Primary Containment Cooling & Drywell Chillers (T47)

Question 1

What are the power supplies for the Dywell coolers 1T47-B007A, 7B, 8A, 8B, 9A, 9B Fan #1? Fan #2?

Answer 1

Fan 1 - 600 “C” (1R24-S011)

Fan 2 - 600 “D” (1R24-S012)

Question 2

What is the cooling medium for Unit 1 drywell cooling units?

Answer 2

PSW

Question 3

What is the cooling medium for Unit 2 drywell cooling units?

Answer 3

Primary containment chill water system which is cooled by PSW

Question 4

How many cooling units are in the Unit 1 drywell? How many fans per unit?

Answer 4

6 cooling units with 2 fans each:
B009A & B - located near Recirc pump motors
B007A & B - located below Recirc pumps
B008A & B - located above Recirc pumps

Question 5

How many cooling units are in the Unit 2 drywell? How many fans per unit?

Answer 5

8 cooling units w/ 1 fan on each unit:
B007A & B - upper portion of the drywell 
B008A & B - near the 2A Recirc Pump 
B009A & B - near the 2B Recirc Pump
B010A & B - bottom of the drywell

4 additional recirculation fans are provided to move air through high heat load areas
C001A & B - upper portion of the drywell
C002A & B - CRD cavity (sub-pile room)

Question 6

What are the power supplies for the 2T47-B007A, 8A, 9A fans and Return fans C001A & C002A? 2T47-B007B, 8B, 9B fans and Return fans C001B & C002B?

Answer 6

A cooler fans and return fans: 600 “C” (2R24-S011)

B cooler fans and return fans: 600 “D” (2R24-S012)

Question 7

What is the power supply for DW cooling units 2T47-B010A and 2T47-B010B?

Answer 7

A - 600 “AA” (2R24-S013)

B- 600 “BB” (2R24-S014)

Question 8

What is the power supply for the 2A/B Drywell chiller?

Answer 8

A - 4160 “E” (2R22-S005)

B - 4160 “G” (2R22-S007

Question 9

What is the normal fan configuration for the Unit 1 Drywell cooling units?

Answer 9

Only one fan on each cooling unit is in RUN, Other fan is in AUTO (standby)

Question 10

What is the normal fan configuration for the Unit 2 Drywell cooling units?

Answer 10

B007A, B007B, B008A, B009A, and B010A are in Run and operating

Question 11

What is the temperature requirement for being allowed to restart Drywell cooling on Unit 2?

Answer 11

Per 31EO-EOP-100, DW cooling can NOT be restarted if Bulk average DW temp > 250°F

Question 12

What DW cooling fans have a LOCA override on Unit 1, where are the override switches located?

Answer 12

Only fans on cooling units B007A&B, B008A&B have LOCA override capability

B009A&B cannot be restarted w/ LOCA signal present

Fan #1 override- P657 Fan #2- P654

Must be manually restarted after LOCA signal is overridden per the SO procedure

Question 13

What DW cooling fans have a LOCA override on Unit 2, where are the override switches located?

Answer 13

2 LOCA override keylock switches, 1 for each group of fans, to allow fan op w/ a LOCA signal present

Fan “A” override- P657 Fan “B”- P654

Must be manually restarted after LOCA signal is overridden per the SO procedure

Question 14

What is the LOCA response for the DW chillers on Unit 2? How are they restored?

Answer 14

LOCA Response:

• Running chiller trips and both chillers are locked out
• Energizes their respective 86 devices
• Energizes the trip coil on the compressor breaker

Restoration:

• Keylock LOCA OVERRIDE to Bypass on P700 panel
• Allows chiller restart w/ signal present once its determines adequate electrical power is available
• 86 device on the compressor motor breaker must be locally reset
• Once the 86 device is reset, the reset pushbutton must be depressed locally for the chiller to be started

Question 15

What is the LOSP response for the DW chillers on Unit 2? How are they restored?

Answer 15

• Op chiller trips, however, shutdown sequence will not begin until respective 600V buses repowered
• Interruption of power to chiller requires a local reset of POR pushbutton to initiate S/D sequence timer (3 min)
• When timer has timed out, operator can start chiller by depressing start button on Basic Panel
• If chiller trips due to power interruption, with SS approval, reset 86 Lockout device
• Local reset of Power On Reset (POR) pushbutton is required anytime power is interrupted to the chiller

Question 16

What is the LOCA/LOSP restoration for the DW chillers on Unit 2?

Answer 16

• Keylock LOCA OVERRIDE switch to Bypass on P700 panel
• Link in associated DG bkr cabinet must be opened (De-energizes the 86 device)
• 86 device on compressor motor breaker locally reset
• Once the 86 device is reset, the reset pushbutton must be depressed locally for the chiller to be started

Question 17

What is the LOCA/LOSP restoration during MCR evacuation for the DW chillers on Unit 2?

Answer 17

• Open Link in the EDG panel (De-energizes the 86 device)
• Jumper installed bypassing the LOCA lockout
• 86 device on the compressor motor breaker must be locally reset
• Once the 86 device is reset, the reset pushbutton must be depressed locally for the chiller to be started

Question 18

What must be done with DW cooling fans prior to initiating DW spray?

Answer 18

Prior to spraying the DW – ALL fans (including recirc fans) must be tripped & placed to OFF

Question 19

What are the timers associated with the DW chillers?

Answer 19

– 15 min timer is START to START / 3 min timer is from STOP to START

• IF the chiller is started and operates <15 minutes, THEN the chiller cycles through two timers (15 min. And 3 min.) Before the chiller can be restarted (15 minute timer starts on a chiller start, 3 minute timer starts on a chiller shutdown).
• IF the chiller has run for >15 minutes and the stop button is depressed, the chiller cycles through a 3 minute timer before the chiller can be restarted