ML20138M597

Proposed Tech Specs,Incorporating Limiting Condition for Operations for turbine-driven Auxiliary Feedwater Pump

ML20138M597
Person / Time
Site:	Maine Yankee
Issue date:	12/16/1985
From:	Maine Yankee
To:
Shared Package
ML20138M592	List: ML20138M589 ML20138M597
References
NUDOCS 8512230056
Download: ML20138M597 (4)

Text

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MAINE YANKEE ATOMIC POWER COMPANY ATTACHWNT A Remedial Actions (Continted)

2. With no cooling mechanisms operable, suspend all operations involving positive reactivity changes, continuously monitor reactor coolant temperature, and restore one cooling mechanism to operation within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> or notify the NRC (using the Emergency Notification System) within the next hour of plans to restore decay heat removal.

B. The following conditions must be met for a steam generator to be considered operable for decay heat removal.

1. The reactor coolant system must be closed and pressurized to 100 psi above saturation pressure.

2. The steam generator must have both the cold and hot leg stop valves fully open.

3. The steam generator water level must be above the top of the tube bundle.

4. An inventory of over 100,000 gallons of primary grade feedwater must be available.

5. A feed pump must be operating or available for operation.

C. The steam generators shall be demonstrated operable in accordance with specification 4.10 before the reactor coolant system T. Ave. can be increased above 2100F.

D. The reactor shall not be in a power operation condition which generates steam at a rate in excess of the on-line steam generator relieving capacity in accordance with Figure 3.8-1.

E. The reactor shall not be maintained in a power operation condition ]

unless at least three independent steam generator auxiliary or emergency ]

feedwater pumps and associated flow paths are PERABLE to supply ]

emergency feedwater to all three steam generators with: ]

a. Two emergency feedwater pumps, each capable of being automatically ]

powered from separate OPERABLE emergency busses, and ]

b. One auxiliary feedwater pump capable of being powered from an ]

TERABLE steam supply system, and ]

c. An inventory of over 100,000 gallons of primary grade feedwater. ]

REEDIAL ACTION:

l

a. With one auxiliary or emergency feedwater pump inoperable, restore the ]

required feedwater pumps to OPERABLE status within 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> or be in at ]

least HOT STANDBY within the next 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the ]

following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />.

8512230056 851216 fR ADom 0500g 3.8-2 12/16/85 6812L-CDW

MAINE YANKEE ATOMIC POWER COMPAPSV

b. With one emergency feedwater and one auxiliary feedwater pump inoperable, ]

be in HOT STANDBY in 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> and in HOT SHUTDOWN within the following ]

6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. ]

c. With two emergency feedwater pumps inoperable be in at least HOT STAtOBY ]

within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. ]

d. With all three auxiliary and emergency feedwater pumps inoperable, immedjately ]

initiate corrective action to restore at least one pump to OPERABLE status ]

as soon as possible. ]

e. With the emergency feedwater flow path to a steam generator out of service, ]

return the flow path to service within 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br />, or be in HOT STANDBY ]

within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and in HOT SHUTDOWN within the following 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. ]

BASIS:

Specifications A and E assure that decay heat removal capability is always available.

A single steam generator is capable of removing core decay heat by natural or forced circulation provided the conditions specified in B are met.

A single cooling mechanism is sufficient to remove decay heat but single failure considerations require that two mechanisms be operable.

Specification C assures the structural integrity of the steam generator tubes which are a fission product barrier.

Specification D assures sufficient relieving capacity during power ]

operation.

Specification E assures sufficient feedwater to maintain an adequate heat sink following a loss of main feedwater. The emergency feed system, ]

including both motor driven pumps, piping, valves, and supply tanks are ]

designed to be safety class, seismic and meet applicable NRC requirements. ]

Each pump is powered from a separate emergency power bus and is capable of ]

supplying the total emergency feedwater flow following a complete loss of ]

main feedwater or any other design basis accident coincident with a loss of ]

all off-site power. An emergency feed pump may be out of service for up to ]

seven days because of the extremely low probability of a design basis ]

accident occurring coincident with a failure of the other emergency feed ]

pump and a complete loss of main feedwater system capability. ]

The remaining portions of the auxiliary feed system, including the turbine ]

driven auxiliary feed pump, are not designed to NRC requirements ]

applicable to emergency feed systems and not required to meet design ]

basis events. However, the turbine driven auxiliary feed pump is ]

capable of providing the required feedwater flow to the steam generator ]

following even lower probability events such as a failure of all ]

main feedwater and emergency feedwater capability. Such an event ]

may be postulated to occur as a result of a loss of all off-site and ]

on-site emergency power sources. This pump may be out of service for ]

up to seven days because of the extremely low probabilty of such an ]

event. ]

]

3.8-3 12/16/85 6812L-GDW

MAINE YANKEE ATOMIC POWER COMPANY A reactor shutdown from power requires removal of core decay heat.

Immediate decay heat removal requirements are normally satisfied by the steam bypass to the condenser. Therefore, core decay heat can be continuously dissipated via the steam bypass to the condenser as long as feedwater to the steam generators is available. Normally, the capability

'to suppply feedwater to the steam generators is'provided by operation of the feedwater system.

In the unlikely event of complete loss of electrical power to the station, decay heat removal is by steam discharge to the atmosphere via the main steam safety valves or the atmospheric steam dump valve. Either of the ]

two steam generator emergency feed pumps or the auxiliary feed pump can ]

supply sufficient feedwater for removal of decay heat from the plant.

3.8-4 12/16/85 6812L-GOW

M AINE Y ANKEE ATOMIC POWER COMPANY ATTACHMENT B SIGNIFICANT HAZARDS EVALUATION

1. Discussion of the Proposed Change:

' The proposed change adds a limiting condition for operation for the turbira driven auxiliary feedwater pump. Operation of the plant is allowr J for up to 168 hours0.00194 days <br />0.0467 hours <br />2.777778e-4 weeks <br />6.3924e-5 months <br /> with the pump out of service and for up to 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> with the turbine driven auxiliary feedwater pump and one of the motor driven emergency feedwater pumps out of service. The current Technical Specifications do not address operability of the auxiliary feedwater pump.

-The proposed change also includes minor changes to the existing Technical Specifications on the motor-driven emergency feedwater pumps, in order to improve consistency with the standard spectifications for CE plants.

2. Does the proposed change involve a significant increase in the probability or the consequences of an accident previously analyzed?

No it does not. The only design basis accident potentially affected by this change is a postJiated loss of main feedwater. The probability of a loss of main feedwater is rat affected.

The proposed change increases the reliability of the feedwater supply and could decrease the consequences of certain loss of feedwater scenarios which are beyond the design basis of the plant.

3. Does the proposed change create the possibility of a new or different kind of accident from any accident prevously analyzed?

No it does not. The requirement for the turbine driven feedpump to be operable could mitigate a postulated loss of all AC power. The proposed change does not create the possibility of any non-design basis accident.

4. Does the proposed change involve a significant reduction in a margin of safety?

No it does not. The requirement for the auxiliary feedwater pump to be operable should result in an increase in the margin of safety.

5. Does the proposed change involve a significant hazards consideration as defined by 10 CFR 50.927 Based on the above, we have concluded that the proposed change does not involve a significant hazards consideration as defined by 10 CFR 50.92.

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