Lgs Ilt - Cs

Front 1

1. State the purpose of the Core Spray System.

Back 1

- Provides core cooling over a wide range of pipe breaks
- Large break LOCA
- Small break LOCA in conjunction with ADS
- Design Basis Accident (DBA) for core spray
- Double ended shear of 28" recirculation loop line
- Designed to limit maximum cladding temperatures during the DBA.

Front 2

2. Identify the purpose of the following components:
a. Core spray pump suction strainers

Back 2

- Removes large particles which prevents plugging of system nozzles and plugging of pump seal flushing water circuits
- Located in suppression pool above bottom to minimize suction of sediment

Front 3

purpose of the following components: b. Core spray spargers

Back 3

- Provides an even spray pattern across the entire core to ensure adequate cooling.
- Each loop penetrates vessel 180º apart (penetration includes thermal sleeve)
- Each pipe divides into a semi-circular header
- A pipe at each end of each header turns down and penetrates upper shroud
- Each pipe penetrating the shroud
- Feeds a semi-circular header (sparger)
- The four spargers form two nearly circular spray rings
- One ring located slightly above the other
- Nozzles are spaced around the sparger to spray water radially over the core
- Nozzles point inward and downward

Front 4

purpose of the following components: c. Safeguard piping fill

Back 4

- Provides a source of makeup water to keep ECCS piping systems full
- Insures instantaneous water injection
- Prevents water hammer
- Two pumps supply independent headers
- Take suction from A(B) Core Spray Pump suction piping. Requires Core Spray suction valves to be open to maintain safeguard fill suction flowpath.
- Safeguard Fill discharges to CS Pump discharge piping downstream of check valves and other keep fill loads (RCIC, HPCI, RHR, Feedwater). Loads are not common (i.e., both pumps should be placed in service to assure keep fill of all lines).
- Min flow protection assured by return flowpath to C(D) Core Spray Pump suction
- System acts as backup to Condensate Transfer system
- Both pumps are manually started and stopped

Front 5

purpose of the following components: d. Core Spray Pump suction and discharge relief valves

Back 5

- Pump discharge relief valves PSV- *F012A/B
- Protects low pressure portion of system piping if injection valves not properly seated
- Set at 500 psig (capacity @ 100 gpm – 10% accumulation)
- Discharge to DRW
- Pump suction relief valves PSV-*F032A-D
- Protects pump low pressure suction piping
- Set at 100 psi (capacity @ 10 gpm – 10% accumulation)
- Discharge to DRW

Front 6

3. Predict how the following systems/components support the operation of the Core Spray System:
a. Condensate Storage and Transfer System

Back 6

- System normally supplies water to ECCS system piping to keep it full of water.
- System provides a means to clean up the suppression pool.

Front 7

3. Predict how the following systems/components support the operation of the Core Spray System:b. Suppression Pool

Back 7

- Normal suction source for core spray system

Front 8

3. Predict how the following systems/components support the operation of the Core Spray System:c. 4KV Distribution

Back 8

- Divisional power supply for 600 HP AC motors

Front 9

3. Predict how the following systems/components support the operation of the Core Spray System:d. 125V DC

Back 9

- Initiation logic powered from 125VDC Buses A-D

Front 10

3. Predict how the following systems/components support the operation of the Core Spray System: e. Core Spray room unit coolers

Back 10

- Maintain temperature in Core Spray room low enough to ensure equipment operates correctly and room remains habitable. Core Spray unit room coolers must remain operable for the Core spray system to be operable.
- Each Core Spray pump room cooler has two cooling coils and fan units normally cooled by service water, and cooled by ESW under accident conditions.
- Fan in AUTO:
- CS Pump running – Fan runs continuously
- CS Pump not running – starts at 100ºF, stops at 80ºF
- Fan in STANDBY:
- CS Pump running – Runs continuously if other fan not running
- CS Pump not running - Starts at 110ºF, stops at 80ºF
- Pump running is sensed by breaker position

Front 11

4. Identify how the Core Spray System supports the operation of the following systems:
a. SLC -

Back 11

SLC system injects via the "B" core spray line

Front 12

4. Identify how the Core Spray System supports the operation of the following systems: b. HPCI –

Back 12

HPCI system injects via the "B" core spray line

Front 13

4. Identify how the Core Spray System supports the operation of the following systems: c. ADS -

Back 13

A loss of ADS could prevent operation of the Core Spray System if the ADS valves cannot be opened individually from Control Room handswitches, unless another method is found to depressurize the reactor to below the CSS discharge pressure.

Front 14

d. Emergency Diesel Generators

Back 14

- Provides emergency power to divisional 4KV safeguard bus during LOOP conditions.

Front 15

5. Predict the values for the following parameters:
a. Core spray pump design flow

Back 15

3175 gpm at 580 ft discharge head (250 psig)

Front 16

5. Predict the values for the following parameters: b. Core spray pump shutoff head

Back 16

– Maximum shutoff head of approximately 330 psig

Front 17

5. Predict the values for the following parameters: c. Discharge pressure setpoint for ADS

Back 17

– 145 psig (PI-052-IN655A/E/C/G)

Front 18

5. Predict the values for the following parameters: 7. Identify the conditions that will cause an automatic start of the Core Spray System, including setpoints.

Back 18

- High Drywell Pressure (1.68 psig) AND Low Reactor Pressure (455 psig)
- OR -
- Low Reactor Level (-129”)
- OR -
- Manual (Push Buttons)

Front 19

8. Predict the sequence of events that occur following the receipt of an initiation signal with and without off site power available.

Back 19

- Off-site power available
- T = 0, C & D RHR pumps start
- T = 5, A & B RHR pumps start
- T = 10, A & C CS pumps start
- T = 15, B & D CS pumps start
T = 0 is the time the LOCA signal is received (Actually all loading is prohibited for 0.5 seconds to ensure load shed)Staggered start times prevent overloading the startup transformer and buses on pump starting currents
- Off-site power not available
- T = 0, All four RHR pumps start
- T = 7, All four CS pumps start

Front 20

automatic functions and interlock a. Inboard and outboard injection valves (*F005, *F037 and *F004A/B)

Back 20

- Under normal conditions
- Inboard valve *F005, *F037 are closed
- Outboard valve *F004A/B are open
- Inboard cannot be opened manually unless outboard is fully closed with no injection signal present
- Both valves receive open signal if:
- Initiation signal is present
- Reactor pressure drops below 455 psig
- Power available to valve motor-operator
- Outboard valves cannot be shut if:
- Initiation signal present
- Reactor pressure is below 455 psig
- Power available to associated bus
- Inboard valve can be shut in manual override with an initiation signal present
- Can be re-opened if Initiation signal still present AND Reactor pressure still less than 455 psig
- Otherwise the outboard valve must be shut to re-open the Inboard valve

Front 21

automatic functions and interlock b. Minimum flow valve (*F031A/B)

Back 21

- Valve normally at open limit
- Closes when loop flow exceeds 775 gpm
- Re-opens if flow drops below 775 gpm
- A Loop valve (Unit 1), B Loop valve (Unit 2), provide path for makeup water to suppression pool. -If valves are not at open limit when CS initiates, it would not reach its rated pressure (250 psig) in the Tech. Spec. time limit (27 sec. min). - Min flow valves are short stroked (close direction) to meet this requirement.

Front 22

automatic functions and interlock c. Full flow test valve (*F015A/B)

Back 22

- Normally closed
- If open, will automatically close if initiation signal is present

Front 23

Loop A (B) Core Spray Injection Line HI/LO Pressure

Back 23

- Abnormal pressure in core spray injection line between pump and *F004A(B) valve. Hi/Lo setpoints: 475 psig / 60 psig.

Front 24

- Loop A (B) Core Spray Inject Line Surge Chamber Lo Level.

Back 24

- Low water level in Core Spray injection line surge chamber. Setpoint: 12" water.

Front 25

- Core Spray Line Internal Break

Back 25

- Caused by Excessive D/P between A and B Core Spray loops inside containment indicating a break, single loop core spray injection, HPCI injection or SLC injection
Setpoint is 3.8 psid.

Front 26

12. Identify the function of the Core Spray Sparger Break Detection Instrumentation. Include a summary of how the design break would be detected.

Back 26

- DP cell connected between loops
- Detects a leak or pipe break between
- Vessel wall
- Shroud penetration
- Possibility of rupture in the drywell should be considered
- Measures DP across shroud/separator assembly
- Provides alarm indication in Main Control room

Front 27

13. Predict the effect that a loss of the following has on the Core Spray System.
a. AC power

Back 27

- Diesel Generators provide backup emergency power in the event of Loss of Offsite Power. If Offsite Power is lost, then the starting sequence of ECCS pumps are changed.
- All four core spray pumps will auto-start 7 seconds from time diesel generator breakers close.
- Provides power to all Core Spray System MOV’s

Front 28

Predict the effect that a loss of the following has on the Core Spray System. b. Diesel generators

Back 28

- If both Offsite Power and Diesel Generators are lost, then the Core Spray system cannot function.

Front 29

Predict the effect that a loss of the following has on the Core Spray System. c. Suppression pool water level / temperature

Back 29

- A loss of Suppression Pool Water level may not provide adequate Net Positive Suction Head (NPSH) for the Core Spray pumps.
- The limiting suppression pool level for operation of Core Spray per T-102 is 13.5' (RHR, Core Spray, and RCIC pump NPSH and vortex limits)
- NPSH limits are defined to be the highest suppression temperature values which provide adequate NPSH for the pumps which take suction on the suppression pool. The NPSH limits are functions of pump flow and suppression pool overpressurization, and are utilized to preclude pump damage from cavitation.
- If in operational conditions 4 or 5, the Core Spray Systems may be manually aligned for CST suction, provided CST level is greater than 29 feet.

Front 30

Predict the effect that a loss of the following has on the Core Spray System.
d. Keep fill system

Back 30

- If the "Keep Full System" is totally lost (both Condensate Transfer and Safeguard Piping Fill are lost) then there is no assurance that the Core Spray discharge piping is filled. Initiation of the Core Spray System could result in water hammer which has the potential to severely damage the discharge piping and possibly prevent injection.

Front 31

Predict the effect that a loss of the following has on the Core Spray System. e. ADS

Back 31

- A loss of ADS could prevent operation of the Core Spray System if the ADS valves cannot be opened individually from Control Room handswitches, unless another method is found to depressurize the reactor to below the CSS discharge pressure.

Front 32

Predict the effect that a loss of the following has on the Core Spray System. - Suppression Pool Cleanup OPERATION

Back 32

- The Suppression Pool Cleanup Pump takes a suction on the Suppression Pool and discharges to the Main Condenser hotwell. Reactor quality water is returned to the Suppression Pool from the respective unit's CST via the "1A" Loop Core Spray Min Flow Return line for Unit 1 and the "2B" Loop Core Spray Min Flow Return line for Unit 2. The Suppression Pool DEOX skid, which removes dissolved oxygen (contributes to corrosion), from the Suppression Pool makeup water also utilizes this flowpath. Loss of the C.S. & T. system would prevent purification of Suppression Pool inventory.

Front 33

1. State the purpose of the Core Spray System.

Back 33

- Provides core cooling over a wide range of pipe breaks
- Large break LOCA
- Small break LOCA in conjunction with ADS
- Design Basis Accident (DBA) for core spray
- Double ended shear of 28" recirculation loop line
- Designed to limit maximum cladding temperatures during the DBA.

Front 34

2. Identify the purpose of the following components:
a. Core spray pump suction strainers

Back 34

- Removes large particles which prevents plugging of system nozzles and plugging of pump seal flushing water circuits
- Located in suppression pool above bottom to minimize suction of sediment

Front 35

purpose of the following components: b. Core spray spargers

Back 35

- Provides an even spray pattern across the entire core to ensure adequate cooling.
- Each loop penetrates vessel 180º apart (penetration includes thermal sleeve)
- Each pipe divides into a semi-circular header
- A pipe at each end of each header turns down and penetrates upper shroud
- Each pipe penetrating the shroud
- Feeds a semi-circular header (sparger)
- The four spargers form two nearly circular spray rings
- One ring located slightly above the other
- Nozzles are spaced around the sparger to spray water radially over the core
- Nozzles point inward and downward

Front 36

purpose of the following components: c. Safeguard piping fill

Back 36

- Provides a source of makeup water to keep ECCS piping systems full
- Insures instantaneous water injection
- Prevents water hammer
- Two pumps supply independent headers
- Take suction from A(B) Core Spray Pump suction piping. Requires Core Spray suction valves to be open to maintain safeguard fill suction flowpath.
- Safeguard Fill discharges to CS Pump discharge piping downstream of check valves and other keep fill loads (RCIC, HPCI, RHR, Feedwater). Loads are not common (i.e., both pumps should be placed in service to assure keep fill of all lines).
- Min flow protection assured by return flowpath to C(D) Core Spray Pump suction
- System acts as backup to Condensate Transfer system
- Both pumps are manually started and stopped

Front 37

purpose of the following components: d. Core Spray Pump suction and discharge relief valves

Back 37

- Pump discharge relief valves PSV- *F012A/B
- Protects low pressure portion of system piping if injection valves not properly seated
- Set at 500 psig (capacity @ 100 gpm – 10% accumulation)
- Discharge to DRW
- Pump suction relief valves PSV-*F032A-D
- Protects pump low pressure suction piping
- Set at 100 psi (capacity @ 10 gpm – 10% accumulation)
- Discharge to DRW

Front 38

3. Predict how the following systems/components support the operation of the Core Spray System:
a. Condensate Storage and Transfer System

Back 38

- System normally supplies water to ECCS system piping to keep it full of water.
- System provides a means to clean up the suppression pool.

Front 39

3. Predict how the following systems/components support the operation of the Core Spray System:b. Suppression Pool

Back 39

- Normal suction source for core spray system

Front 40

3. Predict how the following systems/components support the operation of the Core Spray System:c. 4KV Distribution

Back 40

- Divisional power supply for 600 HP AC motors

Front 41

3. Predict how the following systems/components support the operation of the Core Spray System:d. 125V DC

Back 41

- Initiation logic powered from 125VDC Buses A-D

Front 42

3. Predict how the following systems/components support the operation of the Core Spray System: e. Core Spray room unit coolers

Back 42

- Maintain temperature in Core Spray room low enough to ensure equipment operates correctly and room remains habitable. Core Spray unit room coolers must remain operable for the Core spray system to be operable.
- Each Core Spray pump room cooler has two cooling coils and fan units normally cooled by service water, and cooled by ESW under accident conditions.
- Fan in AUTO:
- CS Pump running – Fan runs continuously
- CS Pump not running – starts at 100ºF, stops at 80ºF
- Fan in STANDBY:
- CS Pump running – Runs continuously if other fan not running
- CS Pump not running - Starts at 110ºF, stops at 80ºF
- Pump running is sensed by breaker position

Front 43

4. Identify how the Core Spray System supports the operation of the following systems:
a. SLC -

Back 43

SLC system injects via the "B" core spray line

Front 44

4. Identify how the Core Spray System supports the operation of the following systems: b. HPCI –

Back 44

HPCI system injects via the "B" core spray line

Front 45

4. Identify how the Core Spray System supports the operation of the following systems: c. ADS -

Back 45

A loss of ADS could prevent operation of the Core Spray System if the ADS valves cannot be opened individually from Control Room handswitches, unless another method is found to depressurize the reactor to below the CSS discharge pressure.

Front 46

d. Emergency Diesel Generators

Back 46

- Provides emergency power to divisional 4KV safeguard bus during LOOP conditions.

Front 47

5. Predict the values for the following parameters:
a. Core spray pump design flow

Back 47

3175 gpm at 580 ft discharge head (250 psig)

Front 48

5. Predict the values for the following parameters: b. Core spray pump shutoff head

Back 48

– Maximum shutoff head of approximately 330 psig

Front 49

5. Predict the values for the following parameters: c. Discharge pressure setpoint for ADS

Back 49

– 145 psig (PI-052-IN655A/E/C/G)

Front 50

5. Predict the values for the following parameters: 7. Identify the conditions that will cause an automatic start of the Core Spray System, including setpoints.

Back 50

- High Drywell Pressure (1.68 psig) AND Low Reactor Pressure (455 psig)
- OR -
- Low Reactor Level (-129”)
- OR -
- Manual (Push Buttons)

Front 51

8. Predict the sequence of events that occur following the receipt of an initiation signal with and without off site power available.

Back 51

- Off-site power available
- T = 0, C & D RHR pumps start
- T = 5, A & B RHR pumps start
- T = 10, A & C CS pumps start
- T = 15, B & D CS pumps start
T = 0 is the time the LOCA signal is received (Actually all loading is prohibited for 0.5 seconds to ensure load shed)Staggered start times prevent overloading the startup transformer and buses on pump starting currents
- Off-site power not available
- T = 0, All four RHR pumps start
- T = 7, All four CS pumps start

Front 52

automatic functions and interlock a. Inboard and outboard injection valves (*F005, *F037 and *F004A/B)

Back 52

- Under normal conditions
- Inboard valve *F005, *F037 are closed
- Outboard valve *F004A/B are open
- Inboard cannot be opened manually unless outboard is fully closed with no injection signal present
- Both valves receive open signal if:
- Initiation signal is present
- Reactor pressure drops below 455 psig
- Power available to valve motor-operator
- Outboard valves cannot be shut if:
- Initiation signal present
- Reactor pressure is below 455 psig
- Power available to associated bus
- Inboard valve can be shut in manual override with an initiation signal present
- Can be re-opened if Initiation signal still present AND Reactor pressure still less than 455 psig
- Otherwise the outboard valve must be shut to re-open the Inboard valve

Front 53

automatic functions and interlock b. Minimum flow valve (*F031A/B)

Back 53

- Valve normally at open limit
- Closes when loop flow exceeds 775 gpm
- Re-opens if flow drops below 775 gpm
- A Loop valve (Unit 1), B Loop valve (Unit 2), provide path for makeup water to suppression pool. -If valves are not at open limit when CS initiates, it would not reach its rated pressure (250 psig) in the Tech. Spec. time limit (27 sec. min). - Min flow valves are short stroked (close direction) to meet this requirement.

Front 54

automatic functions and interlock c. Full flow test valve (*F015A/B)

Back 54

- Normally closed
- If open, will automatically close if initiation signal is present

Front 55

Loop A (B) Core Spray Injection Line HI/LO Pressure

Back 55

- Abnormal pressure in core spray injection line between pump and *F004A(B) valve. Hi/Lo setpoints: 475 psig / 60 psig.

Front 56

- Loop A (B) Core Spray Inject Line Surge Chamber Lo Level.

Back 56

- Low water level in Core Spray injection line surge chamber. Setpoint: 12" water.

Front 57

- Core Spray Line Internal Break

Back 57

- Caused by Excessive D/P between A and B Core Spray loops inside containment indicating a break, single loop core spray injection, HPCI injection or SLC injection
Setpoint is 3.8 psid.

Front 58

12. Identify the function of the Core Spray Sparger Break Detection Instrumentation. Include a summary of how the design break would be detected.

Back 58

- DP cell connected between loops
- Detects a leak or pipe break between
- Vessel wall
- Shroud penetration
- Possibility of rupture in the drywell should be considered
- Measures DP across shroud/separator assembly
- Provides alarm indication in Main Control room

Front 59

13. Predict the effect that a loss of the following has on the Core Spray System.
a. AC power

Back 59

- Diesel Generators provide backup emergency power in the event of Loss of Offsite Power. If Offsite Power is lost, then the starting sequence of ECCS pumps are changed.
- All four core spray pumps will auto-start 7 seconds from time diesel generator breakers close.
- Provides power to all Core Spray System MOV’s

Front 60

Predict the effect that a loss of the following has on the Core Spray System. b. Diesel generators

Back 60

- If both Offsite Power and Diesel Generators are lost, then the Core Spray system cannot function.

Front 61

Predict the effect that a loss of the following has on the Core Spray System. c. Suppression pool water level / temperature

Back 61

- A loss of Suppression Pool Water level may not provide adequate Net Positive Suction Head (NPSH) for the Core Spray pumps.
- The limiting suppression pool level for operation of Core Spray per T-102 is 13.5' (RHR, Core Spray, and RCIC pump NPSH and vortex limits)
- NPSH limits are defined to be the highest suppression temperature values which provide adequate NPSH for the pumps which take suction on the suppression pool. The NPSH limits are functions of pump flow and suppression pool overpressurization, and are utilized to preclude pump damage from cavitation.
- If in operational conditions 4 or 5, the Core Spray Systems may be manually aligned for CST suction, provided CST level is greater than 29 feet.

Front 62

Predict the effect that a loss of the following has on the Core Spray System.
d. Keep fill system

Back 62

- If the "Keep Full System" is totally lost (both Condensate Transfer and Safeguard Piping Fill are lost) then there is no assurance that the Core Spray discharge piping is filled. Initiation of the Core Spray System could result in water hammer which has the potential to severely damage the discharge piping and possibly prevent injection.

Front 63

Predict the effect that a loss of the following has on the Core Spray System. e. ADS

Back 63

- A loss of ADS could prevent operation of the Core Spray System if the ADS valves cannot be opened individually from Control Room handswitches, unless another method is found to depressurize the reactor to below the CSS discharge pressure.

Front 64

Predict the effect that a loss of the following has on the Core Spray System. - Suppression Pool Cleanup OPERATION

Back 64

- The Suppression Pool Cleanup Pump takes a suction on the Suppression Pool and discharges to the Main Condenser hotwell. Reactor quality water is returned to the Suppression Pool from the respective unit's CST via the "1A" Loop Core Spray Min Flow Return line for Unit 1 and the "2B" Loop Core Spray Min Flow Return line for Unit 2. The Suppression Pool DEOX skid, which removes dissolved oxygen (contributes to corrosion), from the Suppression Pool makeup water also utilizes this flowpath. Loss of the C.S. & T. system would prevent purification of Suppression Pool inventory.