Fuel Pool Cooling and Clean-up

Question 1

What is the design heat load of the system?

Answer 1

Design heat load – (17 x 106 BTU/Hr) 16 consecutive reloads based on 1/3 core every 18 months
1. Both Pumps/HXs operating

Question 2

What is the maximum heat load of the system?

Answer 2

Maximum heat load – (43 x 106 BTU/Hr) Entire core offload with the fuel from the previous 13 reloads.
1. FPCCS operated in parallel with RHR.

Question 3

What is the design Keff?

Answer 3

<0.95

Question 4

What are the design temps?

Answer 4

Design temperatures
1. Normal Max - 135F – Maintain water clarity and ensure proper operation of F/D.
2. Maximum -150F – Keep fission product gases in solution

Question 5

How do we maintain isolations between different sections of the fuel pool?

Answer 5

Isolation between reactor wet well and fuel pool maintained by inflatable seals.
1. Normal air supply is service air
2. Air bottles installed as a b/u (normally valved in)

Question 6

What are the FPC pump trips?**

Answer 6

Lo-Lo Skimmer Surge Tank Level (22”)

**These two trips can be bypassed by starting the pump via the keylock switch on the breaker.

Question 7

What is the Fuel Pool F/D hold pump auto start?

Answer 7

F/D Flow (< 215 gpm)

Question 8

What are the filter demin chemistry setpoints?

Answer 8

1. Conductivity - < 1 umho/cm.
2. Chlorides - < 0.05 ppm.
3. pH - 6.0 - 7.5.
   These are PCIS Isolations →
4. Heavy Metals - < 0.05 ppm.
   
   • Maintained to prevent attack on the aluminum fuel support pieces.
5. Silica < 0.05 ppm

Question 9

What is the TWCU pump trip?

Answer 9

Low Flow (300 gpm / 15 sec)

Question 10

What are the TWCU/SUP Pool isolation valves isolation signals?

Answer 10

Reactor Level 2 (-38”)
Hi Drywell Pressure (1.68#)
RB Hi Rad (1x10-3uci/cc)
*HV-4652,4679,4680,4681 MOVs Close on the primary isolation signal (NOT the AOVs)

These are PCIS isolation signals

Question 11

What are the Fuel Pool F/D Isolation Valve isolation signals?

Answer 11

Loss of air or power
Lo-Lo Skimmer Surge Tank Level (22”)
*On a loss of air/power, the FPC pumps will trip on low flow if F/D is not bypassed.

Question 12

What is the skimmer surge tank makeup level?

Answer 12

Opens at 49”

Question 13

What is the F/D high temp alarm?

Answer 13

130°F

Question 14

Where are the leak detection taps?

Answer 14

1. Spent fuel liner
2. Dryer separator pool liner
3. Reactor well liner
4. Cask pool liner

Question 15

What are the sources of make up water?

Answer 15

1. Condensate Transfer/Demin Water
2. Suppression Pool via RHR LPCI Mode during Refueling
3. Fire Water Systems
4. Service Water A OR B(From RHR A or B, entirely from MCR)

Question 16

Describe the operation of fuel pool cooling assist.

Answer 16

1. A / B loops ONLY
2. Uses RHR to supplement cooling when high heat loads are present.
3. Requires an orifice to be installed in the RHR system.

Question 17

How is the FPCC system cooled?

Answer 17

Cooled by SACS
1. SACS can be cross-tied to allow one SACS loop to supply cooling water to both heat exchangers, however cross tied sacs auto isolates on:
* RPV level 1 (-129”)
* High drywell pressure (1.68 psig)
* Core Spray Manual Initiation
* Triple low level in SACS expansion tank

Question 18

What are the water level requirements of the FPCC system?

Answer 18

Minimum Water Level
1. At least 23 feet of water shall be maintained over the top of irradiated fuel assemblies in fuel pool
* (different from 22’2” above FLANGE in OPCON 5 – but still for 99% of 10% iodine gap activity)
* The depth of the spent fuel storage pool is 40 feet which provides 25 feet of water above resting fuel assemblies and 10 feet of water above a fuel assembly in-transit
* This depth ensures sufficient water to remove 99% of the assumed 10% iodine gap activity released from the rupture of an irradiated fuel assembly.
* On FPCPP suction break, min FP lvl is 199’ 4”

Question 19

What are the FPC pumps power supplies?

Answer 19

212 & 222 buses.

Question 20

What are the make up sources of water?

Answer 20

1. CST.
2. Fire water.
3. Both SSW loops.
4. RHR (if flooded up).