Shutdown Cooling Flashcards
LCO 3.4.7 “PCS Loops - Mode 5, Loops Filled” requirement
1 SDC train shall be operable and in operation with >= 2810 gpm flow through the reactor core and either 1 additional SDC train shall be operable, or the secondary side water level of each S/G shall be >= -84%
LCO 3.4.7 “PCS Loops - Mode 5, Loops Filled” applicability
Mode 5 with PCS loops filled
LCO 3.4.7 “PCS Loops - Mode 5, Loops Filled” required action if 1 SDC train inoperable and any S/G with secondary side water level not within limit
IMMEDIATELY initiate action to restore a second SDC train to operable or initiate action to restore S/G secondary side water levels to within limits
LCO 3.4.7 “PCS Loops - Mode 5, Loops Filled” required action if 2 SDC trains inoperable or SDC flow through the core not within limits
IMMEDIATELY suspend all operations involving reduction in PCS boron concentration, and initiate action to restore 1 SDC train to operable and in operation with >= 2810 gpm flow through the reactor core
LCO 3.4.8 “PCS Loops - Mode 5, Loops Not Filled” requirement
2 SDC trains shall be operable and either 1 SDC train in operation with >= 2810 gpm flow through the reactor core, or 1 SDC train in operation with >= 650 gpm flow through the reactor core with 2 of the 3 charging pumps incapable of reducing the boron concentration in the PCS below the minimum value necessary to maintain the required shutdown margin
LCO 3.4.8 “PCS Loops - Mode 5, Loops Not Filled” applicability
Mode 5 with PCS loops not filled
LCO 3.4.8 “PCS Loops - Mode 5, Loops Not Filled” required action if 1 SDC train inoperable
IMMEDIATELY initiate action to restore SDC train to operable
LCO 3.4.8 “PCS Loops - Mode 5, Loops Not Filled” required action if 2 SDC trains inoperable, or SDC flow through the core not within limits
IMMEDIATELY suspend all operations involving reduction of PCS boron concentration, and initiate action to restore 1 SDC train to operable status and in operation with SDC flow through the reactor core within limit
LCO 3.9.4 “Shutdown Cooling (SDC) and Coolant Circulation - High Water Level” requirement
1 SDC train shall be operable and in operation
LCO 3.9.4 “Shutdown Cooling (SDC) and Coolant Circulation - High Water Level” applicability
Mode 6 with the refueling cavity water level >= 647 ft elevation
LCO 3.9.4 “Shutdown Cooling (SDC) and Coolant Circulation - High Water Level” required action if 1 required SDC train inoperable or not in operation
IMMEDIATELY initiate action to restore SDC train to operable status and in operation, and suspend operations involving a reduction in PCS boron concentration, and suspend loading irradiated fuel assemblies in the core
LCO 3.9.5 “Shutdown Cooling (SDC) and Coolant Circulation - Low Water Level” requirement
2 SDC trains shall be operable, and 1 SDC train shall be in operation
LCO 3.9.5 “Shutdown Cooling (SDC) and Coolant Circulation - Low Water Level” applicability
Mode 6 with the refueling cavity water level < 647 ft elevation
LCO 3.9.5 “Shutdown Cooling (SDC) and Coolant Circulation - Low Water Level” required action if 1 SDC train inoperable
IMMEDIATELY initiate action to restore SDC train to operable, or initiate action to establish the refueling cavity water level >= 647 ft elevation
LCO 3.9.5 “Shutdown Cooling (SDC) and Coolant Circulation - Low Water Level” required action if no SDC train operable or in operation
IMMEDIATELY suspend operations involving a reduction in PCS boron concentration, and initiate action to restore 1 SDC train to operable and in operation, and initiate action to close all containment penetrations providing direct access from containment atmosphere to outside atmosphere
What is the purpose/function of the SDC system?
- Removes decay heat from the PCS
- Cools PCS from 300 F to refueling temperature, 130 F, with a CCW temperature of 90 F
What is the SDC operational design pressure and temperature?
270 psia, 300 F
How are SDC from PCS MOVs, MO-3015 and MO-3016 operated?
- 1 switch in Control Room, 1 switch on C-33
- Switches are in parallel, so either switch will open/close the valve
- Switches have a seal in circuit, and spring return to neutral. Operate switch in open or closed direction, release switch, and valve will stroke fully to that position.
What is the interlock associated with opening SDC from PCS MOVs, MO-3015 and MO-3016?
PCS < 275 psia (admin limit of 265 psia) to protect SDC piping from overpressure
What are the power supplies for the SDC from PCS MOVs, MO-3015 and MO-3016?
MO-3015 - MCC-1
MO-3016 - MCC-2
What is the normal position of the SDC from PCS MOVs, MO-3015 and MO-3016 while at power?
Closed with the breaker open