MAINE YANKEE ATOMIC POWER COMPANY.

D. Reactor Coolant System Vent System ]

1. At least one reactor coolant system vent path consisting of at ]least two valves in series capable of being powered from emergency ]busses shall be operable and closed with power removed from ]the actuators at all times except for cold shutdown and refueling ](conditions 1, 2 and 3) at each of the following locations: ]

,

]reactor head-

]pressurizer-

Remedial Action: With less than one vent path operable for the ]reactor head and pressurizer, restore an operable path within ]30 days or make a report to the commission describing the cause and ]nature of the problem and schedule for repair. ]

Note: If the vent path from the pressurizer is inoperable a PORV ]may be considered as the RCS vent path for the purposes of this ]specification. When the PORV is being relied upon as a vent path, ]the block valve is not required to be closed, nor is power ]required to be removed from the actuator so long as the PORV is ]

]operable.

Basis:

Reactor coolant pump flow and steam generator heat transfer capabilitiesare specified to assure adequate core heat transfer capability under alloperating conditons from criticality to full power. Three loop operationis specified to assure plant operation is restricted to conditionsconsidered in the safety analyses.

The exception permits testing to determine decay heat removal capabilitiesof the primary system while on natural circulation, prior to operation athigher power.

Following a loss of offsite power, stored and decay heat from the reactorwould normally be removed by natural circulation using the steamgenerators as the heat sink. Water supply to the steam generators ismaintained by the auxiliary feedwater system. Natural circulation cooling

| of the primary system requires the use of the pressurizer heaters or high| pressure safety injection pumps to maintain a suitable overpressure on the!

reactor coolant system. Alternatively, in the event that natural$, circulation in the reactor coolant system is interrupted, the feed and

ME bleed mode of reactor coolant system operation can be used to remove decay5" heat from the reactor. This method of decay heat removal requires the user

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SE of the emergeacy core cooling system (ECCS) and the power-operated relief9

to valves (PORVs) in the pressurizer,

EThe PORVs can be operated either manually or automatically in the Maineest

-(g Yankee design. Block valves are provided upstream of the relief valves toi

|isolate the valve in the event that a PORV fails.gThe exception permits hydrostatic testing of the Reactor Coolant System inaccordance with the ASE code when the test pressure approaches the PORVsetpoint.

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MAINE YANKEE ATOMIC POWER COMPANY

When reactor coolant boron concentration is being reduced, the processmust be uniform throughout the reactor coolant system volume to preventstratification of reactor coolant at a lower baron concentration whichcould result in a reactivity insertion.

Sufficient mixing of the reactor coolant is assured by one low pressuresafety injection (LPSI) pump operating in the RHR mode. When operated inthis mode it will circulate the reactor coolant system volume in less than12 minutes. The pressurizer volume is relatively inactive; therefore, itwill tend to have a baron concentration higher than the rest of thereactor coolant system during a dilution operation. A continuouspressurizer spray flow will maintain a nominal spread between the baronconcentration in the pressurizer and the reactor coolant system during theaddition of baron. Without residual heat removal, the amount of steamwhich could be generated at safety valve lift pressure with the reactorsubcritical would be less than half of one valve's capacity. One valve,therefore, provides adequate defense against overpressurization when thereactor is subcritical.

Overpressure protection is provided for all critical conditions. The

safety valves are sized to relieve steam at a rate equivalent to the peakvolumetric pressure surge rate. For this purpose one safety valve issufficient; however, a minimum of two safety valves is required by SectionIII of the ASE Code.

Reactor coolant system vent paths provide a means of removing ]non-condensible gasses from the reactor coolant system following ]an extremely unlikely severe nuclear accident. The requirement that ]the RCS vent system be closed with power removed from t.Se actuators ]at or above operating Condition 4, removes the possibility of ]inadvertent opening while at power. ]

The power operated relief valves provide an alternate means of removing ]noncondensible gases should the reactor coolant system vent system ]become inoperable. ]

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5076L-FWS 3.3-3 03/13/85

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MAINE YANKEE ATOMIC POWER COMPANY

4.6 PERIODIC TESTING

SAFETY INJECTION APO CONTAIENT SPRAY SYSTEMSSTEAM GEERATOR AUXILIARY FEED PUPSMAIN STEAM EXCESS FLOW CECK VALVESFEEDWATER TRIP SYSTEMREACTOR COOLANT SYSTEM VENTS ]

Applicability: Applies to the safety injection system, the containmentspray system, chemical injection system, the containmentcooling system, the auxiliary feedwater system, the mainsteam excess flow check valves, the feedwater trip system, ]and reactor coolant system vents. ]

Objective: To verify that the subject systs..T.: will respond promptlyand perform their intended functions, if required.

Specification:

A. . SAFETY INJECTION Ato CONTAIMNT CPMY SYSTEMS

1. The following tests will be performed monthly whenever plantconditions are as defined in Section 3.6.A of these Specifications.

a. Emergency Core Cooling System (ECCS) Pumps:

-Both operable high pressure safety injection (W SI) pumps shallbe tested by operating in the charging mode.

Both operable low pressure safety (CS)jection (LPSI) pumps andin

both operable containment spray pumps shall be tested byoperating in the recirculation mode.

Acceptable performance shall be that pumps attain rated heads,operate for at least 15 minutes, and that the associatedinstrumentation and controls function properly.

b. ECCS Valves:

All automatically operated valves that are required to operateto assure core flooding, or containment spray shall beexercised. The volume control tank (VCT) outlet to chargingpump suction valves shall be exercised through part travel andall other valves shall be visually checked to verify pruperoperating position.

Exception: LSI-M-ll, 21 or 31 shall not be tested when theassociated ECCS check valve barr2er leakage fallsinto Condition 2 or 3, as defined inSpecification 4.6. A.2.f.

2. The following tests will be performed at each refueling interval:

a. ECCS Pumps:

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

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. MAINE YANKEE ATOMIC POWER COMPANY

No additional action required.,

Condition 2 - _ Barrier (a) less than 15 gpm and barrier (b), in' the same loop, greater than 5 gpm.

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The reactor may be made or remain critical for upto 30 days provided the affected ECCS line MotorOperated Valve remains closed.

Condition 3 - Barrier (a) greater than 15 gpm and barrier (b),in the same loop, less than 5 gpm.

The reactor may be made or remain critical for upto 30 days provided the affected ECCS line MotorOperated Valve remains closed.

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Condition - 4 Barrier (a) greater than 15 gpm and barrier (b), i

in the same loop, greater than 5 gpm.

The reactor shall not be made or remain critical' for more than 24 hours.-

g. ReabtorCdolantSystemVentPaths ]

'At"least once-.each refueling interval during cold shutdown ]'

-condition: ].

1) . All remotely. operated valves shall be cycled .]2). flow'through each vent path shall be verified- ]

.3.- Containment Spray Headers:

The containment spray flow ruzzles 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:<

!F _

Where-practicable, each containment isolation valve shall be stroked tor .the position required to fulfill its safety function every threeL ~ months. -Those valves that cannot be tested without possible adverse

effects during plant operation shall be tested during each cold shutdownif not tested during the previous three months.

B. STEAM GENERATOR AUXILIARY FEED PUW S .

'

L _ Prior to plant startup following an extended cold shutdown, a flow test willL - be performed to verify the normal flow path from the decineralized water

.storage tank to the steam generators. The flow test will be conducted with: ' '

the AFW system valves in their normal alignment.

I

i|

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5076L-FWS - 4.6-3 03/13/85-

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MAINE YANKEE ATOMIC POWER COMPANY, ,

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The three month testing interval of the steam generator auxiliary feedpumps verifies their operability by recirculating water to thedemineralized water tank.

Prior to plant startup following an extended cold shutdown, a flow test isperformed on the Auxiliary Feedwater System to functionally verify thesystem alignment from the demineralized water storage tank to the steamgenerators.

Monthly inspections are performed to verify that all manual valves in theAuxiliary Feedwater System from the primary water source to the steamgenerators are locked in the proper position.

Proper functioning of the steam turbine admission valve and starting ofthe auxiliary feed pump will demonstrate the operability of the steamdriven pump. Verification of correct operation will be made both frominstrumentation with the main control room and direct visual observationof the pumps.

The main steam, excess flow check valves serve to limit an excessivereactor coolant system cooldown rate and resultant reactivity insertionfollowing a main steam break incident. Their freedom to move will beverified periodically.

The feedwater trip system acts to limit excessive reactor coolant systemcooldown and the resultant reactivity insertion produced by excessivefeedwater flow to the steam generators in the event of a main steam linebreak. The system acts to trip feedwater pumps, condensate pumps, heaterdrain pumps, and auxiliary feedwater regulating valve bypass valve, andauxiliary feedwater valve to the affected steam generator. Signals

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activating the system are developed by instrumentation, logic, andrelaying associated with the t.afety injection actuation system and thei

excess flow check valve actuation system. The circuitry which developsthese signals is subject to surveillance requirements of Tables 4.1-1 and4.1-2 which assure their reliability.

' The feedwater pumps, condensate pumps, and heater drain pumps trip uponcoincidence of SIAS and a low steam generator pressure. The valves closeon the low steam generator pressure in the affected steam generator. Theauxiliary feedwater pumps trips on low steam generator pressure in any''

steam generator. The reliability of the coincidence logic is assured bytesting in accordance with #20 of Table 4.1-2.

Cycling of the reactor coolant vent valves and verification of flow ]through each path docunents the operability of the system. Operability ]'

of this system assures the ability to remove non-condensible gasses ]from the reactor coolant system under severe post accident conditions ]in order to help prevent or mitigate core damage. ]

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