatic actuation testing dunng '

shutdown of CTS 4.5.2.e has been removed in orooosed specifications SR 3.5.2.4 and SR 3.5.2.ji. The u oronosed change is required and appropriate because the specification a) has also been modified by Note which pc=b to allow credit for actual actuations, and b) the proposed ,

allowed outage times provides adequate time to perform testing, or l portions thereof, while operating. This change is acceotable because it i does not imoact the health and safety of the oublic. This change is consitent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project f has evaluated this proposed Technical Specifications change and determined it does not represent a significant hazards consideration. The following is provided in support of this conclusion.

1. Does the change involve a significant increase in the probability or consequence of an accident previously evaluatedi l

The proposed change removes a restriction on when surveillance testing I may be performed. This change does not effect the probability or l consequences of an accident previously evaluated since its application will result from either crediting a surveillance requirement in the event an actual actuation occurs, or testing could be performed during operation, if the appropriate Action requirements were met. If an actuation occurs, administratively permitting surveillance credit to be taken does not affect the probability or consequences of an accident. If testing is performed while in compliance with an Action, the limitations which are defined by the Action control the probability or consequence of an accident previously l evaluated. Therefore, this change does not involve an increase in the probability or consequences of an accident previously evaluated.

l South Texas Units 1 & 2 Page 17 of 42 Rev. O, 02/05/97

STP ITS CONVERSION l ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION l

SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l

, 2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

The proposed change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of operation of the plant. The proposed change simply permits credit to be taken for actuation and for testing within the limitations of the Actions associated with the specification. Based on this, the change does not create the possibility of a new or different kind of accident from any '

acciderat previously evaluated.

3. Does this change involve a significant reduction in a margin of safety?

As described above, the change removes a restriction on when surveillance testing may be performed. The mugins of safety are not affected by the l proposed change since the two conditions which could result in application of the change are addressed by other controls. If an actuation occurs, administratively permitting surveillance credit to be taken does not affect the probability or consequences of an accident. If testing is performed while in compliance with an Action, the Action requirements control the margin of safety provided, as they do for any other condition in which the system may be unavailable (actually or administratively.) i Therefore, this change does not result in a reduction in a margin of safety. ;

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South Texas Units 1 & 2 Page 18 of 42 Rev. O, 02/05/97 1

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.7 South Texas Project Units 1 and 2 are converting to the improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

The requirements of CTS 4.5.2.g for post-modification performance testing of the ECCS subsystems is being removed. These requirements are adequately addressed by plant administrative controls on plant design modifications. Furthermore. ITS suveillances are orovided to ensure the coerability of the systems. This change is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this proposed Technical Specifications change and determined it does not represent a significant hazards consideration. The following is provided in support of this conclusion.

1. Does the change involve a significant increase in the probability or consequence of an accident previously evaluated?

The proposed change removes the surveillance requirement for post-modification testing of the ECCS system. The req'u irement to perform appropriate post-modification testing of systems continues to be applicable to any modification of the facility, and the surveillance is more i appropriately controlled by those procedures. Since no substantive change l in the plant controls applicable to post-modification testing is proposed, the change does not involve a significant increase in the probability or consequences of an accident previously evaluated.

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated! '

The proposed change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of operation of the plant. The proposed change places the administrative ;

control for post-modification testing with the plant controls established for all other post-modification testing. Based on this, the change does not create the possibility of a new or different kind of accident from any accident previously evaluated. ;

South Texas Units 1 & 2 Page 19 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l

)

3. Does this change involve a significant reduction in a margin of safetyt 1

Existing plant administrative controls based on the regulations and applicable standards provide adequate assurance of the maintenance of the appropriate margin of safety as a result of plant modifications. A part of these controls are the application of post-modification testing criteria to assure the OPERABILITY of systems prior to their return to service. Plant systems other than ECCS, with equal importance to overall plant safety are j adequately tested with these other administrative controls. The removal of l the explicit post-modification surveillance requirement and transfer of the I responsibility for this testing to the other plant controls is consistent with the margin of safety provided for changes to those systems. Therefore, this

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

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South Texas Units 1 & 2 Page 20 of 42 Rev. O, 02/05/97

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STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS s

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South Texas Units 1 & 2 Page 21 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOL.ING SYSTEMS q mL.___. - --,!L n,

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d i South Texas Units 1 & 2 Page 22 of 42 Rev. O, 02/05/97

STP ITS CONVERSION !

l ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS 1

l LESS RESTRICTIVE CHANGE L9 l South Texas Project Units 1 and 2 are converting to the Improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the 1 i current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

The rc triction; en Operating seith an abncrmal pump alignrnent fc!!cwing

MODE change into MODE 1 frcm MODE 5, have been modified and the i 4 hcur !!mit ha; been removed. Thi; change CTS 3.5.3.1 LCO Note (*) l restricts only one of the two OPERABLE HHSI oumn to have its breaker racked in for low Temo Overoressure Protection considerations. The CTS l reauires this to be done within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after enterine MODE 4 from MODE l 3 or orior to an RCS cold lee temoerature decreasine below 325 "F. This restriction is also imoosed within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after enterine MODE 4 from l MODE 5 or orior to an RCS cold lee temocrature exceeding 225 F. The i orooosed change in ITS LCO 3.5.3 is to delete the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months reauirement and only allows abnormal alignments based purely on the temperature of the I RCS cold legs. The !!cwance provide; for nc HHS! pump; breaker; tc be racked in from 200 F to 225 F when entering MODE 1 from MODE 5. !

The cronosed chance reouires all but one HHSI numo breaker be racked out durine (1) after enterine MODE 4 from MODE 3 orior to the temoerature of one or more of the RCS cold lens decreasine below 325 F l or (2) after enterine MODE 4 from MODE 5 orior to the temoerature of one l pr more of the RCS cold lees exceeding 225 "F. The proposed ITS LCO still requires 2 OPERABLE HHSI subsystems before entering MODE 4. This change is also reflected in the performance of the conditional surveillance requirements of proposed SR 3.S.3.2. The change is justified since the j temoerature limit assures that the RCS oressure boundarv stress limits will not be exceeded at any oressure uo to the normal oressurizer relief valve setooints. The olant soecific analysis for the oressure and temoerature limits of the RCS indicate sufficient margin is available between the sn_ ecified 325' F limit for ooeration with more than one HHSI oumo breaker racked in, and the limitine temoerature for maximum desien oressure of the vessel. Additional marein is orovided since the limitine location for stress is within the vessel walls. and durine a cooldown from MODE 3 to MODE 4. the vessel wall internal temocrature will exceed the j RCS cold lee temoeratures for all but extremelv slow cooldown rates. The

allowance for moving the olant from MODE 5 to MODE 4 and not reauirine a HHSI oumo's breaker to be racked in still reauires 2 OPERABLE ,

HHSI subsystems. The allowance oermits a rance of temoerature limit of l

l South Texas Units 1 & 2 Page 23 of 42 Rev. O, 02/05/97 )

STP ITS CONVERSION I ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION i SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS 200 F to 225 F to oerform the racking in of one HHSI oumo breaker. The time durine which the additional HHSI oumos will be aligned is further limited by olant concerns with ooeratine for extended oeriods in what is normally a transition MODE. and tvoical coerations will be limited to enough time to alien the reauired systems and oroceed with a cooldown or heatuo. The four hour limit did little to contribute to minimization of risk, rather it imoosed an additional unnecessary restriction on olant ooerators reauirine diversion of their attention from oroceedine with the reauired !

ooerations to track a time limit of little significance. b :cd on the STP p!:nt ;peci'ic Prczure and Tempcmturc !!mit; vehich provide azumnce that ,

tSc p! ant can adequately re; pend to the !!m!Hg DBA: for the';c condition;.

, in accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this proposed Technical Specifications change and determined it

, does not represent a significant hazards consideration. The following is provided i in support of this conclusion.

l l

1. Does the change involve a significant increase in the probability or l consequence of an accident previously evaluated?

4 The proposed change removes the time limit during which more than one HHSI pump breaker may be racked in after entry into MODE 4 from MODE 3. The time limit is removed while the temperature limit is retained since the temperature limit assures that the RCS pressure boundary stress limits will not be exceeded at any pressure up to the normal pressurizer relief valve setpoints. The plant specific analysis for the

pressure and temperature limits of the RCS indicate that approximately 80 F margin is available between the specified 325* F limit for operation )

with more than one HHSI pump breaker racked in, and the limiting '

temperature for maximum design pressure of the vessel. Additional margin ,

is provided since the limiting location for stress is within the vessel walls, '

and during a cooldown from MODE 3 to MODE 4, the vessel wall internal temperature will exceed the RCS cold leg temperatures for all but extremely slow cooldown rates. The allowance for moving the plant from MODE 5 to MODE 4 and not requiring a HHSI pump's breaker to be racked in still requires 2 OPERABLE HHSI subsystems. The allowance permits a mnge of temperture limit of 200 F to 225 F to perform the I i racking in of one HHSI pump breaker. The time during which the additional HHSI pumps will be aligned is further limited by plant concerns with operating for extended periods in what is normally a transition l MODE, and typical operations will be limited to enough time to align the required systems and proceed with a cooldown or heatup. The four hour limit did little to contribute to minimization of risk, rather it imposed an l i

l South Texas Units 1 & 2 Page 24 of 42 Rev. O, 02/05/97 s

l STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION l SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS l l

additional unnecessary restriction on plant operators requiring diversion of i their attention from proceeding with the required operations to track a time l limit of little significance. Based on this, the proposed change does not involve a significant increase in the probability or consequences of an accident previously identified. l

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

The proposed change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of operation of the plant. The proposed change removes an unnecessary restriction on the operators of the plant, while retaining assurance that the underlying analyses and safety limits are maintained. Based on this, the change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in a margin of safety?

As described above, the proposed change merely removes an unneeded restriction on plant operations, while retaining the appropriate control over the alignment of systems which could challenge the RCS pressure boundary analyses design limits. Since the appropriate temperature controls are retained, the 4 hour4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months limit being removed did not provide any additional margin of safety and its removal does not involve a reduction in a margin of safety.

l l

l 4

South Texas Units 1 & 2 Page 25 of 42 Rev. O, 02/05/97

STP ITS CONVERSION l ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION l SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS 1

LESS RESTRICTIVE CHANGE L.10 i South Texas Project Units 1 and 2 are converting to the improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

CTS 3.5.3 Actions a and b for an inoperable required HHSI pump or flow I path and inoperable RHR heat exchanner or LHSI oumo are modified to I

, reflect the STP three train design and the separate RHR subsystem. The proposed ITS Action A.2 will allow continued operation for up to 14 days with one HHSI pump or flowpath inoperable. The proposed specification, ITS Action A.1, requires inat one OPERABLE HHSI pump breaker be verified racked in within 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months , which provides immediate assurance that one train of ECCS is available to function if actuated. In addition, a specification which allows one hour to restore one required ECCS train if l both required trains are inoperable, has been added in ITS Action B. This l

provides opportunity for restoration of the required function if it is j determined that both trains are inoperable. The one hour time is adequate '

to perform immediate actions to restore a train to OPERABLE status, while minimizing the potential for an event which requires the system's availability. If one train cannot be restored, or if one train is inopera' ole for more than 14 days, the specification requires the plant be placed ir, a condition where the specification no longer applies, MODE 5, within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months in ITS Action C. The new ITS Actions are designed to include consideration of the uniaue STP three train desien, independent RHR subsystems which are utilized for normal shutdown cooline in this condition, and LTOP considerations. The Comoletion Time for an 4 inocerable ECCS train is extended to 14 davs for the HHSI numo and system flow oath (and a slieht extension in the time to reach MODE S if the Action is not comolied with) because of the continued availability of a fully caoable indeoendept ECCS train to nerform the reauired safety function, as well as confirmation within one hour of the reauired breaker alienment of an OPERABLE HHSI oumo. In addition, the availability of RHR subsystems to remove heat from the crimarv system in this mode of operation suonorts the extended Comoletion Time. The extremelv low risk l of a limiting desien basis accident in the reduced oressure and temoerature ;

South Texas Units 1 & 2 Page 26 of 42 Rev. O, 02/05/97

m . . _._ . _. _ _ _ . _ _ _ _ _ . ~ . . . , _ _ . _ . . _ _ _ . _ . _ . _

._._y

. . i STP ITS CONVERSION q e ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION = ;

SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS

{

i :

conditions of MODE 4 oermit credit for manual alienment and actuation of 4

ECCS systems during accident conditions. One' train of ECCS and the

{

reguired RCS / RHR looos orovide assurance that the reauired safety l

,F functions can be performed to mitimate the conseouences of any accident

which occurs. -

i in accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project )

~ has evaluated this proposed Technical Specifications change and determined it i

does not represent a significant hazards consideration. The following is provided j s

m support of this conclusion. '!

i l ' 1. Does the change involve a significant increase in the probability or l j consequence of an' accident previously evaluatedt j

! The proposed change replaces the existing CTS Action limits for the !

j. inoperability of the ECCS subsystems when in MODE '4. It does not ;

i introduce any new initiating mechanism or increase the likelihood for )

[ accidents previously evaluated. The new ITS Action table is designed to j

include consideration of the unique STP three train design, independent i RHR subsystems which are utilized for normal shutdown cooling in this !

! condition, and LTOP considerations. The Completion Time for an inoperable ECCS train is extended to 14 days for the HHSI pump and )

system flow path (and a slight extension in the time to reach MODE 5 if i the Action is not complied with) because.of the continued availability of a !

fully capable independent ECCS train to perform the required safety j function, as well as confirmation within'one hour of the required breaker i alignment of an OPERABLE HHSI pump. In addition, the' availability of j RHR subsystems to remove heat from the primary system in this mode of )

operation supports the extended Completion Time. The extremelv I re!:S !y low risk of a limiting design basis accident in the reduced pressure and temperature conditions of MODE 4 permit credit for manual alignment and actuation of ECCS systems during accident conditions. One train of ECCS and the required RCS / RHR loops provide assurance that the required safety functions can be performed to mitigate the consequences of any accident which occurs. Therefore the proposed change does not involve a significant increase in the probability or consequence of an accident previously evaluated.

South Texas Units 1 & 2 Page 27 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluatedi 4

The proposed change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of l

~

operation of the plant. The proposed change only extends the amount of l time during which the plant may be operated with one OPERABLE HHSI s pump and flow path while in MODE 4, and extends slightly the amount of j

, time permitted to reach MODE 5 if the associated Required Action and !

Completion Time are not met. Based on this, the change does not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in a margin of safety?

The proposed change modifies the amount of time a plant may continue to operate while in MODE 4 with one required HHSI pump or ECCS flow path inoperable. The change does not involve a significant reduction in a margin of safety because the specification continues to require at least one !

l independent and redundant train remain OPERABLE. This is adequate because importance of the ECCS is reduced when operating in MODE 4, as evidenced by allowance for manual alignment and actuation in the event i of an accident. Other plant systems such as charging and the RHR may beutilized to perform the functions which would otherwise be required to be performed by the ECCS if operating at full power, pressure, and !

temperature. Because of the continued availability of an independent and redundant train, as well as potential availability of diverse systems to mitigate any event, the extension of time allowed for an inoperable HHSI pump and ECCS flow path does not represent a significant reduction in a margin of safety.

South Texas Units 1 & 2 P:ge 28 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.11 l

l South Texas Project Units 1 and 2 are converting to the Improved Technical Specifications (ITS) as outlined in NUREG-1431, " Standard Technical Specifications, Westinghouse Plants." The proposed change involves making the l current Technical Specifications (CTS) less restrictive. Below is the description of this less restrictive change and the No Significant Hazards Consideration for conversion to NUREG-1431.

CTS 3.5.5 Action allows 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months for the RWST to be restored to OPERABLE due to the boron concentration beine out of limit. ITS LCO 3.5.4, Action A has been proposed which allows up to 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months to restore the RWST to OPERABLE due to the boron concentration not within limits. This Action is added to CTS LCO 3.5.5 and is designed to permit restoration of the RWST without forcing an immediate shutdown, and is consistent with the amount of time which would be required to restore the boron concentration. A forced shutdown would further jeopardize the plant due to the importance of RWST availability, while an eight hour delay to restore the parameter would have little effect on the probability that a DBA could not be properly mitigated. The oronosed change is reasonable considerine th_aj the RWST volume is still intact and is laree enoueh to assure that any channes in boron concentration will be slow and if the limits are exceeded, it will orobably not be by a sienificant amount. The orooosed chance also orovides a more reasonable time in which to restore boron concentration than the orevious time of 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months . This change is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this proposed Technical Specifications change and determined it does not represent a significant hazards consideration. The following is provided in support of this conclusion.

1. Does the change involve a significant increase in the probability or consequence of an accident previously evaluated?

The proposed change permits up to eight hours to restore the boron concentration of the RWST if it is determined below the specified limit.

The parameter is an assumed initiator of an evaluated accident and therefore a change in the associated Completion Time for restoration l cannot affect the probability of an accident. The change is proposed to l allow action to restore the tank to OPERABLE status without forcing a plant l shutdown. Boron concentration in the RWST is primarily of importance during the unlikely event of a secondary side rupture and potential for a South Texas Units 1 & 2 Page 29 of 42 Rev. O, 02/05/97

l STP ITS CONVERSION l ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS i

return to criticality during the cooldown. The time is short enough to l minimize the risk of an event occurring during the period, while providing '

, enough time to restore the variable using normal plant systems and procedures, minimizing challenges to plant safety systems due to a

. shutdown and minimizing the probability of an impact on the consequences of an accident. Therefore the change does not involve a j significant increase in the probability or consequences of an accident I previously evaluated.

2. Does the change create the possibility of a new or different kind of ,

accident from any accident previously evaluated?

The propcsed change does not involve the installation or use of any new or different equipment. Nor does it involve any new or different mode of operation of the plant. The proposed change only extends the amount of time during which the plant may be operated with the RWST boron outside its specified limit. Based on this, the change does not create the possibility j of a new or different kind of accident from any accident previously

~

evaluated.

3. Does this change involve a significant reduction in a margin of safetyi i

The allowance of up to eight hours to restore the boron concentration I within the RWST only slightly reduces the margin of safety since the ;

likelihood of a design basis event occurring which requires the availability l of the limiting boron concentration of the RWST is low during this short time. Therefore this change does not involve a significant reduction in a margin of safety.

South Texas Units 1 & 2 Page 30 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION l SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.12 South Texas Project Units 1 and 2 are convertine to the Imoroved Technical Soecifications (ITS) as outlined in NUREG-1431. " Standard Technical Specifications. Westinehouse Plants." The orooosed change involves making the current Technical Soecifications (CTS) less restrictive. Below is the descriotion of this less restrictive chance and the No Sienificant Hazards Consideration for conversion to NUREG-1431.

CTS SR 4.5.1.1.d. which reauires an 18 month test to verify that the >

accumulator isolation valves automatically coen when a simulated or actual P-11 interlock setooint is exceeded. or when an SI signal is received, is beine deleted. The CTS alreadv reauires the valves to be verified ooen everv 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and the valve's electrical oower be verified removed once oer 31 days. These reauirements ensure the accumulator isolation valves do not orevent the accumulators from oerformine their safety function. The safety analysis does not reauire the valves to move durine oower operation or in a cost accident situation. Since no automatic action is reauired for the safety function, oerformine this test is unnecessarv and can be deleted.

This less restrictive change is acceotable because it does not imoact the oublic health and safety. This change is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92 the South Texas Project has evaluated this oronosed Technical Soecifications chance and determined it does not reoresent a sienificant hazards consideration. The followine is orovided in sunoort of this conclusion. !

L Does the channe involve a significant increase in the probability or conseauence of an accident previousiv evaluated?

The oronosed channe removes the 18 month test to verify that the accumulator isolation valves automatically ooen when a simulated or actual P-11 interlock setoolnt is exceeded, or when an SI signal is received. The interlock associated with these valves is not assumed to be the initiator of any analyzed event. The valves are verified open everv 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and the oower is verified removed every 31 davs in accordance with the TS. Since the oronosed chance does not affect the way the olant systems are operated, nor does it sienificantiv reduce the assurance of availability of the reauired systems the chance does not involve a significant increase in the orobability or conseauence of an accident oreviousiv evaluated.

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South Texas Units 1 & 2 Page 31 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION i SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS L Does the change create the possibility of a new or different kind of ,

accident from any accident previousiv evaluated? !

The orooosed channe does not involve the installation or operation of any }

new or different kinds of eauioment. Nor does it involve any new or i different mode of operation of the olant. The orooosed chance merelv removes a surveillance reauirement which other reauirements, administrative controls and exoerience demonstrates, orovides little or no additional assurance of the availability of olant systems. Therefore, the l channe does not create the oossibility of a new or different kind of '

accident from any accident oreviousiv evaluated.

L Does this change involve a significant reduction in a margin of safety?

The orooosed chance removes the 18 month test to verify that the ;

ac. cumulator isolation valves automatically ooen when a simulated or actual P-11 interlock setooint is exceeded, or when an 51 sienal is received. The valves are verified ooen everv 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months and the oower is verified removed I every 31 days in accordance with the TS. Should the valves be inadvertently closed, the normal testing would adeauately identify the !

condition. If the condition is recoenized the failure would be addressed bv olant administrative controls that would immediatelv result in the i aoorooriate Actions being taken for all affected systems. Based on the existence of other measures which adeauately address the reason for the current reauirement, this chance does not involve a sienificant reduction in '

a marein of safety.

South Texas Units 1 & 2 Page 32 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION :

SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.13 South Texas Project Units 1 and 2 are converting to the Imoroved Technical ;

Soecifications (ITS) as outlined in NUREG-1431. " Standard Technical l Soecifications. Westinehouse Plants." The oronosed chance involves making the current Technical Soecifications (CTS) less restrictive. Below is the descriotion of l this less restrictive chance and the No Sienificant Hazards Consideration for i conversion to NUREG-1431. 1 l

CTS SR 4.5.1.2 specifies reauirements for testinc the accumulator cressure l

, and level instruments. These reauirements are deleted since they are not necessary to meet the reauirements of operability for the accumulators. !

Ooerability of the accumulators is deoendent on the auantity and concentration of borated water and the oressure of the cover eas. The method of determinine the volume of the borated water and the oressure of the cover eas is not an assumotion or initial condition for any safety analysis. This channe is considered less restrictive because it deletes a test oreviousiv reauired in the CTS and is acceptable because its removal does not alter the safety analysis. This change is consistent with NUREG-1431 and is similar to the CTS for the RWST where the temoerature and level '

limits, not the instrumentation are specified.

in accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this orooosed Technical Soecifications chance and determined it does not reoresent a sienificant hazards consideration. The followine is orovided in suDDort of this conclusion.

.L Does the change involve a sinnificant increase in the probability or

+

conseauence of an accident previously evaluated?

, The oronosed channe removes the reauirement from the Technical Soecifications to oerform surveillances on the accumulator instrumentation.

The verification of accumulator level and oressure may be determined by either installed instrumentation or temoorary test eauioment. The instrumentation used to determine level and oressure in the accumulators is not assumed to be the initiator of any analyzed event, therefore, the chance does not affect the orobability of an event occurrine. The oronosed channe does not affect the contents of the accumulator nor the ability to deliver the contents durine an analyzed event. Therefore, the orooosed chance does not affect the conseauences of a oreviousIv analyzed event.

South Texas Units 1 & 2 Page 33 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS L Does the channe create the possibility of a new or different kind of accident from any accident previousiv evaluated?

The orooosed change does not involve the installation or operation of any D.ew or different kinds of eauioment. Nor does it involve a new or different mode of ooeration. The orooosed changes do not result in systems operatine in a manner different from existing orocedures and oractices.

Therefore, the orooosed change does not create the oossibility of a new or different kind of accident from any accident oreviousiv evaluated.

3 Does this change involve a sienificant reduction in a marrin of safetvf The oronosed change removes the reauirement from the Technical Snecifications to oerform surveillances on the accumulator instrumentation.

The TS does not soecifically reauire this instrumentation to be used to meet the reauired oressure and level verification surveillances. The verification of accumulator level and oressure may be determined by either instal _ led instrumentation or temporary test eauioment. Therefore, the chance does not involve a significant reduction in a margin of safety.

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South Texas Units 1 & 2 Page 34 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION t

SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.14 South Texas Project Units 1 and 2 are convertine to the Imoroved Technical Soecifications (ITS) as outlined in NUREG-1431. " Standard Technical Specifications. Westinghouse Plants." The oronosed change involves making the current Technical Soecifications (CTS) less restrictive. Below is the descriotion of this less restrictive change and the No Sienificant Hazards Consideration for conversion to NUREG-1431.

CTS 4.5.1.1.c reauires verifvine everv 31 davs that the oower to the accumulator isolation valves is removed when the oressurizer oressure is above 1000 osie. The orooosed change in SR 3.5.1.5 is to oerform the same surveillance at the same freauencv but only when the oressurizer oressure is creater than or eaual to 2000 osie. This change allows ooerational flexibility by avoidine unnecessary delavs to manioulate the breakers during olant startuos or shutdowns. This channe is accentable because alternate orotection is orovided durine the oeriod of time the pressurizer oressure is > 1000 osie and < 2000 osie. Alternate orotection is orovider' bv verification that the valves are ooen every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months (S.Ra 3.5.1.1), the oressurizer oressure interlock associated with the valves to orevent their closure above 1000 osie in the cressurizer, and an Si signal orovided to the valves would open a closed valve in the event of a LOCA.

This change is considered less restrictive because ooerators have more time to initially remove oower from accumulator isolation valves durine olant startuos and shutdowns. This channe is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this proposed Technical Specifications change and determined it does not represent a significant hazards consideration. The following is provided in support of this conclusion.

L Does the change involve a significant increase in the probability or conseauence of an accident previousiv evaluated?

The oronosed chance orovides ooerational flexibility by avoidine unnecessary delavs to manioulate the breakers durine olant startuos or shutdowns by oniv reauirine verification that oower has been removed from the accumulator isolation valves after the oressurizer has reached 2000 osie instead of 1000 osie as oreviousiv reauired. Alternate orotection is orovided durine this time by verification that the valves are onen every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months (SR 3.5.1.1) the oressurizer oressure interlock associated with the valves to orevent their closure above 1000 osie in the RCS, and an 51 signal orovided to the valves would onen a closed valve in the event of a South Texas Units 1 & 2 Page 35 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LOCA. Since no assumed initiators of any analyzed event are changed and udeauate orotection is orovided the chance does not affect the orobability ;

of an event occurring. The oronosed change does not affect the contents of the accumulator nor the ability to deliver the contents during an analyzed event. Therefore, the orooosed chance does not affect the J

J conseauences of a oreviousiv analyzed event. i L Does the channe create the possibility of a new or different kind of l accident from any accident oreviousiv evaluated?

The orooosed chance does not involve the installation or operation of any l new or different kinds of eauioment. Nor does it involve a new or different mode of ooeration. The oronosed channes do ne'. result in systems oneratine in a manner different from existine orocedures and oractices.

Therefore. the orongsed chance does not create the oossibility of a new or different kind of accident from any accident oreviousiv evaluated.

L Does this channe involve a sienificant reduction in a marein of safetvf The orooosed change orovides ooerational flexibility by avoiding ,

unnecessary delavs to manioulate the breakers durine olant startuos or !

shutdowns by only reauirine verification that oower has been removed l from the accumulator isolation valves after the oressurizer has reached i 2000 osie instead of 1000 osin as oreviously reauired. Since alternate methods of orotection are orovided durine this oeriod of time the change I does not involve a significant reduction in a margin of safety.

I South Texas Units 1 & 2 Page 36 of 42 Rev. O, 02/05/97

, STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS LESS RESTRICTIVE CHANGE L.15 South Texas Project Units 1 and 2 are convertine to the Imoroved Technical Snecifications 'ITS) as outlined in NUREG-1431. " Standard Technical !

Specifications. Westinehouse Plants." The orooosed change involves makine the '

current Technical Soecifications (CTS) less restrictive. Below is the descriotion of ,

this less restrictive change and the No Sienificant Hazards Consideration for conversion to NUREG-1431.

CTS Action a includes, in part, to reduce pressurizer oressure to less than 1000 osie within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months of reachine HOT STANDBY once an accumulator i cannot be restored to operable status. ITS 3.5.1 Reauired Action C.2 reauires the cressurizer oressure to be reduced to less than or eaual to 1000 osin under the same conditions and time constraints. This change is considered less restrictive because operators have the additional flexibility of reducine oressurizer oressure to 1000 osie and below where oreviousiv thev had to droo the oressure below 1000 osie. Placine the olant in MODE 3 (HOT STANDBY) with the pressurizer oressure at 1000 osin olaces the olant in a mode below the mode of aoolicability. The change is acceotable because this ensures the olant is in a safe condition. This

change is consistent with NUREG-1431.

In accordance with the criteria set forth in 10 CFR 50.92 the South Texas Project has evaluated this oronosed Technical Soecifications change and determined it does not reoresent a significant hazards consideration. The followine is orovided in suooort of this conclusion.

-1 Does the change involve a siaWficant increase in the probability or conseauence of an accident previousiv evaluated?

The orooosed change orovides operational flexibility by allowine operators to olace the olant in MODE 3 with the oressurizer oressure less than or ggual to 1000 osie vice MODE 3 with oressurizer oressure less than 1000

osie. This flexibility still olaces the olant in a MODE below the mode of !

aoolicability. Since no assumed initiators of any analyzed event are changed and adeauate orotection is orovided the change does not affect the orobability of an event occurrine. The orooosed change does not affest the contents of the accumulator nor the ability to deliver the contents

~

durine an analyzed event. Therefore the orooosed change does not affect !

the conseauences of a oreviously analyzed event.

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South Texas Units 1 & 2 Page 37 of 42 Rev. O, 02/05/97 l 4

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOL.ING SYSTEMS L Does the channe create the possibility of a new or different kind of accident from any accident oreviousiv evaluated?

The orooosed change does not involve the installation or coeration of any new or different kinds of eauioment. Nor does it involve a new or different mode of ooeration. The orooosed channes do not result in systems operatine in a manner different from existine orocedures and oractices.

Therefore. the orooosed change does not create the oossibility of a new or different kind of accident from any accident oreviously evaluated.

L Does this channe involve a sienificant reduction in a margin of safetvf The orooosed change orovides operational flexibility by allowine ooerators to olace the olant in MODE 3 with the oressurizer oressure less than or eaual to 1000 osie vice MODE 3 with oressurizer oressure less than 1000 osie. Since this continues to olace the olant in a MODE below the mode of aoolicability the chance does not involve a sienificant reduction in a margin of safety.

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l South Texas Units 1 & 2 Page 38 of,42 Rev. O, 02/05/97

1 STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS I.ESS RESTRICTIVE CHANGE L.16 South Texas Project Units 1 and 2 are convertine to the Imoroved Technical Specifications (ITS) as outlined in NUREG-1431. " Standard Technical Soecifications. Westinehouse Plants." The oronosed chance involves makine the current Technical Specifications (CTS) less restrictive. Below is the descriotion of this less restrictive chance and the No Sienificant Hazards Consideration for conversion to NUREG-1431.

CTS 3.5.2 Action Note (*) orovides for the orovisions for excluding Soecifications 3.0.4 (Prohibits entry into a MODE when the LCO for that MODE can not be met) and 4.0.4 (Prohibits entry into a MODE when the

, SR for that MODE has not been oerformed) for entry into MODE 3 for the Si oumos declared inoperable. The inocerability in this case is due to the motor circuit breakers ;ecured in the open oosition and the Note only anolies if the 51 oumrs are restored within 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or orior to the temoerature of one or more of the RCS cold lees exceeding 37.5 F. This information is caotured in an Anoticability Note in ITS 3.5.2 that states that entry into, and operation in MODE 3 with ECCS numos declared inonerable oursuant to LCO 3.4.12 is allowed for un to 4 hou,rs or until the temoerature of one or more RCS cold lees exceeds 375 F. LCO 3.4.12 renders the HHSI oumos inocerable by removing the power from the numos by rackine the breakers out under administrative controls. It also allows (within the Bases) an alternate method of rendering the HHSI numos inoDerable by usinE two indeDendent means to orevent a oumo start such that a single failure or sincie action will not result in an iniection into the RCS (e.e.. oumo control switch beina olaced in pull to lock and at least one valve in the discharce closed). This chance is considered less restrictive because the alternate method of rendering the HHSI oumo is not available in the CTS. The alternate means of renderine the HHSI oumo inonerable considers sinale failure or sincie action cases and is a oroven method of oreventina Si flow to the RCS. The chance is accentable because allowine a satisfactory alternate method of oreventinn Si flow to the RCS does not imoact oublic health and safety.

In accordance with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated this orooosed Technical Soecifications channe and determined it does not reoresent a sienificant hazards consideration. The followinn is orovided in sunoort of this conclusion.

South Texas Units 1 & 2 Page 39 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS f 1 Does the channe involve a significant incra=== in the orahability or

! conseauence of an accident oreviousiv eva!eatedi The orooosed channe orovides an alternate method of renderine the' HHSI Dumo inoperable to ensure orotection meninst low Temoerature

$ ~ Overoressure Protection (LTOP). - The alternate means of rendering the

[ HHSI oumo inoperable considers single failure or single action cases and is

j. a oroven method of oreventine 51 flow to the RCS. The method of ?

renderine the HHSI oumo inoperable for LTOP ourooses is not an assumed initiator of an evaluated accident and therefore cannot affect the orobability l of an accident. The channe is orooosed to allow two indeoendent means to Drevent a oumD Start such that a single failure or sinele action will not result in an iniection into the RCS. This is an alternate method to rackine j the oumo breakers out under administrative control. Providine an j acceptable alternate method of rendering the HHSI oumos inonerable does not involve a sienificant increase in the orobability or conseauences of an

accident oreviousiv evaluated.

i

1 Does the channe create the nossibility of a new or different kind of

, accident from any accident previousiv evaluatedt i

! The orooosed channe does not involve the installation or use of any new j or different eauioment. Nor does it involve any new or different mode of operation of the olant. The orooosed channe orovides an alternate method of rendering the HHSI oumo inooerable to ensure orotection against low Temoerature Overoressure Protection (LTOP). The alternate means of I. renderine the HHSI oumo inoperable considers single failure or single I l action cases and is a oroven method of oreventine Si flow to the RCS. '

! Based on this, the channe does not create the oossibility of a new or I different kind of accident from any accident oreviousiv evaluated.

i L Does this channe involve a significant reduction in a margin of safetvf

The allowance to orovide an acceptable al' ternate method of renderine the

]

'3 HHSI oumo inonerable to ensure orotection maainst low Temoerature !

Overoressure Protection (LTOP) does not channe the assumotions of the

safety analyses. The alternate means of rendering the HHSI oumo L inooerable considers single failure or single action cases and is a oroven i i method of oreventine 51 flow to the RCS. Therefore, this channe does not l

involve a sienificant reduction in a marein of safety. j t

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I South Texas Units 1 & 2 Page 40 of 42 Rev. O, 02/05/97 3.

1

STP ITS CONVERSION ,

ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS 7 LESS RESTRICTIVE CHANGES - MOVING DETAILS TO LICENSEE CONTROLLED DOCUMENTS South Texas Project Units 1 and 2 are converting to the improved Technical l Specifications (ITS) as outlined in NUREG-1431, " Standard Technical t Specifications, Westinghouse Plants." Some of the proposed changes involve moving details (engineering, procedural, etc.) out of the Technical Specifications and into a licensee controlled document. This information may be moved to the ITS Bases, UFSAR, plant procedures or other programs controlled by the licensee. f The removal of this information is considered to be less restrictive because it is no longer controlled by the Technical Specification change process. Typically, the ;

information moved is descriptive in nature and its removal conforms with NUREG-1431 for format and content.

t in accoidace with the criteria set forth in 10 CFR 50.92, the South Texas Project has evaluated these proposed Technical Specification changes and determined they do not represent a significant hazards consideration. The following is j provided in support of this conclusion.

1. Does the change involve a significant increase in the probability or ,

consequences of an accident previously evaluatedt {

l The proposed changes move details from the Technical Specifications to a l licensee controlled document. The changes do not result in any hardware or operating procedure changes. The details being removed from the Technical Specifications are not assumed to be an initiator of any analyzed event. The licensee controlled document containing the removed Technical Specification details will be maintained using the provisions of 10 CFR 50.59 and is subject to the change control process in the Administrative Controls Section of the Technical Specifications. Since any changes to a licensee controlled document will be evaluated per 10 CFR 50.59, no increase (significant or insignificant) in the probability or consequences of an accident previously evaluated will be allowed without prior NRC approval. Therefore, the changes do not involve a significant increase in the probability or consequences of an accident previously 3 evaluated. 1

2. Does the change create the possibility of a new or different kind of accident from any accident previously evaluated?

The proposed changes move detail from the Technical Specifications to a l licensee controlled document. The changes will not alter the plant l configuration (no new or different type of equipment will be installed) or South Texas Units 1 & 2 Page 41 of 42 Rev. O, 02/05/97

STP ITS CONVERSION ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS make changes in methods governing normal plant operation. The changes will not impose different requirements, and adequate control of information will be maintained. The changes will not alter assumptions made in the safety analysis and licensing basis. Therefore, the changes will not create the possibility of a new or different kind of accident from any accident previously evaluated.

3. Does this change involve a significant reduction in a margin of safety?

The proposed changes move detail from Technical Specifications to a licensee controlled document. The changes do not reduce the margin of safety since the location of details has no impact on any safety analysis assumptions. In addition, the detail to be transposed from the Technical Specification to a licensee controlled document are the same as the existing Technical Specification. Since any future changes to this licensee controlled document will be evaluated per the requirements of 10 CFR 50.59, no reduction (significant or insignificant) in a margin of safety will be allowed without prior NRC approval.

The existing requirement for NRC review and approval of revisions, in accordance with 10 CFR 50.92, to these requirements proposed for movement, does not have a specific margin of safety upon which to evaluate. However, since the proposed change is consistent with the ,

Westinghouse Plants Standard Technical Specification, NUREG-1431 approved by the NRC Staff, revising the Technical Specifications to reflect i the approved level of detail ensures no significant reduction in the margin !

of safety. Therefore, this change does not involve a significant reduction in ;

the margin of safety. '

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South Texas Units 1 & 2 Page 42 of 42 Rev. O, 02/05/97

STP ITS CONVERSION !

ATTACHMENT 4 - NO SIGNIFICANT HAZARDS CONSIDERATION SECTION 3.5 - EMERGENCY CORE COOLING SYSTEMS b./lRONMENTAL ASSESSMENT This proposed Technical Specification Change has been evaluated against the criteria for and identification of licensing and regulatory actions requiring environmental assessment in accordance with 10 CFR 51.21. It has been determined that the proposed changes meet the criteria for categorical exclusion as provided for under 10 CFR 51.22 (c) (9). The following is a discussion of how the proposed Technical Specification Change meets the criteria for categorical exclusion.

1 10 CFR 51.22 (c) (9): Although the proposed change involves changes to {

requirements with respect to inspection or surveillance recjirements; j (i) the proposed change involves no Significant Hazards Consideration (refer to the No Significant Hazards Consideration section of this Technical i Specification Change Request), '

(ii) there is no significant change in the types or significant increase in the amounts of any effluents that may be released offsite since the proposed :

changes do not affect the generation of any radioactive effluents nor do l

they affect any of the permitted release paths, and i

i (iii) there is no significant increase in individual or cumulative occupational l radiation exposure.

Accordingly, the proposed change meets the eligibility criteria for categorical exclusion set forth in 10 CFR 51.22 (c)(9). Based on the aforementioned and pursuant to 10 CFR 51.22 (b), no environmental assessment or environmental impact statement need be prepared in connectbn with issuance of an amendment to the Technical Specifications incorporating the proposed changes of this request.

l l

l 1

1 South Texas Units 1 & 2 Pg 1 of 1 Rev. O, 02/5/97

1 Accumulatcrs 3.5.1 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.1 Accumulators j v LCO 3.5.1 ECCS accumulators shall be OPERABLE.

/,PPLICABILITY: MODES 1 and 2, MODE 3 with pressurizer pressure >f1000 sig.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME A. One accumulator A.1 Restore baron 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months inoperable due to concentration to baron concentration within limits.

not within limits.

B. One accumulator inoperable for reasons B.1 Restore accumulator to OPERABLE status.

@n. Med other than Condition A.

i

/ C. Required Action and C.1 Be in MODE 3.

(w ,, associated Completion 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months l

Time of Condition A AdQ ,

or B not met. !

C.2 Reduce pressurizer 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months i pressure to '

sjl000}'psig.

O D. Two or more D.1 Enter LCO 3.0.3. Immediately accumulators inoperable. s WOG STS 3.5-1 Rev 1, 04/07/95

Accumulators 3.5.1 SURVEILLANCE REQUIREMENTS SURVEILLANCE FREQUENCY SR 3.5.1.1 Verify each accumulator isolation valve is hours fully open. j I

1 SR 3.5.1.2 volume in each rs Verify are mulate!,vcated is >C wa'hh23 gallons Q and SR 3.5.1.3 Verify nitrogen c ver 2ressure in each rs accumulator is 2 ( ipsig and -

s psig. se

(.,70 l SR 3.5.1.4 Verify boron concen ration in each 31 days ac u tor is 2 ppe and i p $ 2 ppm.

blQ l m I 3*oo l -----NOTE------ l only required to be performed for affected accumulators Once within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months after-each solution volume increase of , gg gA of I nn cated levelfthatis not the result of addition om the fuelinglater oragefhnk

,c (continued)

WOG STS 3.5-2 Rev 1, 04/07/95 N

.=. .- - .- - - .

I Accumulators 3.5.1 I

' SURVEILLANCE REOUIREMENTS (enntinued)

SURVEILLANCE $7gf FREQUENCY SR 3.5.1.5 Verify power is removed from . 31 days accumulator isolation vaM1 or when pressurizer pressure is@(YD psig.

(SW Uco91s > t ]

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o l

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.e e, <

WOG STS 3.5-3 Rev1,04/07/95

ECCS-Operating 3.5.2 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) 3.5.2 ECCS-Operating LCO 3.5.2 @A m

ECCS trains shall be OPERABLE.

APPLICABILITY: MODES 1, 2, and 3.

y ---- -

-NOTES-- -------

In MODE 3, b safety injectic SI) pump flow

[pathsmay isolated by clo g the isolation 5 valves r up to 2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months t erform pressure 3 y is ton valve testing

( r SR 3.4.14.l. _

h hhperation in MODE 3 with ECCS pumps declaredg ' ~NDE N t

inoperable pursuant to LCO 3.4.12. "Lopwperature Overpressure Protection (LTOP) System 7' is allowed for up to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months or until the temperature of RCS cold legs exceeds J375]'F, whichever comes cats first. / T. L N

=== ,__..______ ...._____.._. ..

ACTIONS # f ls CONDITION REQUIRED ACTION COMPLETION TIME (A. One or more inoperable ins A.1 Restore train (s) o OPERABLE stat .

72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months \

E east 100% of the Iww.h h CCS flow equivalent ArT ious /

to a single OPERABLE ECCS train available.

/

B. Required Action and B.1 Be in MODE 3. ours associated Complet n

, Time not met. M

( B.2 Be in MODE 4.

12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months j

~

!r ,

i il0G STS 3.5-4 Rev 1, 04/07/95 i

W

_ . - _ .._ -_.. . . . . _ . _ . _ = _ . _ . - _ . _ . _ _ . _ . . . _ _ . _ _ . _ _ _ . . . . _ . - . _ _ .

L l

I Insert ACTIONS l

CONDITION REQUIRED ACTION- COMPLETION TIME-A. One RHR subsystem A.1 Restore RHR subsystem 14 days !

inoperable. to OPERABLE status i 21 days from ,

discovery of

failure to meet *

l. the LCO -

B. One SI subsystem B.1 Restore SI subsystem to 7 days inoperable. OPERABLE status.

AND P i

21 days from !

discovery of failure to meet the LCO C. Two RHR subsystems C.1 Restore one RHR 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7 dy inoperable. subsystem to OPERABLE l status.

l D. Two SI subsystems D.1 Restore one SI 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months g#

, inoperable. subsystem to OPERABLE 1 status. i l

i I

l i

I l Insert Page 3.5-4a l

Insert ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME E. Required Action and E.1 Be in MODE 3. E-ntep 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion LCO 3.0.3. I=cdiately 3 Times for Conditions A. B. pt C, 0, er E AND not met.

L2 Be in MODE 4. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months 9B NOTE cmmm um mm+ ,

5$5i5550Menthree o

R subs" stem: cre incperabic.

Three SI subsystem: Y inoperable.

L Reauired Action and F.1 Enter LC0 3.0.3. Immediate1v L'6D associated Comoletion ' -

Time for Condition D not met.

k m

NOTE----------

Condition not aoolicable when three RHR sut' systems are inocerable.

Three SI subsystems inocerable. Y

' ()

l L Three RHR subsystems L1 Initiate action to Immediately F-- inoperable. F:4 restore RHR subsystem (s) to OPERABLE status.

v Insert Page 3.5-4b

l ECCS-Operating 3.5.2

_ SURVEILLANCE RE0VIREMENTS SURVEILLANCE FREQUENCY l SR 3.5.2. Verify the follo g valves are in the hours j listed positio ith power to the valve operat removed.

Number Position Functio i

^ /

I

, 1

/

i h

[ ] [ ] I ]

i SR 3.5.2 Verify each ECCS manual, power operated, 31 days

, and automatic valve in the fl.ow path, that {

i 3 is not locked, sealed, or otherwise secured in pos tion, is in the correct position.

_ 4%, mas _

Verify ECCS piping is full of water.

[SR 3.5.2 gays' c., t 3

Q El,LH5t g 8 A M gyg SR 3.5.2 Verify each Effd) pump's developed head at In accordance the test flow point is greater than or with the i equal to the required developed head. Inservice Testing Program 3 SR .5.2 Verify each ECCS automatic valve in the nths '

flow path that is not locked, sealed, or i otherwise secured in position, actuates to i the correct position on an actual or simulated actuation signal.

(continued) 4 or nl0G STS 3.5-5 Rev1,04/07/95 l

.____._.__.._.,_..__.-.._._._____.__._.____..._.__..__...__m._ ._. _ _._.

ECCS-Opzrating 3.5.2 SURVEILLANCE REQUIREMENTS (continued)

SURVEILLANCE FREQUENCY

@ gg [ H elsi e-J LMi SR 3.5.2187 Verify each Spump s@ tarts automatically 4 nths on an actual or simulated actuation signal.

SR 3.5.2.7 ify, for each ECCS thrott valve (18] mo s isted below, each positi stop is in the correct position Valve Number

/

(_ t

)

@~

SR 3.5.2 Verify, by visual inspection, each ECCS train containment sump suction inlet is not f18 months restricted by debris and the suction inlet i trash racks and screens show no evidence of structural distress or abnormal corrosion.

w I

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WOG STS 3.5-6 Rev 1, C4/07/95 i

I O

ECCS-Shutdown 3.5.3

~

3.5 EMERGENCYCORECOOLINGSYSTEMS(ECCS) 3.5.3 ECCS-Shutdown LCO 3.5.3 OneECCS,,$rtTiishallbeOPERABCf. g,y ). Lc,o )

APPLICABILITY: MODE 4.

ACTIONS CONDITION REQUIRED ACTION COMPLETION TIME r ^.

A. Require CS residual A.1 nitiate action to fImmediately '

heat moval (RHR) restore required EC l/ i s ystem inoperable. RHR subsystem to # /m*f i dedkw A .

OPERABLE statu !

v / -__;

0 4 Ibl B. equired ECCS B.1 IAI RestorelrequiredECCS I hour a (legVsubgite _hirdrTead suoM stemU ;

i ino itrabl to OPERABLE status, rams C. Required Action and C.1 Be in MODE 5. 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months associated Completion Time ((of CW))

not mer..

h 4

WOG STS 3.5-7 Rev 1, 04/07/95

Insert LC0 Two ECCS Trains shall be OPERABLE with one OPERABLE High Head Safety _

Injection (HHSI) pump breaker racked in.

............................N0TES--------------------------- /

1. After entering MODE 4 from MODE 3. more than one HHSI pump breaker may /

be racked in until one or more RCS cold leg temperature s 5 325 F. -

I r

2. More than one HHSI pump breaker may be energized for testing or .

\

filling accumulators provided the discharge of the pump is isolated from the RCS.

3. After entering MORE 4 from MODE 5. all HHSI pump breakers may be ibi' racked out until one or more RCS cold leg temperature > 225 F. v

4. RHRsubsystemOPERABILITYinMODE4shallbeinaccordancewithLC0@

3.4.6. "RCS Loops - MODE 4."

Insert Condition A A. One required ECCS A.1 Verify one OPERABLE 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months train inoperable HHSI pump breaker is racked in.

lh AND A.2 Restore required ECCS 14 days train to OPERABLE status.

Insert Page 3.5-7 l

l ECCS-Shutdown 3.5.3 '

I SURVEILLANCE REOUIREMENTS SURVEILLANCE FREQUENCY l SR 3.5.3.1 -------NOTE-- --------------A kAn[-

RIF cur ,

--in tra may be congr [dered OPERABLEf. 1 i

ignment and e tion for aere removal fif ca e of being 11y ifalignedtotheE mode of oper on. .

The following SRs are applicable for all In accordance equipment required to be OPERABLE: with applicable

+ fi') SRs

/:SR3.5.2.CT'

!SR3.5.2.3{ f(SR 3R M.53.5.2.

)

f'6T"EEF"4 r 4 N iw m 4- 6 R. 35. 3. t 4

, I i

l l

WOG STS 3.5-8 Rev 1, 04/07/95

. . - . - - ... - . . . - . ~ - - . . . . . . . . - . . . . _ . . _ - . . - . - ~ . - . . - . . . . - .

P I

Insert SR 3.5.3.2 !

SR 3.5.3.2 .

NOTES---------------- .-

,n ;

bg >

1. Not MODE required 4 from MODE to be met whenRCS 3 until-any enterin$d co leg temperature = 5 325'F. I i

2. Not required to be met when enterin %" ' '

MODE 4 from MODE 5 until any RCS co d ;

leg temperature > 225'F.

Verify HHSI pump breaker alignment.

Once after entry into MODE

4. ,- :

.;, q '

AND f 'l ') !

i .

N

! 31 days j ,

l '

thereafter j h

l :

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j i

l Insert Page 3.5-8 I

f RWST 3.5.4 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l 3.5.4 Refueling Water Storage Tank (RWST)

, LCO 3.5.4 The RWST shall be OPERABLE.

i-

. APPLICA81LITY: MODES 1, 2, 3, and 4.

i

ACTIONS i

CONDITION REQUIRED ACTION COMPLETION TIME

? i 4 A. RWST boron A.1 Restore RWST 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months '

I concentration not (OPERABLVst s. I i within limits.

% mbb gg .h sh IWh. ; !

J borated w er emperature limits.

t withi h

1 i

i B. RWST inoperable for B.1 Restore RWST to I hour i

1 reasons other than OPERABLE status.

Condition A.

4 -

! C. Required Action and C.1 Be in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion l 1

Time not met. Ngl C.2 Be in MODE 5. 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months WOG STS 3.5-9 Rev 1, 04/07/95 O - -

RWST

3.5.4 i SURVE!LLANCE REQUIREMENTS SURVEILLANCE FREQUENCY 1

i

[SR 3.5.4.1 ---- ----

NOT - - - - - - - - - - - - - -

7 Only required to be rformed when ambient air temperature i < [35)*F or > [100]'F.

-- ------------------------ y .

Verify RWST orated water temperature i 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months

] h [35)*F s [100]'F. I t

( >

4 SR 3. 4. Verify RWST borated water volume is 7 days <

SR Ve RWST boron ation is 7 days k ppe.

! 1 1

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4

!O i )

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WOG STS 3.5-10 Rev 1, 04/07/95 O ~ ~

. _- ~ -<

.. . - . . . ~ - .-. .-.. . --. - - - . . . - - . . . ., . ~ . . -

Saal Injsetton Flow 3.5.5 (3.5 EMERGENCY CORE COOLING SYST (ECCS) 3.5.5 Seal Injection Flow LC0 3.5.5 Rea r coolant pump seal injection f shall be s [40 gpm w [ centrifugal charging pump dis arge headerl pressu]re

[2480] psig and the [ charging f ] control vaIve full open.

i APP CABILITY: MODES 1, 2, and 3.

ACTIONS CONDITION

[ REQUIRED ACTION COMPLETION E f

A. Seal injection fl A.1 Adjust manual seal 4 ho not within limit injection throttle valves to give a flow j within limit with

[ centrifugal chargin pump discharge header) pressure 2 [2480] psig d the

[ charging fl J control y e full open.

l l

. B. Required Action and 8.1 in MODE 3. 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months associated Completion Time not met. 8llQ B Be in MODE 4. 12 ho s j

i i

WOG STS 3.5-11 Rev1,04/37/95 O ~ ~

Seal Injecticn Flow 4 3.5.5 RVEILLANCE REOUIREMENTS N

f 1

URVEILLANCE

[ FREQUENCY SR 3.5.5.1 --------

NOTE--------- -------- 1 j

Not required to be performed un 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months after the Reactor Coolant Sys pressure stabilizes at 2 [2215 psig i s2255psig).

-; Verify manual seal i ection throttle 31 days valves are adjuste o give a flow within i l

limit with [ centr ugal charging pump !

' discharge heade pressure 2[2480ppsig j andthe[cha ng flow) control vaive full open.

4

( /-

3*

/ )

3 1-4 l

4 i

iv O

l l

1 i

f WOG STS 3.5-12

{ Rev1,04/07/95 O ~ -

BIT 3.5.6 3.5 EMERGENCY CORE COOLING STEMS (ECCS) l 3.5.6 Boron Injection nk (BIT)

! LCO 3.5.6 e BIT shall be OPERABLE.

APPLIC ITY: MODES 1, 2, and 3.

l IONS

/ CONDITION RED ACTION COMPLETION TIME l A. BIT inoperable. Restore BIT to I hour

OPERABLE status.

f 3

! 8. Required Act n and 8.1 Be in MODE 3. 6 ours j associated ompletion i'

Time of ndition A M not me .

i B.2 Borate to an 50M 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months j equivalent to -

j [1]%ak/kat *F.

M }

s T

g B.3 Resto BIT to 7 days ,

OPE LE status. ;

j~

/

C. Required Action and C. Be in MODE 4. 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months

] associated Completion

Time of Condition B l.

not met. /

l D' I

i !

j WOG STS 3.5-13 Rev 1, 04/07/95 t

\

O l

~ ~

4

' BIT 3.5.6 SURVEILLANCE REQUIREMENT f

~

a.

SURVEILLANCE

[ FREQUENCY l SR 3.5.6.1 erify BIT borated water temper ure is 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

2 [145]'F. i i

4 l 5 .5.6.2 Verify BIT borated water olume is 7 days i 2 [1100] gallons.

y- -

? .

SR 3.5.6.3 Verify BIT be concentration is 7 da 4

2[20,000]p and 5 [22,500] pps.

i j

\

i q / / J I 3 i

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s e'

s-b 4

l 4

J 1

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a i

110G STS 3.5-14 Rev1,04/07/95 l

t

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'5 l

]

3 1

STP ITS Conversion I

Attachment 5 - Justification for Deviations l ~ Section 3.5 - Emergency Core Cooling Systems D 1 1 TECHNICAL SPECIFICATlONS.

f NOTE: The first five justifications for these changes from NUREG-1431 were generically used throughout the individual LCO section markups. Not all j

generic justifications are.used in each section.

i . . -

, 1. The brackets have been removed and the proper plant specific information or value has been provided.

i 2. Editorial change for clarity or for consistency with the improved Technical l Specifications (ITS) Writer's Guid ,

3. The requirement / statement has been deleted since it is not applicable to this facility. l The following requirements have been renumbered, where applicable, to reflect this 4

deletion.

4. Changes have been made (additions, deletions, and/or changes to the NUREG) to i reflect the facility specific nomenclature, number, reference, system description,' or analysis description.

S. This change reflects the current licensing basis / technical specifications for STP.

6. Specific Action for the Safety injection (SI) and Residual Heat Removal (RHR) subsystems have been proposed to reflect the unique South Texas Project (STP) design. The Actions acknowledges the relationship between the Si and RHR subsystems. The proposed changes have been subjected to a risi evaluation and the results show an acceotable !ht er nc impact on the overall Core Damage i Frequency for the plant.

' 7. The change is made from 31 days to 92 days based on experience and system

' design of STP. The Emergency Core Cooling System (ECCS) trains are separate, independent and have no common piping. Venting of a ECCS train have not shown gas formation in the piping at the frequency of 31 days. The RHR portion of the ECCS train maintains the piping filled with water through a standpipe arrangement. !

l

8. . An allowance is made to the requirements of the ECCS trains to provide time upon i entering MODE 4 up to 225'F (RCS cold les temoerature) from MODE 5. - The I proposed LCO requires two OPERABLE ECCS trains prior to entering MODE 4. The temperature requirement allows time to rack in a High Head Safety injection (HHSI) pump breaker as the plant is moved inte MODE 4. The 225'F limit allows reasonable time to perform the operation. 2 l

South Texas Units 1 & 2 1 Rev. O, 2/6/97

~- . . .. ..- .. - - . . . . - -

l 1

l STP ITS Conversion j Attachment 5 - Justification for Deviations l Section 3.5 - Emergency Core Cooling Systems l

TECHNICAL SPECIFICATIONS

9. One required ECCS train is allowed to be inoperable for a period of 14 days while the plant is in MODE 4. This is allowed provided the remaining OPERABLE ECCS .)

train's HHSI pump breaker is verified closed within one hour. The one ECCS train !

maintains 100% capacity to mitigate a Design Basis Accident in MODE 4 by manual actions.

m The Note is deleted because STP design does not reouire any manual alienment to

initiate the ECCS mode of ooeration throught the RHR Heat Exchanner if the RHR system is operatine and orovidine decav removal.

f i

i s

l n

i-

. South Texas Units 1 & 2 2 Rev. O, 2/6/97

1

" A'.cumul ators' B 3.5.1 B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) l B 3.5.1 Accumulators BASES i

BACKGROUND The functions of the ECCS accumulators are to supply water )

to the reactor vessel during the blowdown phase of a loss of coolant accident (LOCA), to provide inventory to help accompitsh the refill phase that follows thereafter, and to ,

provide Reactor Coolant System (RCS) makeup for a small l break LOCA.

The blowdown phase of.a large break LOCA is the initial period of the transient during which the RCS departs from equilibrium conditions, and heat from fission product decay, hot internals, and the vassel continues to be transferred to the reactor coolant. The blowdown phase of the transient ends when the RCS pressure falls to a value approaching that of the containment atmosphere. ;

In the refill phase of a LOCA, which immediately follows the blowdown phase, reactor coolant inventory has vacated the core through steam flashing and ejection out through the break. The core is essentially in adiabatic heatup.- The balance of accumulator inventory is then available to help fill voids in the lower plenum and reactor vessel downcomer so as to establish a recovery level at the bottom of the core and ongoing reflood of the core with the addition of safety injection (SI) water.

The accumulators are pressure vessels partially filled with

+ borated water and pressurized with nitrogen gas. The accumulators are passive components, since no operator or control actions are required in order for them to perform their function. Int 6rnal accumulator tank pressure is sufficient to discharge the accumulator contents to the RCS, if RCS pressure decrease low the accumulator pressure. !

~

accumulato ed to GB CS g a g accumulator 1Jine andh< s by the RCS isolated a motor operated isolation valve and two check valves in series.

from/

I The motor operated isolation valves are interlocked by P-11 '

with the pressurizer pressure measurement channels to ensure that the valves will automatically open as pressure increases to above the permissive circuit P-11 setpoint.

(p,.ww]

(continued) !

WOG STS B 3.5-1 Rev 1, 04/07/95

O

Accumulators B 3.5.1

. 4 BASES BACKGROUND This interlock also prevents inadvertent closure of the (continued) valves during normal operation prior to an accident. To valves will automatically open, however, as a result of an SI signal. These features ensure that the valves meet the requirements of the Institute of Electrical and Electronic Engineers (IEEE) Standard 279-1971 (Ref. 1) for " operating

(

bypasses" and that the accumulators will be available for '

g ( injection without reliance on operator action. w l hw Lt.m Mi

- - - r- The accumulator size, water volume, an nitro e cover pressure are selected so that of the accumulators

}gg g4. ,g g od are sufficient to partially.lcmef]the core be ore significant clad melting or zirconium water reacti n can O1 b'- *#

h occur following a LOCA. The need to ensure that accumulators arefademete for this function is consistent

'with the LOCA assumption that the entire contents of one accumulator will be lost via the RCS pipe break during the

@MAe,H blowdown phase of the LOCA.

APPLICABLE The accumulators are assumed OPERABLE in both the large and SAFETY ANALYSES small break LOCA analyses at full power (Ref. 2). These are the Design Basis Accidents (DBAs) that establish the acceptance limits for the accumulators. Reference to the analyses for these DBAs is used to assess changes in the accumulators as they relate to the acceptance limits.

5 In performing the LOCA calculations, conservative assumptions are made concerning the availability of ECCS flow. In the early stages of a LOCA, with or without a loss ,

of offsite power, the accumulators provide the sole source 1 i

of makeup water to th? RCS. The assumption of loss of offsite power is required by regulations and conservatively imposes a delay wherein the ECCS pumps cannot deliver flow j until the emergency diesel generators start, come to rated i speed, and go through their timed loading sequence. In cold leg break scenarios, the entire contents of one accumulator are assumed to be lost through the break.

The limiting large break LOCA is a double ended guillotine break at the discharge of the reactor coolant pump. During this event, the accumulators discharge to the RCS as soon as RCS pressure decreases to below accumulator pressure.

l (continued)

WOG STS B 3.5-2 Rev 1, 04/07/95

1 1

E Insert Backaround Above 1000 psig in the pressurizer, the accumulator's discharge valve is open with electrical power removed from the M0V, and the valves position indication [2 1 is monitored by an independent mechanism. -

i l 1

I l

i b

i 1

i i

s i

Insert Page B 3.5-2 - -

_ _ - - . _ _ - . ~ . - . - - _ . - _ _ _ - . _ . - _ - . - _ . - . - - _ . -

J J Accumulaters B 3.5.1 BASES

~

j%

' \ APPLICABLE As a conservative estimate, no credit is taken for ECCS pump

\ SAFETY ANALYSES flow until an effective delay has elapsed. This delay (continued) accounts for the diesels starting and the pumps being loaded and delivering fuli flow. The delay time is conservatively set with an additional 2 seconds to account for SI signal generation. During this time, the accumulators are analyzed j as providing the sole source of emergency core cooling. No operator action is assumed during tne blowdown stage of a l

large break LOCA. l The worst case small break LOCA analyses also assume a time delay before pumped flow reaches the core. For the larger range of small breaks, the rate of blowdown is such that the ;

increase in fuel clad temperature is terminated solely by

~

.l ,

r the accumulators, with pumped flow then providing continued i \ b '*"V 4 1 m i cooling. AsAbreak size decreases, the accumulators and menrr' 7 . marcnne pumps both play a part in terminating i the rise in clad temperature. As break size continues to !

decrease, the role of the accumulators continues to decrease '

until they are not required and the tente"" , onaraina3 g l 4 pumps become solely responsible for terminating the i temperature increase. l j This LCO helps to ensure that the following acceptance :

' criteria established for the ECCS by 10 CFR 50.46 (Ref. 3) i will be met following a LOCA:

a. Maximum fuel element cladding temperature is s 2200*F; 1 i b. Maximum cladding oxidation is s 0.17 times the total l

cladding thickness before oxidation, i l 1 c. Maximum hydrogen generation from a zirconium water '

i reaction is 5 0.01 times the hypothetical amount that j would be generated if all of the metal in the cladding cylinders surrounding the fuel, excluding the cladding

- surrounding the plenum volume, were to react; and

d. Core is maintained in a coolable geometry.

Since the accumulators discharge during the blowdown phase of a LOCA, they do not contribute to the long term cooling requirements of 10 CFR 50.46.

I 1

For both the large and small break LOCA analyses, a nominal contained accumulator water volume is used. The contained I (continued)

I WOG STS B 3.5-3 Rev 1, 04/07/95 I

I i

C' Q

4

Accumulaters B 3.5.1 BASES f% !

APPLICABLE water volume is the same as the deliverable volume for the :

SAFETY ANALYSES accumulators, since the accumulators are emptied, once (continued) discharged. For small breaks, an increase in water volume :

is a peak clad temperature penalty. For large breaks, an increase in water volume can be either a peak clad temperature penalty or benefit, depending on downcomer filling and subsequent spill through the break during the core reflooding portion of the transient. The analysis .

makes a conservative assumption with respect to ignoring or 2 I taking credit for line water volume from the accumulator to r gq n I the cheele valve. The safety analysis assumesAvalues of N"*

g uneein -o and []iES allons. To al" w for instrument <

g i p inaccuracy, values of gallons and( gallons are spectfled.9 go. '

i

%_sk.1.we.T- I The minimum boron concentration setpoint is used in the post Lgr Nh ~ "

LOCA boron concentration calculation. The calculation is D2, performed to assure reactor suberiticality in a post LOCA environment, uf particular interest is the large break LOCA, since no credit is taken for control rod assembly insertion. A reduction in the accumulator minimum boron concentration would produce a subsequent reduction in the available containment sump concentration for post LOCA shutdown and an increase in the maximum sump pH. The maximum boron concentration is used in detemining the cold )

leg to hot leg recirculation injection switchover time and ;

minimum sump pH.

O The large and small break LOCA analyses are performed at the minimum nitrogen cover pressure, since sensitivity analyses have demonstrated that higher nitrogen cover pressure results in a computed peak clad temperature benefit. The maximum nitrogen cover pressure limit prevents accumulator relief valve actuation, and ultimately preserves accumuistor integrity.

The effects on containment mass and energy releases from the

' < accumulators are accounted for in the appropriate analyses (Ref9. 2 @ .

The accumulators satisfy Criterion 3 of the NRC Policy Statemen jus) .

(continued) il0G STS B 3.5-4 Rev 1, 04/07/95 a .

Accuzulaters-B 3.5.1 BASES (continued)

LCO The tr1 establishes the minimum conditions required to y ensure that the accumulators are available to accomplish their core cooling safety function following a LOCA. %,u, accumulators are required to ensure that 100% of the l

pb contents ofM of the accumulators will reach the core during a LOCA. This is consistent with the assumption that the contents of one accumulator spill through the break. If 5 i less than(EEE m accumulators are injected during the blowdown phase of a LOCA, the ECCS acceptance criteria of 10 CFR 50.46 (Ref. 3) could be violated.

For an accumulator to be considered OPERABLE, the icolation valve must be fully open, power removed ebeme h l psig, and the limits established in the SRs for contained volume, boron concentration, and nitrogen cover pressure must be met d I g2000 (p. w ...o APPLICABILITY In MODES I and 2, and in MODE 3 with41G pressure > 1000 psig, i the accumulator OPERABILITY requirements are based on full power operation. Although cooling requirements decrease as power decreases, the accumulators are still required to provide core cooling as long as elevated RCS pressures and temperatures exist.

a This LCO is only applicable at pressures > 1000 psig. At pressures s 1000 psig, the rate of RCS blowdown is such that the ECCS pumps can provide adequate injection to ensure that peak clad temperature remains below the 10 CFR 50.46 (Ref. 3) limit of 2200'F.

(v=w.x0 In MODE 3, withqLes) pressure $ 1000 psig, and in MODES 4, 5, and 6, the accumuTator motor operated isolation valves are

'f closed to isolate the accumulators from the RCS. This allows RCS cooldown and depressurization without discharging the accumulators into the RCS or requiring depressurization of the accumulators.

ACTIONS L1 If the boron concentration of one accumulator is not within limits, it must be returned to within the limits within 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . In this Condition, ability to maintain subcriticality or minimum boron precipitation time may be

('

(continued),

WOG STS B 3.5-5 Rev1,04/07/g5

Accumulators B 3.5.1 BASES ACTIONS A d (continued) reducahT1heboron n the accumulat contributes to el

1- /assu tion that t combined ECCS er in the partia y h Aa.on A t re vered core ring the early r looding phase of large b ak LOCA is fficient to ke that portion of t core uberitical. One accumulator elow the minimum b on concentrat n limit, howeve , will have no effe on available ECCS wat and an insigni cant effect an cor suberiticality, dur nc __efloodJ~ Bolling et LLLs water in the core during ~

refi ood concentrates boron in the saturated liquid that

1 remains in the core. In addition < current analysis techniques O1 demonstrate snat the accumulatorsW6not discharge followin 13rge main steam line break iror u=- _mmy- n unru.

/f they do discharge, their impact is minor and not a de gn a02. .

limiting event. Thus, 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months is allowed to return the boron concentration to within limits.

4

, If one accumulator is inoperable for a reason other than boron concentration, the accumulator must be returned to OPERABLE 1

A k*"",1 status within Of!{u3. u In this Condition, the required

( . nb*

contents of 6EisiMDaccumulators cannot be assumed to reach the core durina a LOCA. E ue to verny of tho w nuanced 2-Lehnulti M occur in enntfitinnt,I/heQg Completion

, Time to open the valve, remove power to the valve, or restore i the proper water volume or nitrogen cover pressure ensures that prompt action will be taken to return the inoperable a accumulator to OPERABLE status. The Completion Time minimizes 't a the potential for exposure of the plant to a LOCA under these conditions.

C.1 and C.2 If the accumulator cannot be returned to OPERABLE status within the associated Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and pressurizer pressure reduced to (continued).

WOG STS B 3.5-6 Rev 1, 04/07/95

Insert Action A.1 In the reflood phase of the calculated res onse to LOCA. -the boron content of an accumulator is not specifica ly evaluated since it is not of concern during this phase of the accident. During the recirculation

)hase, when the ECCS is taking suction from the containment sump, the

)oron content of the accumulators is considered but its contribution is small when compared with the total volume of the RCS and the Refueling Water Storage Tank (RWST).

O 1

~

e

~ -_ _ ._ _.

Accumulators B 3.5.1 BASES ACTIONS C.1 and C.2 (continued)

$ 1000 psig within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.

D.d 1

If more than one accumulator is inoperable, the plant is in a '

condition outside the acciaent an - ses; tmerefore; LCO 3.0.3 )

must be entered immediately, gg ]

SURVEILLANCE SR 3.5.1.1 1 REQUlfEMENTS q Each accumulator valve should be verified to be fully open every Uc hours. This verification ensures that the ,

accumulators are available for injection and ensures timely 4 discovery if a valve should be less than fully open. If an isolation valve is not fully open, the rate of injection to the RCS would be reduced. Although a motor operated valve position should not change with power removed, a closed valve could result in not meeting accident analyses assumptions.

This Frequency is considered reasonable in view of other administrative controls that ensure a mispositioned isolation valve is unlikely.

4g SA 3.5.1.2 and SR 3.5.1.3 U2 AI4fM% 7 EveryU0 hours, borated water volume and nitrogen cover I pressure are verified for each accumulato . This Frequency is sufficient to ensure adequate injection dur ng a LOC . 2.9 Because of the static design of the accumulator, a hour Frequency usually allows the operator to identify changes i before limits are reached. Operating experience has shown l this Frequency to be appropriate for early detection and correction of off normal trends.

a. i (continued)

WOG STS B 3.5-7 Rev 1, 04/07/95

Accu 2ulators B 3.5.1 l

BASES SURVEILLANCE SR 3.

A sunde.akt-g, ,ut3y,4,fa t, dana & twh h eJhf; m af cA A w h s-REQUIREMENTS (continued) The boron concentration should be verified to be within l required limits for each accumulator every 31 days since the static dasign of the accumulators limits the ways in which the concentration can be changed. The 31 day Frequency is i g __ adequate to identify changes that could occur from mechanisms -

such as cr-munn accumulator within an inleakage.

6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months afterc. Z F5ampling the arrected

=l x ; Jhcrease will L g ggI,y l

( identify whether inleakag7 concentratior1A; @ causeg Z:athe required limitsa ceouan onQ n boron @ f**S $

t is not ct awke up Ge h necessary to verify boron concentration if the added watery

)

a we oder inventory is from the u..........-. .m... ....- mWST , I 8

O'"

1 because the water contained in the RW51 1s within the accumulator boron concentration requirements. This is .-

[ v h.O*

th' N8 y - II consistent with the recommendation of NUREG-1366 (Ref. 5).

SR 3.5.1.5 SIII Verification every 31 ys that power is removed from each accumulator t" valve operator when the pressurizer pressure is psig ensures that an active failure could

>Y; A not result in '.he undetected closure of an accumulator motor h l operated isolationbe accumulato@would valve.

If this were to occur, only h a c 1 available for injection given a single !

h i failure coincident with a LOCAe Since power is removed under

, administrative control, thc 31 day frequency will provide adequate assurance that power is removed. gy j This SR allows power to be supplied to the motor /perated isolation valves when pressurizer pressure is R.200T psig, /b7c b - -)

thus allowing operational flexibility by avoiding unnecessary f delays to manipulate the breakers during plant startups or shutdowns. Even with power supplied to the valves inadvertent closure is prevented by the$ press , interlock ;

associated with the valves. (p,y <

1 Should closure of a valve occur in spite of the interlock, the SI signal provided to the valves would open a closed valve in the event of a LOCA.

(continued) I WOG STS B 3.5-8 Rev 1, 04/07/95 1

i

, Accurulators B 3.5.1 i

, BASES (continued) i REFERENCES 1. IEEE Standard 279-1971.

.h 2. @ FSAR, Chapter / 619

3. 10 CFR 50.46. l i

4. FSM , O.. L. [ Z].*

5.

g NUR5G-1366, (F15153iT'TVRB.h t

ym,,g !

f;AM O

F t Au og TukuA 6g.EA rpm, p.,

IAdeu %wer b(b, ai(Fr. 340L St 3 11, tML C g l

n0G STS B 3.5-9 Rev1,04/07/95

.. ..- - . ~. _ - . .. - - . - . - . - . __. _ . -. - ~. - - . - - . . - . -

i I

! ECCS-Optrating 1 B 3.5.2 l I

\

8 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS)

B 3.5.2 ECCS-Operating

(

3 BASES 1 I

! BACKGROUND The function of the ECCS is to provide core .001 c4 and i

negative reactivity to ensure that the reac or core M l j protected after any of the following accide its

, a. Loss of coolant accident (LOCA), cool nt leakage )

greater than the capability of the ne sal charging system; i

b. Rod ejection accident;

. c. Loss of secondary coolant aci:ident, including l uncontrolled steam release or loss of feedwater; and i

! d. Steam generator tube rupture (SGTR).

! The addition of negative reactivity is designed primarily j for the loss of secondary coolant accident where primary ;

! cooldown could add enough positive reactivity to achieve l'

criticality and return to significant newer.

i ,-( A q.w.D i There are three phases of ECCSAoperation: Injection, cold

leg recirculation, and hot leg' recirculation. In the injection phase, water is taken from the refueling water t I storage tank (RWST) ajn ' injected into the Reactor Coolant ,

t

~ [N , 4.u. System (RCS5 throuchm__2 cold legs. When sufficient water j is removed from the RWST to ensure that enough boron has 1

) been added to maintain it.e reactor subcritical and the l

] containment sumps have enough water to supply the required 1 net positive suction head to the ECCS pumps, suction is -- @ o switched to the containment s for co' d leo recirculation. + 6 N, i

l 9 gg After annroximatelv@ hours, ECCS now is shifted to the hot leg recirculation phase to provide a backflush,

[*M b L

J -

which would reduce the boiling in the top of the core and j any resulting boron precipitation.

IMrd Badym=A l) < Q

- The ECCS consists of ' . -- W subsystems: cent m ucan A - m- -- =au Afety Ajection (SD fl~n2memauun g" i

g4 and sidual heat removal (RHR) flowJtently. tach i rN

. I us consists of redundant, 100% capacity trains.

!

The ECCS accumulators nd the RWST are also part of the .M

, %%4s 1

! (continued)

WOG STS B 3.5-10 Rev1,04/07/95 i ,

l l

4 e

6

J_nsert Backaround 1 Residual Heat Removal'(RHR) system operation may be used after certain DBAs I which occur from a sequence of events that result in a substantially intact l RCS system (e.g Main Steam Line Break (MSLB)). This mode of operation is !

after the RCS coolant temperature has been reduced to less than 350*F after the DBA. Steam Generators are used to reduce the RCS coolant temperature to less than 350*F for these DBAs. This specification assures the availability of an RHR subsystem to be manually aligned if a DBA occurs. Alternate methods of heat removal exist for this function, such as feed and bleed, however the '

RHR is the preferred heat removal method. ,

Insert Backaround 2 .

The SI~ subsystem includes the High Head Safety Injection (HHSI) pumps. Low Head Safety Injection (LHSI) pumps. RHR heat exchangers, and the associated '

valves. The RHR subsystem includes the RHR pump and RHR heat exchangers and valves which are manually aligned to provide long term cooling after a DBA transient which may result in operation of the RHR (e.g.!$1H Main Stc= Linc Break.)

l l

!' Insert Page B 3.5-10

ECCS-Oparating {

. B 3.5.2 l BASES !

l i

l BACKGROUND g

(continued) ECCS, but described by thisareLCO.not considered part of an ECCS flow path as {gQf ll ($E %Q M flow paths consist of piping, valves, heat .

' I

exchangers, and pumps such that water from the RWST can be r

u ym ug injecte( into the RCS following the accidents described !

i g4- 3gt _The major components of eachtsunsv-frans .i cnarging) pumps, thefJtEJpumps, heat excha are IntM A,1 1

j e==a "- - . Each p.ge. j '

w 6d 66 ' hMM@igB> 1005 capacityRDeduncant MI!bsuen traintnat #

i is capable of supplying a .o.h- 2i loss or the flow required to mitigate the accident ww: ma e. This an'- . . .. .m a and redundant ="a%--P :-aa6

+

design provides the operators wut' the ability to dIIIPP21D % j

cer r- - rrom en== m traint in hchieve the ranniend: 005 !

4 -

Mt

] trains ar assumed tu operate due t equirements for I modeli full active containment t removal system 4 oper ton);and

b. small break LOCA event, w h a loss of offsite p r and a single failure dis ing one ECCS train /

During the blowdown stage of a LOCA, the RCS depressurizes ~ as primary coolant is ejected through the break into the containment. The nuclear reaction is terminated either by moderator voiding during large breaks or control rod insertion for small breaks. Following depressurization, emergency cooling water is injected into the cold legs, flows into the downcomer, fills the lower plenum, and refloods the core. (continued) WOG STS B 2.5-13 Rev1,04/07/95 s l 1 _ . . _ . _ . _ _ _ _ _ . _ _ _ _ _ _ _ . . ~ _ . _ _ _ _ _ _ _ _ l i. b a i Insert ASA i l a. A large break LOCA event, with loss of offsite power and a single failure disabling one SDG in combination with a break location which j results in loss of all injection flow from one train: and - ,. 1 l b. A small break LOCA event, with a loss of offsite power and a single i failure disabling one ECCS train in combination with a break location which results in loss of injection flow from one train. 1 i i t-i i . \ ! I i l Insert Page B 3.5-13 ECCS-Op2 rating i B 3.5.2 1 BASES

APPLICABLE /The effirets on c nment mas d energy r g4 i i

' SAFETY ANALYSES ( #nunted for appropriat nalyses (Refs(g,Wases 3 and 4)J arpThe (continued) LCO ensures that an Eccs train will deliver sufficient water ' to match bolloff rates soon enough to minimize the consequences of the core being uncovered following a larg f LOCA. It also ensures that the centerrT charoMd XD-- 4 pumps will deliver sufficient water and goron during a small g LOCAttne to maintain centr core suberiticality. i cnargina a = M - e sea pliFluidAS(td for ""4- i i bnai j CS inventor C For'a small break LOCA, the steam l generators continue to serve as the heat sink, providing I , part of the required core cooling. <W ASAN The ECCS trains satisfy Criterion 3 of the NRC Policy i Statement . 4 \ M LCO In MODES 1.-2, and 3, n pendent (andredundant?ECCS trains are required to ensure that sufficient ECCS f,ow is; %%LM -Wh available, assuming a single failure affecting w.trainr DMh Additionally, individual components within the ECCS trains 4 tw l may be called upon to mitigate the consequences of other , hd- L40 6 transients and accidents. A G D_ Qu % W In MODES 1, 2, and 3, an uu:Mtr,effD cTnsists of a)lHH+L % L% e-O ttentrirug@aruina suosystenean 5i suosysteug and at RHR>LL_akes 1 l R4b]_ C ' lsubsWirr a Eachtuamincludes the piping, instruments, and cosro is to ensure an OPERABLE flow path capable of taking ~ suction from the RWST upon an SI signal and automatically transferring suction to the containment sump. O ~

/ During an event requiring ECCS actuation, a flow path is required to provide an abundant supply of water from the

]i ' RWST to the RCS via the ECCS pumps and their resnective supply headers to each of thegaglTcold leg injection nozzles. In the long term, this flow path may be switched Q i to take its supply from the containment sump and to supply its flow to the RCS hot and cold legs. . The flow path for each traintmuo =+wnTn itD designedD (bL e A +}--An'heem to ensure that[no single failure can disable 4 )ECCStrain$ ( q4&RA44+%d 1 (continued) . WOG STS B 3.5-14 Rev 1, 04/07/95 4 ) e l 4 1 l , > l m i Insert ASA 2 The PSA risk significance is as follows (Ref.1): , Because of the potentially large effect of the High Head Safety Injection l system on accident consequences, this system has a high risk significance. ! Based on the assumed reliability, and relative importance of the Safety Injection system, the Probabilistic Safety Assessment can be used in MODES 1,

2. 3. and 4 to justify one train of Safety Injection out-of-service for 7 days. and two trains of Safety Injection out-of-service if one of them is ;

restored to service within 1 day. ; The Probabilistic Safety Assessment analysis of the effect of the Residual ! Heat Removal system on accident consequences determined that this system has a + medium risk' significance. ) Based on the assumed reliability, availability, and relative importance of the l Residual Heat Removal system, the Probabilistic Safety Assessment can be used ! to justify one Residual Heat Removal train out-of-service for 14 days and two Residual Heat Removal trains arc incperabic, either the SI train cr-the Rc;1 dual Mc;t Rc cval train can be out-of-service for 7 days. Insert LC01d4 The RHR subsystems are required to provide the preferred cooling capability to remove decay heat following certain DBAs. t Insert LC0 2' j In MODES 1, 2, and 3. an RHR subsystem consists of an RHR pump and an RHR heat I : exchanger. Each subsystem includes the piping, instruments, and controls to ' ensure an OPERABLE flow path capable of being aligned to take suction from the - RCS hot legs and pumping the water through an RHR heat exchanger and returning i it to the RCS. 1 k Insert Page B 3.5-14 i ECCS-Operating B 3.5.2 i BASES (continued) APPLICABILITY In MODES 1, 2, and 3, the ECCS OPERABILITY rcoutrements for the limiting Design Basis Accident, a large break LOCA, are based on full powet operation. Although reducei power would not require the same level of performance, the accident (t ggmest43 d analysis does not provide for reduced coolingge uirements in the lower MODES. The gentr

m rai t p 885:

periorwance w based on a small break LOC ^ u s i .... , .L -..anse m vc ano es? (A M Murp. m h E2nd.nen nn I _ ,, ym nrhe L m-r oerror-n i - ou' remontt p w n p.4 I dEre based fer imall bramb+Tf"8 i MODE 2 and MODE 3 f g 4, requirements are bounded by the MODE I analysis. y, i j This LCO is only applicab_le/in MODE 3 and above. Below to laWa"" MODE 3.Tthe SI sianaJ-strtjuntfp is manually bypassed by 0"*

A operator controbantDsystem functional requirements are LO elaxed as descrlbed in LCO 3.5.3, "ECCS-Shutdown."

kEM i (Asindicated .2 hours2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months in ate 1, the f path may be E 3, under e rolled condit' sted for s, to perfd 3 hpressur solation valve esting per SR }A.14.1. JVflo at -readfl9' resto le from t11e conttol room / a (em a J) 2 2 , . As indicate n Note @,Aoperation in MODE 3 with ECCS trains declared inoperable pursuant to LCO 3.4.12. " Low Temperature gg q3 h - Overpressure Protection (LTOP) SystemP is necessary GED 2 JuAo LetJa an LTOP arming temperature G5lD near the MODE 3 boundary temperature of 350"F. LC0Y3.4.12 rau-s 'nm certain pumps be rendered inoperable at and below the L'IOP

Idj2 91.6 M 7/Q"WlIMk"

-w ra d c-+f 5'a* MODE 3boundarytemperature,timeisneededto arming temperature. When this temperature is at or near the I finoperablepumpstoOPERABLEstatus. {+rwoc4 c 4+ occuww

w. AwbJ i uo s.5,3, + eg,_ In MODES 5 and 6, plant conditions are such that the cA ,, % '. ] probability of an event requiring ECCS injection is extremely low. Core cooling requirements in MODE 5 are g addressed by LCO 3.4.7, "RCS Loops-MODE 5, Loops Filled,"

and LCO 3.4.B, "RCS Loops-MODE 5, Loops Not Filled." MODE 6 core cooling requirements are addressed by LCO 3.9.5, _ " Residual Heat Removal (RHR) and Coolant Circulation-High 7 Water Level," and LCO 3.9.6, " Residual Heat Removal (RHR) Q WOJ and Coolant Circulation-Low Water Level." (continued) . 1 WOG STS B 3.5-15 Rev1,04/07/95 b l l l - - . . . . . . - . _ - . _ . . - . . - . - . - _ . - - ~ . - . - - - - . --. - _. , 4 1 ECCS-Oparating 8 3.5.2 BASES (continued) ' ACTIONS I With one or more trains i erable and at least 100% of

ECCS flow equivalent to single OPERABLE ECCS train ,

available, the inoper e components must be returned to / OPERABLE status wit n 72 hours8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months . The 72 hour8.333333e-4 days 0.02 hours 1.190476e-4 weeks 2.7396e-5 months Completion / Time is based on NRC reliability evaluation (Ref. 5 ' ] is a reasonabl ime for repair of many ECCS componen ). 4 i An ECCS tr n is inoperable if it is not capable deliver design flow to the RCS. Individual onents i are i perable if they are not capable of per ming their iQ des n function or supporting systems are avail ble. he LC0 requires the OPERABILITYff a r r of independent Acnom // i subsystems. Due to the redundancy o rains and the diversity of subsystems, the inope 111ty of one component in a train does not render the E incapable of performing its function.. Neither does th noperability of two ' different components, each i a different train, necessarily result in a loss of functi for the ECCS. The intent of this Condition is to mai in a combination of equipment such that 100% of the 5 flow equivalent to a single OPERABLE ECCS train r ins available. This allows

increased flexibili in plant operations under a

circumstances wh components in opposite trains are inoperable. An event ac spanied by a loss of offsite power and the

failure an EDG can disable one ECCS train until power

qv restor . A reliability analysis (Ref. 5) has shown t the act of having one full ECCS train inoperable

su ciently small to justify continued operation r

hours.

4 Reference 6 describes situations in which o component, 2 such as an RHR crossover valve, can disa both ECCS trains. With one or more component (s operable such that 100% of the flow equivalent to a sin OPERABLE ECCS train ] is not available, the facility is a condition outside the accident analysis. Therefore, L 3.0.3 must be imeediately i entered. j i

(continued) i WOG STS B 3.5-16 Rev1,04/07/95 E

] fk l * ~ ~ I i i l Insert ACTIONS s e ! L1 ! 1 - With one RHR subsystem inoperable, the inoperable components must be returned j to OPERABLE status within 14 days. The 14 day Completion Time is based on the ; availability of two redundant and independent 100% capacity RHR subsystems, i and alternative means of removing decay heat below 350*F. An STP analysis i (Ref.1) has shown that the impact of having an RHR subsystem inoperable is sufficiently small to justify continued operation for 14 days. , The 21 day portion of the Completion Time for Required Action A.1 is based - upon engineering judgment. It takes into account the low probability of ' coincident entry into two Conditions in this Specification coupled with the : low probability of an accident occurring during this time. Refer to Section , 1.3 for a more detailed discussion of the purpose of the "from discovery of l failure to meet the LC0" portion of the Completion Time. j i A RHR subsystem is ino)erable if it is not capable of being aligned to j provide flow through t1e RHR heat exchanger for the removal of decay heat from the 3rimary system following a reduction of RCS temperature to less than i 350* . l t Due to the redundancy and independence of the subsystems, the inoperability of one RHR subsystem does not render the other two subsystems or alternative l r - methods (e.a. feed and bleed) of heat removal incapable of performing the I , required function. ! M $ With one SI subsystem inoperable, the ir. operable components must be returned ! to OPERABLE status within 7 days. The 7 day Completion Time is based on the ! E continued availability of two 100% ca>acity SI subsystems, either capable of providing the required cooling, if a _0CA were to occur. The only restriction , on continued operation is the possible inability of the subsystems to respond ' ' to a DBA with-certain unlikely combinations of RCS break locations and a , single active failure of an additional ECCS subsystem. An STP analysis , (Ref.1) has shown that t . impact of having an SI subsystem ino)erable is ! sufficiently small to jf ,1fy continued operation for 7 days. T1e time is also reasonable for repair and testing of inoperable components. The 21 day portion of. the Completion Time for Required Action B.1 is based upon engineering judgement. It takes into account the low probability of coincident entry into two Conditions in this Specification coupled with the , '.ow probability of an accident occurring during this time. Refer to Section ; 1.3 for a more detailed discussion of the purpose of the "from discovery of ' failure to meet the LC0" portion of the Completion Time. , An SI subsystem is inoperable if it is not capable of delivering design flow n to the RCS. Individual components are' inoperable if they are not capable of '

performing their design function or supporting systems are not available.

Insert Page B 3.5-16a ; 1 Insert ACTIONS Due to the redundancy and independence of subsystems, the inoperability of one component in a subsystem does not render the ECCS incapable of performing its function. Neither does the inoperability of multiple different components. in different subsystems. necessarily result in a loss of function for the ECCS. The intent of this Condition is to maintain two subsystems of 100% ECCS available. .C.d With two RHR subsystems inoperable, one RHR subsystem must be restored to OPERABLE status within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7 tys. The 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7-day Completion Time is I based on the availability of a separate redundant and independent 100% capacity RHR subsystem, and alternative means of removing decay heat below 350*F. An STP analysis (Ref.1) has shown that the impact of having two RHR subsystems inoperable is sufficiently small to justify continued operation for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months 7 dys. 1 An RHR subsystem is inoperable if it is not capable of being aligned to provide flow through the RHR heat exchanger for the removal of decay heat from the 3rimary system following a reduction of RCS temperature to less than 350*:. This Action is not intended to be used to voluntarily remove two subsystems from service. It is intended, however, to allow time to restore one subsystem to OPERABLE status when one subsystem has been intentionally removed from service for testing or maintenance and another subsystem becomes inoperable l

for unplanned reasons. j Due to the redundancy of subsystems and the diversity of potential heat removal methods, the ino)erability of two RHR pumps does not render the other l train or alternative met 1ods of heat removal incapable of performing the )

required function. l 1 U 4 With two SI subsystems %. arable, one inoperable subsystem must be returned I to OPERABLE status witic n _4 hours. In this Condition the plant maintains l 100% of a single OPERABLE SI subsystem available: however some DBAs such as a 1 break in a location which diverts all flow, preventing it from reaching the i RCS. could prevent one SI subsystem from providing the required function. The i 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months Completion Time is based on an NRC reliability evaluation (Ref. 6). ! and is a reasonable time for repair of many ECCS components. An STP analysis ! (Ref.1) has shown that the impact of having two SI subsystems inoperable is sufficiently small to justify continued o)eration for 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months . An SI l subsystem is inoperable if it is not ca)a]le of delivering design flow to the l RCS. Individual components are inoperaale if they are not capable of performing their design function or supporting systems are not available. Insert Page B 3.5-16b 1 l Insert ACTIONS This Action is not intended to be used to voluntarily remove two subsystems from service. It is intended, however, to allow time to restore one subsystem to OPERABLE status when one subsystem has been intentionally removed from service for testing or maintenance and another subsystem becomes inoperable for unplanned reasons. E.1 and E.2 If the Reauired Action and Comoletion Times of Conditions A. B. or C are not met. the )lant must be brouaht to a MODE in which the LCO does not acolv. To achieve t1is status. the olant must be brouaht to MODE 3 within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 4 within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months . The allowed Comoletien Times are reasonable. based on - operatina exoerience. to reach the reauired olant conditions from full owoer conditions in an orderly manner and without challenaino olant systems. f.d M , If the Required Action and Com)letion Times of Condition: A. B. C. cr D in we not met, risk assessment has slown that the plant is in a condition which jeopardizes continued plant safety, and a shutdown is appropriate. Therefore, immediate entry into LCO 3.0.3 is appropriate. Similarly, when three subsystems of SI are inoperable exclusively for reasons other than inoperabilities associated with the RHR heat exchanger, the plant is in a condition outside the accident analyses: therefore, LC0 3.0.3 must be entered immediately. A Note has been included which indicates that this Condition is not applicable if three subsystems of RHR are inoperable. Condition G F requires immediate action to restore one subsystem of RHR to l OPERABLE status, and when completed. this Condition will apply. With three trains of RHR inoperable, the plant cannot shutdown in a normal controlled manner. GJ. M I With three RHR subsystems inoperable the plant is not capable of providing decay heat removal via the preferred and required method. This Condition is applicable only if all three RHR subsystems are inoperable. Action must be immediately initiated and continued until one train is restored to OPERABLE ! status. The Required Action for inoperable RHR subsystems does not require a shutdown because the RHR subsystems are used to perform the shutdown. A forced shutdown would direct the plant to take actions which required systems could not support and could result in challenging safety systems. The immediate Completion Time reflects the importance of returning an RHR l subsystem heat excher.ger to OPERABLE status. Other methods of post accident l l decay heat removal exist below 350*F. The immediate Completion Time also reflects the importance of maintaining the availability of the balance of the RHR subsystem to support the availability of this method of heat removal. Insert Page B 3.5-16c l l l - . - _ ~ _ . . _ . . . - .-- _.. _...--.._- ---.-.- - - . - . _ - . _ _ _ - . . ! ECCS-Oparating

B 3.5.2 1

l BASES ACTIONS B.1 and B k _ (continued) y e inoperable trains cannot be i turned to BLE

] status within the associated Complet kn Ti e plant must be brought to a MODE in which the LCO co not apply. To I

achieve this status, the plant must rought to MODE 3 i within 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and MODE 4 within ours. The allowed I Completion Times are reasonabl ased on operating ; j experience, to reach the r red plant conditions from full 1 power conditions in an erly manner and without ' j challenging plant s ens. F l SURVEILLANCE sR 3.5.2.1 . { REQUIREMENTS 3 i . fVerificationofpropervalv ksition ensures that the flow l path from the ECCS pumps tie RCS is maintained. Misalignment of these ves could render both ECCS trains

inoperable. Secur these valves in position by removal i power or by key cking the control in the correct pos on ensures that ey cannot change position as a resul f an

! active fa or be inadvertently misaligned. se valves

are of a type, described in Reference 6, th can disable

the etion of both ECCS trains and invali e the accident i yses. A 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Frequency is consid reasonable in

view of other administrative controls t will ensure a l taispositioned valve _is unlikely.

SR 3.5.2

.s

] Verifying the correct alignment for manual,' power operated, and automatic valves in the ECCS flow paths provides assurance that the proper flow paths will exist for ECCS 4 operation. This SR does not apply to valves that are

locked, sealed, or otherwise secured in position, since

these were verified to be in the correct position prior to

locking, sealing, or securing. A valve that receives an actuation signal is allowed to be in a nonaccident position l provided the valve will automatically reposition within the i proper stroke time. This Surveillance does not require any 1 testing or valve manipulation. Rather, it involves l verification that those valves capable of being i mispositioned are in the correct position. The 31 day j ' Frequency is appropriate because the valves are operated l

f (continued) WOG STS B 3.5-17 Rev1,04/07/95 I l t 4 4 l ECCS-Operating ' B 3.5.2 BASES SURVEILLANCE SR 3.5.2 6) ( inued) REQUIREMENTS under administrative control, and an improper valve position would only affect a single train. This Frequency has been shown to be acceptable through operating experience. SR 3.5.2 hW4T Wit _ exception awe coeratina.4Entrifuaal charuinD . the ECCS pumps are normally in a standby, nonoperating mode. As such, flow path piping has the potential to ; develop volds and pockets of entrained gases. Maintaining j the piping from the ECCS pumps to the RCS full of water 4 ensures that the system will perform properly, injectino its J 4 full capacity into the RCS upon demand.ginis will also ./ prevent water hammer, pump cavitation, and pumping of y noncondensible gas (e. ., a g the reactor vessel foi owin.ir, nitrogen, or hydrogen) into i >*b N T o an SI sional or durina shutdown coolin . TheT$ruay rrequency takes into consiaeration the STET eMe d +L 44% Aa: %Wf**h+i gradua nature of gas accumulation in the ECCS pipin , we 4Aad ne ornc.eetrrn controls coverninn.evnem operauun.~- .h+, 4 ( wg nk:nN lt$da uAsk sI 4 SR 3.5.2. 1 Periodic surveillance testing o (f23 umps to detect gross , degradation caused by impeller structural damage or other hydraulic component problems is required by Section XI of a the ASME Code. This type of testing may be accomplished by measuring the pump developed head at only one point of the

pump characteristic curve. This verifies both that the

' measured performance is within an acceptable tolerance of the original pump baseline performance and that the performance at the test flow is greater than or equal to the performance assumed in the plant safety analysis. SRs are specified in the Inservice Testing Program, which encompassesSection XI of the ASME Code.Section XI of the

ASME Code provides the activities and Frequencies necessary

, to satisfy the requiraments. 3 g SR 3.5.2.E and SR 3 . 5. 2 .s i These Surveillances demonstrate that each automatic ECCS valve actuates to the required position on an actual or , (continued) WOG STS B 3.5-18 Rev 1, 04/07/95 i e 0 l Insert ACTIONS Insert SR 3.5.2.2 This is accomolished by ventina the ECCS oumo casinos and accessible discharae D1Dina hiah ooints. Insert Paae B 3.5-18 ECCS-Op; rating B 3.5.2 BASES SR 3.5.2 Y @ SURVEILLANCE and SR 3.5.2.@ (co u REQUIREMENTS simulated SI signal and that eat ump s rts on 3 receipt of an actual or simulated SI signal. Th s "5urventianc ot requirea lor ves that are lock , seale herwise securad +ha vaanirad ane4+ under i trative controls fihe 18 month' Frequency is based on the need to perform these Surveillances under the conditions that apply during a plant outage and the potential for unplanned plant transients if the Surveillances were performed with the reactor at power. The 18 month Frequency J is also acceptable based on consideration of the design reliability (and confirming operating experience) of the equipment. The actuation logic is tested as part of ESF Actuation System testing, and equipment performance is monitored as part of the Inservice Testing Program. ) r gp 3,g,7,7\ 5 Realignment r[alves in the flow path o an SI signal is necessary proper ECCS performance These valves have stops to low proper positioning f restricted flow to a ruptur col;l leg, ensuring that e other cold legs receiv at ast the required minimum f w. This Surveillance is required for plants with ow limiting orifices. T 8 month Frequency is base n the same reasons as th e , (statedinSR3.5.2.5and 3.5.2.6. , i SR 3. 5.2 zO 1 . 1 Periodic inspections of the containment sump suction inlet ensure that it is unrestricted and stays in proper operating condition. The 18 month Frequency is based on the need to - perform this Surveillance under the conditions that apply I catleA G<3 during a plant outage, on the need to have access te the } locationT and because of the potential dEEWI!EfMBER l ( ALARA Mas s Em** if the Surveillance were performed with the l / reactor at power. This Frequency has been found to be f sufficient to detect abnormal degradation and is confirmed J by operating experience. Gr..t.4 g , . a., .a i punaseun (continued) WOG STS B 3.5-19 Rev1,04/07/95 l l f ! ECCS-OpIrating B 3.5.2 ) 1 , BASES (continued) l V REFERENCES g@ 10 CFR 50, Appendix A, GDC 35. j g$ 10 CFR 50.46. . @FSAR, Section - j @ @ SAR, Chapter / 15}7 N :it-+ A-t';- 5 3 [NRCMemo um to V. Sta o, Jr., from .L. Baer, " Rec ed Interim isions to LCO for ECCS loup ts," December , 1975. i {

(@D _!E Iprormattopolotice No. 87-01.7 i

l 4. L-Te4 F; J. % M Tc.<1 w d h t{su h 5 f g# h (c N.M u L w b <. 6 , 4's F L W M ; T*d3 St. j LT93,f f l 4 1 % l:u b f A N bb W S k g A55< M -b J Q w.. v g m,--a ru.a s c.a. f - l WOG STS B 3.5-20 Rev 1, 04/07/95 9 i - . J i U I ECCS-Shutdown B 3.5.3 B 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) B 3.5.3 ECCS-Shutdown BASES BACKGROUND The Background section for Bases 3.5.2, "ECCS-Operating," l 1s applicable to these Bases, with the following j modifications. ; 2 In MODE 4, the required ECCS trai consist @of two separate l %4 \ i G .rying m enai ano re u ouav 4 [gg g Jj Tuosystem I (W at remo (low head W i The ECCS flow paths consist of piping, valves, heat exchangers, and pumps such that water from the refueling - water storage tank (RWST) can be injected into the Reactor Coolant System (RCS) following the accidents described in Bases 3.5.2. APPLICABLE The Applicable Safety Analyses section of Bases 3.5.2 also SAFETY ANALYSES applies to this Bases section. slees, Io 3 Due to the stable conditions associated with operation in i MODE 4 and the reduced probability of occurrence of a Desig Pemw l Basis Accident (DBA), the ECCS operational requirements are pryMetf*t9 i reduced. It is understood in these reductions that --- - 1 automatic safety injection (SI) actuation is not available. In this MODE, sufficient time exists for manual actuation of the re uired ECCS to mitigate the consequences of a DBA. y* Only GDP trai of ECCS equired for MODE 4. This requirement dictates that single failures are not considered ' during this MODE of operation. The ECCS trains satisfy Criterion 3 of the NRC Policy Statement. LCO In MODE 4, of the independenttandredundantNCCS f trains is required to be OPERABLE to, ensure that sufficient ECCS flow is available to the core following a DBA. p.mewJ k., MJ" In MODE 4, an ECCS train consists of accen1.revai diartrtno uomz.amuna an sum suosystem Each train includes the ""*"P' piping, instruments, and controls to ensure an OPERABLE flow (continued) WOG STS B 3.5-21 Rev1,04/07/95

e e

1 Insert Backaround d i i trains of High Head Safety Injection (HHSI) and Low Head Safety Injection (LHSI) pumps. In MODE 4 the OPERABILITY requirements for the RHR pumps are described in LCO 3.4.6 "RCS Loops - MODE 4'. and are not a part of this

specification.

1 a 3 i )I i i i i i l 2 j i i l 4 i Insert Page B 3.5-21 ECCS-Shutdown q B 3.5.3 1 . BASES fm n.ocq ogcumuW ' LC0 path capable of taking suction from the RWST and wvu CA saa. - (continued) transferring suction to the containment sump. W ypppf During an event requiring ECCS actuation, a flow path is ' required to provide an abundant supply of water from the ]- g ,w 't RWST to the RCS via the ECCS pumps == ma6m a aa 4:

__.am to each m.<ve coun cold. leg injection nozz'es. In the long ters, th's flow path may be switched

' to take its supply from the containment sump and to deliver-its flow to the RCS hot and cold legs.

4 h AfL60 b c

, APPLICABILITY In MODES 1, 2, and 3, the OPERABILITY requirements for(LR5H!J 4-4**O

g 4 M are covered by LC0 3.5.2.

@ In MODE 4 with RCS temperature below 350*F, ECCS train @ acceptable without single failure OPERABLE consideration, reactor and the limit'1 on thecore basis coolingof the stable reactivity requirements. W of the /;4 - \ Ay .ALLg\ )-- In MODES 5 and 6, plat.L conditions are such that the probability of an event requiring ECCS injection is L extremely low. Core cooling requirements in MODE 5 are i addressed by LC0 3.4.7, "RCS Loops-MODE 5, Loops Filled," j- and LC0 3.4.8, "RCS Loops-MODE 5, Loops Not Filled." MODE 6 core cooling requirements are addressed by LC0 3.9.5, " Residual Heat Removal (RHR) and Coolant Circulation-High Water Level," and LC0 3.9.6, " Residual Heat Removal (RHR)

and Coolant Circulation-Low Water Level."

7- ; j ACTIONS . With no ECCS subsystem OPERABLE, the plant is no ; i prepared to spond to a loss of coolant accident to continue cooldown using the RHR pumps and he exchangers. I , The C etion Time of immediately to initia actions that ! .t - \A we restore at least one ECCS RHR subsys to OPERABLE

4 atus ensures that prompt action is tak to restore the

/ U Acmf required cooling capacity. Normally, decay heat is removed from the RCS MODE 4, reactor an RHR loop. If no RHR loop is OPERABLE for this fu ton, reactor decay heat must be removed by some alte e method, such as use of the generators. The alte ate means of heat removal musty ; (continued) WOG STS B 3.5-22 Rev 1, 04/07/95 i y l i . - - - - , m __ _, - - . - . - _ . .. - -. .- . . .. . . . _ . . - - - ~ l l i [ 'Q l Insert LCO N J v The LC0 is modified by four Notes. The first Note provides an allowance for entry into MODE 4 from MODE 3 with more than one HHSI pump breaker racked in. j This Note permits entry into MODE 4. followed by a system alignment which i consistent with the assumptions of Low Temperature Overaressure Protection s l (LTOP) analyses assumptions. ~ The temperature limit is )ased on the P/T curve . i in the LTOP analyses (Ref.-1.) ; i The second Note is provided to permit the filling of accumulators or l performance of system testing. Before an additional HHSI pump breaker may be racked in, the discharge of the associated pump.must be isolated from the RCS l to prevent a mass addition excursion beyond the capability of the LTOP system. < To assure that the RCS is protected, an isolation valve is closed with the : power removed. The third Note is provided to permit entry into MODE 4 from MODE 5 with no HHSI pump breaker racked in. Specification 3.4.13. "LTOP System - MODE 5 and MODE 6 with Head On" requires all three HHSI pump breakers to be racked out. , This Note provides operational margin to enter MODE 4 and then place a Sum) in , service with its breaker racked in. The temperature limit is low enoug1 tlat - an event which requires HHSI pump actuation will not occur too quickly for operator intervention to restore a pump to service. Bekw At 225 F and below. I i after being in MODE 5. the RCS remains near cold shutdown conditions, and HHSI ! ECCS response will not typically be required. The fourth Note is provided to clarify the applicable specification for RHR i OPERABILITY in MODE 4. This Note is necessary because the RHR provides an ECCS support function for some DBAs when the plant is operating in MODES 1. 2. l and 3. as described in LCO 3.5.2 and associated Bases. However in MODE 4. the -RHR OPERABILITY requirements are specified in the Reactor Coolant System i chapter of the Technical Specifications since the RHR system becomes one of i the primary methods of heat removal. The Note assures that the user properly refers to LC0 3.4.6. "RCS Loops - MODE 4." for the use and requirements applicable to the RHR subsystem. -Q Jnsert Acolicability Two trains are required because the system must be ca)able of res)onding to a DBA pipe break which could occur at a cold leg such tlat one of tie injection flows would be diverted away from the core cooling function. l Insert Page B 3.5-22a ,- n InsertACTIONS"y7.( ~U A.1 and A.2 i With one required ECCS train inoperable, the plant is not prepared to respond to the relatively unlikely event of a loss of coolant accident which occurs at . a location which diverts the flow of the remaining OPERABLE ECCS train. l Required Actions for this condition include verification that the OPERABLE : HHSI pump breaker is racked in to support immediate operation and to restore - the second ECCS train within 14 days. The Completion Time of I hour to verify an HHSI subsystem is OPERABLE with l l the > ump's breaker properly aligned ensures that the required ECCS train is t capa)le of performing its function if manually actuated. Verification of an OPERABLE HHSI pum) with its breaker closed is not intended to require the pump - be associated wit 1 the OPERABLE ECCS train. This s)ecification requires many components within the ECCS to be OPERABLE. Inopera)ility of one com]onent may not affect the OPERABILITY of another. For example, an inoperable LiSI pump may not prevent a HHSI pump from performing its function. :or this Condition, the HHSI pump, in the same train as an inoperable LHSI pump, may continue to serve as an OPERABLE HHSI pump. The intent of this Condition is to ensure that 100% capacity of a single train of ECCS remains OPERABLE. . The Completion. Time of 14 days to restore the second ECCS train is appropriate ! based on the low probability of a LOCA in MODE 4 which results in a loss of injection flow from the OPERABLE train. IL1 With two required ECCS trains inoperable, the 31 ant is not prepared to respond to Design Basis Events requiring SI. T1e 1 hour1.157407e-5 days 2.777778e-4 hours 1.653439e-6 weeks 3.805e-7 months Com)letion Time to restore at least one ECCS train to OPERABLE status ensures tlat prompt action is taken to provide the required cooling capacity Or to initiate action: to place the plant in MODE 5. 2cre an ECCS train is not required. This Action is not intended to be used to voluntarily remove two required j trains from service. It is intended, however, to allow time to restore one : required train to OPERABLE status when one train has been intentionally ' removed from service for testing or maintenance and another required train t becomes inoperable for unplanned reasons. Insert Page B 3.5-22b l ECCS-Shutdown B 3.5.3 BASES ACTIONS L1 (continur. continue il the inoperable RHR loop components can restore o operation so that decay heat removal is Cont Ous. ith both RHR pumps and heat exchangers inope 1e, it would be unwise to require the plant tc go to MO 5, where the only available heat removal system is th R. Therefore, the appropriate action is to initiate asures to restore ! one ECCS RHR subsystem and to conti the actions until the i subsystem is restored to OPERABLE atus. U

With no ECCS high head bsystem OPERABLE, due to the l inoperability of the entrifugal charging pump or flow path from the RWST, the lant is not prepared to provide high ,

j pressure respons to Design Basis Events requiring SI. The l f I hour Comple n Time to restore at least one ECCS high head subsys to OPERABLE status ensures that prompt ac n is taken provide the required cooling capacity or t initiat actions to place the plant in MODE 5, where n ECCS trat s not required. y u v.- @ When the Required Actions of Condition)E cannot be completed within the required Completion Tine, a controlled shutdown ~ should be initiated. Twenty-four hours is a reasonable time, based on operating experience, to reach MODE 5 in an orderly manner and without challenging plant systems or operators. SURVEILLANCE SR 3.5.3.1 REQUIREMENTS The appl: sable Surveillance descriptions from Bases 3.5.2 apply. I nu an is an en mea oy a note snat an ,I praintobeconsid ed OPERABLE during ali n t and operation for dec heat removal, if capab f being I anually realig (remote or local) to th ECCS mode of J (continued) WOG STS B 3.5-23 Rev 1, 04/07/95

O

ECCS-Shutdown B 3.5.3 BASES SURVEILLANCE SR 3.5.3.1 (continued) REQUIREMENTS yu ation not otherwise inopera . This ainw., boerat the RHR mode during ild 4, if necessary c = REFERENCES The applic ble references from Bases 3.5. ply. 4 I I ff. RuP-o7ft, *cew.+ Nr teAc= b L & Ak 3 \,,) C.\A o*puw N;6yb % h 'is M bb- upS ~4 4 ber %A Tem W45 l $ 2. , (Res.z")", 563istiq, L (wt 5 A 3.0 3,2. I

i l

i 1 WOG STS B 3.5-24 Rev 1, 04/07/95 , ...+.

O

4 Insert SR 3.5.3.2 f s/ SR 3.5.3.2 This SR is provided to assure that the assumptions of the LTOP analyses for the plant are maintained. The analyses assumed that for the mass and pressure , transients in H0DE 4. the potentially OPERABLE Jumps were limited to one L 1 centrifugal) charging pum) and one HHSI pump. T1e SR is modified by two Notes wucn require the SR to )e met at a tem >erature of > 225'F. when entering from H0DE 5 and < 325'F. if entering from M0)E 3. The Frequency provides verification that the HHSI pump breakers are appropriately aligned upon entry into MODE 4 and once per 31 days. This frequency is adequate to assure the appropriate alignment is maintained when considered with the other

administrative controls over plant equipment, i.

l O V i l Insert Page B 3.5-24 l RWST B 3.5.4 0 3.5 EMERGENCY CORE COOLING SYSTEMS (ECCS) B 3.5.4 Refueling Water Storage Tank (RWST) , BASES BACKGROUND The RWST supplies borat water to the Chemical and Volume Control System (CYCS) uring abnormal operating conditions, to the refueling during refueling, and to the ECCS and p the Containment Spray System during accident conditions. The RWST suppliesD trains of the ECCS and the ContainmentSpraySystemthrough(separzer-reaunaan/@usupply l header $ during the injection phase of a loss of coo'lant I - h -, accident (LOCA) recovery. A motor operated isolation valve is provided in each header to isolate the RWST from the ECCS i S Mc SM once the system has been transferred to the recirculation hF*4J40ekw %i mode.YThe recirculation mode is entered when pump suction

w1 M % .* 1s transferred to the containment sump following receipt of apukd % .dt3 the RWST-Low Low (Level 1) signal. Use of a single RWST to suppiy w trains of the ECCS and Containment Spray System is acceptable since the RWST is a passive component, and gf passive failures are not required to be assumed to occur l coincidentally with Design Basis Events. '

FThe switcho r from normal ration to the inj ion phasel of ECCS o ration requir changing centrifug charging pump s ion from the S volume w trol k (VCT) to th i , RWS" hrough the us f isolation vahes Each set of ! js(ation valves 's interlocked so tha the VCT isol on valves will b n to close once the ST isolation Ives are fully n. Since the VCT is nder pressure the preferr pump suction will be om the VCT u 1 the tank is is ated. This will resu in a delay i obtaining the RW borated water. The ects of this lay are diseu ed the Applicable Safety nalyses sect n of these Bas .. During normal operation in MODES 1, 2 nd the EM M I ! (injetuerrT51) ana reslauarneat remova L.mm)1 pumps are M.M aligned to take suction from the RWST. 5P r* 5 s i l The ECCS and Containment Spray System pumps are provided with recirculation lines that ensure each pump can maintain l minimum flow requirements when operating at or near shutoff ! head conditions. ' (continued) WOG STS B 3.5-25 Rev 1, 04/07/95 I 1 RWST B 3.5.4 i BASES i BACKGROUND When the suction for the ECCS and Containment Spray System (continued) pumps is transferred to the containment sump, the RWST flow i natheN isolated to prevent a release of the containment sump contents to the RWST, which could result in MS a release of contaminants to the atmosphere (and tnemaD Qoss oLeecuan nead fama FCcs nuino3 @ This LC0 ensures that:

a. The RWST contains sufficient borated water to support the ECCS during the injecti,on phase;

b. Sufficient water volume exists in the containment sump to support continued operation of the ECCS and 4

Containment Spray System pumps at the time of transfer to the recirculation mode of cooling; and

c. The reactor remains suberitical following a LOCA.

Insufficient water in the RWST could result in insufficient cooling capacity when the transfer to the recirculation mode occurs. Improper boron concentrations could result in a l reduction of SDM or excessive boric acid orecipitation in the core following the LOCAr as wel excessive causuc ress curr or mecnarncal onents and systems i de , the co menir; i APPLICABLE During accident conditions, the RWST provides a source of SAFETY ANALYSES borated water to the ECCS and Containment Spray System i pumps. As such, it provides containment cooling and depressurization, core cooling, and replacement inventory I and is a source of negative reactivity for reactor shutdown 1 (Ref.1). The design basis transients and applicable safety analyses concerning eact, of these systems are discussed in the Applicable Safety Analyses section of B 3.5.2, "ECCS-Operating"; B 3.5.3, "ECCS-Shutdown"; and B 3.6.6, " Containment Spray and Cooling Systems." These analyses are

used to assess changes to the RWST in order to evaluate their effects in relation to the acceptance limits in the analyses, g The RWST must also meet volume n a=% , - -, ronevents.

- = for non-LOCA concentration The volume @ 15 not an explicit assumption in non-LOCA events since the i (continued) WOG STS 8 3.5-26 Rev1,04/07/95

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1 RWST , B 3.5.4 l l BASES APPLICABLE required volume is a small fraction of the available volume. SAFETY ANALYSES $The deliverable volume limit is set by the LOCA and (continued) containment analyses.$ For the RWST, the deliverable volume is different from the total volume contained since, due to i the design of the tank, more water can be contained than can be delivered. The minimum boron concentration is an explicit assumption in the main steam line break (MSLB' analysistoensuretherequiredshutdowncapability.69-h 71mpor of its value small for units in a Doron in n tank (BIT) a high boron ntratio a Lu with no BIT o duced BIT boron nuirements e

minimum boron concentration limit is an important assumption in ensuring the required shutdown capability.

_ e maximum toron concentratio s an explicit assumon o n the ' i inadvertent ECCS ctuation analysis, alth it is typically a n initing event and the r ults are very insensitiv o baron concentrations. he maximum 1 temperat ensures that the amoun f cooling provided from i the R during the heatup phase a feedline break is co stent with safety analysi ssumptions; the minimum s assumption in both the MS and inadvertent ECCS actuation analyses, altho the inadvertent ECCS ac atio 4Lvent is typically non1 ting.J ) IThe MSLB analy has considered a d ay associated with t interlock be een the VCT and RWST solation valves, and e results s that the departure om nucleate boiling d ign basis i t. The delay has b n established as [27 conds, with offsite p er available, or [37) econds wit ut offsite power. Thi response time include [ seconds for electroni delay, a [15) second troke time or the RWST valves, an a[10)secondstroke me for the VCT valves. Plants w a BIT need not be c cerned with the delay since the IT will supply highly rated water prior to RWST swi over, provided the BI is Letween the gumpsandthecyeg A For a 1arce break LOCA analysis, the minimum awater volume

3 1 limit of f 4fhaecT ga11nnsfand the lower Doron concentration 16eo} # limit of ugggy ppa are used to compute the post LOCA sump g y.Jgg i boron concentration necessary to assure suberiticality. The 4g,,,,yg, M;gdl large break LOCA is the limiting case since the safety ,

analysis assumes that all control rods are out of e core. The upper limit on boron concentration of ppm is used to detemine the maximum allowable time to switch to hot leg (continued) WOG STS B 3.5-27 Rev 1, 04/07/95 E - _ - . - - - - ~ - . - . _ . - . . - . . - - . . . - . - . . . . - . . . - ~ . _ . - - - . - - ..-- i RWST i B 3.5.4 i BASES i

l APPLICABLE recirculation following a LOCA. The purpose of switching SAFETY ANAL)SES from cold leg to hot leg injection is to avoid boron j (continued) precipitation in the core following the accident. ;

i. i I In the ECCS anal s, the containment spr temperature is ! assumed to be al to the RWST lower erature limit of I [35]'F. If e lower temperature li is violated, the . l containee spray further reduces ntainmant pressure, l which reases the rate at whi steam can be vented ou the ak and increases peak ad temperature. The up I t rature limit of LOCA alysisandcontainme[ntI00]* is used analysis. ERABILITY in the small Ex eding br i this temperature will r uit in a higher peak c1 temperature, because ere is less heat transf from the core to the inject water for the small bre LOCA and higher contai pressures due to reduc containment spray coolin pacity. For the contai nt response following LB, the lower limit on ron concentratioy and the er limit on RWST water t eratureareusep4c] taaximi t a total energy release o containment a , The RWST satisfies Criterton' 3 of the NRC Policy Statementh _% 2Y LC0 The RWST ensures that an adequate supply of borated water is available to cool and depressurize the containment in the 1 event of a Design Basis Accident (DBA), to cool and cover the core in the event of a LOCA, to maintain the reactor i suberitical following a DBA, and to ensure adequate level in the containment sump to support ECCS and Containment Spray l System pump operation in the recirculation mode. To be considered OPERABLE, the RWST must meet the water I } l I Mr volumeMboron concentrationt-GJ3t'EireFaNPBlimits j estab1Tshed in the SRs. I ' l APPLICABILITY In MODES I, 2, 3, and 4, RWST OPERABILITY requirements are dictated by ECCS and Containment Spray System OPERABILITY requirements. .Since both the ECCS and the Containment Spray System must be OPERABLE in MODES 1, 2, 3, and 4, the RWST must also be OPERABLE to support their operation. Core cooling requirements in MODE 5 are addressed by LC0 3.4.7, "RCS Loops-MODE 5, Loops Filled," and LCO 3.4.8, "RCS (continued) WOG STS 8 3.5-28 RevI,04/07/95 e 9 l RWST l B 3.5.4 BASES i APPLICABILITY Loops-MODE 5, Loops Not Filled." MODE 6 core cooling (continued) requirements are addressed by LC0 3.9.5, " Residual Heat Removal (RHR) and Coolant Circulation-High Water Level," and LCO 3.9.6, " Residual Heat Removal (RHR) and Coolant Circulation-Low Water Level." ACTIONS L1 ;4 Z With RWST baron co centratio Er M :L water tamnaraturei

1. not within limits, must be returned to within limits g -

within 8 hours9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months . Unitar conditiore - ar> M a ECCS U erna 1 - i -a 3- an- canAperform its design functiork Therefore, prompt action must be taken to restor . ne tank to OPERABLE condition. The 8 hour9.259259e-5 days 0.00222 hours 1.322751e-5 weeks 3.044e-6 months limit to restore the RWST(TiiiiiEPRTriT6 boron concentration to within its was developed considering the time required to change $ the boron concentration or 1 - ..ture;and the fact that the contents of the tank are still available for injection. l With the RWST inoperable for reasons other than Condition A i 2 e.g.Mvolumel), it must be restored to OPERABLE status I within I hour. ' A:. 2 In this Condition, neither the ECCS nor the Containment ; Spray System can perform design function. Therefore, ! prompt action must be taken to restore the tank to OPERABLE v status or to not required. place the plant The short timeinlimit a MODE in which of I hour the RWST to restore the is RWST to OPERABLE status is based on this condition simultaneously affecting redundant trains. C.1 and C.2 If the RWST cannot be returned to OPERABLE status within the associated Completion Time, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within , 6 hours6.944444e-5 days 0.00167 hours 9.920635e-6 weeks 2.283e-6 months and to MODE 5 within 36 hours4.166667e-4 days 0.01 hours 5.952381e-5 weeks 1.3698e-5 months . The allowed ' Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full (continued) WOG STS B 3.5-29 Rev1,04/07/95

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RWST B 3.5.4 BASES i ACTIONS C.1 and C.2 (continued) power conditions in an orderly manner and without I challenging plant systems. s l l SURVEILLANCE SR 3.5.4.1 l REQUIREMENTS rThe RWST bora water temp ture should be rified every 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months to e within the sits assumed i he accident analyses nd. This Fr uency is suffic nt to identify a i a' temper .ure change th would approach ither limit and h ! bee shown to be ac ptable through erating experienc . l ~ <. \ The SR is modif d by a Note th eliminates the re tremen ! to perform th Surveillance n ambient air te ratures are within e operating li s of the RWST. W ambient ; air temp atures within t band, the RWST te erature i shoul at exceed the 1 ts. F A 3.5.4.2 i The RWST water volume should be verified every 7 days to be I above the required minimum level in order to ensure that a l sufficient initial supply is available for injection and to l support continued ECCS and Containment Spray System pump -l operation on recirculation. Since the RWST volume is , normally stable and is protected by an alarm, a 7 day Frequency is appropriate and has been shown to be acceptable ' r-- ~ through operating experience. SR 3.5.4. The boron concentration of the RWST should be verified every 7 days to be within the required limits. This SR ensures that the reactor will remain suberitical following a LOCA. Further, it assures that the resulting sump pH will be maintained in an acceptable range so that boron precipitation in the core will not occur and the effect of chloride and caustic stress corrosion on mechanical systems and components will be minimized. Since the RWST volume is normally stable, a 7 day sampling Frequency to verify boron (continued) ] WOG STS B 3.5-30 Rev 1, 04/07/95 4 4 ~ RWST . B 3.5.4 ) ) BASES .i l i SURVEILLANCE SR 3.5.4.3 (continued) I i REQUIREMENTS ! concentration is appropriate and has been shown to be j acceptable through operating experience. REFERENCES 1. FSAR, Chapter had(6htetedf15}f' s' i i - 1 M Mg% W ~Mouf.6enQA.g p g ( bk Bee Reu6, sf ra.stesa., r:,g3 a.s, \q,3, 9 !M W j k i WOG STS 8 3.5-31 Rev 1, 04/07/95 sN Ssal Injsetien Flow B 3.5.5 t f b b5 B EMERGENCY CORE C00LIN YSTEMS (ECCS) 8 3.5.5 Seal Injection .. w j l BASES [ $ BACKG This LCO is applicable only to those nits that utilize the i centrifugal charging pumps for saf y injection (SI). The function of the seal injection t ottle valves during an i accident is similar to the fun on of the ECCS throttle valves in that each restrict ow from the centrifugal 4 charging pump header to th eactor Coolant System (RCS). l The restriction on rea r coolant pump (RCP) seal injection i flow limits the amou of ECCS flow that would be diverted i from the injection ath following an accident. This limit l 1s based on safe analysis assumptions that are required r because RCP se injection flow is not isolated during SI. i APPLICABLE All EC subsystems are taken credit for in the la l SAFETY ANALYSES bre oss of coolant accident (LOCA) at full p i ( . 1). The LOCA analysis establishes the a num flow 1 r the ECCS pumps. The centrifugal chargin umps are also credited in the small break LOCA analysis. his analysis i establishes the flow and discharge head the design point for the centrifugal charging pumps. T steam generator ! tube rupture and main steam line bre event analyses also credit the centrifugal charging > s, but are not limiting in their design. Reference to t se analyses is made in assessing changes to the Seal jection System for , evaluation of their effects relation to the acceptance limits in these analyses.

This LCO ensures that 1 injection flow of s [40] gpe,

with centrifugal cha ng pump discharge header pressure i h 12480)psigand rging flow control valve full open, wi'1 be sufficie for RCP seal integrity but limited s that the ECCS t ins will be capable of delivering

! sufficient wa r to match bolloff rates soon enough 4 minimize un vering of the core following a large . It ! also ensu s that the centrifugal charging pumps 11 1 deliver ufficient water for a small LOCA and s ficient ) boron o maintain the core subcritical. For 11er LOCAs, th harging pumps alone deliver sufficient uid to i rcome the loss and maintain RCS invent y. Seal 1 (continued) i WOG ST B 3.5-32 Rev 1, 04/07/95 1 h 4 1 j - . ( i _ _ _ _ . _ _ _ _ _ _ - . . - _ _ . . _ _ _ _ _ _ _ _ . _ . _ _ . . _ . . _ . _ _ ~ . _ i

Szal Injecticn Flow B 3.5.5 l' ;

i BASES f f -, APPLICABLE in tion flow satisfies Criterion 2 of he NRC Policy i SAFETY ANALYSES tenent. ; j (continued) ; i i .- i i LCO The intent of the LCO limit n seal injection flow is to l make sure that flow thro the RCP seal water injection 1 line is low enough to ure that sufficient centrifugal ! charging pump inject' flow is directed to the RCS via the i injection points ( . 2). i - j The LC0 is not rictly a flow limit, but rather a f1 limit based a flow lins resistance. In order t i establish e proper flow line resistance, a pre re and flow mu be known. The flow line resistance determined

by as ing that the RCS pressure is at no operating ,

pre ure and that the centrifugal charging discharge + p ssure is greater than or equal to the a ue specified in ! I his LCO. The centrifugal charging p discharge header ! pressure remains essentially consta t rough all the , applicable MODES of this LCO. A uction in RCS pressure > would result in more flow being verted to the RCP seal i injection line than at normal erating pressure. The valve ' settini;s established at the escribed centrifugal charging / ; j pump discharge header pre ure result in a conservative - i valve position should R pressure decrease. The additio l modifier of this LCO, e control valve (charging fin f I 4 i-O four loop units and ir operated seal injection fo. th e loop units) bein ull open, is required since the y e is designed to fa discharge p open for the accident condition. ure and control valve position as by the LC0 a flow limit is established. It is his flow th the f ecified F limit th is used in the accident analyses. ( ! The mit on seal injection flow, combine with the i c rifugal charging pump discharge hea r pressure limit i an open wide condition of the cha ng flow control i i valve, must be met to render the EC OPERABLE. If these conditions are not met, the ECCS will not be as assumed in the accident analyses. ICA8ILITY In MODES 1, 2, and 3, th seal injection flow limit is dictated by ECCS flow quirements, which are specif for i continued) (: WDG STS B 3.5-33 Rev 1, 04/07/95 l i A - t i i I Ssal Injecticn Flow l B 3.5.5 l i BASES f f 3 4 \ APPLICABILITY MODES 1 , 3, and 4. The seal injection ow limit is not (continued) appli le for MODE 4 and lower, however cause high seal I inj ion flow is less critical as a re it of the lower i tal RCS pressure and decay heat r val requirements in j , ese MODES. Therefore, RCP seal i ction flow must be - i limited in MODES 1, 2, and 3 to en re adequate ECCS j performance. f ACTI Ad With the seal injection low exceeding its limit, the amount of charging flow avai le to the RCS may be reduced. Under this Condition, act n must be taken to restore the flow to below its limit. e operator has 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months from the time the flow is known t above the limit to correctly position the manual val s and thus be in compliance with the accident ana sis. The Completion Time minimizes the potential posure of the plant to a LOCA with insuffici injectio ow and provides a reasonable time to resto seal in etion flow within limits. This time is conse ative with respect to the Completion Times of ther ECC C0s; it is based on operating experience and s su icient for taking corrective actions by oper tons rsonnel. O Y B.1 and B.2 When the Required Actions cannot be c required Completion Time, a contro11 leted within the shutdown must be initiated. The Completion Time of hours for reaching MODE 3 from MODE 1 is a reasonab time for a controlled shutdown, based on operating e erience and normal cooldown rates, and does not challenge lant safety systems or operators. Continuing the ant shutdown begun in Requir Action B.1, an additional hours is a reasonable time, based on operating expe ence and normal cocidown rate to reach MODE 4, where t s LCO is no longer applicable. (continued) WOG STS B 3.5-34 Rev1,04/07/95 l \

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I ) S2al Injacticn Flow l i t B 3.5.5 j BASES (continued) j f 3 i . SURVEILLANCE SR .5.5.1 i REQUIREMENTS ] Verification every 31 days that e manual seal injection throttle valves are adjusted t give a flow within the limit ensures that proper manual s injection throttle valve a, position, and hence, proper eal injection flow, is maintained. The Frequene of 31 days is based on j j engineering judgment a s consistent with other ECCS valve

Surveillance Frequenci . The Frequency has proven to be 4

acceptable through o rating experience. j As noted, the sur 111ance is not required to be perfo until 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months a er the RCS pressure has stabilized wit na i 20 psig ra of normal operating pressure. The~RC pressure re resent is specified since this config tion will prod the required pressure conditions nece ary to 3 1 assure t the manual valves are set correctly. he t excep n is limited to 4 hours4.62963e-5 days 0.00111 hours 6.613757e-6 weeks 1.522e-6 months to ensure that e -) Sury 11ance is timely. l REFERENCES 1. FSAR, Chapter [6] and Chapter [15

2. 10 CFR 50.46.

J / i 110G STS B 3.5-35 Rev 1. 04/07/95 l . . e - . .. - - - -. - - . ~.- .- . . ~ _ . . - . - - - - _ = _ - . . - . . - _ . 4 BIT j B 3.5.6 _ )

83.5 EMERGENCY CORE C00LI SYSTEMS (ECCS)

N 8 3.5.6 Boron Injectio ank (BIT)

BASES 3

/ -

BACKGROUND The BIT is part of the Boron Injec on System, which is the primary means of quickly introdu ng negative reactivity ) into the Reactor Coolant Syst RCS) on a safety injection (SI) signal. l The main flow path throug he Baron Injection System is i from the discharge of th centrifugal charging pumps thro

lines equipped with a ow element and two valves in parallel that open o an SI signal. The valves can be '

operated from the in control board. The valves and ow elements have ma control board indications. Down ream of these valves, e flow enters the BIT (Ref.1), 1 The BIT is stainless steel tank containing co entrated boric ac . Two trains of strip heaters are nted on the , tank t eep the temperature of the boric ac" solution above he precipitation point. The strip h iters are con olled by temperature elements locate near the bottom i o he BIT. The temperature elements al activate High and i ow alarms on the main control board. addition to the strip heaters on the BIT, there is a circulation system i with a heat tracing system, includi the piping section between the motor operated isolati valves, which further ensures that the boric acid stay in solution. The BIT is i > also equipped with a High Pres e alarm on the main control

board. The entire contents o the BIT are injected when i re,1uired; thus, the contain and deliverable volumes are

{ the same. I I)uring normal operatio , one of the two BIT recirculation l ! pumps takes suction f on the boron injection surge tank l 1 - (BIST) and discharg to the BIT. The solution then retur s ; , to the BIST. No ly, one pump is running and one is s t l ! off. On receipt f an SI signal, the running pump shu off ; and the air o ated valves close. Flow to the BIT 1 then ! r supplied fr he centrifugal charging pumps. The ution j of the BIT injected into the RCS through the RC cold legs. i l (continued)

if06 STS B 3.5-36 Rev 1, 04/07/95 1

~ d 4 I - . f , . , ..m, ._. . ..- _ . _ . . _ -. _ _ _ _ _ I ~ BIT B 3.5.6 l BASES (continued) f , 33 APPLICABLE During a main eam line break (MSLB) or loss of olant

SAFETY ANALYSES accident (L ), the BIT provides an immediate rce of concentra boric acid that quickly introduc negative reactiv into the RCS.

I \ l The ontents of the BIT are not credite or core cooling or i diate boration in the LOCA analys , but for post LOCA

ecovery. The BIT maximum boron co entration of i [22,500? ppe is used to determine e minimum time for hot j 'eg rec 1rculation switchover. minimum boron i

concentration of [20,000] ppe used to determine the i minimum mixed mean sump bor concentration for post LOCA i shutdown requirements. For the MSLB analysis he BIT is the primary mechanism for ~ , injecting boron into he core to counteract any positive increases in reac ity caused by an RCS cooldown. The analysis uses t minimum boron concentration of the BIT, i which also aff ts both the departure from nucleate boiling i and contai t design analyses. Reference to the LOCA a MSLB analy s is used to assess changes to the BIT to evaluate air effect on the acceptance limits contai in these alyses. T minimum temperature limit of [145]*F for ti. IT ensures at the solution does not reach the kric a precipitation point. The temperature of t solution is monitored and alarmed on the main contro mard. The BIT boron concentration limits e established to ensure that tha core remains subcritical uring post LOCA recovery. The BIT will ;ounteract any po ive increases in reactivity caused by an RCS cooldown. The BIT minimum water v limit of [1100] gallons is used to ensure that the ap opriate quantity of highly borated water with suffici negative reactivity is injected into the RCS to shut the core following an MSLB, to determine the leg recirculation switchover time, an o safeguard a nst boron precipitation. The BIT tisfies Criteria 2 and 3 of the NRC P cy Stat t. (continued) WOG S B 3.5-37 Rev 1, 04/07/95 l + _ _ =-- - ,- - , - - - - . - . . . . _ . . _ - _ _ . - - - _ - - - . . . ~ . . - . . - - . . . - - ll; BIT B 3.5.6 BASES (continued) , '3 (" LCO This LCO estdii'. s the minimum requirements for contained j l volume, boron c centration, and temperature of the BIT - 1 ' inventory (Re . 2). This ensures that an adequate supp of borated va is available in the event of a LOCA or 8 to -

j. maintain ' e reactor subcritical following these ac dents. >

I To considered OPERABLE, the limits establish in the SR i i f water volume, boron concentration, and t erature must { met. , If the equipment used to verify BIT par ters(temperature, volume, and boron concentration) is ermined to be inoperable, then the BIT is also i perable.

LICABILITY In MODES I, 2, and 3, the T OPERABILITY requirements are consistent with those o C0 3.5.2, 'ECCS-Operating."

} In MODES 4, 5, and , the respective accidents are less l severe, so the B is not required in these lower MODES. l j ACTIONS Ad ! If e required volume is not present in the BIT, both e leg recirculation switchover time analysis and th boron i(

(

h recipitation analysis would not be met. Under the conditions, prompt action must be taken to restor the - volume to above its required limit to declare t tank 1 OPERABLE, or the plant must be placed in a in which the f BIT is not required. The BIT boron concentration is consid d in the hot leg recirculation switchover time analy s, the boron precipitation analysis, and the r ctivity analysis for an MSLB. If the concentration we not within the reouired limits, these analyses cou1( t be relied on. Underthese conditions, prompt action at be taken to restore the concentration to within s required limits, or the plant must be placed in a in which the BIT is not required. The BIT temperat limit is established to ensure th the solution does t reach the boric acid crystallizat ! point. If temperature of the solution drops ow the < 1 (continued) 'if0G STS B 3.5-38 Rev1,04/07/95 s , ..- - . . - - . - ~ . - . . - ~ - - - - . . - - - . - - - - - . - . . - . - ~ _ . - l 1 BIT ~ B 3.5.6 BASES / c ACTIONS L.1 (continued) minimum, pr action must be takers to raise the i temperatur and declare the tank OPERABLE, or th lant must be plac in a MODE in which the BIT is not re red. Th hour Completion Time to restore the to OPERABLE i tus is consis'.ent with other Complet Times established I or loss of a safety function and ens s that the plant - will not operate for long periods o side of the safety j analyses. i B.1. B.2. and B.3 l When Required Action cannot be completed within the i required Completion me, a controlled shutdown should be l initiated. Six h s is a reasonable time, based on operating exper ce, to reach MODE 3 from full power conditions a o be borated to the required SOM with challenging ant systems or o rators. Borating t he required assures that the lant is in a safe dition, without eed for any additiona boration. Aft determining that the BIT is inoperabl nd the R ired Actions of B.1 and B.2 have been leted, the nk must be returned to OPERABLE statu ithin 7 days. These actions ensure that the plant W not be operated with an inoperable BIT for a length eriod of time. It should be noted, however, that ch ges to applicable MODES s3' cannot be made until the BIT is estored to OPERABLE status pursuant to the provisions of 0 3.0.4. ful Even though the RC as been borated to a safe and stab condition as a r uit of Required Action B.2, either e BIT must be restor to OPERABLE status (Required Acti C.1) or the plant au be placed in a condition in which e BIT is not requi (MODE 4). The 12 hour1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months Completion me to reach MODE 4 i reasonable, based on operating ex tence and nonnal ooldown rates, and does not chall e plant safety syst or operators. I (continued) WOG STS B 3.5-39 Rev 1, 04/07/95

O

_ . _ . . _ _ . _ _ _ . _ _ _ ._._ - _ _._.. . - _ . . _ _ _ . _ . . _ _ . _ . . _ . . _ _ _ . . _ . ~ _ _ _ _ . _ _ . _ . _ _ 1 BIT l 8 3.5.6 0 BASES (continued) - -= I f 1 k SURVEILLANCE SR 3.5.6.1 REQUIREMENTS Verification ry 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .2 , the BIT water temperatu } is at or a e the specified minimum temperature is fr uent i enough to dentify a temperature change that would a roach the ac table limit. The solution temperature is so i moni ed by an alare that provides further assu nce of pr etion against low temperature. This Fre ncy has been ! own to be acceptable through operating exp ience. I 1 l SR 3.5.6.2- - Verification every 7 days that th IT contained volume is above the required limit is fre nt enough to assure that ! this volume will be available r quick injection into the i RCS. If the volume is too , the BIT would not provide i enough borated water to e re subcriticality during vacirculation or to shu down the core following an MSLB. . Since the BIT volume normally stable, a 7 day Frequency ! is appropriate and s been shown to be acceptable through , operating experie . 1 SR 3.5.6.3 ! Verific ion every 7 days that the boron concentration of

the B is within the required band ensures that the re tor

r ns subcritical following a LOCA; it limits retu to

! r following an MSLB, and maintains the resultin sump pH l ( n an acceptable range so that boron precipitatio will not

.

occur in the core. In addition, the effect of loride and

, caustic stress corrosion on mechanical syst and

- components will be minimized. j

The BIT is in a recirculation loop tha provides continuous circulation of the boric acid solut through the BIT and

! the boric acid tank (BAT). There e a number of points

along the recirculation loop wh e local samples can be i taken. The actual location to take a sample of the I' i solution is specified in t plant Surveillance procedures i Sampling from the SAT to erify the concentration of the BIT 1 i is not recommended, si e this sample may not be homogenous ,

l and the boron conce ation of the two tanks may differ. l l i i i 4 - (co inued) i l 1 l WOG STS B 3.5-40 R I,04/07/95 l k 4 It a h - . - - - . . . - - . . - . - - . . . . . . - . . .. - -- . ~. - . - . - . . . . - - - - . - .. - - - - . - - - - - . - - 8 BIT B 3.5.6 W- } ~ l !- SURVEILLANCE SR .5.6.3 (continued) } REQUIREMENTS .i he sample should be taken from the BIT from a point in j the flow path of the BIT recirculatio cop. REFER ES 1. FSAR, Chapter [6] and Cha r[15). I

2. 10 CFR 50.46.

i l l Y j _ ? 4 i 1 4 l - l i 4 1 l' 4 i i a i i I i i i i i if0G STS B 3.5-41 Rev 1, 04/07/95 l 1 1 4 \, 4 j - . 1 4 i l l L STP ITS Conversion l Attachment 5 - Justification for Deviations Section 3.5 - Emergency Core Cooling Systems i 1 BASES l l 1 ; l NOTE: The first five justifications for these changes from NUREG-1431 were j generically used throughout the individual Bases section markups. Not all l generic justifications are used in each section. i

1. The brackets have been removed and the proper plant specific information or value j has been provided. !

)

2. Editorial change for clarity or for consistency with the improved Technical :

Specification (ITS) Writer's Guide. l

3. The requirement / statement has been deleted since it is not applicable to this facility.

The following requirements have been renumbered, where applicable, to reflect this deletion.

4. Changes have been made (additions, deletions, and/or changes to the NUREG) to f reflect the facility specific nomencidure, number, reference, system description, or !

analysis description. ! ! ? l

5. Changes have been made to reflect those changes made to the Specification. The 1 l following requirements have been renumbered, where applicable, to reflect this i change.

l

6. Information is added to explain the status of the accumulator's isolation valve under required conditions. !

l 7. Changes have been made which state the assumptions for the large break loss of coolant accident with a lower boron concentration in an accumulator. i

8. Changes have been made to describe the application of the STP Probabilistic Safety

! Assessment to the specifications. 1 Additional words included as a result of relocatine words in the CTS to the Bases. l l l l 1 1 i ! ! I i South Texas Units 1 & 2 1 Rev. O, 2/6/97 !

ML20138K971

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