SFP Cooling Flashcards
What is the purpose of the SFP Cooling System?
Removes decay heat from spent fuel stored in the SFP
What is the design SFP temperature maintained by the SFP Cooling System?
150 F with a minimum of 1 SFP Cooling Pump operating
What design features of the SFP Cooling System prevent from draining the SFP?
- There are no drains in the SFP
- Inlet/outlet piping enter the SFP at a high enough level that, if the piping failed, adequate level would be maintained for shielding and cooling
What are the power supplies for the SFP Cooling Pumps?
P-51A - MCC-7
P-51B - MCC-8
What is the flow capacity of the SFP Cooling Pumps?
1700 gpm each
SFP Heat Exchangers design?
- 2 heat exchangers in series
- SFP water on the tube side, CCW on the shell side
- Designed to withstand a temperature transient of 60 F to 212 F in 5 seconds
Where can SFP level be monitored from?
- Control Room via camera or digital level indicator
- Locally at the SFP
- C-40 via digital level indicator
Where can SFP temperature be monitored from?
- Control Room via camera or PPC
- Locally at the SFP
What temperature is the SFP normally maintained at?
75 F to 125 F
What are the SFP temperature limits?
68 F to 150 F
What are the PPC SFP temperature alarms?
Lo - 75 F
Hi - 125 F
Hi-Hi - 140 F
What are the SFP level alarms?
Lo - 646’
Hi - 647’ 10”
What is the SFP Booster Pump power supply?
MCC-8
What is the design flow rate of the SFP Booster Pump?
160 gpm
What are the design ratings of the SFP Heat Exchanger (flow, pressure, temperature)?
150 gpm
200 psig
220 F
What is the interface between the SFP Cooling System and the SDC System?
Temporary connections are provided to allow the SDC System to be used to cool the SFP in the event of an equipment failure or full core offload
What is the interface between the SFP Cooling System and the SIRWT?
- Water can be transferred between the 2
- P-51B can be used to recirc the SIRWT
What is the interface between the SFP Cooling System and the Fire Protection System?
Fire Protection System provides an emergency supply of makeup water to the SFP
What is the interface between the SFP Cooling System and the PMU System?
PMU is a source for filling the SFP
Precautions for filling the SFP
- SFP level shall be continuously monitored via camera from the Control Room, or locally.
- SFP level should not be allowed to be higher than 3” below the skimmers due to known liner leaks
Precautions for SFP level and LPSI Pump monitoring when using SDC for SFP Cooling with a full core offload
monitored continuously until stable for 10 minutes, and then hourly after that
Tech Spec 3.7.14 “SFP Water Level” LCO statement
water level shall be >= 647’ elevation
Tech Spec 3.7.14 “SFP Water Level” applicability
during movement of irradiated fuel assemblies in the SFP or during movement of a fuel cask in or over the SFP.
Tech Spec 3.7.14 “SFP Water Level” required actions in less than 1 hour
If level is not within limits, the IMMEDIATELY suspend movement of irradiated fuel assemblies in the SFP and suspend movement of the fuel cask in or over the SFP
Tech Spec 3.7.15 “SFP Boron Concentration” LCO statement
SFP Boron Concentration shall be >= 1720 ppm
Tech Spec 3.7.15 “SFP Boron Concentration” applicability
When fuel assemblies are stored in the SFP
Tech Spec 3.7.15 “SFP Boron Concentration” required actions in less than 1 hour
If boron concentration not within limit, then IMMEDIATELY suspend movement of fuel assemblies in the SFP and initiate actions to restore boron concentration within limit
Tech Spec 3.7.14 “SFP Water Level” basis
647’ meets the assumptions for the iodine decontamination factors following a fuel handling or cask drop accident
Tech Spec 3.7.15 “SFP Boron Concentration” basis
Ensures sub criticality is maintained for a dropped spent fuel assembly accident or loading of a spent fuel assembly with improper burnup or enrichment
ORM 3.17.6.19 “SFP Area Radiation Monitors”
If a SFP radiation monitor becomes inoperable, fuel moves in the SFP are to be stopped IMMEDIATELY until monitoring capability is restored
