ML19253B826

Modified Proposed Tech Specs for Overpressure Protection Sys

ML19253B826
Person / Time
Site:	North Anna
Issue date:	10/18/1979
From:	VIRGINIA POWER (VIRGINIA ELECTRIC & POWER CO.)
To:
Shared Package
ML19253B823	List: ML19253B822 ML19253B826
References
NUDOCS 7910220287
Download: ML19253B826 (3)

Text

- - ATTACHMENT 2 PROPOSED UNIT 2 TECHNICAL SPECIFICATION REACTOR COOLANT SYSTEM OVERPRESSURE PRffTECTIONISYSTEMS LIMITING CONDITION FOR OPERATION ' '

3.4.9.3 At least one of the following overpressure protection systems shall be OPERABLE:

a. Two power operated relief valves (PORVs) with a lift setting of: 1) less than or equal to 475 psig whenever any RCS cold leg temperature is less than or equal to 3400F, and 2) less than or equal to 405 psig whenever any RCS cold leg temperature is less than 1400 F, or

b. A reactor coolant system '

vent of greater than or equal to 2.07 square inches, or

c. A maximum pressurizer volume of 457 cu ft with all RCS cold leg temperatures greater than or equal to 3200F.

APPLICABILITY: When the temperature of one gr more of the RCS cold legs is less than or equal to 340 F, except when the reactor vessel head is removed.

ACTION:

a. With the PORVs required and one PORV inoperable, either restore the '

inoperable PORV to OPERABLE status within 7 days or depressurize and vent the RC5 through a 2.07 square inch vent (s) within the next 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />; maintain the RCS in a vented condition until both PORVs have restored to OPERABLE status.

b. With the PORVs required and both PORVs inoperable, depressurize and vent the RCS through a 2.07 square inch vent (s) within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />; maintain the RCS in a vented condition until both PORVs have been restored to OPERABLE status.

c. In the event either the PORVs or the RCS vent (s) are used to mitigate a RCS pressure transient, a Special Report shall be prepared and submitted to the Commission pursuant to Specification 6.9.2 within 30 days. The report shall describe the circumstances initiating the transient, the effect of the PORVs or vent (s) on the transient and any corrective action necessary to prevent recurrence.

d. The provisions of Specification 3.0.4 are not applicable.

NORTH ANNA - UNIT 2 3/4 4-31 i 7 910220 Z F [

REACTOR COOLANT SYSTEM SURVEILLANCE REQUIREMENTS 4.4.9.3.1 Each PORV shall be demonstrated OPERABLE by:

a. Perfomance of a CHANNEL FUNCTIONAL TEST on the PORV actuation channel, but excluding valve operation, within 31 days prior to entering a condition in which the PORV is required OPERABLE and at least once per 31 days thereafter when the PORV is required OPERABLE.

b. Perfo'rmance of a CHANNEL cat.IBRATION on the PORV actuation channel, at least once per 18 months.

c. Verifying the PORV key switch is in the AUTO position, and the PORV isolation valve is open, at least once per 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> when the PORV is being used for overpressure protection.

d. Testing in accordance with the in-service test requirements for ASME Category C valves pursuant to Specification 4.0.5.

4.4.9.3.2 The RCS vent (s) shal' be verified to be open at least once per 12 hours1.388889e-4 days <br />0.00333 hours <br />1.984127e-5 weeks <br />4.566e-6 months <br />

• when the vent (s) is being used for overpressure protection.

• Except when the vent pathway is provided with a valve which is locked, sealed, o -

otherwise secured in the open position, then verify these valve (s) open at least once per 31 days when being used for overpressure protection.

NORTH ANNA - UNIT 2 3/4 4-32 1150 i43

BASES The OPERABILITY of two PORVs or an RCS vent opening of greater than 2.07 square inches ensures that the RCS will be protected from pressure transients which could exceed the limits of Appendix G to 10 CFR Part 50 when one or more of the RCS cold legs is c 3400F, and the Reactor Vessel Head is bolted. Either PORV has adequate relieving capability to protect the RCS from overpressurization when the transient is limited to either (1) the start of an idle RCP with the secondary water temperature of the steam gererator <;500F above the RCS cold leg temperature, 'r (2) the start of a charging pump and its injection into a water solid RCS.

When the temperature of the RCS cold legs is between 3200F and 340 F, overpressure protection can also be provided by a bubble in the pressurizer. In such a case, a maximum cressurizer water volume of 457 cu. ft. has been selected to provide at least 10 minutes for operator res'honse in the event of a malfunction resulting in maximum ficw from one charging pump.

1150 i44 NORTH ANNA - UNIT 2

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