ML20083C905
| ML20083C905 | |
| Person / Time | |
|---|---|
| Site: | Farley  |
| Issue date: | 05/15/1995 |
| From: | SOUTHERN NUCLEAR OPERATING CO. |
| To: | |
| Shared Package | |
| ML20083C900 | List: |
| References | |
| NUDOCS 9505230062 | |
| Download: ML20083C905 (5) | |
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LIMITING _FAFETY SYSTEM SETTINGS BASES 2.2.1 (continued) latter trip will ensure that the DNB design criterion is met during normal operational transients and anticipated transients when 2 loops are in operation and the Overtemperature delta T trip setpoint is adjusted to the value specified for all loops in operation.
With the Overtemperature delta T trip setpoint adjusted to the value specified for 2 loop operation, the P-8 trip at 66% RATED THERMAL POWER will ensure that the DNB design criterion is met during normal operational transients and anticipated transients with 2 loops in operation.
Steam Generator Water Level The Steam Generator Water Level Low-Low trip provides core protection by preventing operation with the steam generator water level below the minLmum volume required for adequate heat removal capacity.
The specified setpoint providos allowances that there will be sufficient water inventory in the steam generators at the time of trip to allow for starting delays of the auxiliary feedwater system.
Undervoltace and Underfrecuency - Reactor Coolant Pumo Bueoes The Undervoltage and Underfrequency Reactor Coolant Pump Bus trips are provided as anticipatory trips for reactor core protection against DNB as a result of loss of voltage or underfrequency to more than one reactor coolant pump bus.
Primary core protection for these events is provided by the Loss of Flow trips. The specified setpoints for undervoltage and underfrequency generate an anticipatory reactor trip signal before the low flow trip setpoint is reached.
No credit was taken in accident analyses for the operation of these trips.
Their functional capability enhances the overall reliability of the Reactor Protection System.
Time delays are incorporated in the underfrequency and undervoltage trips to prevent spurious reactor trips from momentary electrical power transients.
For undervoltage, the delay is set so'that the time required for a signal to reach the reactor trip breakers following the simultaneous loss of power of two or more reactor coolant pump busses shall not exceed 0.9 seconds (an additional time delay is allotted for EMF decay).
For underfrequency, the delay is set so that the time required for a signal to reach the reactor trip breakers after the underfrequency trip setpoint is reached shall not exceed 0.6 seconds.
FARLEY-UNIT 1 B 2-6 May 15, 1995 9505230062 950515 PDR ADOCK 05000348 P
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b EIMITING SAFETY SYSTEM SETTINGS BASES 2.2.1 (Continued)
Turbine Trim A Turbine Trip causes a direct reactor trip when operating above P-9.
Each of the turbine trips provide turbine protection and reduce the severity of the ensuing transient.
No credit was taken in the accident analyses for operation of these trips.
Their functional capability at the specified trip settings is required to enhance the overall reliability of the Reactor Protection System.
Safety Iniection Inout from ESF-If a reactor trip has not already been generated by the reactor protective instrumentation, the ESF automatic actuation logic channels will initiate a reactor trip upon any signal ~which initiates a safety injection.
This trip is provided to protect the core in tr.e event of a LOCA.
The ESF instrumentation chaniiels which initiate a safety injection signal are shown in Table 3.3-3.
Peactor Co_0lant Pumo Breaker Position Trip The Reactor Coolant Pump Breaker Position Trips are anticipatory trips which provide reactor core protection against DNB resulting from the opening of any one pump breaker above P-8 or the opening of two or more pump breakers below P-8.
These trips are blocked below P-7.
The open/close position trips assure a reactor trip signal is generated before the low flow trip setpoint is reached.
No credit was taken in the accident analyses for operation of these trips.
Their functional capability at the open/close position settings is required to enhance the overall reliability of the Reactor Protection System.
FARLEY-UNIT 1 B 2-7 May 15, 1995
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Revised Technical Specification Pages UnLt 2 Page Instruction B 2-6 Replace B 2-7 Replace 1
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g 4
LIMITING SAFETY SYSTEM _ SETTINGS BASES 2.2.1 (Continued) latter trip will ensure that the DNB design criterion is met during normal operational transients.and anticipated transients.when 2 loops. are in operation and the overtemperature delta T trip setpoint is adjusted to the value specified for all loops in operation.
With the overtemperature delta T trip setpoint adjusted to the value specified for 2 loop operation, the P-8 trip at 66% RATED THERMAL POWER will ensure that the DNB design criterion is met during normal operational transients and anticipated transients with 2 loops in operation.
Steam Generator Water Level The steam Generator Water Level Low-Low trip provides core protection by preventing operation with the steam generator water level below the minimum j
volume required for adequate host removal capacity.
The specified setpoint provides allowances that there will be sufficient water inventory in the steam generators at the time of trip to allow for starting delays of the auxiliary feedwater system.
Undervoltaae and Underfrecuency - Reactor Coolant Pumo Busses The Undervoltage and Underfrequency Reactor Coolant Pump Bus trips are provided as anticipatory trips for reactor core protection against DNB as a result of loss of voltage or underfrequency to more than one reactor coolant i
pump bus.
Primary core protection for these events is provided by the Loss of Flow trips. The specified setpoints for undervoltage and underfrequency f
generate an anticipatory reactor trip signal before the low flow trip setpoint is reached.
]
No credit was taken in accident analyses for the operation of these.
trips. Their functional capability enhances the overall reliability of the Reactor Protection System.
Time delays are incorporated in the underfrequency and undervoltage trips to prevent spurious reactor trips from momentary electrical power transients.
For undervoltage, the delay is set so that the time required for a signal to reach the reactor trip breakeria following the simultaneous loss of power of two or more reactor coolant pump busses shall not exceed 0.9 seconds (an additional time delay is allotted for EMF decay).
For underfrequency, the delay is set so that the time required for a signal to reach the reactor trip breakers af ter the underfrequency trip setpoint is reacned shall not exceed 0.6 seconds.
FARLEY-UNIT 2 B 2-6 May 15, 1995
)
EIMITING SAFETY SYSTEM SETTIyg BASES 2.2.1 (Continued)
Turbine Trio A Turbine Trip causes a direct reactor trip when operating above P-9.
Each of the turbine trips provide turbino protection and reduce the severity of the ensuing transient.
No credit was taken in the accident analyses for' operation of these trips.
Their functional capability at the specified trip nettings is required to enhance the overall reliability of the Reactor Protection System.
Safety Iniection Input from ESF If a reactor trip has not already been generated by the reactor protective instrumentation, the ESF automatic actuation logic channels will initiate a reactor trip upon any signal which initiates a safety injection.
This trip is provided to protect the core in the event of a LOCA.
The ESF instrumentation channels which initiate a safety injection signal are shown in Table 3.3-3.
}Leactor Coolant Pumo Breaker Position Trio The Reactor Coolant Pump Breaker Position Trips are anticipatory trips which provide reactor core protection against DNB resulting from the opening of any one pump breaker above P-8 or the opening of two or more pump breakers below P-8.
These trips are blocked below P-7.
The open/close position trips assure a reactor trip signal is generated before the low flow trip setpoint is reached.
No credit was taken in the accident analyses for operation of these trips.
Their functional capability at the open/close position settings is required to enhance the overall reliability of the Reactor Protection System.
FARLEY-UNIT 2 B 2-7 May 15, 1995
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