Ac Distribution

Front 1

4160 Bus 1A

Back 1

1. Circulating Water Pump 1A

2. Circulating Water Pump 1B

3. Condensate Booster Pump 1A

4. Condensate Pump 1A

5. 4160V Bus 1F (NORMAL)

6. 345 KV Switchyard Power

(NORMAL) Station

TRANSFORMER C (480V)

7. 480V bus 1A via breaker SS1A

8. 4160V bus 1E via breaker 1AE (NORMAL)

Front 2

4160 Bus 1B

Back 2

1. Circ water pump 1C
2. Circ water pump 1D
3. Condensate booster pump 1B
4. Condensaate pump 1B
5. 4160G Normal
6. 345 switchyard power (ALTERNATE)
7. 480 1B via breaker SS1b
8. 4160 1E via breaker 1BE (ALTERNATE)

Front 3

4160 Bus 1C

Back 3

RRMG 1A

Front 4

4160 Bus 1D

Back 4

RRMG 1B

Front 5

4160 Bus 1E

Back 5

1. Condensate Booster pump 1C
2. Condensate pump 1C
3. Screen wash pump 1C
4. Screen wash pump 1D
5. 480V 1E via breaker SS1E

Front 6

4160 Bus 1F

Back 6

1. Core spray A
2. RHR A
3. RHR B
4. RHR SWBP 1A
5. RHR SWBP 1C
6. Service Water pump A
7. Service Water pump C
8. 480 1F via breaker SS1F

Front 7

4160 Bus 1G

Back 7

1. Core Spray B
2. RHR pump 1C
3. RHR pump 1D
4. RHR SWBP 1B
5. RHR SWBP 1D
6. Service water pump 1B
7. Service Water pump 1D
8. 480 1G via breaker SS1G

Front 8

480 1A

Back 8

1. TEC pump 1A
2. TEC pump 1B
3. Mechanical Vacuum pump 1A
4. MCC-A
5. MCC-B

Front 9

480 1B

Back 9

1. TEC pump C
2. Mechanical Vacuum pump B
3. SAC C
4. MCC-F
5. MCC-G
6. SWBD MSA for machine shop
7. Security building Feeder
8. South Warehouse

Front 10

480 E

Back 10

1. Fire pump C
2. Screen Wash pump A
3. Screen wash pump B
4. MCC-Z

Front 11

480 F

Back 11

1. CRD Hydraulic pump A
2. SAC A
3. MCC-K
4. MCC-L
5. MCC-M
6. MCC-N
7. MCC-P
8. MCC-LX
9. MCC-CA
10. MCC-OG-1 (which supplies OG2)

Front 12

480 G

Back 12

1. CRD Hydraulic pump B
2. SAC B
3. MCC-S (and N2 tank control power through LPREMG)
4. MCC-T
5. MCC-U
6. MCC-V
7. MCC-W
8. MCC-TX
9. MCC-CB
10. MCC-MR

Front 13

Plant response to loss of all off-site power (simultaneous loss of 345KV, 161KV and 69KV lines)

Back 13

If all off-site power sources are lost simultaneously, the Main Generator will trip, causing loss of NSST. If there is no bus lockout, 1AS and 1BS will close onto the SSST when 1AN and 1BN trip open. 1AS and 1BS will close even if there is no voltage on the SSST secondary. 1AF, 1FA, 1BG, and 1GB will trip in <1 second (with an inverse time constant; "0" volts will result in a very short delay before the breakers trip on first level protection). The DGs will receive an auto start signal at the same time these breakers receive a trip signal. The voltage permissive for 1FS and 1GSwill not be met, so these breakers will not close. When DGs reach rated voltage and speed, and at least 10 seconds after the first level voltage protection signal was sensed, DG output breakers will close and energize 4160 F/G. The only 4160 loads that trip on undervoltage are the RRMG sets and Circ water pumps (setpoints similar to the first level undervoltage protection) The condensate booster pumps will trip on low suction pressure or low oil pressure. All 4160 loads powered from 1F/1G will trip except the 480V transformer feed. In addition, once the first level protection signal has been sensed for at least 5.5 seconds, load shedding of selected 480V loads will occur. These breakers require manual operator action to be restored to service. CRD pumps A and B, SAC A and B, MCCs OG1, P, N and M(480F) and MCCs MR, U, W, and V(480G) are the breakers that receive a trip from the 480 load shedding relays. If reactor power is >30%, the reactor will scram immediately when the loss of off-site power occurs.

Front 14

Expected plant response to all off-site power degraded with DGs available

Back 14

If all off-site power sources degrade simultaneously at a similar rate, the first alarm will be the 1FS/GS auto closure prohibited annunciator, and these breakers will not automatically close. As voltage lowers below 3880, a 7.5 second timer begins (no alarm). When this times out, C-1/A-7(C-4/A-2), 4160V Bus 1F(1G) LOW VOLTAGE, alarms. If a LPSCI initiation signal is present, breaker 1FA/1GB will trip immediately (at this point). If no LPCI initiation, these breakers will trip a5 seconds later. This results in bus 1F/1G de-energizing and starting the first level under voltage protection scheme as described in the preceding paragraph. When RPS frequency or voltage drops too low, EPAs trip and the RPS buses will de-energize. When RPS is lost, the reactor scrams and PCIS group isolations occur. The RRMC sets will not reach their under voltage trip setting, but will trip due to loss of lube oil after 6 second pressure switch delay. 4160 BOP loads will not trip, but continue to run on degraded voltage. 1AS and 1BS will close on the SSST when breakers 1AN and 1BN rip open. These breakers will close even if there is low voltage on the SSST secondary. Load-shedding of the 480V breakers occur as described in preceding paragraph