ML20126B691

Proposed TS 3.19 Re Position Restrictions on Loop Isolation Valves,Safety Injection Header Isolation Valves & Safety Injection Tank Isolation Valves

ML20126B691
Person / Time
Site:	Maine Yankee
Issue date:	12/15/1992
From:	Maine Yankee
To:
Shared Package
ML20126B685	List: ML20126B682 ML20126B691
References
NUDOCS 9212220176
Download: ML20126B691 (6)

Text

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ATTACHMENT B Proposed Technical Specification Pages 3.19-2. 4.6-1, 4.6-2, 4.6-3 and 4.6-5 Q

9212220176 PDR 921215 P ADOCK 05000309 PDR Lt\peopchng\PC176

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Remedial Action: If any of the ECCS check valve barriers specified above do not meet the acceptance criteria of Technical S)ecification 4.6.A.2.f, the reactor shall not remain critical for more t1an 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, or shall not be made critical if subcritical.

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The position restrictions on the loos isolation valves, safety injection header isolation valves, and the safety injection tank isolation valves are necessary to assure that plant operation is restricted to conditions considered in the loss-of-coolant accident analysis.

The three check valves in the ECCS line to each loop provides assurance that a valve failure will not result in unrestricted flow of pressurized reactor coolant into lower pressure connecting p'iping outside the containment. The valve integrity testing required by Technical Specification 4.6.A.2.f assures that the rate of flow under a valve failure condition will not exceed the pressure relief capacity of the line. It further provides periodic assurance that the check valves are intact.

The two check valves closest to the loop are grouped together as a single check valve barrier for test purposes. The first valve arovides a thermal barrier preventing thermal distortion from affecting the tigitness of the second valve.

• The third valve alone constitutes a check valve barrier.

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The remedial action permits time to correct check valve leakage and/or schedule an orderly shutdown.

Amendment No. 56, 58, 65 3.19-2 u\prepong\pcsts - - - - - -

l 4.6 PERIODIC TESTING I

SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEMS

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STEAM GENERATOR EMERGENCY FEED PUMPS HAIN STEAM EXCESS FLOW CHECK VALVES FEEDWATER TRIP SYSTEM REACTOR COOLANT SYSTEM EMERGENCY VENT SYSTEM Aeolicability l 1

! Applies to the safety injection system, the containment spray system, chemical injection system, the containment cooling system, the emergency feedwater

system, the main steam excess flow check valves, the feedwater trip system, and the reactor coolant system emergency vent system.

Ob.iective To verify that the subject systems will respond promptly and perform their intended functions, if required.

Specification A. SAFETY INJECTION AND CONTAINMENT SPRAY SYSTEMS

1. The fc11owing tests will be performed whenever plant conditions are as defined in Section 3.6.A of these Specifications.

a. Emergency Core Cooling System (ECCS) Pumps:

Both operable high pressure safety injection (HPSI) pumps shall be tested quarterly in accordance with Specification 4.7 by operating in the charging mode.

Both operable low pressure safety injection (LPSI) pumps and both operable containment spray (CS) pumps shall be tested quarterly in accordance with Specification 4.7 by operating in the recirculation mode.

b. ECCS Valves:

All automatically operated valves that are required to operate to assure core flooding, or containment spray shall be exercised monthly.

. The volume control tank (VCT) outlet to charging pump suction valves shall be exercised through part travel and all other valves shall be visually checked to verify proper operating position.

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4.6-1 Amendment No. 45, 58, 62, 87, 100, .21 Lt\propchag\9C176

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9 2: The following tests will be performed at each refueling interval or as otherwise stated:

a. ECCS Pumps:

One HPSI pump shall be flow tested at 1000 psig discharge head.

One LPSI ) ump and one CS pump shall be flow tested at 100 pst discharge lead.

During these tests flow distribution through the HPSI and LPSI flow orifices will be checked.

Acceptance performance shall be that the pumps and orifices attain flow values used in the safety analysis.

Alternate pumps will be tested at each refueling interval, so that all pumps will be tested within any five year period,

b. ECCS Valves:

All automatically operated valves and the motor operated fill header root valves shall be exercised through their full travel in conjunction with the Lctuation signal testing set forth in Table 4.1-2 of Technical Specifications.

c. Safety Injection Tanks:

Each safety injection tank will be flow tested by opening the tank isola'.lon valve sufficient to verify check valve operation.

d. The correct position of each electrical and mechanical position stop for the following throttle valves shall be verified:

1) Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following completion of maintenance on the valve when the HPSI system is required to be operable.

2) At least rnce per 4 months Valve Numbers HSI-M-11 HSI-M-21 HSI-M-31 HSI-M-12 PSI-H-22 HSI-M-32

e. A flow balance test, as described in 4.6.A.2 above, shall be performed during shutdown to confirm the injection flow rates assumed in the Safety Analysis following completion of HPSI or LPSI system modifications that alter system flow characteristics.

Amendment No. 19, 45, 55, 58, 91, 121 4.6-2 Le\prepoao\pctu

f. ECCS Check Valves:

The check valve barriers defined in Technical Specification 3.19.A.4 shall be determined to be intact by leak testing.

! Check valve barriers shall be determined to be intact if each barrier (a) leakage is less than 15 gpm and each barrier (b) leakage is less L than 5 gpm.

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3. Containment Spray Headers:

The containment spray flow nozzles will be tested every five years. The test will consist of pressurizing the headers with air and verifying that the nozzles are free of obstruction.

4. Containment Isolation Valves:

Where practicable, each containment isolation valve shall be stroked to the position required to fulfill its safety function every three months. Those valves that cannot be tested without possible adverse effects during plant o)eration shall be tested during each cold shutdown if not tested during tie previous three months.

B. EMERGENCY FEEDWATER PUMPS l Prior to plant startup following an extended cold shutdown, a flow test will be performed to verify the normal flow path from the demineralized water storage l tank to the steam generators. The flow test will be conducted with the i emergency feedwater system valves in their normal alignment.

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Amendment'No. 45, 55, 58, 87 4.6-3 Li\propchng\PC176 l

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i tests performed during refueling shutdowns and inservice testing of active system com operation.ponents The test(pumps interval isand valves) based on the which can bethat judgement performed during reactor more frequent testing would not significantly increase the reliability the probability that the com)onent would operate when required),(i.e., yet more frequent tests would resu' t in increased wear over a long period of time.

The monthly part travel exercising of the VCT outlet to charging pump 1 suction valves, in lieu of the full travel exercise is conductec to

)reclude an interruption of normal plant operations. Reclundant valves have seen used to assure proper lineup in the event of ECCS actuation.

Other ECCS valves whose o>eration is not required to assure core flooding or containment spray shal' be tested during each refueling shutdown period in accordance with 2.b.

The three check valves in the ECCS line to each loop provide assurance that a valve failure will not result in unrestricted flow of pressurized reactor

! coolant into lower pressure connecting piping outside the containment. The valve integrity testing required by Technical Specification 4.6.A.2.f assures that the rate of flow under a valve failure condition will not exceed the pressure relief capccity of the line. It further provides l periodic assurance that the check valves are intact.

The two check valves closest to the loop are grouped together as a single check valve barrier for test purposes. The first valve provides a thermal barrier preventing thermal distortion from affecting the tightness of the second valve. The third valve alone constitutes a check valve barrier.

The check valves are hard seated swing checks designed to withstand the rigors of long term RHR operation wi+hout damage and the greatest assurance of integrity and dependability.

The leakage criteria provide an acceptable balance between the need to maintain a degree of tightness as a criterion of integrity and Al. ARA on one hand and power dependability considerations on the other. This criteria gives due credit to the design of, and protection provided by, the three check valves in series.

Verification that the spray piping and nozzles are open will be made and at least every five years initially by aSince thereafter. suitably all sensitive method,ll

)iping material is a stainless steel, normally in a dry condition and witi no plugging mechanism available, the retest every five years is considered to be more than adequate.

Other systems that are important to the emergency cooling function are the SI tanks, the component cooling system and the service water system. The SI tanks are a passive safety feature. In accordance with Specification 4.1 (Table 4.1-2, Item 11), the water volume and pressure in the SI tanks Amendment No. 62, 87, 100, 121 4.6-5 u\propone\pcus

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