ML20005B406
| ML20005B406 | |
| Person / Time | |
|---|---|
| Site: | Maine Yankee |
| Issue date: | 06/30/1981 |
| From: | Maine Yankee |
| To: | |
| Shared Package | |
| ML20005B405 | List: |
| References | |
| NUDOCS 8107080187 | |
| Download: ML20005B406 (10) | |
Text
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3.19 SAFETY INICTION SYSTEM Acolicability:
Applies to the condition of safety injection system.
Objective:
To define the condition of the safety injection system required during reactor operation.
Soecification:
a) None of the following valves may be closed unless the reactor is subcritical:
1.
Any safety injection tank isolation valve (SIA-M-ll, 21, 31) 2.
Any safety injection header isolation valve (HSI-16, 26, 36) 3.
Any loop isolation valve (RCM-ll, 12, 21, 22, 31, 32) b)
The reactor shall not be critical unless the following conditions are met:
1.
The breakers shall be racked out and tagged open for the safety injection tank isolation valves, the power leads shall be removed from the breakers, the bare metal terminal ends taped, and the breakers locked out.
I 2.
The breakers for the loop isolation valves:
(a) Shall be opened, and padlocked in the open l
position.
(b)
The breaker thermal overload links shall be l
physically removed from the breakers.
(c)
An entry describing the above action shall be placed in the Shift Supervisor's Log Book'.
Exception: Breakers for loop isolation valves l
RC-M-21 and RC-M-22 need not be opened and padlocked l
and the thermal overload links for these valves need not be physically removed during the period between May 5, 1981 and May 9, 1981.
i 3.
The following ECCS check valve barriers shall have been determined to be intact in accordance with l
Tecnnical Specification 4.6. A.2(f).
I Barrier l
Loop 1 a
HSI-17 and HSI-61 I
b LSI-12 Loop 2 a
HSI-27 and HSI-62 b
LSI-22 l
8107080187 810630 PDR ADOCK 05000309I P
PDR) 3.19-1
Loop 3 a
HSI-37 and HSI-63 b
LSI-32 Exceotion:
If any of the ECCS check valve barriers specifieo above have not been determined to be in-tact in accordance with Technical Specification 4.6.A.2(f), then the reactor may be made or remain critical for 30 days provided that in the affected ECCS line Motor Operated Valve remains closed and the*
other check valve barrier has been determined to be intact.
Basis:
The position restrictions ca the loop isolation valves, safety injection header isolation valves, and the safety injection tank isolation valves are necessary to assure that plant operation is restricted to conditions considered in the loss-of-coolant accident analysis.
The exception with respect to valves RC-M-21 ano RC-M-22 ensures that loop two can be isolated rapidly following a postulated plant shutdown necessitated by degradation at the loop two reactor coolant pump seals.
The three check valves in the ECCS line to each loop provioes*
assurance that a valve failure will not result in un-restricted flow of pressurized reactor coolant into lower pressure connecting piping outside the containment.
The valve integrity testing required by Technical Specification 4.6. A.2(f) assures that the rate of flow under a valve failure condition will not exceed the pressure relief capacity of the line.
It further provides poriodic assurance
- that the check valves are intact.
The two check valves closest to the loop are grouped together*
as a single check valve barrier for test purposes.
The first*
valve provides a thermal barrier preventing thermal dis-tortion from affecting the tightness of the second valve.
The third valve alone constitutes a check valve barrier.
In addition to the check valves the ECCS line to each loop l
contains a Motor Operated valve (MOV) which is closed except
- l for periodic monthly testing.
The MOV and reactor side
[
piping is designed for full system pressure and also capable
- l of preventing an overpressure condition of connecting piping.*
l The exception permits time to schedule an orderly shutdown and maintenance of a defective valve while providing assurance that two separate intact barriers always exist.
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3.19-2 L
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4.6 PERIODIC TESTING J
SAFETY INJECTION AND CONTAItNENT SPRAY SYSTEMS STEAM GENERATOR AUXILIARY FEED PUMPS MAIN STEAM EXCESS FLOW CFECK VALVES Applicability:
Applies to the safety injection system, the containment spray system, chemical injection system, the containment cooling system, the auxiliary feedwater system, and the main steam excess flow check valves.
Objective:
To verify that the subject systems will respond promptly and perform their intended functions, if required.
Specification:
A.
SAFETY INJECTION AND CONTAItNENT SPRAY SYSTEMS 1.
The following tests will be performed monthly whenever plant conditions are as defined in Section 3.6. A of these Specifications.
a.
Emergency Core Cooling System (ECCS) pumps:
Both operable high pressure safety injection (HPSI) pumps shall be tested by operating in the charging mode.
Both operable low pressure safety injection (LPSI) pumps and both operable containment spray (CS) pumps shall be tested by operating in the recirculation mode.
Acceptable performance shall be that pumps attain rated heads, operate for at least 15 minutes, and that the associated instrumentation and controls function properly.
b.
ECCS Valves:
All automatically operated valves that are required to operate to assure core flooding, or containment spray shall be exercised.
The volume control tank (VCT) outlet to charging pump suction valves shall be exercised through part travel and all other valves shall be visually checked to verify proper operating position.
2.
The following tests will be pertormed at each refueling interval:
a.
ECCS Pumps:
One HPSI pump shall be flow tested at 1000 psig discharge head.
One LPSI pump and one CS pump shall be flow tested at 100 psi discharge head.
During these tests flow distribution thnj the HPSI and LPSI flow orifices will be checked.
Acceptable performance shall be that the pumps and orifices attain flow values used in the safety analysis.
4.6-1
Alternate pumps will be tested at each refueling interval, so lL that all pumps will be tested within any five year period.
D.
ECCS Valves:
All automatically operated valves and the motor operated fill header root valves shall be exercised through their ful) travel in conjunction with the actuation signal testing set forth in Table 4.1-2 of Technical Specifications.
c.
Safety Injection Tanks:
Each safety injection tank will be flow tested by opening the tank isolation valve sufficient to verify check valve operation.
d.
The correct position of each electrical and mechanical position stop for the following throttle valves shall be verified:
- 1) Within 4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following completion of maintenance on the valve when the HPSI system is required to be operable.
- 2) At least once per 4 months Valve Numbers, HSI-M-ll HSI-M-12 HSI-M-21 HSI-M-22 HSI-M-31 HSI-M-32 e.
A f. low balance test, as described la 4.6.A.2 above, shall be performed during shutdown to confirm the injection flow rates assumed in the Safety Analysis fcilowing completion of HPSI or LPSI system modifications that alter system flow characteristics.
i f.
ECCS Check Valves The check valve barriers defined in Technical Specification 3.19.b.3 shall be determined to be intact.
Check valve barriers shall be determined to be intact through satisfaction of one of the following criteria and its associated
- additional action requirement.
1.
Acceptance Criterion:
Barrier leakage equal to or less than 5 gpm.
tb additional action required.
2.
Acceotance Criterion:
Barrier leak &ge greater than 5 gpm but less than 15 gpm.
Additional action required:
I
a)
At the next cold shutdown scheduled for a duration of ten days or more the barrier shall be inspected and refurbished as required.
b) Before and during the cycle testing of the affected ECCS
- line motor opeated valve (LSI-M-ll, 21 or 31) for surveill n a testing in accordance with Technical Soecification 4.6. A.l(o) the reactor side piping of the valve shall be depressurized to less than 200 psi.
3.
The containment mray flow nozzles will be tested every five years.
The test will c0r..ist of pressurizing the headers with air and verifying that the nozzles are free of obstruction.
4.
Containment Isolation Valves:
Where practicable, each contalv'ent isolation valve shall be stroked to the position required to fulfill its safety function every three months.
Those valves that cannot be tested without possible adverse effects during plant operation shall be tested during each cold shutdown if not tested during the previous three months.
B.
STEAM GENERATOR AUXIGMY FEED PJMPS Prior to plant startup following an extended cold shutdown, a flow test will be performed to verify the normal flow path from the demineralized water storage tank to the steam generators.
The flow tct will be conducted with the AFW system valves in their normal alignment.
Monthly inspections shall be performed to verify that all manual vidves in the AFW system necessary to assure flow from the primary water source to the steam generators are locked in the proper position.
During normal plant operation, each auxiliary feed pump shall be tested i
at quarterly intervals to demonstrate operability of pumps, system valves l
and instrumentation.
C.
MAIN STEAM EXCESS FLOW CF.CK VALVES The main steam excess flow check velves shall be tested once every 6 weeks for movament of the valva disc through a distance of approximately l
one and one.nalf inchee.
These valves will be tested tarough full travel l
distance during each refueling interval.
Basis:
The safety injection system and the containment spray system are l
principal plant safeguards systems that are normally operable during l
reactor operation.
Complete system tests cannot be performed when the reactor is operating l
because of their inter-relation with operating systems.
The method of i
assuring operability of these systems is a combination of complete system j
tests performed during refueling shutdowns and monthly tests of active system components (pumps and valves) which can be performed curing l
l 4.6-3
reactor operation. The test interval is based on the judgment that more frequent testing would not significantly increase the reliability-(i.e.,
the probability that the component would operate when required), yet more frequent tests would result in increased wear over a long period of time.
The monthly part travel exercising of the VCT outlet to charging pump suction valves, in lieu of the full travel exercise, is conducted to preclude an interruption of normal plant operations. Redundant valves have been used to assure proper lineup in the event of ECCS actuation.
Other ECCS valves whose operation is not required to assure core flooding or containment spray shall be tested during each refueling shutdown period in accordance with 2.b.
The three check valves in the ECCS line to each loop provides assurance that a valve failure will not result in unrestricted flow of pressurized
- reactor coolant into lcwer pressure connecting piping outside the contain*
ment.
The valve integrity testing required by Technical Specification 4.6. A.2(f) assures that the rate of flow under a valve failure candition
- will not exceed the pressure relief capacity of the line.
It further provides periocic assurcnce tnat the check valves are intact.
The two check valves closest to the loop are grouped together as a single
- check valve barrier for test purposes.
The first valve provides a thermal barrier preventing thermal distortien from affecting the tight-ness of the second valve.
The third valve alone constitutes a check valve barrier.
The check valves are hard seated swing checks designed to withstand the rigors of long term RFR operation without damage and the greatest assurance of integrity and defendability.
In addition to the check valves the ECCS line to each loop contains a Motor Operated valve (MOV) which is closed except for periodic monthly testing.
The MOV and reactor side piping is designed for full system pressure and also capable of preventing an overpressure condition of
,,onnecting piping.
i
(
By relieving the reactor side pressure when cycle testing the MOV, additional protection is provided against a hypothetical event sequence I
i wherein a gross undetected failure of a check valve barrier exists and the cycling the MOV results in a shock loading of the second check valve
- barrier, causing it too to fail, resulting in a backflow through the l
three checks in excess of relief valve capacity, overpressurizing and rupturing the low pressure piping, and a leak of reactor coolant outside *
[
of the containment.
The leakage criteria provide an acceptable balance between the need to maintain a degree of tightness as a criterion of integrity on one hand i
l and ALARA and power dependability considerations on the other giving due
- credit to the unique design feature of and protection provided by the four valves in series.
With barrier leakage between 5 gpm and 15 gpm it 13 not necessary to shut
- down for the purpose of restoring the leakage to less than or equal to 5
- gpm.
Fewever, if a cold shutdown is necessitated by other factors and i
[
4.6-4
there is time to inspect and refurbish the affected barrier, it is prudent to do so. Since inspection and refurbishment of the check valve
- closest to the reactor coolant system in barrier a would involve high ~
exposure of personnel to radiation, when barrier a is involved, corrective action is best applied to the other valve.
Verification that the spray piping and nozzles are open will be made initially by a suitably sensitive method, and at least every five years thereafter. Since all piping material is all stainless steel, normally in a dry condition, and with no plugging mechanism available, the retest every five years is considered to be more than adequate.
Other systems that are important to the emergency cooling function are the SI tanks, the component cooling system and the service water system.
The SI tanks are a passive safety feature.
In accordance with the Specification 4.1 (Table 4.1-2, Item 11), the water volume and pressure in the SI tanks are checked periodically.
The component cooling and service water systems operate when the reactor is in operation and are continously monitored for satisfactory performance.
The three month testing interval of the steam generator auxiliary feed pumps "erifies their operability by recirculating water to the demineralized water tank.
Prior to plant startup following an extended cold shutdown, a flow test is performed on the Auxiliary Feedwater System to functionally verify the system alignment from the demineralized water storage tank to the steam generators.
Monthly inspections are performed to verify that all manual valves in tne Auxiliary Feedwater System from the primary water source to the steam generators are locked in the proper position.
Proper functioning of the steam turbine admission valve and starting of the auxiliary feed pump will demonstrate the operability of the steam driven pump.
Verification of correct operation will be made both from instrumentation with the main control room and direct visual observation of the pumps.
The main steam, excess flow check valves serve to limit an excessive I
l reactor coolant system cooldown rate and resultant reactivity insertion l
following a main steam break incident.
Their freedom to move will be l
verified periodically.
l l
l l
l 4.6-5
1 Specification h
3.19 (Alternative) 4 e
D
= ' ' ' w w---
~
v
3.19 SAFETY INJECTION SYSTEM Apolicability:
Applies to the condition of safety injection system.
Objective:
To define the condition of the safety injection system required during reactor operation.
Soecification:
a) None of the following valves may be closed unless the reactor is subcritical:
1.
Any safety injection tank isolation valve (SIA-M-ll, 21, 31) 2.
Any safety injection header isolation valve (HSI-16, 26, 36) 3.
Any loop isolation valve (RCM-ll, 12, 21, 22, 31, 32) b)
The reactor shall not bt critical unless the following conditions are met:
1.
The safety injection tank isolation valves shall be disabled in the open position.
This shall require the following:
a.
The breakers shall be locked and tagged open.
b.
The disconnect switches for each valve power operator shall be locked and tagged open.
2.
The loop isolation valves shall be disabled in the open position.
This shall require the following:
a.
The breakers shall be locked and tagged open.
b.
The disconnect switches for each valve power operator shall be locked and tagged open.
3.
The following ECCS check valve barriers shall have been determined to be intact in accordance with Technical Specification 4.d. A.2(f).
Barrier Loop 1 a
HSI-17 and HSI-61 b
LSI-12 Loop 2 a
HSI-27 and HSI-62 b
LSI-22 Loop 3 a
HSI-37 and HSI-63 b
LSI-32
~
+
Exceotion:
If any of the ECCS check valve barriers specifieo above have not been determined to be in-tact in accordance with Technical Specification 3.19-1
,o.-
4.6.A.2(f), then the reactor may be made or remain critical for 30 days provided that in the affected ECCS line Motor Operated Valve remains closed and the*
other check valve barrier has been determined to be intact.
Basis:
The position restrictions on the loop isolation valves, safety injection header isolatian valves, and the safety injection tank isolation valves are necessary to assure that plant operation is restricted to conditions consicered in the loss-of-coolant accident analysis.
The three check valves in the ECCS line to each loop provides*
assurance that a valve failure will not result in un-restricted flow of pressurized reactor coolant into lower pressure connecting piping outside the containment.
The valve integrity testing required by Technical Specification 4.6. A.2(f) assures that the rate of flow under a valve failure condition will not exceed the pressure relief capacity of the line.
It further provides periodic assurance
- that the check valves are intact.
The two check valves closest to the loop are grouped together*
as a single check valve barrier for test purposes.
The first*
valve provides a thermal barrier preventing thermal dis-tortion from affecting the tightness of the second valve.
The third valve alone constitutes a check valve barrier.
In addition to the check valves the ECCS line to each loop contains a Motor Operated Valve (MOV) which is closed except
- for periodic monthly testing.
The MOV and reactor side piping is designed for full system pressure and also capable
- of preventing an overpressure condition of connecting piping.*
The exception permits time to schedule an orderly shutouwn and maintenance of a defective valve while providing assurance that two separate intact barriers always exist.
3.19-2