ML20093A440

Proposed Revs to Tech Spec Sections 3.2 Re Protective instrumentation,3.7 Re Limiting conditions,4.7 Re Surveillance Requirements & Table 4.7.2 Re Containment Isolation Valves,Incorporating Leak Rate Testing Program

ML20093A440
Person / Time
Site:	Vermont Yankee
Issue date:	06/26/1984
From:	VERMONT YANKEE NUCLEAR POWER CORP.
To:
Shared Package
ML20093A437	List: ML20093A436 ML20093A440 ML20093A441
References
NUDOCS 8407100501
Download: ML20093A440 (8)

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I 3.2 PROTECTIVE INSTRUMENTATION l In addition to reactor protection instrumentation which initiates a reactor scram, station protective j instrumentation has been provided which initiates action to mitigate the consequences of accidents which are beyond the reactor operators ability to control, or terminate a single operator error before it results in serious consequences. This set of Specifications provides the limiting conditions of operation for the primary system isolation function and initiation of the core standby cooling and standby gas treatment systems. The objectives of the Specifications are (i) to assure the effectiveness of any component of such systems even i during periods when portions of such systems are out of service for maintenance, testing, or calibration; and

. (ii) to prescribe the trip settings required to assure adequate performance. This set of Specifications also

) provides the limiting conditionslof operation for the control rod block system and surveillance instrumentation.

Isolation valves (Note 1) are installed in those lines that penetrate the primary containment and must be j isolated during a loss-of-coolant accident so that the radiation dose limits are not exceeded during an accident

condition. Actuation of these. valves is initiated by protective instrumentation shown in Table 3.2.2 wh;-h l

senses the condition for which isolation is required. Such instrumentation must be available whenever primary l containment integrity is required. The objective is to isolate the primary' containment so that the limits of i 10CFR100 are not exceeded during an accident. The objective of the low turbine condenser vacuum trip is to l minimize the radioactive effluent releases to as low as practical in case of a main condenser failure.

l Subsequent releases would continue until operator action was taken to isolate the main condenser unless the main steam line isolation valves were closed automatically on low condenser vacuum. The manual bypass is required to

! permit initial startup of the reactor during low power operation.

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The instrumentation which initiates primary system isolation is connected in a dual-channel arrangement. Thus, L the discussion given in the bases for Specification 3.1 is applicable here.

}' The low reactor water level instrumentation is set to trip when reactor water level is 127" above the top of the enriched fuel. This trip initiates closure of Groups 2 and 3 prim 9ry containment isolation valves. For a trip setting of 127" a one the top of the enriched fuel, the valves will be closed before perforation of the clad occurs even for the maximum break and, therefore, the setting is adequate.

The top of the enriched fuel (351.5" from vessel bottom) is designated as a common reference level for all reactor water level instrumentation. The intent is to minimize tha potential for operator confusion which may 4

I result from different scale references.

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Note - Isolation valves are grouped as listed in Table 4.7.2.

i 47 1 62 Amendment No. 68,

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VYNPS 3.7 LIMITING CONDITIONS FOR OPERATION 4.7 SURVEILLANCE REQUIREMENTS

e. Minimum Water Volume - 68,000 cubic feet

f. Maximum Water Volume - 70,000 cubic feet 4.7 STATION CONTAINMENT SYSTEMS

2. Primary containment integrity shall be 2. The primary containment integrity shall be maintained at all times when the reactor is demonstrated as required by Appendix J to 10 critical or When the reactor water CFR Part 50 except where specific written temperature is above 2120F and fuel is in relief has been granted by the NRC persuant the reactor vessel except while perfonains to 10CFR50, Sectiin 50.12.

low power physics tests at' atmospheric pressure at power levels not to exceed 5 Mw(t).

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Amendment No. 50, i * . a, 126a '"

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4.7 LIMITING CONDITIONS FOR OPERATION 4.7 SURVEILLANCE REQUIREMENTS 1

3. Whenever primary containment is required, the total primary centainment leakage rate shall not exceed 0.8 weight' percent per day (La) at a pressure of 44 psis (Pa). ,

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4. Whenever primary containment is required, the combined leakage rate for all penetrations and valves, except for MSIVs, shall be less then or equal to 0.6LA. The leakage from any one main steam line isolation valve shall not exceed 15.5 I

scf/hr at 44 psig (Pa). -

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5. pressure Suppression Chamber - Reactor 5. Pressure Suppression Chamber -

Building Vacuum Breakers . Reactor #2].lding Vacuum Breakers

a. Two of two pressure suppression a. The pressure suppression chamber-Reactor chamber-Reactor Building vacuum breaker Building vacuum breaker systems and

systems shall be operable at all times when ~ associated instrumentation including setpoint the primary containment integrity is shall be checked for proper operator every required. The setpoint of the differential three months.

pressure instrumentation which actuates the pressure suppression chamber-Reactor Building b. During each refueling outage, each vacuum air-operated vacuum breakers shall be f 0.5 breaker shall be tested to determine that the psid. The self actuating vacuum breakers force required to open the vacuum breaker shall open fully when subjected to a force does not exceed the force specified in equivalent to or less than 0.5 psid acting on Specification 3.4.A.S.a and each vacuum the valve disk. breaker shall be inspected and verified to meet design requirements,

b. From and after the date that one of the pressure suppression chamber-Reactor Building vacuum breaker systems is made or found inoperable for any reason, the vacuum breaker shall be locked closed and reactor operation is permissible only during the succeeding sovon (7) days unless such vacuum breaker system is soon made operable provided that the procedure does not violate containment integrity.

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TABLE 4.7.2 PRIMARY CONTAINMENT ISOLATTON VALVES Number of Power Maximum Action on Isolation Operated Valves Operating Normal Initiating Group (Note 1) Valve Identification Inboard Outboard Time (sec) Position Signal (CC=Coes Closed)

(SC= Stays Closed) 1 Main Steam Line Isolation (2-80A, D & 2-86A, D) 4 4 5(note 2) Open GC 1 Main Steam Line Drain (2-74, 77) 1 1 35 Closed SC 1 Recirculation Loop Sample Line (2-39, 2-40) 1 1 5 Closed SC I 2 Drywell Floor Drain (20-82, 20-d3) 2 20 Open CC 2 Drywell Equipment Drain (20-94, 20-95) 2 20 ,

open CC 3 Drywell Air Purge Inlet (16-19-9) 1 10 Closed EC 3 Drywell Air Purge Inlet (16-19-8) 1 10 Open CC

! 3 Drywell Purge & Vent Outlet (16-19-7A) 1 - 10 closed SC 3 Drywell Purge & Vent Outlet Bypass (16-19-6A) '1 10 C16 sed SC 3 Drywell & Suppression Chamber Main Exhaust (16-19-7) 1 10 Closed SC 3 Suppression Chamber Purge Supply (16-19-10) 1 10 . Closed SC 3 Suppression Chamaber Purge & Vent Outlet (16-19-7B) 1 10 Closed SC 3 Suppression Chamber Purge & Vent Outlet Bypass (16-19-6B) 1 10 Open GC 3 Exhaust to Standby Cas Treatment System (16-19-6) 1 10 Open CC 3 Containment Purge Supply (16-19-23) 1 10 Open CC I

3 Containment Purge Makeup (16-20-20, 16-20-22A, 16-20-22b) 3 NA Closed SC 5 Reactor Cleanup System (12-15, 12-18) 1 1 25 Open CC l 6 HPCI (23-15, 23-16) 1 1 55 Open GC l' 1 1 20 Open CC 6 RCIC (13-15, 13-16)

Primary / Secondary Vacuum Relief (16-19-11A, 16-19-11B) 2 NA Closed SC Primary / Secondary Vacuum Relief (16-19-12A, 16-19-12B) 2 NA Closed Process l

3 Containment Air Sampling (VG 23, VG 26, 109-76A&B) 4 5 Open GC Amendment No. 58, SI, 7A 135

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.VYNPS TABLE 4.7.2 (Continued) xy PRIMARY CONTAINMENT ISOLATION VALVES Number of Power Maximum Action on Isolation Operated Valves Operating Normal Initiating Group (Note 1) Valve Identification

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Inboard Outboard Time (sec) Position' Signal (GC = Goes Closed) X (SC = Stays Close.d) x 7 RHR Return to Suppression Pool (10-39A,B) 2 70 Closed SC 7 RHR Return to Suppression Pool (10-34A,B) 2 120 Closed SC 7 RHR Drywell Spray (10-26A, B & 10-31A,B) 4 70 closed SC RHR Suppression Chamber Spray (10-38A,B) Closed

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7 2 45 SC 3 Containment Air Compressor Suction (72-38A,B) 2 20 Open 'CC 4 RHR Shutdown Cooling Supply (10-18, 10-17) 1 1 28 Closed SC -

4 RHR Reactor Head Cooling (10-32, 10-33) 1 1 25 Closed SC Feedwater Check Valves (2-28A,B,27A,96A) 2 2 NA Open Proc.

Reactor Head Cooling Check Valve (10-29) 1 ,

NA Closed Proc. .

Standby Liquid Control check Valves (11-16, 11-17) 1 1 NA Closed Proc.

NOTE: Additional manual valves, which are considered primary containment isolation valves, are identified in the Vermont Yankee Primary Containment Leak Rate Testing Program.

Amendment No. 61, 136 i *

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VYNPS Table 4.7.2 Notes

1. Isolation Signals are as follows:

Group 1: The valve in Group 1 are closed upon any one of the following conditions:

1. Low-low reactor water level

2. High main' steam line radiation

3. High main steam line flow

4. High main steam line tunnel temperature

5. Low main steam line pressure (run mode only)

6. Condenser low vacuum Group 2: The valves in Group 2 are closed upon any one of the following conditions:

1. Low reactor water level

2. High drywell pressure Group 3: The valves in Group 3 are closed upon any one of the following conditions:

1. Low reactor water level

2. High drywell pressure

3. High/ low radiation - Reactor Building ventilation exhaust plenum or refueling floor Group 4: The valves in Group 4 are closed upon any one of the following conditions:

1. Low reactor water level

2. High drywell pressure

3. High reactor pressure Amendment No. 137 i . 'i ,S 4 's0

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Table J.7.2 Notes _ (Continued)

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