Text

Proposed Changes to Tech Specs 3.9 & 4.9 for Auxiliary Electrical Sys
	ML18025B433
Person / Time
Site:	Browns Ferry
Issue date:	04/09/1981
From:	; TENNESSEE VALLEY AUTHORITY
To:	;
Shared Package
ML18025B432	List: ML18025B431; ML18025B433;
References
	NUDOCS 8104130163
	Download: ML18025B433 (60)
	v • d • e

ENCLOSURE 1

PROPOSED CHANGES TO TECHNICAL SPECIFICATIONS BROWNS FERRY NUCLEAR PLANT UNITS 1

AND 2 (DOCKET NOS. 50-259, 50-260)

fi

PROPOSED UNIT 1

TECHNICAL SPECIFICATIONS

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM A licabilit A licabilit Applies to all the auxiliary electrical power system.

Applies to the periodic testing requirements of the auxiliary electrical systems.

Ob ective Ob ective To assure an adequate supply of electrical power for-operation of

'those systems required for safety.

Verify the operability of the auxiliary electr ical system.

S ecification A. Auxiliar Electrical E ui ment A. Auxiliar Electrical E ui ment A reactor shall not be started up (made critical) from the cold condition unless four'nits 1

and 2 diesel generators are

operable, the requirements of 3.9.A.4 through 3.9.A.7 are met and two of the following off-site power sources are available as stated with no credit taken for the two 500-kV Trinity lines.

- Both 161-kV lines and common station service transformers provided the second source is from the 500kV system.

- The unit 1 unit station service transformer TUSS1B is available.

If the unit 2 station service transformers is the second

source, a minimum of two 500-kV lines must be available.

The unit 2 unit station service transformer TUSS2B is available. If the unit 1

station service transformers is the second

source, a minimum of two 500kV lines must be available.

Both 161-kV lines, both cooling

1. Diesel Generators a.

Each diesel generator shall be manually started and loaded once each month to demonstrate operational readiness.

The test shall continue for at least a one hour period at 75$ of rated load or greater.

Dur ing the monthly generator

test, the diesel generator starting air compressor shall be checked for operation and its ability to recharge air receivers.

The operation of the diesel fuel oil transfer pumps shall be demonstrated, and the diesel starting time to reach rated voltage and speed shall be logged.

b. Once per operating cycle, a

test will be conducted-simulating a loss of offsite power and similar conditions that would exist with the pr esence of an actual safety-injection signal to demonstrate the 292

'Ijt>v)V r -)OIL vg, Tvj, Ir

~ 4 I

t JM Vt'),)4'j I,,'

L 4

L~

Y L=

I If ttf II

~ '.p0 "O.,

I 4

v)PPV H)M)-', 44 4, I f Ij 4

If

'I t

I

<<I, I

'I 4 I ~

'I 4,

I 444

~ P rjM M

4=I

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM tower transformers, and the bus tie.board energized and capable of supply power to the units 1

and 2 shutdown boards, provided that the second source is from the 500-kV system.

following:

1. Deenergization of the emergency buses and load shedding from the

~ emergency buses.

Both 161-kV lines, one common station service transformer, and one cooling tower transformer (through the bus tie board) provided the cooling tower transformer is not. parallel to the common station service transformer 'and provided that the second source is from the 500-kV system.

A reactor shall not be star ted up (made critical) from the Hot Standby Condition unless all of the following conditions are satisfied:

1.

One of the off-site power sources listed above is available and capable of supplying auxiliary power to the shutdown boards.

2. Three units 1 and 2 diesel generators shall be operable.

3.

An additional source of power consisting of one of the following:

a.

A second off-site power source available and capable of supplying power to the shutdown boards.

2. The diesel starts from ambient condition on the auto-start signal, energizes the emergency buses with permanently connected

loads, energizes the auto-connected emergency loads through the load sequencer, and operates for greater than or equal to five minutes while its generator is loaded with the emergency loads.

3.

On diesel generator breaker trip, the loads are shed from the emergency buses and the diesel restarts on the auto-start signal, the emergency buses are energized with permanently connected

loads, the auto-connected emergency loads are energized through the load sequencer, and the diesel operates for greater than or equal to five minutes while its generator is loaded with the emergency loads.

b.

A fourth operable units 1

and 2 diesel generator.

4. Buses and Boards Available

a. Start buses 1A and 1B are energized.

293 c.

Once a month the quantity of diesel fuel available shall be logged.

d. Each diesel generator shall be given an annual inspection in accordance

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM

b. The units 1 and 2 4-kV shutdown boards are energized.

c. The 480-V shutdown boards associated with the unit are energized.

d. The units 1 and 2 diesel auxiliary boards are energized.

e.

with instructions based on the manufacturer's

=

recommendations.

Once a month a sample of diesel fuel shall be checked for quality.

The quality shall be within acceptable limits specified in Table 1 of the latest revision to ASTM D975 and logged.

e. Undervoltage relays operable on start buses 1A and 1B and 4-kV shutdown boards A, B, C, and D.

f. Shutdown busses 1 and 2

energized.

g. The 480V Rx.

MOV Boards D&E are energized with M-G Sets IDN, IDA, IEN, and IEA in service.

a ~ Every week the specific gravity and the voltage of the. pilot cell, and temperature of an adjacent cell and overall battery voltage shall be measured and logged.

2. D. C. Power System - Unit Batteries (250-Volt) Diesel Generator Batteries

( 125-Volt) and Shutdown Board Batteries (250-Volt)

5. The 250-volt unit and shutdown board batteries and a battery charger for each battery boards are operable.

6. Logic Systems a.

Common accident signal logic system is operable.

b. 480-V load shedding logic system is operable.

7. There shall be a minimum of 103,300 gallons of diesel fuel in the standby diesel generator fuel tanks.

b.

C ~

Every three months the measurement shall be made of voltage of each cell to nearest 0.1 volt, specific gravity of each cell, and temperature of every fifth cell.

These measurements shall be logged.

A battery rated discharge (capacity) test shall be performed and the voltage, time, and output current measurements shall be logged at intervals not to exceed 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

293a

0

LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM 4.9 AUXILIARYELECTRICAL SYSTEM

3. Logic Systems a ~ Both divisions of the common accident signal logic system shall be tested every 6 months to demonstrate that it will function on actuation of the core spray system of each reactor to provide an automatic start signal to all 4 units 1 and 2 diesel generators.

b.

Once every 6 months, the condition under which, the 480-Volt load shedding logic system is required shall be simulated using pendant test switches and/or pushbutton'est switches to demonstrate that the load shedding logic system would initiate load shedding signals on the diesel auxiliary

boards, reactor MOV boards, and the 480-Volt shutdown boards.

4. Undervoltage Relays a ~ Once every 6 months, the conditions under which the undervoltage relays are required shall be simulated with an undervoltage on star t buses 1A and 1B to demonstrate that the diesel generators will start.

b.

Once every 6 months, the conditions under which the undervoltage relays are required shall be simulated with an undervoltage on each shutdown board to 0

294.

0

LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM 4.9 AUXILIARYELECTRICAL SYSTEM demonstrate that the associated diesel generator will start.

0

c. The undervoltage relays which start the diesel generators from start buses 1A and 1B and the 4-kV shutdown boards shall be calibrated annually for trip and reset and the measurements logged.

These relays shall be calibrated as specified in Table 4.9.A.4.c.

d. 4-kV shutdown board voltages shall be recorded once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .

5. 480-V RMOV boards D and E

a.

Once per operating cycle the automatic transfer feature for 480-V RMOV boards D and E shall be functionally tested to verify auto-transfer capability.

294a

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM B. 0 eration with Ino erable

~Eut ment t

e Whenever a reactor is in'Startup mode or, Run mode and not in a cold condition, the availability of electric power shall be as specified in 3.9.A except as specified herein.

B. 0 eration with Ino erable EcCEuk ment 1.

When only one offsite power source is inoperable, all units 1 and. 2 diesel generators and associated boards must be demonstrated to be operable immediately and daily thereafter.

1..From and after the date that only.one off-site power source is available, reactor operation is permissible for seven days.

2 ~ N.A.

2. From and after the date that the 4-kV bus tie board becomes inoperable, reactor operation 'is permissible indefinitely provided one of the required off-site power source is not supplied from the 161-kV system through the bus tie board.

3.

When one of the units 1 and 2

diesel generator is inoperable, continued reactor operation is permissible during the succeeding 7 days, provided that two offsite power sources are available, and all of the CS, RHR (LPCI and Containment Cooling)

Systems, and the remaining three units 1 and 2 diesel generators are operable.

If this requirement cannot be

met, an orderly shutdown, shall be initiated and. the reactor shall be shut down and in the-cold condition

'ithin 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

4.

When one units 1 and 2 4-kV shutdown board is inoperable, continued reactor operation is permissible for a period not to exceed 5 days, 3 ~

,5.

6.

When one of the units 1 and 2

diesel generator is found to be inoperable, all'f the CS.,

RHR (LPCI and Containment Cooling) Systems and the remaining diesel generators and associated boards shall be demonstrated to be operable immediately and daily thereafter.

When one 4-kV shutdown board is found to be inoperable, all remaining 4-kV shutdown boards and associated diesel

'enerators, CS, and RHR (LPCI and Containment Cooling)

Systems supplied by the remaining 4-kV shutdown boards shall be demonstrated to be

operable, immediately and daily thereafter

.=

When one shutdown bus is found

'to.be inoperable all 1 and.2 diesel generators shall be proven operable immediately and daily thereafter.,

When one units 1 and 2 Diesel.

Aux. board is found to be inoperable, the remaining diesel Aux. board and each unit 1 and 2.diesel generator 295

0

LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM 4.9 AUXILIARYELECTRICAL SYSTEM provided that two off-site power sources are available, and the remaining 4-kV shutdown boards and associated diesel generators, CS, RHR (LPCI and Containment Cooling) Systems, and all 480-V emergency power boards are operable.

If this requirement cannot be met, an orderly shutdown shall be initiated and the reactor shall be shut down and in the cold condition by the end of the fifth day.

shall be proven operable immediately and daily thereafter.

5 ~

6.

When one of the shutdown busses is inoperable, reactor operation is permissible for a period of 7 days.

When one of the 480-V diesel Aux. boards becomes inoperable, reactor operation is permissible for a period of 5 days.

7 ~ From and after the date that one of the three 250-Volt unit batteries and/or its associated battery board is found to be inoperable for any reason, continued reactor operation is permissible during the succeeding seven days.

Except for routine surveillance testing, the NRC shall be notified within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the situation, the precautions to be taken during this period, and the plans to return the failed component to an operable state.

8. From and after the date that one of the 250-volt shutdown board batteries and/or its associated battery board is found to be inoperable for 296

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM any.reason, continued reactor operation is permissible during the succeeding five days in accordance with 3.9.B.7.

9 ~

I When one division of the

'ogic System is inoperable, continued reactor operation is permissible under this condition for seven days, provided the CSCS requirements listed in specification 3.9.B.3 are satisfied.

The NRC shall be notified within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the situation, the precautions to be taken during this period, and the plans to return the failed component to an operable state.

0

10. Undervoltage relays on 1A or 1B start bus may be inoperable for a period of 7 days provided the other start bus and undervoltage relay are operable (within surveillance schedule of 4.9.A.4.a).

The following limiting conditions for operation exists for the undervoltage relays which start the diesel generators on the 4-kV shutdown boards.

'4

a. Undervoltage relays which start the"diesel generators for a complete, loss of voltage on a 4-kV shutdown board may be inoperable for 5 days provided the degraded voltage sensing relays on that shutdown board are fully operable (within the surveillance schedule of 297

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM 4.9.A.4.b).

b. Undervoltage relays which start the diesel generators for degraded voltage on a 4-kV shutdown board may be inoperable for 5 days provided the complete loss of voltage relays on the shutdown

'board are operable (within the surveillance schedule of 4.9.A.4.b).

c.

One of the three phase-to-phase undervoltage relays provided to detect a

degraded voltage on a 4-kV shutdown board may be inoperable for 15 days provided both of the following conditions are satisfied.

1. The other two phase-to-phase undervoltage relays provided to detect degraded voltage on that 4-kV shutdown board, are operable (within the surveillance schedule of 4.9.A.4.b).'.

The complete loss of voltage relays on the shutdown board are operable (within the surveillance schedule of 4.9.A.4.b).

d. Both complete sets of undervoltage relays (degraded. voltage and complete loss of voltage) may be inoperable for 5

days provided the other shutdown boards and undervoltage relays are operable.

(Within the 297 a

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM surveillance schedule of 4.9.A.4.b).

12.

When one 480-volt shutdown board is found to be inoperable, the reactor will be-.'- placed, in hot standby within.12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and cold shutdown within, 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

'13. If one 480-VRMOV board M-G set is inoperable, the reactor may remain i' operation for a period not to exceed seven days, provided the remaining 480-V RMOV, board m-g sets and their associated loads remain operable.

14. If any two 480-V RMOV board M-G sets. become inoperable, the reactor shall be placed in the cold shutdown condition within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

15. If the requirements for operating in the conditions specified by, 3.9.B.1 through 3.9.B.14 cannot be met, an orderly shutdown shall be initiated and the reactor shall be shutdown and in the cold condition'ithin 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .

0 P ')

297 b F

LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM Whenever the reactor is in cold shutdown condition with irradiated fuel in the reactor, the availability of electric power shall be as specified in Section 3.9.A except as specified herein.

1. At least two units 1 and 2

diesel generators and their associated 4-kV shutdown boards shall be operable.

2. An additional source of power consisting of at least one of the following:

a.

The unit 1 or 2 unit station service transformers energized.

b.

One 161-kV transmission line and its associated common station service transformer energized.

c. Either 161-kV line, one cooling tower transformer and the bus tie board energized and capable 'of supplying power to the units 1 and 2 shutdown boards energized.

d.

A third operable diesel generator.

3. At least one 480-V shutdown board for each unit must be operable.

4. One 480-V RMOV board motor-generator (M-G) set is required for each RMOV board (D or E) required to support operation of the RHR system in accordance with 3.5.B.9.

298

'I

'ft)r/I>')P-I g h

m II m

l )

..dmt II ff >>li l

ftl httf

m ~

. I II' II I,

it' I

,I

,4 4

II fl I>>

I, C

I p

~,

I ~.J I

Jf 4

fl 5

'I I

I 4 I

It

h I 'I

I)

J I

l

'l tf 4

I It

'l

4.9.A'.4.c VOLTAGE RELAY INTS/DIESEL GENERATE NNT Rela Location.

Tri Level.-Settin Remarks 1.

4-kV Start Bus lA and 1B

'- Trip Setpoint:

0 volts with a 5-second time delay Start diesel generators on loss of offsite power.

+

Allowable Values:

.1 second "Trip Range:

4.9 to 5.1 seconds Reset Setpoint:

2870-V Allowable Values:

2% of 2870-V

+

Reset Range:

2813-V to 2927-V 2.

4-kU Shutdown Boards Trip Setpoint:

Allowable Values:

0 volts with a 1.5-second time delay.

+.1 second Start diesel generators on loss of offsite power.

Trip Range:

1.4 to 1.6 seconds Reset Setpoint:

Allowable Values:

Reset Range:

2870-V

+ 2% of 2870-V 2813-U to 2927-V 3.

4-kV.'hutdown Boards Trip Setpoint:

Allowable Values:

Trip Range:

Reset Setpoint:

Allowable Values:

Reset Range:

Under 3920 1% of 3920-V 3880-V to 3959-V 3998-V

+ 1% of 3998-V 3958-V to '4038-V Over 4400

+ 1% of 4400 4358-V to 4444-V 4312-V-

+

1% of 4312-4269-V to 4355-V Second level undervoltage sensing relays start diesel generators on degraded voltage.

3920 volts with 4 seconds time de-lay start diesel generator 3920 volts with N second trip, ormal off-site power source.

0 0,

3

~ 9 BASES The objective of this specification is to assure an adequate source of electrical power to operate facilities to cool the plant during shutdown and to operate the engineered safeguards following an accident.

There are three sources of alternating current electrical energy available,

namely, the 161-kV transmission

system, the 500-kV system by way of either or both nuclear generating units 1

and 2 unit station service transformer B,

and the diesel generators.

The generator breaker for units 1

and 2 can provide non-'interruptible sources of off-site power from the 500-kV tiansmission system to the units 1

and 2 shutdown boards.

A source of auxiliary power can be supplied from the 161-kV transmission system through the common station service transformers or the cooling tower transformer by way of the bus tie board.

The 4-kV bus tie board may remain out of service indefinitely provided one of the required off-site power sources is not supplied from the 161-kV system through the bus tie board.

The minimum fuel oil requirement of 103,300 gallons is sufficient for seven days of full load operation of three diesels and is conservatively based on availability of a replenishment supply.

The degraded voltage sensing relays provide a start signal to the diesel generators in the event that a deteriorated voltage condition exists on a 4-kV shutdown board.

This starting signal is independent of the starting signal generated by the complete loss of voltage relays and will continue to function and start the diesel generators on complete loss of voltage should the loss of voltage relays become inoperable.

The 15-day inop'erable time limit specified when one of the three phase-to-phase degraded voltage relays is inoperable is justified based on the two out of three permissive logic scheme provided with these relays.

A 4-kV shutdown board is allowed to be out of operation for a brief period to allow for maintenance and testing, providing all remaining 4-kV shutdown boards and associated diesel generators CS,

RHR, (LPCI and Containment Cooling)

Systems supplied by the remaining 4-kV shutdown

boards, and all emergency 480-V power boards are operable.

There are eight 250-volt d-c battery systems each of which consists of a battery, battery charger, and distribution equipment.

Three of these systems provide power for unit 299

1 It>> I I

)

fj I

I l

j PV)Pf P'1 FV P

't

~ <<)

D,l,(

'f j /he P'4

~,v.>>

lt e el j.

j'4 4 <>F e

lt 4, I I

F I

'i p

3.9 BASES (con't) 0 control functions, operative power for unit'otor loads, and alternative drive power for a 115-volt a-c unit preferred motor-generator set.

One 250-volt d-c system provides power for common, plant and transmission system control functions, drive-powei -for a 115-volt a-c plant preferred motor-generator

set, and emergency drive power for certain unit large motor loads.
The four remaining systems deliver control power to the 4160-volt shutdown boards.
Each',250-Volt d-c shutdown board control power supply can receive power from its own battery, battery charger, or from a spare charger.
The chargers are powere'd from normal plant auxiliary power or from the standby diesel-driven generator system.
Zero resistance short circuits,'etween the control power supply and the shutdown board'are cleared by'uses located in the respective control power supply.
Each power supply is located in the reactor building near the shutdown board it suppli~~
~
Each battery-is located in its own independently ventilated battery room.
The 250-volt d-c system is so arranged, and the batteries sized
such, that the loss of any one unit battery will not prevent the safe shutdown and cooldown of all three units in the event of the loss of offsite power and a design basis accident in any one unit.
Loss of control power to any engineered safeguards control circuit is annunciated in the main control room of the unit affected.
The loss of one 250-Volt shutdown board battery affects normal control power "only for the 4160-Volt shutdown board which is supplies.
The station battery supplies loads that are not essential for safe shutdown and cooldown of the nuclear system.
This battery was not considered in the:
accident load calculations.
There are two. 480-V ac Reactor Motor-Operated Valve (RMOV) Boards that contain motor-generator (M-G) sets in their feeder lines.
These
,'480-V ac RMOV boards have an automatic transfer from their normal to alternate power source (480-V ac shutdown boards).
.The M-G sets
- act as electrical isolators to prevent a fault from propagating b'etween electrical divisions due to an automatic transfer.
The 480-V ac RMOV boards involved =provide motive power to valves associated, with the LPCI mode of the RHR system.'avin'g an M-G set out 'of service reduces the assurance that full RHR'(LPCI) capacity will be available when required.
Since sufficient equipment is available to maintain the-minimum complement required 'for RHR '(LPCI) operation, a 7-day servicing period is justified.
Having,two M-G sets out of service can considerably reduce equipment availability.
Therefore, the.affecte'd unit shall be p'laced in cold shutdown within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .
300
N I
PROPOSED UNIT 2
TFCl1NICAL SPECIFICATIONS
LIMITING
" CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM 4.9 AUXILIARYELECTRICAL SYSTEM A licabilit Applies to all the auxiliary electrical power system.
~Ob ective To assure an adequate supply of electrical power for operation of those systems required for safety.
Applies to the periodic testing requirements of the auxiliary electrical systems.
~Ob ective Verify the operability of the auxiliary electrical system.
S ecification S ecification A. Auxiliar Electrical E ui ment A. Auxiliar Electrical E ui ment 0
A reactor shall not be started up (made critical) from the cold condition unless four units 1
and 2 diesel generators are
operable, the requirements of 3.9.A.4 through 3.9.A.7 are met and two of the following off-site power sources are available as stated with no credit taken for the two 500-kV Trinity lines.
- Both 161-kV lines and common station service transformer s provided the second source is from the 500kV system.
The unit 1 unit station service transformer TUSS1B is available.
If the unit 2 station service transformers is the second
source, a minimum of two 500-kV lines must be available.
- The unit 2 unit station service transformer TUSS2B is available. If the unit 1
station service trans'formers is the second
source, a minimum of two 500kV lines must be available.
- Both 161-kV lines, both cooling 292
1. Diesel Gener ator s a.
Each diesel generator shall be manually started and loaded once each month to demonstrate operational readiness.
The test shall continue for at least a one hour period at 75$ of rated load or greater.
During the monthly generator test, the diesel generator starting air compressor shall be checked for operation and its ability to recharge air receivers.
The operation of the diesel fuel oil transfer pumps shall be demonstrated, and the diesel starting time to reach rated voltage and speed shall be logged.
b.
Once per operating cycle, a
test will be conducted simulating a loss of offsite power and similar conditions that would exist with the presence of an actual safety-injection signal to demonstrate
.the
LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM tower transformers, and the bus tie board energized and capable of supply power to the units 1
and 2 shutdown boards, provided that the second source is from the 500-kV system.
following:
1. Deenergization of the emergency buses and load shedding from the emergency buses.
0
- Both 161-kV lines, one common station service transformer, and one cooling tower transformer (through the bus tie board) provided the cooling tower transformer is not parallel to the common station service transformer and provided that the second source is from the 500-kV system.
A reactor shall not be started up (made critical) from,the Hot Standby Condition unless all of the following conditions are satisfied:
1.
One of the off-site power sources listed above is available and capable of supplying auxiliary power to the shutdown boards.
2. Three units 1 and 2 diesel generators shall be operable.
3.
An additional source of power consisting of one of the following:
a.
A second off-site power source available and capable of supplying power to the shutdown boards.
2. The diesel starts from ambient condition on the auto-start signal, energizes the emergency buses with permanently connected
loads, energizes the auto-connected emergency loads through the load sequencep, and operates for greater than or equal to five minutes while its generator is loaded with the emergency loads.
3.
On diesel generator breaker trip, the loads are shed from the emergency buses and the diesel restarts on the auto-start signal, the emergency buses are energized with permanently connected
loads, the auto-connected emergency loads are energized through the load sequencer, and the diesel operates for greater than or equal to five minutes while its generator is loaded with the emergency loads.
b.
A fourth operable units 1
and 2 diesel generator.
4. Buses and Boards Available
a. Start buses 1A and 1B are energized.
c.
Once a month the quantity of diesel fuel available shall be logged.
d. Each diesel generator shall be given an annual inspection in accordance 293
a
LIMITING CONDITIONS 'FOR OPERATION SURVEILLANCE REQUIREMENTS" 3.9 AUXILIARYELECTRICAL SYSTEM 4.9 AUXILIARYELECTRICAL SYSTEM
b. The units 1 and 2 4-kV shutdown boards are energized.
c. The 480-V shutdown boards associated with the unit are energized; I
d. The units 1 and 2 diesel, auxiliary'boards are energized.
with instructions based on the manufacturer's recommendations.
e.
Once a month a sample of diesel fuel shall be checked for quality.
The quality shall be within acceptable limits specified in Table 1 of the latest revision to ASTM D975 and logged.
0
e. Undervoltage relays operable
.on start.buses 1A and 1B and 4-kV. shutdown boards A,= B, C, and D.
f. Shutdown.busses' and 2
energized.
5. The 250-volt'nit and shutdown board batteries and a battery charger for each battery boards are operable.
6. Logic Systems W
a.
Common accident signal logic system:is operable.,
b. 480-V load shedding logic system is operable.
7. There shall be a minimum of 103,300 gallons of diesel fuel in the standby diesel generator fuel tanks.
2. D. C. Power System - Unit Batteries (250-Volt) Diesel Generator Batteries
( 125-Volt) aqd Shutdown Board Batteries (250-Volt)
a. Every week the specific gravity and the voltage of
, the pilot cell, and temperature of an adjacent cell and overall battery voltage shall be measured and logged.
b. Every three months'he measurements shall be made of,voltage of each cell to, nearest 0.1 volt, specific gravity of each cell, and temperature of every fifth
'ell.
These measurements shall be logged.
c.
A battery rated discharge (capacity) test shall be performed and the voltage, time, and output current measurements shall be logged at intervals not to exceed 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months '.
293a
0
LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS' 3.9 AUXILIARYELECTRICAL SYSTEM
3. Logic Systems a ~ Both divisions of the common accident signal logic system shall be tested every 6 months to demonstrate that it will function on actuation of the core spray system of each reactor to provide an automatic start signal to all 4 units 1 and 2 diesel generators.
4.9 AUXILIARYELECTRICAL SYSTEM b.
Once every 6 months, the condition upder which the 480-Volt load shedding logic system is required shall be simulated using pendant test switches and/or pushbutton test switches to demonstrate that the load shedding logic system would initiate load shedding signals on the diesel auxiliary
boards, reactor MOV boards, and the 480-Volt shutdown boards.
4. Undervoltage Relays a ~ Once every 6 months, the conditions under which the undervoltage relays are required shall be simulated with an undervoltage on start buses 1A and 1B to demonstrate that the diesel generators will start.
b.
Once every 6 months, the conditions under which the undervoltage relays are required shall be simulated with an undervoltage on each shutdown board to 294
0
LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM demonstrate that the associated diesel generator will start.
c. The undervoltage relays which start the diesel generators from start buses 1A and 1B and the 4-kV shutdown boards shall be calibrated annually for trip and reset and the measurements logged.
These relays shall be calibrated as specified in Table 4.9.A.4.c.
d. 4-kV shutdown board voltages shall be recorded once every 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months .
294 a
0
LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM B.
0 eration with Ino erable
~Eui ment Whenever a reactor is in Startup mode or Run mode and not in a
, cold condition, the availability of electric power shall be as specified in 3.9.A except as specified herein.
SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL'YSTEM B. 0 eration with Ino erable
~Eui, ment When only one offsite power source is inoperable, all units 1 and 2 diesel generators and associated boards must be demonstrated to be operable immediately and daily thereafter.
1. From and after the date that only one off-site power source is available, reactor operation is permissible for seven days.
2. N.A.
2. From and after the date that the 4-kV bus tie board becomes inoperable, reactor operation is permissible indefinitely provided one of the required off-site power source is not supplied from the 161-kV system through the bus tie board.
3.
When one of the units 1 and,2 diesel generator is inoperable, continued reactor operation is permissible during the succeeding 7 days, provided that two offsite power sources are available, and all of the CS, RHR (LPCI and Containment Cooling)
Systems, and the remaining three units 1 and 2 diesel generators are operable.
If this requirement cannot be
met, an orderly shutdown shall be initiated and the reactor shall be shut down and in the cold condition within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .
3 ~
5.
When one of the units 1 and 2
diesel generator is found to be inoperable, all of the CS, RHR (LPCI and Containment Cooling) Systems and the remaining diesel generators and associated boards shall'e demonstrated to be operable immediately and daily thereafter.
When one 4-kV shutdown board is found to be inoperable, all remaining 4-kV shutdown boards and associated diesel generators, CS, and RHR (LPCI and Containment Cooling)
Systems supplied by the remaining 4-kV shutdown boards shall be demonstrated to be
operable, immediately and daily thereafter.
When one shutdown bus is found to be inop'erable all 1 and 2
diesel generators shall be proven operable immediately and daily thereafter.
4.
When one units 1 and 2 4-kV shutdown board is inoperable, continued reactor operation is permissible for a period not to exceed 5 days, 6.
When one units 1 and 2 Diesel Aux. board is found to be inoperable, the remaining diesel Aux. board and each unit 1 and.2 diesel generator 295
LIMITING CONDITIONS FOR'PERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM provided that two off-site power sources are available, and the remaining 4-kV.
shutdown boards and associated diesel generators, CS, RHR (LPCI and Containment Cooling) Systems, and all 480-V emergency power boards are operable.
If this requirement cannot be met, an orderly shutdown shall be initiated and the reactor shall be shut down and in the
'old condition by the end of the fifth day."
4.9 AUXILIARYELECTRICAL SYSTEM shall be proven operable immediately and daily thereafter.
5.
When one of the shutdown busses is inoperable, reactor operation is permissible for a period of 7 days.
6.
When one of the 480-V diesel Aux. boards becomes inoperable, reactor operation is permissible for a period of 5 days.
7 ~ -From and after the date that one of the three 250-Volt unit batteries andfor its associated 'battery board is found to be inoperable for any reason, continued reactor operation is permissible during the succeeding seven days.
Except for routine surveillance testing, the NRC shall be notified within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the situation, the precautions to be taken during this period, and the plans to return the failed component to an operable state.
8. From and after the date that one of the 250-volt shutdown board batteries and/or its associated battery board is found,to be inoperable for 296
LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM 4.9 AUXILIARYELECTRICAL SYSTEM any reason, continued reactor operation is permissible during the succeeding five days in accordance with 3.9.B.7.
9 ~ When one division of the Logic System is inoperable, continued reactor operation is permissible under this condition for seven days, provided the CSCS requirements listed in specification 3.9.B.3 are satisfied.
The NRC shall be notified within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months of the situation, the precautions to be taken during this period, and the plans to return the failed component to an operable state.
10. Undervoltage relays on 1A or 1B start bus may be inoperable for a period of 7 days provided the other start bus and undervoltage relay are operable (within surveillance schedule of 4.9.A.4.a).
The following limiting conditions for operation exists for the undervoltage relays which start the diesel generators on the 4-kV shutdown boards.
a. Undervoltage relays which start the diesel generators for a.,complete loss of voltage on a 4-kV shutdown.board may be inoperable for 5 days provided the degraded voltage sensing relays on
'97
LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 AUXILIARYELECTRICAL SYSTEM that shutdown board are fully operable (within the surveillance schedule of 4.9.A.4.b).,
4.9 AUXILIARYELECTRICAL SYSTEM
b. Undervoltage relays which
- start the diesel generators for degraded voltage on a 4'-kV shutdown board may be. inoperable for 5 days provided the complete loss of voltage relays on the shutdown board "are operable '(within the surveillance schedule of 4.9.A.4.b).
0 c.
One of the three phase-to-phase undervoltage relays provided to detect a
degraded voltage on a 4-kV
'shutdown board may be inoperable for 15 days provided both of the following conditions are satisfied.
1. The other two phase-to-phase under voltage relays provided to detect degraded voltage on that 4-kV shutdown board.are operable (within the surveillance schedule of 4.9.A.4.b).
2. The complete loss of voltage relays on the shutdown board are operable (within the surveillance schedule of 4.9.A.4.b).
0
d. Both complete sets of undervoltage relays (degraded voltage and complete loss of voltage) may be 'inop'erable for 5 days provided the other 297a
0
LIMITING CONDITIONS FOR OPERATION SURVEILLANCE REQUIREMENTS 3.9 'AUXILIARYELECTRICAL SYSTEM shutdown"boards and undervoltage relays are operable.
(Within the.
surveillance schedule of 4.9.A.4.b).
12.
When one 480-volt shutdown board is found to be inoperable, the reactor will be placed in hot standby within 12 hours1.388889e-4 days 0.00333 hours 1.984127e-5 weeks 4.566e-6 months and cold shutdown within 24 hours2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months .
13. If the requirements'or operating in the conditions specified by 3.9.B.1 through 3.9.B.12 cannot be met, an orderly shutdown shall be initiated and the reactor shall be shutdown and in the cold condition within 24 hour2.777778e-4 days 0.00667 hours 3.968254e-5 weeks 9.132e-6 months s.
4.9 AUXILIARYELECTRICAL SYSTEM 0
297 b
LIMITING CONDITIONS FOR OPERATION 3.9 AUXILIARYELECTRICAL SYSTEM t
C.
0 eration in Cold Shutdown Whenever the reactor is in cold shutdown condition with irradiated fuel in the reactor, the availability of electric
power shall be as specified in Section 3.9.A except as specified herein.
SURVEILLANCE REQUIREMENTS 4.9 AUXILIARYELECTRICAL SYSTEM
1. At least two units 1 and 2
diesel generators and their associated 4-kV shutdown boards shall be operable.
2. An additional source of power consisting of at least one of the following:
a.
The unit 1 or 2 unit station service transformers energized.
b.
One 161-kV transmission line and its associated common station service transformer energized.
c. Either 161-kV line, one cooling tower transformer and the bus tie board energized and capable of supplying power to the units 1 and 2 shutdown boar'ds energized.
d.
A third operable diesel generator.
3. At least one 480-V shutdown board for each unit must be operable.
298
4.9.A.4.c VOLTAGE RELAY TS/DIESEL GENERATOR START Rela Location Tri Level Settin Remarks 1.
4-kV Start Bus lA and 1B Trip Setpoint:
0 volts with a 5-second time delay Start diesel generators on loss of offsite power.
Allowable Values:
.1 second
+
Trip Range:
Reset Setpoint:
Allowable Values:
4.9 to 5.1 seconds 2870-V
+ 2% of 2870-V Reset Range:
2813-V to 2927-V 2.
4-kV Shu'tdown Boards Trip Setpoint:
Allowable Values:
0 volts with a 1.5-second time delay.
+.1 second Start diesel generators on loss of offsite power.
Trip Range:
Reset Setpoint:
Allowable Values:
Reset Range:
1.4 to 1.6 seconds 2870-V
+ 2% of 2870-V 2813-V to 2927-V "3.
4-kV Shutdown Boards Trip Setpoint:
Allowable Values:
Trip Range:
Reset Setpoint:
Allowable Values:
Reset Range:
Under 3920 1% of 3920-V 3880-V to 3959-V 3998-V
+ 1% of 3998-V 3958-V to 403S-V Over 4400
+ 1% of 4400 4358-V to 4444-v 4312 V
+
1% of 4312-4269-V to 4355 V Second level undervoltage sensing relays start diesel generators on degraded voltage.
3920 volts with 4 seconds time de-lay start diesel generator 3920 volts with 8'q second trip, normal off-site power source..
3
~ 9 BASES 0
The objective of this specification is to assure an adequate source of electrical power to operate facilities to cool the plant during shutdown and to operate the engineered safeguards following an accident.
There are three sources of alternating current electrical energy available, namely-,
the 161-kV transmission
system, the 500-kV system by way of either or both nuclear generating units 1
and 2 unit station service transformer B,
and the diesel generators.
The generator breaker for units 1-, and 2 can provide non-interruptible sources of off-site power from the 500-kV transmission, system to the units 1
and 2 shutdown boards.
A source of auxiliary power can be supplied from the 161-kV transmission system through the common station.service transforme'rs or the. cooling tower transformer by way of the bus tie board.
The 4-kV. bus tie board may remain out of service indefinitely provided one of the required off-site power sources is not supplied from the 161-kV system through the bus tie'oard.
The minimum fuel oil requirement of 103,300 gallons is sufficient for seven days of full load operation of three diesels and is conservatively based on availability of a
'replenishment supply.
The degraded voltage sensing relays provide a start signal to the diesel generators in the event that a deteriorated voltage condition exists on a 4-kV shutdown board.
This starting signal is independent of the starting signal generated by the complete loss of voltage relays and will continue to function and start the diesel'generators o'
complete loss of voltage should the loss of voltage relays bec'ome inoperable..
The 15-day inoperable time limit specified when one.of the three phase-to-phase degraded voltage relays is inoperable is justified based on the two out of three, permissive logic scheme provided with these relays.
('
4-kV shutdown board is allowed to be out of operation for, a.brief period to allow for maintenance and testing, providing all'emaining 4-kV shutdown boards and associated diesel generators CS,
RHR, (LPCI and Containment Cooling)
Systems supplied by the remaining 4-kV shutdown boards; and
='ll emergen'cy 480-V power boards ai e o'perab1e.
There are eight 250-volt* d-c battery, systems each of wh'ich.
consists of a battery, battery charger, and distribution..
equipment.
Three of, these systems provide power for unit
'99
3.9 BASES (con't) control functions, operative power for unit motor loads, and alternative drive-power for a 115-volt a-c unit preferred motor-generator set.
One 250-volt d-c system provides power for common plant and transmission system control functions, drive power for a 115-volt a-c plant preferred motor-generator
set, and emergency drive power for certain unit large motor loads.
The four remaining systems deliver control power to the 4160-volt shutdown boards.
Each 250-Volt d-c shutdown board control power supply can receive power from its own battery, battery charger, or from a spare charger.
The chargers are powered from normal plant auxiliary power or from the standby diesel-driven generator system.
Zero resistance short circuits between the control power supply and the shutdown board are cleared by fuses located in the respective control power supply.
Each power supply is located in the reactor bui3.ding near the shutdown board it supplies
~
Each battery is located in its own independently ventilated battery room.
The 250-volt d-c system is so arranged, and the batteries sized such, that the loss of any one unit battery will not prevent the safe shutdown and cooldown of all three units in the event of the loss of offsite power and a design basis accident in any one unit.
Loss of control power to any engineered safeguards control circuit is annunciated in the main control room of the unit affected.
The loss of one 250-Volt shutdown board battery affects normal control power only for the 4160-Volt shutdown board which is supplies.
The station battery supplies loads that are not essential for safe shutdown and cooldown of the nuclear system.
This battery was not considered in the accident load calculations.
0 300
4.9 BASES The monthly tests of the diesel generators are primarily to check for failures and deterioration in the system since last use.
'The diesels will be loaded to at least 75 percent of rated power while engine and generator temperatures are stabilized (about one hour).
The minimum 75 percent load will prevent soot formation in the cylinders and injection nozzles.
Operation up to an equilibrium temperature ensures that there is no overheat problem.
The test also provides an engine and generator operating history to be compared with subsequent engine-generator test data to identify and to correct any mechanical or electrical deficiency before it can result in a system failure.
The test during refueling outages is more comprehensive, including procedures that are most effectively conducted at that time.
These include automatic actuation and functional capability tests to verify that the generators can start and be ready to assume load in 10 seconds.
The annual inspection will detect any signs of wear long before failure.
The diesel generators are shared by units 1 and 2.
Therefore, the capability for the units 1 and 2 diesel generators to accept the emergency loads will be performed during the unit 1 operating cycle using the unit 1 loads.
Battery maintenance with regard to the floating charge, equalizing charge,, and electrolyte level will be based on the manufacturer's instruction and sound maintenance practices.
In addition, written records will be maintained of the battery performance.
The plant batteries will deteriorate with time but precipitous failure is unlikely.
The type of surveillance called for in this specification is that which has been demonstrated through experience to provide an indication of a cell becoming irregular or unserviceable long before it becomes a failure.
The equalizing 'charge, as recommended by the manufacturer, is vital to maintaining the Ampere-hour capacity of the battery, and will be applied as recommended.
The testing of the logic systems willverify the ability of the logic systems to bring the auxiliary electrical system to running standby readiness with the presence of an accident signal from any reactor or an undervoltage signal on the start buses or 4-kV shutdown boards.
The periodic simulation of accident signals in con)unction with diesel generator voltage available 'signals will confirm the ability of the 480-volt load shedding logic system to sequentially shed and restart 480-volt loads if an accident signal were present and diesel generator voltage were the only source of electrical power.
REFERENCES 1.
Normal Auxiliary Power System (BFNP FSAR subsection 8.4)
\\
2.
Standby A'. C. Power Supply and Distribution (BFNP FSAR subsection 8.5) 3.
250-volt D.
C. Power Supply and Distribution (BFNP FSAR subsection 8.6) 301
w1
\\
~-

ML18025B433

Text

Navigation menu

Search