ML19340C212

Proposed Revision to Tech Spec 3.1.1.5 & Table 4.1-2 to Include Electromagnetic Relief Valve Setpoint as Condition for Operationality When RCS Pressure Exceeds Low Pressure Trip Setpoint

ML19340C212
Person / Time
Site:	Arkansas Nuclear
Issue date:	10/31/1980
From:	ARKANSAS POWER & LIGHT CO.
To:
Shared Package
ML19340C210	List: ML19340C209 ML19340C212
References
NUDOCS 8011140197
Download: ML19340C212 (3)

Text

, l V l l

3.1.1.5 PRESSURIZER ELECTROMATIC RELIEF VALVES AND ASSOCIATED BLOCK VALVE I

A. Whenever the reactor coolant system pressure is above the low reactor coolant system pressure [

trip setpoint specified in Table 2.3-1, either

1) The pressurizer electromatic relief valve (ERV) should be operational with a setpoint of 22450 psig and an allowable value of 22425 psig, or

2) The associated block valve should be closed with the power removed from the block valve.

B. The ERV block valve should be operational or closed with the power removed from the block valve when the reactor coolant system pressure is above the low reactor coolant system pressure trip setpoint specified in Table 2.3-1.

C. If the ERV is not operational for more than a 24 hour2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br /> period, a special report on the status of the ERV shall be submitted in the same manner as those events in Specification 6.12.3.1.

BASES A reactor coolarit pump or decay heat removal pump is required to be in operation before the boron concentration is reduced by dilution with makeup water. Either pump will provide mixing which will prevent sudden positive reactivity changes caused by dilute coolant reaching the reactor.

One decay heat removal pump will circulate the equivalent of the reactor coolant system volume in one half hour or less. (1)

The decay hee removal system suction piping is designed for 300 F thus, the system can ramove decay heat when the reactor coolant system is below this temperature. (2,3)

One pressurizer code safety valve is capable of preventing overpressurization when the reactor is not critical since its relieving capacity is greater than that required by the sum of the available heat sources which are pump energy, pressurizer heaters, and reactor decay heat. (4) Both pressurizer code safety valves are required to be in service prior to criticality to conform to the system design relief capabilities. The code safety valves prevent overpres-sum for a rod withdrawal accident. (5) The pressurizer code safety valve

REFERENCES:

(1) FSAR, Tables 9-10 and 4-3 through 4-7 (2) FSAR, Section 4.2.5.1 and 9.5.2.3 (3) FSAR, Section 4.2.5.4 (4) FSAR, Section 4.3.10.4 and 4.2.4 (5) FSAR, Section 4.3.7 001.1140l

1 .

i lift set pointshall be set at 2500 psig + 1 percent allowance for error

and each valve shall be capable of relieving 300,000 lb/h of saturated steam at a pressure not greater than 3 percent about the set pressure.

! The internals lent valves are provided to relieve the pressure generated by steaming in the core following a LOCA so that the core remains sufficiently covered. Inspection and manual actuation of the internals vent valves (1) ensure operability, (2) ensure that the valves are not open during normal operation, and (3) demonstrate that the valves begin to open and are fully open at the forces equivalent to the differential pressures assumed in the safety analysis.

l The electromatic relief valve (ERV) is provided for LT0P relief and to prevent unnecessary challenges to the code safety valves. However, failure of the ERV in the open position can be a major contributor to loss of inventory in the primary coolant.

i 4

L

\

l TABLE 4.1-2 (Continued)

MINIMUM EQUIPMENT TEST FREQUENCY ITEM TEST FREQUENCY

17. Pressurizer Electromatic Demonstrate operational by:

ReliefValve(ERV) Instrument Channel Each Refueling Shutdown Calibration (Setpoint)

18. Pressurizer Electromatic Demonstrate operational by:

Relief Valve Block Valve operating through one Each Refueling Shutdown complete cycle of full travel i 19. Emergency Power for ERV Demonstrate operational by

! and Associated Block transferring motive and Each Refueling Shutdown Valve control power from normal to emergency power supply and operating valves through a complete cycle of full travel.

i l