ML20195B827

Proposed Final Tech Specs Pages for License Change Application ECR 96-01511 Re Rev to Loss of Power Setpoints for 4 Kv Emergency Buses

ML20195B827
Person / Time
Site:	Peach Bottom
Issue date:	05/25/1999
From:	PECO ENERGY CO., (FORMERLY PHILADELPHIA ELECTRIC
To:
Shared Package
ML20195B822	List: ML20195B817 ML20195B827
References
NUDOCS 9906030115
Download: ML20195B827 (18)

Text

7

}c l

l ATTACHMENT 1 PEACH BOTTOM ATOMIC POWER STATION UNITS 2 AND 3 Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 LICENSE CHANGE APPLICATION ECR 96-01511 ~

" Interim" Pages j

i Unit 2 Unit 3 3.3 3.3-65 8 3.3-188-B 3.3-188 B 3.3-189 8 3.3-189 i

B 3.3-190 B 3.3-190 9906030115 990525

~

PDR ADOCK 05000277 P

PDR L

LOP Instrumentation 3.3.8.1 Table 3.3.8.1 1 (page 1 of 1)

Loss of Power Instrumentation REQUIRED CHANNELS SURVE!LLANCE ALLOWABLE FUNCTION PER BUS REQUIREMENTS VALUE 1.

4 kV Emergency sus Undervoltage (Loss of Voltage) a.

Bus undervoltage 1

SR 3.3.8.1.3 NA SR 3.3.8.1.4 2.

4 kV Emergency Bus Undervoltage (Degraded Voltage Low Setting) l~

a.

Bus Undervoltage 2

SR 3.3.8.1.1 t 2286 V and s 2706 V (1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 t 1.5 seconds and (1 per SR 3.3.8.1.2 s 2.1 seconds source)

- SR 3.3.8.1.4 3.

4 kV Emergency Bus Undervoltage (Degraded Voltage High Setting) l a.

Bus Undervoltage 2

SR 3.3.8.1.1 2 3409 Y and 5 3829 V (1 per SR 3.3.8.1.2 tource)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 4 23.0 seconds and (1 per SR. 3.3.8.1.2 s 37.0 seconds source)

SR 3.3.8.1.4

-4 4 kV Emergency Bus undervoltage (Degraded Voltage LOCA)

. a.' Bus Undervoltage 2

SR 3.3.8.1.1 2 3766 V and 5 3836 V (a)

(1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 t 9.2 seconds and (1 per SR 3.3.8.1.2 5 10.8 seconds (a) source)

SR 3.3.8.1.4 5.

4 kV Emergency Bus Undervoltage (Degraded Voltage non-LOCA) a.

Bus Undervoltage-2 SR 3.3.8.1.1 2 4116 Y and s 4186 V (a)

(1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.5.1.1 a 57.8 seconds and 5 64.2 (1 per SR 3.3.8.1.2 seconds (a) source)

SR 3.3.8.1.4 (a) Prior.to the laplementation of modification 96 01511, the Allowable Values of the Functions below are:

4.s a 3691 V and 5 3713 V, with internal time delay set t 0.9 seconds and 51.1 seconds, 4.b t 8.4 seconds and s 9.6 seconds, 5.a a 4065 y and s 4089 V, with internal time delay' set t 0.9 seconds and 51.1 seconds,

~ ~ '

5.b t 57.0 seconds and s 63.0 seconds.

l PBAPS UNIT 2 3.3-65 Amendment No.

. ~.

LOP Instrumentation B 3.3.8.1 BASES (continued)

' APPLICABLE The LOP instrumentation is required for Engineered Safety

~ SAFETY ANALYSES, - Features to function in any accident with a loss of offsite LC0, and power. The required channels of. LOP instrumentation ensure APPLICABILITY that the ECCS and other assumed systems powered from the DGs, provide plant protection in the event of any of the i

Reference 1 (UFSAR) analyzed accidents in which a loss of offsite power is assumed. The first level is loss of voltage. This loss of voltage level detects and disconnects the Class IE buses from the offsite power source upon a total loss of voltage. The second level of undervoltage protection is provided by the four levels of degraded grid voltage relays which are set to detect a sustained low voltage condition. These degraded grid relays disconnect i

the Class IE buses from the offsite power source if the degraded voltage condition exists for a time interval which could prevent the Class 1E equipment from achieving its safety function. The degraded grid relays also prevent the Class IE equipment from sustaining damage from prolonged operation at reduced voltage. The combination of the loss of voltage relaying and the degraded grid relaying provides protection to the Class IE distribution system for all credible conditions of voltage collapse or sustained voltage degradation. The initiation of the DGs on loss of offsite power, and subsequent initiation of the ECCS, ensure that

' the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.

Accident analyses credit the loading of the DG based on the loss of offsite power during a loss of coolant accident.

l The diesel starting and loading times have been included in the delay time associated with each safety system component requiring DG supplied power following a loss of offsite i

power.

The LOP instrumentation satisfies Criterion 3 of the NRC Policy Statement.

The OPERABILITY of the LOP instrumentation is dependent upon the OPERABILITY of the individual instrumentation relay channel Functions specified in Table 3.3.8.1-1.

Each Function must have-a required number of OPERABLE channels per 4 kV emergency bus with their setpoints within the j

specified Allowable Values except the bus undervoltage relay which does not have an Allowable.Value. A degraded voltage l

channel is inoperable if its actual trip setpoint is not

' within its required Allowable Value.

Setpoints are calibrated consistent with the Improved Instrument Setpoint Control Program (IISCP) methodology assumptions.

(Note-Table 3.3.8.1-1 contains a note that prior to the implementation of modification 96-01511, the relay voltage

[

and timer trip setpoint Allowable Vaulues for the indicated l

Sontinued)

I' PBAPS UNIT 2 B 3.3-188 Revision No.

a i

c.

LOP Instrumentation B 3.3.8.1 BASES APPLICABLE functions remain at the previously approved values on a SAFETY ANALYSES, relay by relay basis.) The loss of voltage channel is LCO and inoperable if it will not start the diesel on a loss of APPL.ICABILITY power to a 4 kV emergency bus.

(continued)

The Allowable Values are specified for each applicable-Function in the Table 3.3.8.1-1.

The nominal setpoints are selected to ensure that the setpoints do not exceed the Allowable Value between CHANNEL CALIBRATIONS. O with a trip setpoint within the Allowable Value,peration is acceptable. Trip setpoints are those predetermined values of output at which an action should take place.

The setpoints are compared to the actual process parameter (e.g., voltage), and when the measured output value of the process parameter exceeds the setpoint, the protective relay output changes state.

The Allowable Values were set equal to the limiting values determined by the voltage regulation calculation.

The setpoints were corrected using IISCP methodology to account for relay drift, relay accuracy potentialtransformeraccuracy,measuringandtestequIpment accuracy margin, and includes a calibration leave alone zone.

IISCP methodology utilizes the square root of the sum of the squares to combine random non-directional accuracy values.

IISCP then includes relay drift, calibration leave alone zones, and margins.

Note: Table 3.3.8.1-1 contains a note that prior to the imple(mentation of modification 96-01511, the relay voltage and timer trip setpoint Allowable Values for the indicated functions remain at the previously approved values on a relay by relay basis.) The set assumes a nominal 35/1 potential transformer ratio. point The specific Applicable Safety Analyses, LCO, and Applicability discussions for Unit 2 LOP instrumentation are listed below on a function by Function basis.

In addition, since some equi powered from Unit 3 sources,pment required by Unit 2 is the Unit 3 LOP in'strumentation supporting the required sources must also be OPERABLE.

The OPERABILITY requirements for the Unit 3 LOP instrumentation is the same as described in this section, except Function 4 (4 kV Emergency Bus Undervoltage, Degraded Voltage LOCA)ted is not required to be OPERABLE since this Function is rela to a LOCA on Unit 3 only. theUnit3instrumentationis listed in Unit 3 Table 3.3.8.1-1.

1. 4 kV Emeraency Bus Undervoltaae (Loss of Voltaae)

When both offsite sources are lost, a loss of voltage condition on a 4 kV emergency bus indicates that the respective emergency bus is unable to supply sufficient power for Therefore, proper operation of the applicable equipment.

the power suppl offsite power to DG power.y to the bus is transferred fromThis ensures that will be available to the required equipment.

-(continued)

PBAPS UNIT 2 B 3.3-189 Revision No.

4 LOP Instrumentation

~

B 3.3.8.1 BASES APPLICABLE

1. 4 kV Emeraency Bus Undervoltaae (Loss of Voltaae)

SAFETY ANALYSIS, (continued)

LCC. and 1

APFLICABILITY The single channel of 4 kV Emergency Bus Undervoltage (Loss of Voltage) Function )er associated emeregncy bus is only required to be OPERABLE when the associated DG and offsite circuit are required to be OPERABLE. This ensures no single instrument failure can preclude the start of three of four DGs.

(One channel inputs to each of the four DGs.

Refer to LCO 3.8.1, "AC Sources-Operating," and 3.8.2, }AC Sources-Shutdown," for Applicability Bases for the DGs.

2.

3.

4.

5. 4 kV Emeraency Bus Undervoltaae (Dearaded Voltaae)

A degraded voltage condition on a 4 kV emergency bus indicates that, while offsite power may not be completely lost to the respective emergency bus, available power may be insufficient for starting large ECCS motors without risking damage to the motors that could disabia the ECCS function.

Therefore, power to the bus is transferred from offsite power to onsite DG power when there is insufficient offsite power to the bus.

This transfer will occur only if the voltage of the preferred and alternate power sources drop below the Degraded Voltage Function Allowable Values (degraded voltage with a time delay) and the source breakers trip which causes the bus undervoltage relay to initiate the DG. This ensures that adequate power will be available to the required equipment.

Four Functions are provided to monitor degraded voltage at four different levels. These Functions are the Degraded "oltage Non-LOCA, Degraded Voltage LOCA, Degraded Voltage High Setting, and Degraded Voltage Low Setting. These relays monitor the followiny voltage levels with the following time delays:

the Function 2 relay, 2286 - 2706 volts in approximately 2 seconds when source volta e is reduced abruptly tb _ero volts (lts in c) proximate y 30 inverse time delay ; the Function 3 relay, 3409 - 3829 vo seconds when source volta e is reduced aaruptly to 2940 volts (lts in approximate y 10 seconds; and the Function 5 inverse time delay ; the Function 4 relay, 3766 -

3836 vo relay, 4116 - 4186 volts in approximately 60 seconds.

(Note: Table 3.3.8.1-1 contains a note that prior to the implementation of modification 96-01511, the relay voltage and timer trip setpoint Allowable Values for the indicated functions remain at the previously approved values on a relay by relay basis.) The Function 2 and 3 relays are inverse time delay relays. These relays operate along a repeatable characteristic curve. With relay operation being inverse with time, for Tc.ontinued)

PBAPS UNIT 2 B 3.3-190 Revision No.

~

LOP Instrumentation 3.3.8.1 Table 3.3.8.1 1 (page 1 of 1)

Loss of Power Instrtmentation REQUIRED CHANNELS SURVEILLANCE ALLOW 48LE FUNCTION PER SUS REQUIREMENTS VALUE 1.

4 kV Emergency Bus undervoltage (Loss of Voltage) a.

Bus Undervoltage 1

SR 3.3.8.1.3 NA SR 3.3.8.1.4 2.

4 kV Dergency Bus Undervoltage (Degraded Voltage Low Setting) l a.

Bus Undervoltage 2

3R 3.3.8.1.1 t 2286 V and s 2706 V (1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 t 1.5 seconds and (1 per SR 3.3.8.1.2 s 2.1 seconds source)

SR 3.3.8.1.4 3.

4 kV Emergency Bus Undervoltage (Degraded Voltage High Setting) l a.

Bus Undervoltage 2

SR 3.3.8.1.1 2 3409 V and 5 3829 Y (1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 t 23.0 seconds and (1 per SR 3.3.5.1.2 s 37.0 seconds source)

SR 3.3.8.1.4 4.

4 kV Emergency Bus Undervoltage (Degraded Voltage LOCA) a.

Sus Undervoltage 2

SR 3.3.8.1.1 e 3766 V and 5 3836 V (a)

(1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 t 9.2 seconds and (1 per SR 3.3.8.1.2 s 10.8 seconds (a) source)

SR 3.3.8.1.4 5.

4 kV Emergency Bus Undervoltage (Degraded Voltage ren-LOCA) a.

Bus undervoltage 2

SR 3.3.8.1.1 2 4116 V and s 4186 V (a)

(1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 a 57.8 seconds and 5 64.2 (1 per SR 3.3.8.1.2 seconds (a) source)

SR 3.3.8.1.4 (a) Prior to the inplementation of modification 96-01511, the Allowable values of the Ftsictions below aret 4.a a 3691 y and 5 3713 V, with internal time delay set t 0.9 seconds and 51.1 seconds, 4.b t 8.4 seconds and s 9.6 seconds, 5.s a 4065 V and s 4089 V, with internal time dels,.et t 0.9 seconds and s 1.1 seconds, 5.b t 57.0 seconds and s 63.0 seconds.

PBAPS UNIT 3 3.3-65 Amendment No.

'i

~

LOP Instrumentation B 3.3.8.1 BASES (continued)

APPLICABLE The LOP instrumentation is required for Engineered Safety SAFETY ANALYSES, Features to function in any accident with a loss of offsite LCO, and power. The required channels of LOP instrumentation ensure APPLICABILITY that the ECCS and other assumed systems powered from the DGs, provide plant protection in the event of any of the Reference 1 (UFSAR) analyzed accidents in which a loss of i

offsite power is assumed. The first level is loss of l

voltage.

This loss of voltage level detects and disconnects the Class 1E buses from the offsite power source upon a total loss of voltage. The second level of undervoltage protection is provided by the four levels of degraded grid i

voltage relays which are set to detect a sustained low voltage condition. These degraded grid relays disconnect the Class 1E buses from the offsite power source if the degraded voltage condition exists for a time interval which could prevent the Class IE equipment from achieving its safety function.

The degraded grid relays also prevent the Class 1E equipment from sustaining damage from prolonged operation at reduced voltage.

The combination of the loss of voltage relaying and the degraded grid relaying provides protection to the Class 1E distribution system for all credible conditions of voltage collapse or sustained voltage degradation. The initiation of the DGs on loss of offsite power, and subsequent initiation of the ECCS, ensure that the fuel peak cladding temperaturc remains below the limits of 10 CFR 50.46.

Accident analyses credit the loading of the DG based on the loss of offsite power during a loss of coolant accident.

The diesel starting and loading times have been included in the delay time associated with each safety system component requiring DG supplied power following a loss of offsite power.

The LOP instrumentation satisfies Criterion 3 of the NRC Policy Statement.

The OPERABILITY of the LOP instrumentation is dependent upon the OPERABILITY of the individual instrumentation relay channel Functions specified in Table 3.3.8.1-1.

Each Function must have a required number of OPERABLE channels per 4 kV emergency bus with their set)oints within the s)ecified Allowable Values except the aus undervoltage relay w11ch does not have an Allowable Value. A degraded voltage channel is inoperable if its actual trip setpoint is not within its required Allowable Value.

Setpoints are calibrated consistent with the Improved Instrument Setpoint Control Program (IISCP) methodology assumptions.

(Note:

Table 3.3.8.1-1 contains a note that prior to the implementation of modification 96-01511, the relay voltage and timer trip setpoint Allowable Vaulues for the indicated (continued)

PBAPS UNIT 3 B 3.3-188 Revision No.

LOP Instrumentation B 3.3.8.1 BASES APPLICABLE functions remain at the previously approved values on a SAFETY ANALYSES, relay by relay basis.) The loss of voltage channel is LCO, and inoperable if it will not start the diesel on a loss of APPLICABILITY power to a 4 kV emergency bus.

(continued)

The Allowable Values are specified for each applicable Function in the Table 3.3.8.1-1.

The nominal setpoints are selected to ensure that the setpoints do not exceed the Allowable Value between CHANNEL CALIBRATIONS. Operation with a trip setpoint within the Allowable Value is acceptable.

Trip setpoints are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., voltage), and when the measured output value of the process parameter exceeds the setpoint, lues were set equalthe pro output changes state. The Allowable Va to the limiting values determined by the voltage regulation calculation.

The setpoints were corrected using IISCP methodology to account for relay drift, relay accuracy, potential transformer accuracy, measuring and test equipment and includes a calibration leave alone accuracy margin {hodology utilizes the square root of the sum zone.

IISCP me of the squares ta combine random non-directional accuracy values.

11SCP then includes relay drift, calibration leave alone zones, and margins.

Table 3.3.8.1-1 contains a note that prior to the imple(Note:

mentation of modification 96-01511, the relay voltage and timer trip setpoint Allowable Values for the indicated functions remain at the previously approved values on a relay by relay basis.) The set assumes a nominal 35/1 potential transformer ratio. point i

i The specific Applicable Safety Analyses, LCO, and Applicability discussions for Unit 3 LOP instrumentation are l

listed below on a Function by Function basis.

i In addition, since some equipment required by Unit 3 is powered from Unit 2 sources, the Unit 2 LOP instrumentation j

sunorting the required sources must also be OPERABLE. The OP RABILITY requirements for the Unit 2 LOP instrumentation i

is the same as described in this section, except Function 4 (4 kV Emergency Bus Undervoltage, Degraded Voltage LOCA)ted is not required to be OPERABLE since this Function is rela to a LOCA on Unit 2 only. theUnit2instrumentationis listed in Unit 2 Table 3.3.8.1-1.

1. 4 kV Emeraency Bus Undervoittae (Loss of Voltaae)

When both offsite sources are lost, a loss of voltage condition on a 4 kV emergency bus indicates that the respective emergency bus is unable to supply sufficient i

power for proper operation of the a)plicable equipment.

q Therefore, the power supply to the aus is transferred from offsite power to DG power. This ensures that adequate power will be available to the required equipment.

~(continued)

PBAPS UNIT 3 B 3.3-189 Revision No.

LOP Instrumentation B 3.3.8.1 BASES I

APPLICABLE

1. 4 kV Emeraency Bus Undervoltaae (Loss of Voltaae)

-SAFETY ANALYSIS, (cont < nued)

LCO, and APPLICABILITY The single channel of 4 kV Emergency Bus Und Loss Function per associated emergency bus is on required to circuit are required to be OPERABLE. This ensures no single instrument failure can preclude the start of three of four DGs.

(One channel inputs to each of the four DGs.

Refer to LCO 3.8.1, "AC Sources-Operating," and 3.8.2, )AC Sources-Shutdown," for Applicability Bases for the DGs.

2.

3.

4.

5. 4 kV Emeraency Bus Undervoltaae (Dearaded Voltaael A degraded voltage condition on a 4 kV emergency bus indicates that, while offsite power may not be completely lost to the respective emergency bus, available power may be ins'ifficient for starting large ECCS motors without risking damage to the motors that could disable the ECCS function.

Therefore, power to the bus is transferred from offsite power to onsite DG power when there is insufficient offsite power to the bus. This transfer will occur only if the voltage of the preferred and alternate power sources drop below the Degraded Voltage Function Allowable Values (degraded voltage with a time delay) and the source breakers trip which causes the bus undervoltage relay to initiate the DG. This ensures that adequate power will be available to the required equipment.

Four Functions are provided to monitor degraded voltage at four different levels. These-Functions are the Degraded i

Voltage Non-LOCA, Degraded Voltage LOCA, Degraded Voltage High Setting, and Degraded Voltage Low Setting. These relays monitor the following voltage levels with the-following time delays:

the Function 2 relay, 2286 - 2706 volts in approximately 2 seconds when source volta e is i

inverse time delay ; the reduced abruptly to zero volts (lts in approximate y 30 Function 3 relay, 3409 - 3829 vo seconds when source volta e is reduced abruptly to 2940 inverse time delay ; the Function 4 relay, 3766 -

volts (lts in approximate y 10 seconds; and the Function 5 3836 vo i

relay, 4116 - 4186 volts in approximately 60 seconds.

(Note: Table 3.3.8.1-1 contains a note that prior to the implementation of modification 96-01511, the relay voltage and timer trip setpoint Allowable Values for the indicated functions remain-at the previously approved values on a relay by relay basis.) The Function 2 and 3 relays are inverse time delay relays.

These relays operate along a repeatable characteristic curve. With relay operation being inverse with time, for

'YEontinued)

PBAPS UNIT 3 B 3.3-190 Revision No.

l

7.

l ATTACHMENT 2 -

PEACH BOTTOM ATOMIC POWER STATION UNITS 2 AND 3 Docket Nos. 50-277 50-278 License Nos. DPR-44 DPR-56 LICENSE CHANGE APPLICATION ECR 96-01511

" Final" Pages Unit 2 Unit 3 3.3-65 3.3-65 B 3.3-188 B 3.3-188 8 3.3-189 B 3.3-189 B 3.3-190 B 3.3-190

' sky..

LOP Instrumentation 3.3.8.1 Table 3.3.8.1 1 (page 1 of 1)

Loss of Power Instrumentation REQUIRED CHANNELS SURVE!LLANCE ALLOWABLE FUNCTION PER BUS REQUIREMENTS VALUE 1.

4 kV Emergency Bus Undervoltage (Loss of Voltage) a.

Sus Undervoltage 1

SR 3.3.8.1.3 NA st 3.3.8.1.4 2.

4 kV Emergency Bus Undervoltage (Degraded Voltage Low setting) l a.

Bus undervottage 2

SR 3.3.8.1.1 a 2286 V and 5 2706 V (1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

sa 3.3.8.1.1 t 1.5 seconds and (1 per SR 3.3.8.1.2 s 2.1 seconds source)

SR 3.3.8.1.4 3.

4 kV Emergency Bus Undervoltage (Degraded Voltage High setting) l a.

Bus undervoltage 2

SR 3.3.8.1.1 t 3409 V and s 3829 V (1 per SR 3.3.8.1.2 i

source)

SR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 t 23.0 seconds and (1 per SR 3.3.8.1.2 s 37.0 seconds source) st 3.3.8.1.4 4 4 kV Emergency Bus Undervoltage (Degraded Voltage LOCA)

. a.

Sus undervoltage 2

SR 3.3.8.1.1 2 3766 y and 5 3836 V (1 per SR 3.3.8.1.2-source)

SR 3.3.8.1.4 l

1 b.

Time Delay 2

SR 3.3.8.1.1 t 9.2 seconds and i

(1 per SR 3.3.8.1.2 s 10.8 seconds source)

SR 3.3.8.1.4 5.

4 kV Emergency sus Undervoltage (Degraded Voltage non-LOCA) 4.

Bus undervoltage 2

SR 3.3.8.1.1 2 4116 V and s 4186 V (1 per SR 3.3.8.1.2 source)

SR 3.3.8.1.4 j

l b.

Time Detey 2

st 3.3.8.1.1 t 57.8 seconds and s 64.2 (1 per SR 3.3.8.1.2 seconds 1

source)

SR 3.3.8.1.4 I

l PBAPS UNIT 2 3.3-65 Amendment No.

I

LOP Instrumentation B 3.3.8.1 BASES (continued) i APPLICABLE The LOP instrumentation is required for Engineered Safety SAFETY ANALYSES, Features to function in any accident with a loss of offsite j

LCO, and power. The required channels of LOP instrumentation ensure APPLICABILITY that the ECCS and other assumed systems powered from the DGs, provide plant protection in the event of any of the Reference 1 (UFSAR) analyzed accidents in which a loss of j

offsite power is assumed. The first level is loss of voltage. This loss of voltage level detects and disconnects the Class IE buses from the offsite power source upon a total loss of voltage. The second level of undervoltage protection is provided by the four levels of degraded grid voltage relays which are set to detect a sustained low voltage condition.

These degraded grid relays disconnect the Class 1E buses from the offsite power source if the degraded voltage condition exists for a time interval which could prevent the Class 1E equipment from achieving its safety function. The degraded grid relays also prevent the Class IE equipment from sustaining damage from prolonged operation at reduced voltage. The combination of the loss of voltage relaying and the degraded grid relaying provides protection to the Class 1E distribution systea for all credible conditions of voltage collapse or sustained voltage degradation.

The initiation of the DGs on loss of offsite power, and subsequent initiation of the ECCS, ensure that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.

Accident analyses credit the loading of the DG based on the loss of offsite power during a loss of coolant accident.

The diesel starting and loading times have been included in the delay time associated with each safety system component requiring DG supplied power following a loss of offsite power.

The LOP instrumentation satisfies Criterion 3 of the NRC Policy Statement.

The OPERABILITY of the LOP instrthnentation is dependent upon the OPERABILITY of the individual instrumentation relay channel Functions specified in Table 3.3.8.1-1.

Each Function must have a required number of OPERABLE channels per 4 kV emergency bus, with their setpoints within the specified Allowable Values except the bus undervoltage relay which does not have an Allowable Value. A degraded voltage channel is inoperable if its actual trip setpoint is not within its required Allowable Value.

Setpoints are calibrated consistent with the Improved Instrument Setpoint Control Program (IISCP) methodology assumptions.

-(continued)

PBAPS UNIT 2 B 3.3-188 Revision No.

LOP Instrumentation B 3.3.8.1

BASES, i

APPLICABLE The loss of voltage channel is inoperable if it will not SAFETY ANALYSES, start the diesel on a loss.of power to a 4 kV emergency bus.

LCO, and

--APPLICABILITY The Allowable Values are specified for _each applicable (continued)_

Function in the Table 3.3.8.1-1.

The nominal setpoints are selected to ensure that the setpoints do not exceed the

' Allowable Value between CHANNEL CALIBRATIONS. Operation with a trip setpoint within the Allowable Value, is acceptable. Trip setpoints are those predetermined values of output at which'an action should take place. The setpoints are compared to the actual process parameter (e.g., voltage), and when the measured output value of the process parameter exceeds the setpoint, the protective relay output changes state. The Allowable Values were set equal to the. limiting values determined by the voltage regulation

- calculation.

The setpoints were corrected using IISCP methodology to account for relay drift, relay accuracy, j

potential transformer accuracy, measuring and test equipment u

accuracy margin, and includes a calibration leave alone zone.

IISCP methodology utilizes the square root of the sum of the squares to combine random non-directional accuracy values.

IISCP then includes relay drift, calibration leave.

alone zones,'and margins. The setpoint assumes a nominal 35/1 potential transformer ratio.

i The specific Applicable Safety Analyses, LCO, and j

, Applicability discussions for Unit 2 LOP instrumentation are listed below on a Function by Function' basis.

In addition, since some equipment required by Unit 2 is powered from Unit 3 sources,.the Unit 3 LOP instrumentation supporting ~ the required sources must also be OPERABLE. The OPERABILITY requirements for the Unit 3 LOP instrumentation is the same as described in this section, except Function 4 (4 kV Emergency Bus Undervoltage, Degraded Voltage LOCA) is not required to be OPERABLE, since this Function is related

-to a LOCA on Unit 3 only. The Unit 3 instrumentation is listed in Unit 3 Table 3.3.8.1-1.

1. 4 kV Emeroency Bus Undervoltaae (Loss of Voltaael When both offsite sources are lost, a loss of voltage condition on aL4 kV emergency bus indicates:that.the j

respective emergency bus is unable to supply sufficient

~

power for proper operation of the applicable. equipment.

Therefore, the power supply to the bus is transferred from offsite power to DG power. This ensures'that adequate power will be available to the required equipment.

-(continued)

PBAPS' UNIT 2 B 3.3-159 Revision No.

V I

LOP Instrumentation B 3.3.8.1 BASES APPLICABLE

1. 4 kV 'Emeroency Bus Undervoltaae (Loss of Voltaae)

SAFETY ANALYSIS, (continued)

LCO, and APPLICABILITY =

The single channel of 4 kV Emergency Bus Undervoltage (Loss of Voltage) Function per associated emergency bus is only required to be OPERABLE when the associated DG and offsite circuit are required to be OPERABLE. This ensures no single instrument failure can preclude the start of three of four DGs.

(One channel inputs to each of the four DGs.) Refer to LCO 3.8.1, "AC Sources-Operating," and 3.8.2, "AC Sources-Shutdown," for Applicability Bases for the DGs.

2.

3.

4.

5. 4 kV Emeraency Bus Undervoltaae (Dearaded Voltaae)

A degraded voltage condition on a 4 kV emergency bus indicates that, while offsite power may not be completely lost to the respective emergency bus, available power may be insufficient for starting large-ECCS motors without risking damage to the motors that cou'd disable the ECCS function.

Therefore, power to the bus is transferred from offsite power to onsite DG power when there is insufficient offsite power to the bus. This transfer will occur only if the voltage of the preferred and alternate power sources drop below the~ Degraded Voltage Function Allowable Values (degraded voltage with a time delay) and the source breakers trip which_causes the bus undervoltage relay to initiate the DG. This ensures that adequate power will be available to the required equipment.

Four Functions are provided to monitor degraded voltage at four different levels. These Functions are the Degraded Voltage Non-LOCA, Degraded Voltage LOCA, Degraded Voltage High Setting, and D%raded Voltage Low Setting. These relays _ monitor the following voltage levels with the following time delays: the Function 2 relay, 2286 - 2706 volts in approximately 2 seca ds when source voltage is reduced abruptly to zero volts (inverse time delay); the Function 3 relay, 3409 - 3829 volts in approximately 30 seconds when source voltage is reduced abruptly to 2940 volts (inverse time delay); the Function 4 relay, 3766 -

3836 volts in approximately 10 seconds; and the Function 5 relay, 4116 - 4186 volts in approximately 60 seconds. The Function 2 and 3 relays are inverse time delay relays.

1 These relays operate along a repeatable characteristic i

curve. With relay operation being inverse with time, for (continued)

PBAPS UNIT 2 B 3.3-190 Revision No.

c LOP Instrumentation 3.3.8.1 Table 3.3.8.1 1 (page 1 of 1',

Loss of Power Instrumentation am REQUIRED CHANNELS

$URVEILLANCE ALLOWABLE FUNCTION PER Bus REQUIREMENTS VALUE 1.

4 kV Emergency Bus Undervoltage (Loss of Voltage) a.

Bus Undervoltage 1

SR 3.3.5.1.3 NA

$R 3.3.8.1.4 2.

4 kV Emergency Bus undervoltage (Degraded Voltage Low setting) l a.

Bus Undervoltage 2

SR 3.3.8.1.1 t 2286 y and s 2706 V (1 per sR 3.3.8.1.2 source)

SR 3.3.8.1.4 b.

Time Delay 2

rA 3.3.8.1.1 a 1.5 seconds and (1 per SR 3.3.8.1.2 5 2.1 seconds source) sR 3.3.8.1.4 3.

4 kV Emergency Bus Undervoltage (Degraded Voltage High setting) l a.

Bus Undervoltage 2

sR 3.3.8.1.1 a 34D9 Y and 5 3829 Y (1 per SR 3.3.8.1.2 source) sR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 a 23.0 seconds and (1 per SR 3.3.8.1.2 s 37.0 seconds source)

$R 3.3.8.1.4 4.

4 kW Emergency Bus undervoltage (Degraded Voltage LOCA) a.

Bus Undervoltage 2

SR 3.3.8.1.1 2 3766 y and 5 3836 V (1 per SR 3.3.8.1.2 source) sR 3.3.8.1.4 b.

Time Delay 2

SR 3.3.8.1.1 e 9.2 seconds and l

(1 per SR 3.3.8.1.2 s 10.8 seconds source) sR 3.3.8.1.4 l

5.

4 kV Emergency Bus Undervoltage (Degraded Voltage non LOCA) a.

Bus Undervoltage 2

st 3.3.8.1.1 t 4116 V and 5 4186 Y (1 per SR 3.3.8.1.2 source) st 3.3.8.1.4 l

b.

Time Delay 2

sR 3.3.8.1.1 t 57.8 seconds and s 64.2 (1 per SR 3.3.8.1.2 seconds source) sR 3.3.8.1.4

)

)

PBAPS UNIT 3 3.3-65 Amendment No.

l 1

LOP Instrumentation B 3.3.8.1 BASES (continued)

APPLICABLE The LOP instrumentation is required for Engineered Safety SAFETY ANALYSES, Features to function in any accident with a loss of offsite LCO, and power.

The required channels of LOP instrumentation ensure APPLICABILITY that the ECCS and other assumed systems powered from the DGs, provide plant protection in the event of any of the Reference 1 (VFSAR) analyzed accidents in which a loss of offsite power is assumed. The first level is los. of voltage. This loss of voltage level detects and disconnects the Class IE buses from the offsite powar source upon a total loss of voltage. The second level of undervoltage protection is provided by the four levels of degraded grid voltage relays which are set to detect a sustained low voltage condition.

These degraded grid relays disconnect the Class IE buses from the offsite power source if the degraded voltage condition exists for a time interval which could prevent the Class IE equipment from achieving its safety function. The degraded grid relays also prevent the l

Class IE equipment from sustaining damage from prolonged operation at reduced voltage. The combination of the loss of voltage relaying and the degraded grid relaying provides protection to the Class IE distribution system for all credible conditions of voltage collapse or sustained voltage degradation. The initiation of the DGs on loss of offsite power, and subsequent initiation of the ECCS, ensure that the fuel peak cladding temperature remains below the limits of 10 CFR 50.46.

Accident analyses credit the loading of the DG based on the loss of offsite power during a loss of coolant accident.

The diesel starting and loading times have been included in the delay time associated with each safety system component requiring DG supplied power following a loss of offsite power.

The LOP instrumentation satisfies Criterion 3 of the NRC Policy Statement.

The OPERABILITY of the LOP instrumentation is dependent upon the OPERABILITY of the individual instrumentation relay channel Functions specified in Table 3.3.8.1-1.

Each Function must have a required number of OPERABLE channels per 4 kV emergency bus, with their setpoints within the specified Allowable Values except the bus undervoltage relay which does not have an Allowable Value. A degraded voltage channel is inoperable if its actual trip setpoint is not within its required Allowable Value.

Setpoints are calibrated consistent with the Improved Instrument Setpoint Control Program (IISCP) methodology assumptions.

-(continued)

PBAPS UNIT 3 8 3.3-188 Revision No.

t

LOP Instrumentation B 3.3.8.1 BASES APPLICABLE The loss of voltage channel is inoperable if it will not SAFETY ANALYSES, start the diesel on a loss of power to a 4 kV emergency bus.

LCO, and APPLICABILITY The Allowable Values are specified for each applicable (continued)

Function in the Table 3.3.8.1-1.

The nominal setpoints are selected to ensure that the setpoints do not exceed the Allowable Value between CHANNEL CALIBRATIONS. Operation with a trip setpoint within the Allowable Value, is acceptable. Trip setpoints are those predetermined values of output at which an action should take place. The setpoints are compared to the actual process parameter (e.g., voltage), and when the measured output value of the process parameter exceeds the setpoint, the protective relay output changes state. The Allowable Values were set equal to the limiting values determined by the voltage regulation calculation. The setpoints were corrected using IISCP methodology to account for relay drift, relay accuracy, potential transformer accuracy, measuring and test equipment accuracy margin, and includes a calibration leave alone zone.

IISCP methodology utilizes the square root of the sum of the squares to combine random non-directional accuracy values.

IISCP then includes relay drift, calibration leave

)

alone zones, and margins. The setpoint assumes a nominal 35/1-potential transformer ratio.

The specific Applicable Safety Analyses, LCO, and Applicability discussions for Unit 3 LOP instrumentation are i

listed below on a Function by function basis.

In addition, since some equipment required by Unit 3 is powered from Unit 2 sources, the Unit 2 LOP instrumentation supporting the required sources must also be OPERABLE. The j

OPERABILITY requirements for the Unit 2 LOP instrumentation

)

is the same as described in this section, except Function 4

)

(4 kV Emergency Bus Undervoltage, Degraded Voltage LOCA) is 4

not required to be OPERABLE, since this Function is related to a LOCA on Unit 2 only. The Unit 2 instrumentation is listed in Unit 2 Table 3.3.8.1-1.

1. 4 kV Emeraency Bus Undervoltaae (Loss of Voltagg1 When both offsite sources are lost, a loss of voltage condition on a 4 kV emergency bus indicates that the respective emergency bus is unable to supply sufficient power for proper operation of the applicable equipment.

Therefore, the power supply to the bus is transferred from offsite power to DG power. This ensures that adequate power will be available to the required equipment.

.(continued)

PBAPS-UNIT'3 8 3.3-189 Revision No.

't

h i

LOP Instrumentation B 3.3.8.1 BASES APPLICABLE

1. 4 kV Emercency Bus Undervoltaae (Loss of Voltagg),

SAFETY ANALYSIS, (continued)

LCO, and APPLICABILITY The single channel of 4 kV Emergency Bus Undervoltage (Loss of Voltage) Function per associated emergency bus is only required to be OPERABLE when the associated DG and offsite circuit are required to be OPERABLE.

This ensures no single instrument failure can preclude the start of three of four DGs.

(One channel inputs to each of the four DGs.) Refer to LCO 3.8.1, "AC-Sources -Operating," and 3.8.2, "AC Sources-Shutdown," for Applicability Bases for the DGs.

2.

3.

4.

5. 4 kV Emeraency Bus Undervoltaae (Dearaded Voltaae)

A degraded voltage condition on a 4 kV emergency bus indicates that, while offsite power may not be completely lost to the respective emergency bus, available power may be insufficient for starting large ECCS motors without risking damage to the motors that could disable the ECCS function.

Therefore, power to the bus is transferred from offsite power to onsite DG power when there is insufficient offsite power to the bus. This transfer will occur only if the voltage of the preferred and alternate power sources drop below the Degraded Voltage Function Allowable Values (degraded voltage with a time delay) and the source breakers trip which causes the bus undervoltage relay to initiate the DG. This ensures that adequate power will be available to the required equipment.

Four Functions are provided to monitor degraded voltage at four different levels. These Functions are the Degraded Voltage Non-LOCA, Degraded Voltage LOCA, Degraded Voltage High Setting, and Degraded Voltage Low Setting. These relays monitor the following voltage levels with the following time delays:

the Function 2 relay, 2286 - 2706 volts in approximately 2 seconds when source voltage is reduced abruptly to zero volts (inverse time delay); the Function 3 relay, 3409 - 3829 volts in approximately 30 seconds when source voltage is reduced abruptly to 2940 volts (inverse time delay); the Function 4 relay, 3766 -

3836 volts in approximately 10 seconds; and the Function 5 relay, 4116 - 4186 volts in approximately 60 seconds. The Function 2 and 3 relays are inverse time delay relays.

These relays operate along a repeatable characteristic curve. With relay operation being inverse with time, for

-(continued)

PBAPS UNIT 3 8 3.3-190 Revision No.

-