ML24317A249
| ML24317A249 | |
| Person / Time | |
|---|---|
| Site: | Hatch, Vogtle, Farley  |
| Issue date: | 11/18/2024 |
| From: | John Lamb NRC/NRR/DORL/LPL2-1 |
| To: | |
| References | |
| Download: ML24317A249 (1) | |
Text
Technical Specifications Bases ESFAS Actuation Logic
- Operating B 3.3.15 VEGP Units 3 and 4 B 3.3.15 - 4 Revision 71__
BASES SURVEILLANCE REQUIREMENTS Due to self-checking features that continuously monitor logic OPERABILITY and alert the operator to any failures, there are no Surveillances required for ESF Coincidence Logic. Similarly, there are no Surveillances required for ESF Actuation. with the exception of the required actuation test SRs, which test the end devices. Nearly all similar actuation tests are found in the various system or valve LCOs. The actuated device tests included in LCO 3.3.15 were added to cover unique actuation tests for components that do not otherwise have a separate TS for the end devices. Failure of these SRs result in inoperability of ESF Actuation subsystem.
SR 3.3.15.1 This SR demonstrates that the pressurizer heater circuit breakers trip open in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the circuit breakers. The OPERABILITY of the motor control center breakers is checked by opening these breakers using the Plant Control System.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation. This Frequency is adequate based on the use of multiple circuit breakers to prevent the failure of any single circuit breaker from disabling the function and that all circuit breakers are tested.
This Surveillance Requirement is modified by a Note that states that the SR is only required to be met when all four cold leg temperatures are
> 275°F.
SR 3.3.15.2 This SR demonstrates that the RCP breakers trip open in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the circuit breakers.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
SR 3.3.15.3 This SR demonstrates that the main feedwater and startup feedwater pump breakers trip open in response to an actual or simulated actuation
Technical Specifications Bases ESFAS Actuation Logic
- Operating B 3.3.15 VEGP Units 3 and 4 B 3.3.15 - 5 Revision 71__
signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the circuit breakers.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
SR 3.3.15.4 This SR demonstrates that the auxiliary spray and purification line isolation valves actuate to the isolation position in response to an actual or simulated actuation signal. In the case of CVS-V092 & -V094 (Zinc Injection Isolation) and CVS-V219 (Hydrogen Injection Isolation) these end devices are also Containment Isolation Valves and have actuation tests covered by LCO 3.6.3, Containment Isolation Valves. As such, only CVS-V084 (Aux Spray Isolation) and CVS-V001, -V002, -V003 (Purification Line Isolations) are addressed by SR 3.3.15.4. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valves.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
This Surveillance Requirement is modified by a Note that states that the SR is only required to be met in MODES 1 and 2.
REFERENCES None.1.
FSAR Chapter 15, Accident Analysis.
Technical Specifications Bases ESFAS Actuation Logic
-- Shutdown B 3.3.16 VEGP Units 3 and 4 B 3.3.16 - 5 Revision __71 BASES ACTIONS (continued)
Completion Times are reasonable, based on operating experience, to reach the required plant conditions in an orderly manner without challenging plant systems.
Required Action C.2 minimizes the consequences of a loss of decay heat removal event by optimizing conditions for RCS cooling in MODE 6 using IRWST injection. Additionally, the potential for a criticality event is minimized by suspension of positive reactivity additions.
D.1 If the Required Action and associated Completion Time of Condition A is not met during movement of irradiated fuel assemblies, or one or more ESFAS actuation logic Functions within two or more divisions are inoperable, the plant must be placed in a condition in which the likelihood and consequences of an event are minimized. Required Action D.1 requires immediately suspending movement of irradiated fuel assemblies.
This required action suspends activities with potential for releasing radioactivity that might enter the Main Control Room. This action does not preclude the movement of fuel to a safe position.
SURVEILLANCE REQUIREMENTS Due to self-checking features that continuously monitor logic OPERABILITY and alert the operator to any failures, there are no Surveillances required for ESF Coincidence Logic. Similarly, there are no Surveillances required for ESF Actuation. with the exception of the required actuation test SRs, which test the end devices. Nearly all similar actuation tests are found in the various system or valve LCOs. The actuated device tests included in LCO 3.3.16 were added to cover unique actuation tests for components that do not otherwise have a separate TS for the end devices. Failure of these SRs result in inoperability of ESF Actuation subsystem.
SR 3.3.16.1 This SR demonstrates that the RCP breakers trip open in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the circuit breakers. The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation. The SR is modified by a Note stating that the SR is only required to be met in MODE 5.
Technical Specifications Bases ESFAS Actuation Logic
-- Shutdown B 3.3.16 VEGP Units 3 and 4 B 3.3.16 - 6 Revision __71 BASES ACTIONS (continued)
SR 3.3.16.2 This SR demonstrates that the CVS letdown isolation valves actuate to the isolation position in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valves.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown to prevent any upsets of plant operation.
The SR is modified by a Note stating that the SR is not required to be met in MODE 5 above the P-12 (Pressurizer Level) interlock. A second Note states that the SR is not required to be met in MODE 6 with water level 23 feet above the top of the reactor vessel flange.
REFERENCES
- 1.
None.FSAR Chapter 15, Accident Analysis.
Technical Specifications Bases Pressurizer Heater Circuit Breakers B 3.4.18 VEGP Units 3 and 4 B 3.4.18 - 1 Revision __
B 3.4 REACTOR COOLANT SYSTEM (RCS)
B 3.4.18 Pressurizer Heater Circuit Breakers BASES BACKGROUND Electrical immersion heaters, located in the lower section of the pressurizer vessel, keep the water in the pressurizer at saturation temperature and maintain a constant operating pressure. Power to the pressurizer heaters is blocked when the core makeup tanks are actuated.
This action reduces the potential for steam generator overfill for a steam generator tube rupture accident.
Pressurizer heaters are automatically tripped to reduce the potential for steam generator overfill and automatic ADS Stages 1, 2, and 3 actuation for a steam generator tube rupture event. Automatically tripping the pressurizer heaters reduces the pressurizer level swell for certain non-LOCA events such as loss of normal feedwater, inadvertent CMT operation, and CVS malfunction resulting in an increase in RCS inventory.
For small break LOCA analysis, tripping the pressurizer heaters supports depressurization of the RCS following actuation of the CMTs.
As described in Updated Safety Analysis Report subsection 7.3.1.2.23, Division A of the protection and safety monitoring system provides actuation signals to five load center circuit breakers which provide the power feed to five pressurizer heater electrical control centers. When these five power feed breakers are opened, the electrical power is removed from the pressurizer heaters. In addition, each division of the protection and safety monitoring system provides a separate signal to the plant control system. Within the plant control system, these signals are voted two-out-of four and the result is used to open the pressurizer heater circuits at the motor control center. This arrangement provides for complete disabling of the pressurizer heaters, even if a single component failure occurs. Pressurizer heater trip on High-3 pressurizer water level may be manually blocked when wide range RCS pressure is below the P-19 interlock.
APPLICABLE SAFETY ANALYSES For Condition II non-LOCA events, such as inadvertent operation of the core makeup tanks during power operation (Ref. 1) and chemical and volume control system malfunction that increases reactor coolant inventory (Ref. 2), the blocking of pressurizer heater operation may be required to prevent long-term pressurizer overfill.
Technical Specifications Bases Pressurizer Heater Circuit Breakers B 3.4.18 VEGP Units 3 and 4 B 3.4.18 - 2 Revision __
BASES APPLICABLE SAFETY ANALYSES (continued)
For the steam generator tube rupture events, power to the pressurizer heaters is shut off so that they will not provide additional heat to the primary should the pressurizer level return (Ref. 3).
The pressurizer heater circuit breakers satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO The requirement that each pressurizer heater circuit breaker be OPERABLE ensures that upon signal to block pressurizer heaters the breakers will trip open as assumed in the DBA safety analyses.
For a pressurizer heater circuit breaker to be considered OPERABLE, it must be capable of tripping on an actuation signal or maintained in the tripped condition.
APPLICABILITY In MODES 1, 2, and 3, and MODE 4 with all four cold leg temperatures
> 275°F, the pressurizer heater circuit breakers must be OPERABLE to mitigate the potential consequences of any event which causes an increase in the pressurizer water level that could otherwise result in overfilling of the pressurizer.
In MODE 4, any cold leg temperature 275°F, and in MODES 5 and 6, pressurizer overfill is not a concern since overpressure protection in these MODES is provided by LCO 3.4.14, Low Temperature Overpressure Protection (LTOP), and the credited valves are designed for water relief.
ACTIONS The actions are modified by a Note indicating that separate Condition entry is allowed for each pressurizer heater. This is acceptable, since the Required Actions provide appropriate compensatory actions for each pressurizer heater with inoperable breaker(s). Complying with the Required Actions allows subsequent inoperable circuit breakers to be governed by subsequent Condition entry and application of associated Required Actions.
A.1 If one or more pressurizer heaters with one circuit breaker is inoperable, action must be taken to restore the breaker(s) to OPERABLE status within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowed to restore the inoperable breaker(s) is reasonable based on the low probability of an event occurring during this interval.
Technical Specifications Bases Pressurizer Heater Circuit Breakers B 3.4.18 VEGP Units 3 and 4 B 3.4.18 - 3 Revision __
BASES ACTIONS (continued)
B.1 and B.2 If the Required Action and associated Completion Time of Condition A is not met or if one or more pressurizer heaters with two circuit breakers are determined to be inoperable, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 4 with at least one cold leg temperature 275°F within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner, without challenging plant systems.
SURVEILLANCE REQUIREMENTS SR 3.4.18.1 This SR demonstrates that the pressurizer heater circuit breakers trip open in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the circuit breakers. The OPERABILITY of the motor control center breakers is checked by opening these breakers using the Plant Control System.
The SR excludes circuit breakers that are maintained in the tripped position since a tripped open circuit breaker is already performing the safety function. Restoration of a circuit breaker to the non-tripped position requires verification that the SR has been met within its required Frequency.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation. This Frequency is adequate based on the use of multiple circuit breakers to prevent the failure of any single circuit breaker from disabling the function and that all circuit breakers are tested.
Technical Specifications Bases Pressurizer Heater Circuit Breakers B 3.4.18 VEGP Units 3 and 4 B 3.4.18 - 4 Revision __
BASES REFERENCES
- 1.
FSAR Section 15.5.1, Inadvertent Operation of the Core Makeup Tanks During Power Operation.
- 2.
FSAR Section 15.5.2, Chemical and Volume Control System Malfunction That Increases Reactor Coolant Inventory.
- 3.
FSAR Section 15.6.3, Steam Generator Tube Rupture.
Technical Specifications Bases Auxiliary Spray and Purification Line Isolation Valves B 3.4.19 VEGP Units 3 and 4 B 3.4.19 - 1 Revision __
B 3.4 REACTOR COOLANT SYSTEM (RCS)
B 3.4.19 Auxiliary Spray and Purification Line Isolation Valves BASES BACKGROUND The Chemical and Volume Control System (CVS) maintains the reactor coolant system (RCS) fluid purity and activity level within acceptable limits. The CVS purification line receives flow from the discharge of the reactor coolant pumps (RCPs). The CVS also provides auxiliary spray to the pressurizer. To preserve the reactor coolant inventory in the event of a break in the CVS loop piping, the auxiliary spray line, purification line, zinc addition line, and hydrogen addition line are isolated on Pressurizer Water Level - Low to help maintain reactor coolant system inventory.
In the case of CVS-V092 & -V094 (Zinc Injection Isolation) and CVS-V219 (Hydrogen Injection Isolation) these end devices are also Containment Isolation Valves and have OPERABILITY covered by LCO 3.6.3, Containment Isolation Valves. As such, only CVS-V084 (Aux Spray Isolation) and CVS-V001, -V002, -V003 (Purification Line Isolations) are addressed by this LCO.
Auxiliary Spray and Purification Line Isolation is actuated on the following signals:
Pressurizer Water Level - Low; and Chemical and Volume Control System Makeup Isolation - Manual Initiation.
APPLICABLE SAFETY ANALYSES To help preserve the reactor coolant inventory in the event of a break in the CVS loop piping the auxiliary spray and purification line isolation valves can be closed (Ref. 1).
LCO The requirement for OPERABILITY of the CVS auxiliary spray and purification line isolation valves ensures that upon signal to isolate the valves will be isolated. For each auxiliary spray and purification line isolation valve to be considered OPERABLE, it must be capable of tripping on an actuation signal.
Technical Specifications Bases Auxiliary Spray and Purification Line Isolation Valves B 3.4.19 VEGP Units 3 and 4 B 3.4.19 - 2 Revision __
BASES APPLICABILITY This Function is required to be OPERABLE in MODES 1 and 2. In MODES 3, 4, 5, and 6, this Function is not needed for accident detection and mitigation.
ACTIONS The ACTIONS are modified by two Notes. Note 1 allows the auxiliary spray and purification line flow path to be unisolated intermittently under administrative control. These administrative controls consist of stationing a dedicated operator at the valve controls, who is in continuous communication with the control room. In this way the flow path can be rapidly isolated when a need for auxiliary spray and purification line isolation is indicated.
Note 2 indicates that separate Condition entry is allowed for each flow path. This is acceptable, since the Required Actions provide appropriate compensatory actions for each inoperable isolation valve. Complying with the Required Actions may allow for continued operation, and subsequent inoperable isolation valves are governed by subsequent Condition entry and application of associated Required Actions.
A.1 In the event the auxiliary spray flow path isolation valve and/or one or two of the purification line flow path isolation valves is inoperable, the valve(s) must be restored to OPERABLE stratus in 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Completion Time is reasonable considering the time required to isolate the penetration, the relative importance of supporting automatic RCS isolation.
B.1 and B.2 If the Required Action and associated Completion Time of Condition A is not met or if three purification line flow path isolation valves are inoperable then the affected flow path must be isolated by use of at least one closed and deactivated automatic valve within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. Alternatively, the plant must be placed in a MODE 3 in which the likelihood and consequences of an event are minimized. The 6 hour6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> Completion Time is a reasonable time based on operating experience, to isolate the flow path or reach MODE 3 from full power in an orderly manner and without challenging plant systems.
Technical Specifications Bases Auxiliary Spray and Purification Line Isolation Valves B 3.4.19 VEGP Units 3 and 4 B 3.4.19 - 3 Revision __
BASES SURVEILLANCE REQUIREMENTS SR 3.4.19.1 This SR demonstrates that the auxiliary spray and purification line isolation valves actuate to the isolation position in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valves.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
REFERENCES
- 1.
FSAR Section 7.3.1.2.18, Auxiliary Spray and Purification Line and Zinc/Hydrogen Addition Isolation.
Technical Specifications Bases CVS Letdown Isolation Valves B 3.4.20 VEGP Units 3 and 4 B 3.4.20 - 1 Revision __
B 3.4 REACTOR COOLANT SYSTEM (RCS)
B 3.4.20 Chemical and Volume Control System (CVS) Letdown Isolation Valves BASES BACKGROUND The CVS provides letdown to the liquid radwaste system to maintain the pressurizer level. To help maintain RCS inventory in the event of a LOCA, the CVS Letdown Isolation is actuated on Hot Leg Level - Low 2.
APPLICABLE SAFETY ANALYSES Letdown isolation assists the operators when draining the RCS to a mid-loop level. If the operators fail to isolate letdown, these channels send a signal to close the letdown valves and stop the draining process (Ref. 1).
LCO The requirement for OPERABILITY of the CVS letdown isolation valves ensures that upon signal to isolate the penetration will be isolated. For each CVS letdown isolation valve to be considered OPERABLE, it must be capable of isolating on an actuation signal.
APPLICABILITY This Function is required to be OPERABLE in MODE 5 below the P-12 (Pressurizer Level) interlock, and in MODE 6 with the water level
< 23 feet above the top of the reactor vessel flange to assist the operators when draining the RCS to a mid-loop level.
In other conditions, the RCS is not being drained to mid-loop and operator assistance is not needed.
ACTIONS The Action are modified by a Note allowing the CVS letdown flow path to be unisolated intermittently under administrative control. These administrative controls consist of stationing a dedicated operator at the valve controls, who is in continuous communication with the control room.
In this way the flow path can be rapidly isolated when a need for CVS letdown isolation is indicated.
A.1 If one CVS letdown isolation vlaave is inoperable, action must be taken to restore the valve within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> allowed to restore the inoperable valve is reasonable based on the low probability of an event occurring during this interval and OPERABILITY of the redundant letdown isolation valve.
Technical Specifications Bases CVS Letdown Isolation Valves B 3.4.20 VEGP Units 3 and 4 B 3.4.20 - 2 Revision __
BASES ACTIONS (continued)
B.1 If the Required Action or associated Completion Time of Condition A is not met or two CVS letdown isolation valves are inoperable, action must be initiated immediately to isolate the CVS letdown flow. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure. Isolation barriers that meet this criterion are a closed and de-activated automatic valve.
SURVEILLANCE REQUIREMENTS SR 3.4.20.1 This SR demonstrates that the CVS letdown isolation valves actuate to the isolation position in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valves.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown to prevent any upsets of plant operation.
REFERENCES
- 1.
FSAR Section 19E.2.1.2.4, Improved RCS Draindown Method.
Technical Specifications Bases CMTs - Operating B 3.5.2 VEGP Units 3 and 4 B 3.5.2 - 1 Revision __71 B 3.5 PASSIVE CORE COOLING SYSTEM (PXS)
B 3.5.2 Core Makeup Tanks (CMTs) - Operating BASES BACKGROUND Two redundant CMTs provide sufficient borated water to assure Reactor Coolant System (RCS) reactivity and inventory control for all design basis accidents (DBAs), including both loss of coolant accident (LOCA) events and non-LOCA events (Ref. 1). Flow from the core makeup tank increases if the reactor coolant pumps (RCPs) have coasted down, therefore, the RCP breaker OPERABILITY is addressed in LCO 3.5.9, Reactor Coolant Pump Breakers.
The CMTs are cylindrical tanks with hemispherical upper and lower heads. They are made of carbon steel and clad on the internal surfaces with stainless steel. They are located in containment at an elevation slightly above the reactor coolant loops. Each tank is full of borated water at > 3400 ppm. During normal operation, the CMTs are maintained at RCS pressure through a normally open pressure balance line from the cold leg.
The outlet line from each CMT is connected to one of two direct vessel injection lines, which provides an injection path for the water supplied by the CMT. The outlet line from each CMT is isolated by parallel, normally closed, fail open valves. Upon receipt of a safeguards actuation signal, these four valves open to align the CMTs to the RCS.
The CMTs will inject to the RCS as inventory is lost and steam or reactor coolant is supplied to the CMT to displace the water that is injected.
Steam or reactor coolant is provided to the CMT through the cold leg balance line, depending upon the specific event that has occurred. The inlet line from the cold leg is sized for LOCA events, where the cold legs become voided and higher CMT injection flows are required.
The injection line from each CMT contains a flow tuning orifice that is used to provide a mechanism for the field adjustment of the injection line resistance. The orifice is used to establish the required flow rates for the associated plant conditions assumed in the CMT design. The CMT flow is based on providing injection for approximately 20 minutes after CMT actuation.
The CMT size and injection capability are selected to provide adequate RCS boration and safety injection for the limiting DBA. One CMT is adequate for this function during a small break LOCA where one CMT completely spills via the pipe break (Ref. 2). The Probabilistic Risk Assessment (PRA) (Ref. 3) shows that none of the CMTs are required for small LOCAs, assuming that at least one accumulator is available.
Technical Specifications Bases RCP Breakers B 3.5.9 VEGP Units 3 and 4 B 3.5.9 - 1 Revision __
B 3.5 PASSIVE CORE COOLING SYSTEM (PXS)
B 3.5.9 Reactor Coolant Pump Breakers BASES BACKGROUND Core Makeup Tank (CMTs) provide sufficient borated water to assure Reactor Coolant System (RCS) reactivity and inventory control for all design basis accidents (DBAs), including both loss of coolant accident (LOCA) events and non-LOCA events. CMT performance assumes reactor coolant pumps (RCPs) have tripped (Ref. 1). Flow from the core makeup tank increases if the RCPs have coasted down, therefore, the RCP breakers are required to trip open after time delay to support the assumptions for CMT injection.
RCP trip is actuated on the following signals (refer to the Bases for LCO 3.3.8, Engineered Safety Feature Actuation System (ESFAS)
Instrumentation):
Safeguards Actuation; ADS Stages 1, 2, & 3 Actuation; Reactor Coolant Pump Bearing Water Temperature - High 2; Pressurizer Water Level - Low 2; and CMT Injection Actuation - Manual Initiation.
Each RCP is powered through two Class 1E circuit breakers connected in series, with one breaker receiving a trip signal from either Protection and Safety Monitoring System (PMS) Division B and the second breaker from Division C. The two breakers in series scheme is used to ensure that the RCPs are shutdown when the PMS tripping signal is initiated.
APPLICABLE SAFETY ANALYSES When the CMTs are actuated, the RCPs are tripped (after a time delay) to allow steam and water to separate in the RCS and to allow steam displacement draindown. Tripping of the RCPs is done to enhance safety injection and avoid potential adverse interactions.
RCP Breakers satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
Technical Specifications Bases RCP Breakers B 3.5.9 VEGP Units 3 and 4 B 3.5.9 - 2 Revision __
BASES LCO This LCO establishes the OPERABILITY for two RCP breakers for each RCP. For RCP breakers to be considered OPERABLE they must trip open on an actuation signal or be maintained in the tripped condition.
APPLICABILITY The Applicability is established consistent with the CMTs, which are required to be OPERABLE to provide borated water for RCS inventory makeup and reactivity control following a design basis event and subsequent cooldown. In MODES 1, 2, 3, and 4 CMT OPERABILITY is required to provide borated water for RCS inventory makeup and reactivity control following a design basis event and subsequent cooldown.
In MODE 5 with the RCS not VENTED, CMT OPERABILITY is required to provide borated water to the RCS in the event the nonsafety related chemical and volume control system makeup pumps are not available to provide RCS inventory control.
The RCP breakers are not required to be OPERABLE while in MODE 5 with the RCS VENTED, or in MODE 6, because the RCS is depressurized and borated water can be supplied from the In-containment Refueling Water Storage Tank (IRWST), if needed. The RCS is considered VENTED when the ADS stage 1, 2, and 3 flow paths (or alternative flow path with equivalent area) required by LCO 3.4.13, "Automatic Depressurization System (ADS) - Shutdown, RCS Open," are open, such that when combined with required ADS stage 4 actuation, sufficient steam venting area is provided to lower RCS pressure sufficiently to allow IRWST injection.
ACTIONS The ACTIONS are modified by a note indicating that separate condition entry is allowed for each RCP. This is acceptable, since the Required Actions provide appropriate compensatory actions for each RCP.
Complying with the Required Actions allows subsequent RCPs with inoperable breakers to be governed by subsequent Condition entry and application of associated Required Actions.
A.1 With one or more RCPs with one breaker inoperable in MODE 1, 2, 3, or 4, action must be taken to restore the breaker(s) within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> allowed to restore the inoperable breaker is reasonable based on the capability of the remaining OPERABLE breaker to mitigate all DBAs and the low probability of an event occurring during this interval and OPERABILITY of the redundant RCP breaker.
Technical Specifications Bases RCP Breakers B 3.5.9 VEGP Units 3 and 4 B 3.5.9 - 3 Revision __
BASES ACTIONS (continued)
B.1 and B.2 If the Required Action or associated Completion Time of Condition A is not met or one or more RCPs with two breakers are inoperable in MODE 1, 2, 3, or 4, the plant must be brought to a MODE in which the LCO does not apply. To achieve this status, the plant must be brought to at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> and to MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required plant conditions from full power conditions in an orderly manner and without challenging plant systems.
C.1 With one or more RCPs with one breaker inoperable in MODE 5, action must be taken to restore the breaker(s) within 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is reasonable considering the remaining OPERABLE breaker is capable of performing the associated safety function and the low probability of an event occurring during this interval.
D.1 If the Required Action or associated Completion Time of Condition C is not met or one or more RCPs with two breakers are inoperable in MODE 5, action must be initiated immediately to trip the inoperable RCP breaker(s).
Tripping the affected RCP(s) accomplishes the necessary safety function to support CMT OPERABILITY.
SURVEILLANCE REQUIREMENTS SR 3.5.9.1 This SR verifies that RCP breakers trip open on an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valve.
The SR excludes circuit breakers that are maintained in the tripped position since a tripped open circuit breaker is already performing the safety function. Restoration of a circuit breaker to the non-tripped position requires verification that the SR has been met within its required Frequency.
The Frequency of 24 months is based on the need to perform this surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
Technical Specifications Bases RCP Breakers B 3.5.9 VEGP Units 3 and 4 B 3.5.9 - 4 Revision __
BASES REFERENCES
- 1.
FSAR Section 6.3, Passive Core Cooling System.
Technical Specifications Bases Containment Isolation Valves B 3.6.3 VEGP Units 3 and 4 B 3.6.3 - 3 Revision __66 BASES LCO (continued)
The automatic power operated isolation valves are required to have isolation times within limits and to actuate on an automatic isolation signal. The valves covered by this LCO are listed along with their associated stroke times in the FSAR Section 6.2 (Ref. 1).
The normally closed isolation valves are considered OPERABLE when manual valves are closed, automatic valves are de-activated and secured in their closed position, or blind flanges are in place. These passive isolation valves/devices are those listed in Reference 1.
This LCO provides assurance that the containment isolation valves, except for the closed system valves and vacuum relief valves, and purge valves will perform their designed safety functions to minimize the loss of reactor coolant inventory and establish the containment boundary during accidents. The containment isolation valves associated with closed systems are not included in this LCO since they are covered in LCO 3.7.1, "Main Steam Safety Valves (MSSVs)," LCO 3.7.2, Main Steam Line Flow Path Isolation Valves, LCO 3.7.3, Main Feedwater Isolation Valves (MFIVs), and Main Feedwater Control Valves (MFCVs), and Main Feedwater (MFW) Pump Breakers, LCO 3.7.7, Startup Feedwater (SFW) Isolation Valves, and Control Valves, and Pump Breakers, and LCO 3.7.10, Steam Generator (SG) Isolation Valves.
The containment system vacuum relief valves provide containment isolation but are also required to open to mitigate a negative pressure event within containment. Therefore, the vacuum relief valves are not included in this LCO since they are covered in LCO 3.6.9, Vacuum Relief Valves.
APPLICABILITY In MODES 1, 2, 3, and 4 a DBA could cause a release of radioactive material to containment. In MODES 5 and 6, the probability and consequences of these events are reduced due to the pressure and temperature limitations of these MODES. Therefore, containment isolation valves are not required to be OPERABLE in MODES 5 and 6 to prevent leakage of radioactive material from containment. However, containment closure capability is required in MODES 5 and 6. The requirements for containment isolation valves during MODES 5 and 6 are addressed in LCO 3.6.7, Containment Penetrations.
Technical Specifications Bases MFIVs, and MFCVs, and MFW Pump Breakers B 3.7.3 VEGP Units 3 and 4 B 3.7.3 - 1 Revision __71 B 3.7 PLANT SYSTEMS B 3.7.3 Main Feedwater Isolation Valves (MFIVs), and Main Feedwater Control Valves (MFCVs), and Main Feedwater (MFW) Pump Breakers BASES BACKGROUND The MFIVs isolate main feedwater (MFW) flow to the secondary side of the steam generators following a high energy line break. The safety related function of the MFCVs is to provide the second isolation of MFW flow to the secondary side of the steam generators following a high energy line break. Closure of the MFIVs or MFCVs terminates flow to the steam generators, terminating the event for feedwater line breaks occurring upstream of the MFIVs or MFCVs. The MFW pumps also trip to prevent damage to the turbine due to water in the steam lines and to stop the excessive flow of feedwater into the steam generators. The consequences of events occurring in the main steam lines or in the MFW lines downstream from the MFIVs will be mitigated by their closure and the MFW pump trip. Closure of the MFIVs or MFCVs, and trip of the MFW pumps, effectively terminates the addition of main feedwater to an affected steam generator, limiting the mass and energy release for steam or feedwater line breaks inside containment, and reducing the cooldown effects for steam line breaks (SLBs).
The MFIVs or MFCVs isolate the nonsafety related portions from the safety related portions of the system. In the event of a secondary side pipe rupture inside containment, the valves isolate and the pumps trip to limit the quantity of high energy fluid that enters containment through the break, and provide a pressure boundary for the controlled addition of startup feedwater (SFW) to the intact loops of the steam generator.
One MFIV and one MFCV are located on each MFW line, outside but close to containment. The MFIVs and MFCVs are located in the MFW line and are independent of the delivery of the MFW or SFW via the SFW line which is separately connected and isolated from the steam generator.
This configuration permits MFW or SFW to be supplied to the steam generators following MFIV or MFCV closure. The piping volume from these valves to the steam generators must be accounted for in calculating mass and energy releases following either an SLB or FWLB.
The three MFW pumps operate in parallel each constituting a MFW pump flow path. The MFW pumps discharge to a common header, which then feeds two MFW flow paths each to one steam generator.
The MFIVs and MFCVs close, and the MFW pump breaker trips, on receipt of engineered safeguards feedwater isolation signal generated from any of the following conditions:
Technical Specifications Bases MFIVs, and MFCVs, and MFW Pump Breakers B 3.7.3 VEGP Units 3 and 4 B 3.7.3 - 2 Revision __71 BASES BACKGROUND (continued)
Automatic or manual safeguards actuation S signal; High 3 steam generator level; Low-2 Tavg signal coincident with reactor trip (P-4) (for the MFIVs and MFW pumps);
Low Tavg signal coincident with reactor trip (P-4) (for the MFCVs); and Manual actuation Each valve and each pump may be actuated manually. In addition to the MFIVs and the MFCVs, a check valve is available outside containment to isolate the feedwater line penetrating containment. In the event of feedwater line depressurization due to pump trip on line break, the check valve provides rapid backup isolation of the steam generators limiting the inventory loss. A description of the MFIVs and MFCVs is found in Reference 1.
APPLICABLE SAFETY ANALYSES The design basis of the MFIVs, and MFCVs, and MFW pump trip is established by the analyses for the large SLB. It is also influenced by the accident analysis for the large Feedwater Line Break (FWLB). Closure of the MFIVs (or MFCVs), and trip of the MFW pump, may also be relied on to mitigate an SLB for core response analysis and excess feedwater event upon the receipt of a steam generator water level - High 3 signal.
Failure of an MFIV (or MFCV), to close, or the MFW pumps to trip, following an SLB or FWLB, can result in additional mass and energy being delivered to the steam generators, contributing to cooldown. This failure also results in additional mass and energy releases following an SLB or FWLB event.
In addition, the MFIVs are containment isolation valves and support the assumptions related to minimizing the loss of inventory and establishing the containment boundary during major accidents. Therefore, the safety analysis of any event requiring isolation of containment is applicable to the MFIVs.
The MFIVs and MFCVs satisfy Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO This LCO ensures that the MFIVs and the MFCVs will isolate the main feedwater system to the secondary side of the steam generators and ensures that the MFW pumps will trip.
Technical Specifications Bases MFIVs, and MFCVs, and MFW Pump Breakers B 3.7.3 VEGP Units 3 and 4 B 3.7.3 - 3 Revision __71 BASES LCO (continued)
This LCO requires that the one isolation valve and one control valve on each feedwater line and each MFW pump breaker be OPERABLE.
These valves are considered OPERABLE when their isolation times are within limits and they close on an isolation actuation signal. For a MFW pump breaker to be considered OPERABLE, it must trip on an actuation signal or be in the tripped condition.
Failure to meet the LCO requirements can result in additional mass and energy being released to containment following an SLB or FWLB inside containment. A main feedwater isolation signal on High 3 steam generator level is relied on to terminate an excess feedwater flow event, and therefore failure to meet the LCO may result in the introduction of water into the main steam lines.
APPLICABILITY The MFIVs, and MFCVs, and MFW pump breakers must be OPERABLE whenever there is significant mass and energy in the Reactor Coolant System and the steam generators. This ensures that, in the event of a high energy line break, a single failure cannot result in the blowdown of more than one steam generator. In MODES 1, 2, 3, and 4, these valves and pump trips are required to be OPERABLE to limit the amount of available fluid that could be added to the containment in the case of a secondary system pipe break inside containment and where a DBA could cause a release of radioactive material to containment.
In MODES 5 and 6 steam generator energy is low. Therefore, the MFIVs and the MFCVs are normally closed, and MFW pumps are not running, since MFW is not required.
ACTIONS The ACTIONS table is modified by a Note indicating that separate condition entry is allowed for each feedwater flow path, where there are two MFW flow paths with an MFIV and MFCV in series and three MFW pump flow paths with one MFW pump in each flow path.
A.1 and A.2 With one or both feedwater flow paths with an MFIV or MFCV inoperable (one or two MFIVs, or one or two MFCVs inoperable), the affected flow path must be isolated in 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. When these flow paths are isolated, they are performing their required safety function.
Technical Specifications Bases MFIVs, and MFCVs, and MFW Pump Breakers B 3.7.3 VEGP Units 3 and 4 B 3.7.3 - 4 Revision __71 BASES ACTIONS (continued)
The 72 hour8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> Completion Time takes into account the redundancy afforded by the remaining OPERABLE valves, and the low probability of an event that would require isolation of the main feedwater flow paths occurring during this period.
For inoperable MFIVs and MFCVs that cannot be restored to OPERABLE status within the specified Completion Time but whose affected flow path is isolated, the flow paths must be verified on a periodic basis to be isolated. This is necessary to ensure that the assumptions in the safety analyses remain valid. The 7 day Completion Time is reasonable based on engineering judgment, in view of valve status indications available in the control room, and other administrative controls, to ensure that these flow paths are isolated.
B.1 With one or both feedwater flow paths with associated MFIV and MFCV inoperable (two inoperable valves in the same flow path), there may be no redundant system to operate automatically to perform the required safety function. Under these conditions, one valve in the affected flow path must be restored to OPERABLE status, or the affected flow path isolated within 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. This action returns the system to the situation in which at least one valve in the affected flow path is performing the required safety function. The 8 hour9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br /> Completion Time is a reasonable amount of time to complete the actions required to close the MFIV, or MFCV, which includes performing a controlled plant shutdown. The Completion Time is reasonable based on operating experience to reach MODE 2 with the MFIV or MFCV closed, from full-power conditions in an orderly manner and without challenging plant systems.
C.1 With one or more feedwater flow paths with a MFW pump breaker inoperable, the affected MFW pump breaker must be restored to OPERABLE status within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The Completion Time takes into account the redundancy afforded by the MFIV and MFCV and the low probability of an event that would require tripping the MFW pump during this period.
Technical Specifications Bases MFIVs, and MFCVs, and MFW Pump Breakers B 3.7.3 VEGP Units 3 and 4 B 3.7.3 - 5 Revision __71 BASES ACTIONS (continued)
DC.1, DC.2, and DC.3 If the affected flow path cannot be isolated or the MFIVs, and MFCVs, or MFW pump breaker cannot be restored to OPERABLE status, or the affected flow paths cannot be isolated within the associated Completion Time, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the plant must be placed in at least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, in MODE 4 with the normal residual heat removal system in service within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />. The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.
SURVEILLANCE REQUIREMENTS SR 3.7.3.1 This SR verifies that the closure time of each MFIV and MFCV is 5.0 seconds, on an actual or simulated actuation signal. The MFIV and MFCV isolation times are assumed in the accident and containment analyses. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valves. This Surveillance is normally performed upon returning the unit to operation following a refueling outage. These valves should not be tested at power, since even a part stroke exercise increases the risk of a valve closure when the unit is generating power.
The Frequency is in accordance with the Inservice Testing Program.
The SR is modified by a note which states that the SR is only required to be performed prior to entry into MODE 2. This allows the option to perform testing in MODES 3 or 4.
SR 3.7.3.2 This SR verifies that each main feedwater pump breaker trip open in response to an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the pump breaker.
Technical Specifications Bases MFIVs, and MFCVs, and MFW Pump Breakers B 3.7.3 VEGP Units 3 and 4 B 3.7.3 - 6 Revision __71 BASES SURVEILLANCE REQUIREMENTS (continued)
The SR excludes main feedwater pump breakers that are maintained in the tripped position since a tripped open MFW pump breaker is already performing the safety function. Restoration of a breaker to the non-actuated position requires verification that the SR has been met within its required Frequency.
The 24 month Frequency is based on the need to perform this Surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
REFERENCES
- 1.
FSAR Section 10.4.7, Condensate and Feedwater System.
Technical Specifications BasesStartup Feedwater SFW Isolation Valves, and Control Valves, and Pump Breakers B 3.7.7 VEGP Units 3 and 4 B 3.7.7 - 1 Revision __56 B 3.7 PLANT SYSTEMS B 3.7.7 Startup Feedwater (SFW) Isolation Valves,and Control Valves, and Pump Breakers BASES BACKGROUND The startup feedwaterSFW system supplies feedwater to the steam generators during plant startup, hot standby and cooldown, and in the event of main feedwater unavailability.
The startup feedwaterSFW system serves no safety related function and has no safety related design basis, except to isolate feedwater in the event of a Feedline Break (FLB), Steam Line Break (SLB), a steam generator tube rupture (SGTR), or other secondary side event.
The startup feedwaterSFW system consists of two SFW pumps, which are headered at the pump discharge, and a separate flow path to each of the steam generators. Each flow path consists of two series startup feedwaterSFW valves to provide feedwater control for low feedwater demand conditions. Feedwater can be supplied to the startup feedwaterSFW line via either the main or startup feedwaterSFW pumps.
The feedwater is delivered directly to the steam generator (SG) independent of the main feedwater line. Each startup feedwaterSFW line contains one control valve and one isolation valve (Ref. 1).
APPLICABLE SAFETY ANALYSES The basis for the requirement to isolate the startup feedwaterSFW system is established by the analysis for large SLB inside containment. It is also based on the analysis for a large FLB and a steam generator tube rupture. Failure to isolate the startup feedwaterSFW system following a SLB or FLB can lead to additional mass and energy being delivered to the steam generators, resulting in excessive cooldown and additional mass and energy release in containment. Failure to isolate the startup feedwaterSFW following a steam generator tube rupture may result in overfilling the steam generator.
Low 2 Tcold or high steam generator level signals close the startup feedwaterSFW control and isolation valves and trips the startup feedwaterSFW pumps.
In addition, the startup feedwaterSFW isolation valves are containment isolation valves and support the assumptions related to minimizing the loss of inventory and establishing the containment boundary during major accidents. Therefore, the safety analysis of any event requiring isolation of containment is applicable to these valves.
Technical Specifications BasesStartup Feedwater SFW Isolation Valves, and Control Valves, and Pump Breakers B 3.7.7 VEGP Units 3 and 4 B 3.7.7 - 2 Revision __56 BASES APPLICABLE SAFETY ANALYSES (continued)
The startup feedwaterSFW isolation and control valves are components which actuate to mitigate a Design Basis Accident, and as such meet Criterion 3 of 10 CFR 50.36(c)(2)(ii).
LCO This LCO ensures that the startup feedwaterSFW isolation and control valves will actuate isolate, and SFW pump breakers will trip, on command, following a SLB, FLB or SGTR, and to isolate startup feedwaterSFW flow to the steam generators.
The startup feedwaterSFW isolation and control valves are considered OPERABLE when they automatically close on an isolation actuation signal and their isolation times are within the required limits. For a SFW pump breaker to be considered OPERABLE, it must trip on an actuation signal or be in the tripped condition.
APPLICABILITY The startup feedwaterSFW isolation and control valves, and SFW pump breakers, must be OPERABLE whenever there is significant mass and energy in the Reactor Coolant System and the steam generators. In MODES 1, 2, 3 and 4, the startup feedwaterSFW isolation and control valves, and SFW pump breakers, are required to be OPERABLE in order to limit the amount of mass and energy that could be added to containment in the event of a SLB or FLB and prevent steam generator overfill in the event of an SGTR and where a DBA could cause a release of radioactive material to containment.
In MODES 5 and 6, the energy in the steam generators is low, and isolation of the startup feedwaterSFW system and trip of the feedwater pump breakers are is not required.
ACTIONS The ACTIONS are modified by atwo Notes. Note 1 allowsing flow paths to be unisolated intermittently under administrative controls. These controls consist of stationing a dedicated operator at the valve controls, who is in continuous communication with the control room. In this way, the flow paths can be rapidly isolated.
The second Note allows separate Condition entry for each flow path, where there are two flow paths each with an isolation and control valve in series and two SFW pump flow paths. This is acceptable, since the Required Actions for each Condition provide appropriate compensatory actions for each inoperable flow path.
Technical Specifications BasesStartup Feedwater SFW Isolation Valves, and Control Valves, and Pump Breakers B 3.7.7 VEGP Units 3 and 4 B 3.7.7 - 3 Revision __56 BASES ACTIONS (continued)
A.1 and A.2 With only one isolation or control valve OPERABLE in one or more flow paths, there is no redundant capability to isolate the flow paths. In this case, both an isolation and a control valve in each flow path must be restored to OPERABLE status with 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />, or the flow path must be isolated. A Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br /> is acceptable since, with one valve in a flow path inoperable, there is a second valve available in the flow path to isolate the line.
If the inoperable valve in the flow path cannot be restored to OPERABLE status, then the flow path must be isolated within a Completion Time of 72 hours8.333333e-4 days <br />0.02 hours <br />1.190476e-4 weeks <br />2.7396e-5 months <br />. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure.
For flow paths isolated in accordance with Required Action A.1, the affected flow paths must be verified to be isolated on a periodic basis.
This is necessary to ensure that flow paths required to be isolated following an accident will be in the isolation position should an event occur. This Required Action does not require any testing or device manipulation. Rather, it involves verification that the isolation devices are in the correct position. The Completion Time of once per 7 days is appropriate considering the fact that the devices are operated under administrative controls, valve status indications in the main control room and the probability of their misalignment is low.
B.1 With both the isolation and control valves inoperable in one flow path, the affected flow path must be restored to OPERABLE status or isolated within a Completion Time of 8 hours9.259259e-5 days <br />0.00222 hours <br />1.322751e-5 weeks <br />3.044e-6 months <br />. The method of isolation must include the use of at least one isolation barrier that cannot be adversely affected by a single active failure.
C.1 With one or more flow paths with the pump breaker inoperable the affected pump breaker must be restored to OPERABLE status within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />. The Completion Time takes into account the redundancy afforded by the isolation and control valves and the low probability of an event that would require tripping the SFW pump during this period.
Technical Specifications BasesStartup Feedwater SFW Isolation Valves, and Control Valves, and Pump Breakers B 3.7.7 VEGP Units 3 and 4 B 3.7.7 - 4 Revision __56 BASES ACTIONS (continued)
DC.1, DC.2, and DC.3 If the the affected flow paths cannot be isolated or the isolation valves, and control valves, or pump breakers cannot be restored to OPERABLE status, closed, or isolated within the associated Completion Times, the unit must be placed in a MODE in which the LCO does not apply. To achieve this status, the plant must be placed in least MODE 3 within 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br />, in MODE 4 with RCS cooling provided by the normal residual heat removal system within 24 hours2.777778e-4 days <br />0.00667 hours <br />3.968254e-5 weeks <br />9.132e-6 months <br />, and in MODE 5 within 36 hours4.166667e-4 days <br />0.01 hours <br />5.952381e-5 weeks <br />1.3698e-5 months <br />.
The allowed Completion Times are reasonable, based on operating experience, to reach the required unit conditions from full power conditions in an orderly manner and without challenging plant systems.
SURVEILLANCE REQUIREMENTS SR 3.7.7.1 This surveillance requires verification in accordance with the Inservice Testing Program to assure that each startup feedwaterSFW isolation and control valve is OPERABLE. The Surveillance Frequency is provided in the Inservice Testing Program.
SR 3.7.7.2 This SR ensures that each startup feedwaterSFW isolation valve and startup feedwaterSFW control valve will actuate to its isolation position on an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the valves.
The 24 month Frequency is based on the need to perform this Surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
SR 3.7.7.3 This SR verifies that each SFW pump breakers trip open on an actual or simulated actuation signal. The actual or simulated signal is processed through the component interface module to verify the continuity between the output of the component interface module and the pump breaker.
Technical Specifications BasesStartup FeedwaterSFW Isolation Valves, and Control Valves, and Pump Breakers B 3.7.7 VEGP Units 3 and 4 B 3.7.7 - 5 Revision __56 BASES SURVEILLANCE REQUIREMENTS (continued)
The SR excludes SFW pump breakers that are maintained in the tripped position since a tripped open SFW pump breaker is already performing the safety function. Restoration of a breaker to the non-actuated position requires verification that the SR has been met within its required Frequency.
The 24 month Frequency is based on the need to perform this Surveillance during periods in which the plant is shutdown for refueling to prevent any upsets of plant operation.
REFERENCES
- 1.