Core Spray

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Author:
heidin
ID:
140531
Filename:
Core Spray
Updated:
2012-03-15 12:55:35
Tags:
ECCS Core Spray ILC
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Description:
LP ECCS systems
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  1. What initiates Core Spray?
    LL3 45"

    or

    Hi DW press (1.7#) AND Lo RPV press (410#)
  2. What happens on Core Spray initiation? (CS specific)
    • Signal seals in and gives a white light
    • BOTH Pumps start at 15 sec → CS Room coolers start
    • F015 close signal and blocked from opening
    • F004 and F005 OPEN when P < 410 psig
    • F031 will close with pump breaker shut and > 603 gpm
  3. What is the normal suction path for Core Spray?

    Alternate supply?
    F001 TORUS SUCTION – manually controlled, normally OPEN

    Alternate: F002 CST SUCTION – manually operated, normally SHUT

    • THERE ARE NO INTERLOCKS BETWEEN THESE TWO VALVES
    • ** Core Spray pumps will NOT trip on loss of suction, they will run until destroyed
  4. Core Spray Room cooler controls
    AUTO/OFF/TEST control on RTGB

    • AUTO will start cooler and open SW valve when CS pump breaker shuts
    • TEST will only start the fan – NO COOLING IS AVAILABLE (ie. Cannot manually run CS room coolers)
  5. Core Spray Injection valve permissives/interlocks
    both AUTO OPEN when P < 410psig with LOCA (10 sec TD)

    • F005 (IB) is Normally closed
    • To open w/o initiation signal present, must have F004 closed or be <410#
    • F004 (OB) is Normally open, CANNOT BE MANUALLY SHUT WITH A LOCA SIGNAL PRESENT
    • To open w/o initiation signal present, F005 must be closed

  6. Purpose of CS leak detection

    How does it work?
    Indicate a leak between the vessel and the shroud

    • Measure the D/P between:
    • Injection line after the F007 (Low P)
    • AND
    • ABOVE the core plate SLC line (High P) (outer pipe)

    If a break occurs → Low P side P ↓ → D/P ↑ → the indication will move in the positive direction (read less negative)
  7. Override CS pump off
    White light seals in when Pump control switch taken to OFF w/initiation signal present

    CAN be restarted

    STR relay will re-start pumps after LOOP (seal-in drops out)
  8. CS Injection valve override
    white light when control switch taken to close with initiation and LP permissive present.
  9. CS discharge pressure switch
    >115 psig inputs to opposite division ADS logic
  10. Unit Two is performing a startup per GP-02. Plant conditions are:
    RPV level 187”
    RPV pressure 350 psig
    A small steam leak results in a scram on high drywell pressure. RPV level shrinks to LL1, then rises to the RFP trip setpoint. What is the expected response of the Core Spray Pumps?

    a. Not running.

    b. Running with no flow.

    c. Running with minimum flow.

    d. Running and injecting to the RPV.
    c. Running with minimum flow.
  11. Following a Unit Two LOCA. Plant conditions are:
    RPV level 187”
    RPV pressure 50 psig
    Drywell pressure 20 psig
    CS Pump 2A Off
    Inj. Valve (F005A) ClosedThe Unit 2 SAT trips and locks out. DG3 ties to E3. What is the expected status of Core Spray Loop A one minute later (assume no operator action)?

    a. Core Spray Pump 2A is running, F005A is open .

    b. Core Spray Pump 2A is running, F005A is closed .

    c. Core Spray Pump 2A is not running, F005A is open .

    d. Core Spray Pump 2A is not running, F005A is closed .
    a. Core Spray Pump 2A is running, F005A is open .
  12. Following a Unit Two LOCA. Plant conditions are:
    RPV level -100”
    RPV pressure 50 psig
    Drywell pressure 20 psig
    CS Logic 2A Fuse Blown
    What is the expected status of Core Spray Loop 2A?

    a. Core Spray Pump 2A is running, injection valve E21-F005A is open provided Division II Core Spray has initiated.

    b. Core Spray Pump 2A is not running, injection valve F005A is closed. The operator cannot start the Pump or open F005A.

    c. Core Spray Pump 2A is not running, injection valve F005A is closed. The operator can start the Pump and can open F005A.

    d. Core Spray Pump 2A is not running, injection valve F005A is closed. The operator can start the Pump but cannot open F005A.
    d. Core Spray Pump 2A is not running, injection valve F005A is closed. The operator can start the Pump but cannot open F005A.
  13. A feedwater line rupture has occurred on Unit Two and the following conditions exist:

    Drywell pressure 8.8 psig
    Reactor water level - 35 inches
    N036/N037 Reference leg temp 225° F
    RPV pressure 500 psig

    What is the expected configuration of both loops of Core Spray?

    A. Shutdown with 2E21-F031A(B), and 2E21-F004A(B) open and 2E21-F005A(B) is closed.

    B. Running with 2E21-F004A(B) and2E21-F005A(B) injection valves open and flow to the vessel.

    C. Running with 2E21-F031A(B), and 2E21-F004A(B) open and 2E21-F005A(B) is closed.

    D. Running with 2E21-F004A(B) and2E21-F005A(B) injection valves open but no flow to the vessel
    C. Running with 2E21-F031A(B), and 2E21-F004A(B) open and 2E21-F005A(B) is closed.
  14. A LOCA occurred on Unit 2. Plant conditions are:

    Reactor pressure 650 psig lowering
    Drywell temperature 240° F
    Wide Range Level Instruments +30 inches, lowering
    Suppression Pool Temperature 96° F, rising
    Suppression Pool Level -24", rising
    CS Pumps "A" and "B" Running

    Regarding the Core Spray system, what action(s) should be taken?

    A. Stop both Core Spray pumps to prevent damage due to extended operation on minimum flow.

    B. Immediately open SRV's and depressurize below the Core Spray discharge pressure to recover RPV level.

    C. Verify that CS pump discharge pressure is approximately 330 psig; verify the Core Spray Inboard Injection Valve opens when reactor pressure reaches 410 psig.

    D. Verify the Core Spray outboard Injection Valve opens when reactor pressure reaches 410 psig; throttle the valve closed as soon as the CS pumps start to inject to avoid exceeding NPSH limit.
    C. Verify that CS pump discharge pressure is approximately 330 psig; verify the Core Spray Inboard Injection Valve opens when reactor pressure reaches 410 psig.
  15. A feedwater line rupture has occurred on Unit Two and the following conditions exist:

    Drywell pressure 8.8 psig
    Reactor water level - 35 inches
    NO36/No37 Reference leg temp 225° F
    RPV pressure 500 psig

    What is the expected configuration of both loops of Core Spray?

    A. Running with Outboard Injection valve, E21-F004 and Inboard Injection valve, E21-F005 open and flow to the vessel.

    B. Running with Outboard Injection valve, E21-F004 and Inboard Injection valve, E21-F005 open but no flow to the vessel.

    C. Running with Min Flow valve, E21-F031, and Outboard Injection valve, E21-F004 open; Inboard Injection valve, E21-F005 closed.

    D. Running with Min Flow valve, E21-F031, and Inboard Injection valve, E21-F005 open; Outboard Injection valve, E21-F004 is closed.
    C. Running with Min Flow valve, E21-F031, and Outboard Injection valve, E21-F004 open; Inboard Injection valve, E21-F005 closed.
  16. During an ATWS, emergency depressurization becomes required. Plant conditions are:

    RPV Level 80 inches
    RPV Pressure 1000 psig
    Drywell Pressure 1.0 psig
    All 4KV Buses Energized from Off-Site Power

    Direction has been given to Terminate and Prevent injection from Core Spray during the depressurization. This is accomplished by placing the Core Spray Pump control switch to STOP:

    A. Immediately when RPV level drops to LL3.

    B. 15 seconds after RPV level drops to LL3.

    C. Immediately when RPV pressure drops below the injection valve pressure permissive.

    D. 15 seconds after RPV pressure drops below the injection valve pressure permissive.
    B. 15 seconds after RPV level drops to LL3.
  17. A Feedwater line has ruptured in the MSIV pit. The Feedwater line check valve in the drywell failed to close. Plant conditions are:

    Reactor level +60 inches, lowering
    Reactor pressure 375 psig, lowering
    Drywell pressure 1.5 psig, steady

    What is the expected response of the Core Spray System pumps and Inboard Injection valve, E21-F005A(B)?

    Core Spray pumps:

    A. are running and injecting to the reactor vessel.

    B. remain off and the Inboard Injection valves are closed.

    C. are running and the Inboard Injection valves are closed.

    D. are running on minimum flow with the Injection valves open.
    B. remain off and the Inboard Injection valves are closed.
  18. Unit One (1) is in heatup and pressurization of the Reactor per GP-02. A small steam leak in the drywell results in the following plant conditions:

    Reactor pressure 385 psig
    Reactor water level 180 inches
    Drywell pressure 2.3 psig

    The correct alignment of the Core Spray (CS) System is Core Spray pumps . . .

    A. not running, Inboard Injection Valves closed, Minimum Flow Valves open.

    B. not running, Inboard Injection Valves closed, Minimum Flow Valves closed.

    C. running, Inboard Injection Valves open, Minimum Flow Valves open.

    D. running, Inboard Injection Valves open, Minimum Flow Valves closed.
    C. running, Inboard Injection Valves open, Minimum Flow Valves open.
  19. A LOCA has occurred on Unit 1 causing low pressure ECCS to re-flood the vessel. To control RPV level, both Core Spray and all four RHR pumps are taken to STOP. Core Spray Logic has not been reset. Current plant conditions:

    Indicated Rx Water Level 60 inches lowering
    Reactor Pressure 100 psig
    Drywell Pressure 10 psig

    What action is required to start the Core Spray pumps?

    A. Both Core Spray pumps must be started manually.

    B. Core Spray pumps cannot be started with current plant conditions.

    C. Both Core Spray pumps will auto start when level drops below +45 inches.

    D. The initiation signal must be reset, then both Core Spray pumps will auto start.
    A. Both Core Spray pumps must be started manually.
  20. The following LOCA conditions exist on Unit 2:

    Reactor level +35 inches, lowering
    Reactor pressure 525 psig, lowering
    Drywell pressure 3.5 psig, rising
    Control Rods All Rods In
    E4 Bus Deenergized
    Core Spray A Initiation Light (white) On
    Core Spray B Initiation Light (white) Off
    Core Spray Pump 2B Off

    Why is the Core Spray "B" Initiation Light "Off"?

    A. Loss of bus E4.

    B. System logic reset prematurely.

    C. Failure of Core Spray "B" Initiation Logic.

    D. Core Spray Initiation conditions not fully satisfied.
    C. Failure of Core Spray "B" Initiation Logic.
  21. A feedwater line rupture has occurred on Unit Two and the following conditions exist:

    Drywell pressure Above Rx SCRAM setpoint
    Reactor water level Below TAF
    RPV pressure Above the LOCA low pressure setpoint (ie 500 psig)

    Given SD-18, Figure 18-1, what is the expected configuration of both loops of Core Spray?

    A. Pump shutdown, with the E21-F031 (min. flow valve) & E21-F004 (inboard isolation valve) and the E21-F005 (outboard isolation valve) all open.

    B. Pump running, with the E21-F004 and E21-F005 (inboard and outboard injection) valves open and flow to the vessel.

    C. Pump shutdown, with the E21-F031 (min. flow valve) & E21-F004 (inboard isolation valve)open and the E21-F005 (outboard isolation valve) closed.
    D. Pump running, with the E21-F031 (min. flow valve) & E21-F004 (inboard isolation valve) open and the E21-F005 (outboard isolation valve) closed.
    D. Pump running, with the E21-F031 (min. flow valve) & E21-F004 (inboard isolation valve) open and the E21-F005 (outboard isolation valve) closed.
  22. A Loss of Offsite Power and LOCA (LOOP/LOCA) occurred on Unit Two (2) simultaneously. DG #3 energizes Bus E3 10 seconds after the LOOP/LOCA signal. The 2A Core Spray pump starts:

    A. 5 seconds after the bus is energized.

    B. 25 seconds after the bus is energized.

    C. 15 seconds after the LOOP/LOCA signal.

    D. 25 seconds after the LOOP/LOCA signal.
    D. 25 seconds after the LOOP/LOCA signal.
  23. Following a transient, Unit 2 is shut down. Plant conditions are:

    RPV level +65 inches
    RPV pressure 300 psig
    DW pressure 1.0 psig
    DW temperature 140°F

    Due to multiple failures, the 'A' Core Spray system is the only injection source available. Core Spray is in a normal standby lineup except that, BOTH the Inboard Injection valve, E21-F005A, and the Outboard Injection valve, E21-F004A, are CLOSED. The 'A' Core Spray pump is started and the F005A valve is OPENED. The E21-F004A valve remains closed when its control switch is taken to "open" for injection.

    What action(s) should be taken to establish an injection flowpath?

    A. The F004A valve is malfunctioning and should be opened locally.

    B. The initiation signal must be reset before opening the F004A valve.

    C. The F004A valve closed seal-in logic must be reset before opening the valve.
    D. The F005A valve should be closed. The F004A valve can then be opened; then open the F005A valve.
    D. The F005A valve should be closed. The F004A valve can then be opened; then open the F005A valve.
  24. Unit 2 is shut down, with Shutdown Cooling in service on the "B" loop of RHR. Core Spray loop "A" is considered the primary source of RPV makeup. CS "A" is in a normal standby lineup except that BOTH the Inboard Injection valve, E21-F005A, and the Outboard Injection Valve, E21-F004A, are CLOSED.

    A small break LOCA causes the isolation of Shutdown Cooling, requiring Core Spray injection to maintain RPV level. RPV level is currently 80 inches lowering, and drywell pressure 1.5 psig rising. The "2A" CS pump is started and the E21-F005A valve is OPENED. When the control switch for the E21-F004A is taken to open, the valve remains closed.

    What action(s) should be taken to establish an injection flowpath?

    A. The F004A valve must be opened locally.

    B. The F004A valve can only be open when the LL3 signal is received.

    C. An initiation signal must be received before the F004A and F005A can be opened simultaneously.

    D. The F005A valve should be shut. The F004A valve can then be opened; and the F005A valve re-opened.
    D. The F005A valve should be shut. The F004A valve can then be opened; and the F005A valve re-opened.
  25. Unit One is in Mode 2 performing heatup and pressurization of the reactor. Reactor pressure is currently 350 psig. The Core Spray Inboard Isolation Valve, E21-F005A, needs to be stroked following a packing adjustment.

    The Core Spray Inboard Injection Valve, E21-F005A:

    A. cannot be opened with current plant conditions.

    B. can be opened only if the Outboard Injection Valve, E21-F004A, is closed.

    C. can be stroked close, but cannot be reopened with current plant conditions.

    D. can be opened regardless of the Outboard Injection Valve, E21-F004A, position.
    D. can be opened regardless of the Outboard Injection Valve, E21-F004A, position.
  26. With a Core Spray Loop B Initiation signal present, the Core Spray Inboard Injection Valve (2E21-F005B) is overridden full closed.

    E8 to MCC 2XD trips, then is reclosed.

    Following reenergization of MCC 2XD the Core Spray Inboard Injection Valve, 2E21-F005B, will be

    A. full open with the F005B Closed Signal Sealed In "white light" extinguished.

    B. full open with the F005B Closed Signal Sealed In "white light" illuminated.

    C. full closed with the F005B Closed Signal Sealed In "white light" illuminated.

    D. full closed with the F005B Closed Signal Sealed In "white light" extinguished.
    C. full closed with the F005B Closed Signal Sealed In "white light" illuminated.

    Closed Signal Sealed In will clear if 4KV Bus experiences undervoltage and the valve will reopen if the Core Spray initiation signal is still sealed in.
  27. Each Core Spray Inboard Injection Valve, E21-F005 A/B has an associated white light that is normally:

    A. lit and will extinguish when an initiation signal is received.

    B. off and will light when the valve receives an auto open signal.

    C. lit and indicates the injection valve is full closed OR an initiation signal is not present. If a valve auto open signal is overridden, the white light will only light when the valve is full closed.
    D. off and will light when a valve auto open signal is manually overridden, regardless of valve position. The light will also light while the valve control switch is held in the CLOSE position when there is no initiation signal present.
    D. off and will light when a valve auto open signal is manually overridden, regardless of valve position. The light will also light while the valve control switch is held in the CLOSE position when there is no initiation signal present.
  28. Primary Containment Control Procedure, EOP-02-PCCP, is entered on low suppression pool level when a leak developed on the RHR 'A' loop suction line for Unit 1. If the leak is isolated, but pool level is -37 inches, then: (Select the correct answer)

    A. Insert a reactor scram, enter EOP-01-RSP and maintain level above the Heat Capacity Level Limit.

    B. Fill the suppression pool by running Core Spray in full flow test with a suction from the CST.

    C. Fill the suppression pool by placing RHR in pool cooling and using the keepfill station bypass.

    D. Fill the suppression pool using the Core Spray system in standby by throttling open the Core Spray pump CST suction valve.
    D. Fill the suppression pool using the Core Spray system in standby by throttling open the Core Spray pump CST suction valve.
  29. Following a Loss of Coolant Accident, the reactor is depressurized and reactor water level is below Top of Active Fuel (TAF).

    If the control switches for the Inboard (E21-F005) and Outboard (E21-F004) Core Spray injection valves are placed in CLOSE:

    A. Only the F004 valve will shut.

    B. Only the F005 valve will shut.

    C. Both the F004 and F005 valve shut.

    D. Neither the F004 or F005 valve will shut.
    B. Only the F005 valve will shut.
  30. Unit One (1) is operating at 100% power when the CORE SPRAY SYSTEM II ACTUATED annunciator is received. The actuation has been caused by a I&C error which energized the Core Spray B Loop initiation logic.

    Which of the following describes a related plant/system response to the Core Spray System II actuation?

    A. Core Spray 1B pump starts, EDGs 2 and 4 start, drywell coolers 1B and 1D trip, Division II RNA Isolation valve closes, Division II Back Up Nitrogen Isolation system aligns.

    B. Both Core Spray pumps start, all EDGs start, all drywell coolers trip, Division II Back Up Nitrogen Isolation system aligns and Division II RNA Isolation valve closes.

    C. Both Core Spray pumps start, EDGs 2 and 4 start, all drywell coolers trip, both RNA Isolation valves close and both Backup Nitrogen Isolation system aligns.

    D. Core Spray 1B pump starts, all EDGs start, drywell coolers 1B and 1C trip, both RNA Isolation valves close and both Backup Nitrogen Isolation system aligns.
    D. Core Spray 1B pump starts, all EDGs start, drywell coolers 1B and 1C trip, both RNA Isolation valves close and both Backup Nitrogen Isolation system aligns.
  31. A LOCA outside the primary containment caused reactor water level to lower below TAF; actions have been taken to mitigate the accident. Plant conditions are:

    Reactor pressure 50 psig
    Reactor level +180 inches
    Drywell pressure 1.5 psig
    Core Spray Pump A Overridden OFF
    Core Spray Pump B Injecting to maintain level

    Both Core Spray initiation white lights are illuminated. A loss of off-site power occurs.

    Predict the Core Spray PUMP RESPONSE as the Diesel Generatore energize the E buses.

    A. Both Core Spray Pumps (A/B) auto start 15 seconds after the E bus energization.

    B. Both Core Spray Pumps (A/B) remain deenergized until another LOCA signal is received.

    C. Core Spray Pump B auto starts 15 seconds after E bus energization; Core Spray Pump A remains overridden off.

    D. Core Spray Pump B auto starts immediately after E bus energization; Core Spray Pump A remains overridden off.
    A. Both Core Spray Pumps (A/B) auto start 15 seconds after the E bus energization.
  32. 595. During the performance of the Reactor Low Level Instrument MST (Maintenance Surveillance Test) for Core Spray, I&C discovers the Spray "A" LL3 instruments (B21-N031A and B21-N031C) inoperable.

    If a valid initiation signal were received, what would be the expected response for Core Spray Loop "A" components?

    Core Spray Loop "A" components will:

    A. not function automatically. Manual actuation is required.

    B. only function automatically on RPV low pressure with coincident high drywell pressure.

    C. function automatically from the redundant Core Spray Loop "B" pump start logic.

    D. function as required.
    D. function as required.
  33. With Unit 1 operating at rated conditions and Unit 2 at 75% power, Unit 2 annunciator A3 2-6, CORE SPRAY SYS 2 LOGIC PWR FAILURE, is received. Investigation reveals a tripped circuit breaker in Panel 4B which powers CORE SPRAY SYS 2 LOGIC.

    What interrelated effect does this produce on a subsequent Unit 2 LOCA initiation?

    A. DIV II Emergency diesel generators will not auto start.

    B. DIV II Non Interruptible RNA isolation valve will not isolate and DIV II N² BU isolation valve will not open.

    C. HPCI High Drywell pressure initiation will not occur.

    D. DIV II RHR pumps will not auto start.
    C. HPCI High Drywell pressure initiation will not occur.
  34. Unit 2 is in COLD SHUTDOWN with the Condensate Storage tank drained for maintenance. For the Core Spray to be OPERABLE, the Suppression Pool water level is required to be at least:

    A. -25 inches.

    B. -27 inches.

    C. -29 inches.

    D. -31 inches.
    D. -31 inches.
  35. A feedwater line rupture has occurred on Unit Two and the following conditions exist:

    Drywell pressure 8.8 psig
    Reactor water level -35”
    N036/N037 Reference leg temp 225 deg F
    RPV pressure 500 psig

    What is the expected configuration of both loops of Core Spray?


    A. Running with Outboard Injection valve, E21-F004 and inboard Injection valve, E21-F005 open and flow to the vessel.
    B. Running with Outboard Injection valve, E21-F004 and Inboard Injection valve, E21-F005 open but no flow to the vessel.
    C. Running with Min Flow valve, E21-F031, and Outboard Injection valve, E21-F004 open; Inboard Injection valve E21-F005 closed.
    D. Running with Min Flow valve, E21-F031, and Inboard Injection valve E21-F005 open; Outboard Injection valve, E21-F004 is closed
    C. Running with Min Flow valve, E21-F031, and Outboard Injection valve, E21-F004 open; Inboard Injection valve E21-F005 closed.
  36. The following conditions exist on Unit Two:

    RPV Level 80 inches
    RPV Pressure 1000 psig
    Drywell Pressure 1.0 psig
    All 4KV Buses Energized from Off-Site Power

    Emergency Depressurization is required. Direction has been given to Terminate and Prevent injection from Core Spray during the depressurization.

    When should the Core Spray Pump control switches be placed in STOP?


    A. Immediately when RPV level drops to LL3.
    B. 15 seconds after RPV level drops to LL3.
    C. Immediately when RPV pressure drops below the injection valve pressure permissive.
    D. 15 seconds after RPV pressure drops below the injection valve pressure permissive.
    B. 15 seconds after RPV level drops to LL3.
  37. A LOCA outside the primary containment caused reactor water level to lower below TAF; actions have been taken to mitigate the accident. Plant conditions are:

    Reactor pressure 50 psig
    Reactor level +180 inches
    Drywell pressure 1.5 psig
    Core Spray Pump A Overridden OFF
    Core Spray Pump B Injecting to maintain level

    Both Core Spray initiation white lights are illuminated. A loss of Off-site power occurs.

    Predict the Core Spray PUMP RESPONSE as the Diesel Generators energize the E buses.


    A. Both Core Spray Pumps (A/B) auto start 15 seconds after the E bus energization.
    B. Both Core Spray Pumps (A/B) remain deenergized until another LOCA signal is received.
    C. Core Spray Pump B auto starts 15 seconds after E bus energization; Core Spray Pump A remains off.
    D. Core Spray Pump B auto starts immediately after E bus energization; Core Spray Pump A remains overridden off.
    A. Both Core Spray Pumps (A/B) auto start 15 seconds after the E bus energization.


    ECCS initiation logic resets on a loss and restoration of power. => overridden pumps will restart if a LOCA signal remains (NRC 5, 10, 15 from re-energization). The logic is DC power, not E-bus.
  38. During accident conditions, the following sequence of events occurs:

    T= 0 seconds Drywell pressure rises above the scram setpoint
    T= 4 seconds Off-site power is lost
    T= 5 seconds Reactor pressure drops below 410 psig
    T = 14 seconds Diesel Generators energize their respective E Buses
    T = 16 seconds Reactor level drops below LL3

    The Core Spray Pumps will auto start at:

    A. T = 20 seconds.
    B. T = 24 seconds.
    C. T = 29 seconds.
    D. T = 31 seconds.
    C. T = 29 seconds.


    Sequential timing relays start 10 second time delay when LOCA signal present and E Bus has voltage. LOCA signal at T = 5 (if bus was energized, pump would start at T= 20). Bus energized at T = 14 so sequential timing relays time out at T = 24 (this starts RHR and initiates additional 5 second TD in Core spray logic. Core spray pump starts when additional 5 seconds elapses (T = 29). If LOCA signal had not previously sealed in, LL3 would initiate the sequence at T = 16 for a pump start of T = 31.
  39. During accident conditions, the following sequence of events occurs:

    T= 0 seconds Drywell pressure rises above the scram setpoint
    T= 4 seconds Reactor level drops below LL2
    T= 5 seconds Reactor pressure drops below the low pressure initiation setpoint for ECCS
    T = 14 seconds Diesel Generators at rated voltage & frequency

    The Core Spray Pumps will auto start at:

    A. T = 14 seconds.
    B. T = 19 seconds.
    C. T = 20 seconds.
    D. T = 29 seconds.
    C. T = 20 seconds.


    Sequential timing relays (15 seconds) will not initiate until a LOCA signal is present AND the associated E bus has power.
  40. Unit Two is in Mode 1. An operator is performing the CO DSR at 1200. The 0800 drywell leakage calculations were 1.3 gpm floor drain leakage and 3.5 gpm equipment drain leakage. At 1200, the difference in integrator readings is:

    Floor drain 816 gallons
    Equipment drain 960 gallons

    Which of the following is correct concerning Reactor Coolant System Operational Leakage Technical Specification limits?

    A. Technical Specification limits are met.
    B. Total leakage is greater than the 25 gpm limit.
    C. Unidentified leakage is greater than the 5 gpm limit.
    D. Unidentified leakage has increased greater than the 2 gpm limit since the previous reading.
    D. Unidentified leakage has increased greater than the 2 gpm limit since the previous reading.


    Floor drain leakage is 3.4 gpm (816 gal/240 minutes). Equipment drain leakage is 4.0 gpm (960 gallons/240 minutes). Total leakage is 7.4 gpm. Unidentified (floor drain) is <5 gpm and total leakage is <25 gpm, but unidentified increased by 2.1 gpm within the previous 4 hours which does not meet LCO 3.4.4.d.
  41. Unit One is at power performing PT-02.3.1a due to loss of position indication on a Suppression Pool to Drywell Vacuum Breaker. Drywell pressure was raised to 1.0 psig and the following one hour data taken using CAC-PI-2685-1 per step 7.9:

    Time Drywell Pressure

    0 min (initial) 1.0 psig
    10min 0.9 psig
    20 min 0.8 psig
    30 min 0.7 psig
    40 min 0.6 psig
    50 min 0.5 psig
    60 min (final) 0.4 psig

    Suppression chamber pressure was 0 psig during the entire one hour period. The results of PT-02.3.1a are:


    A. satisfactory. Acceptance criteria 6.1 and 6.2 are both met.
    B. unsatisfactory. Neither acceptance criteria 6.1 nor 6.2 was met.
    C. satisfactory. Acceptance criteria 6.2 was not met, but 6.1 was met.
    D. unsatisfactory. Acceptance criteria 6.1 was met, but 6.2 was not met.
    D. unsatisfactory. Acceptance criteria 6.1 was met, but 6.2 was not met.


    This PT verifies vacuum breakers are closed by meeting both of two criteria. First a differential pressure must be established between the drywell and suppression chamber. This criterion was established. Second the differential pressure must remain greater than one-half the differential pressure for one hour without makeup. Since the suppression chamber is vented the entire time (0 pressure), the final dp (0.4 psid) is less than one-half the initial dp (1.0 psid), therefore this second criteria is not met and the PT is unsat.
  42. Following a valid automatic initiation of Core Spray on Unit Two the RO verifies proper system response without taking any manual operator action. Subsequently, the following alarms are received:

    (A-03 6-6) Core Spray Pump 2B Overload
    (UA-18 6-1) BUS E4 4KV MOTOR OVLD

    Assume that both alarms are sealed in and that no operator action has been taken.

    Which ONE of the following describes the expected status of P603 control board pump motor red/green lights and stop signal sealed in white light for Core Spray Pump 2B?

    RED Light GREEN Light WHITE Light


    A. ON OFF OFF

    B. OFF ON OFF

    C. ON OFF ON

    D. OFF ON ON
    A. ON OFF OFF



    With alarms shown sealed in operator should be able to determine that the pump is still running with an overcurrent condition on the B phase. The APP allows continued operation with an overload condition as necessary under accident conditions. When pump breaker trips open (UA-18 6-1) BUS E4 4KV MOTOR OVLD clears and the pump breaker will indicate OPEN with green light lit. WHITE light is only lit if the pump has been overridden off with control switch while an initiation signal is present.
  43. A feedwater line break has occurred on Unit One (1). Plant conditions are:

    Reactor condition SHUTDOWN
    RPV level +75 inches
    RPV pressure 850 psig
    DW temperature 200°F
    DW pressure 7.5 psig
    Suppression pool level -15 inches

    Describe the expected configuration of both loops of Core Spray.


    A. Both CS pumps are running on minimum flow with the inboard injection valves open.
    B. Both CS pumps are running on minimum flow with the inboard injection valves closed.
    C. Neither CS pump is running. The minimum flow bypass valves and inboard injection valves are closed.
    D. Neither CS pump is running. The minimum flow bypass valves are open and the inboard injection valves are closed.
    D. Neither CS pump is running. The minimum flow bypass valves are open and the inboard injection valves are closed.
  44. The Core Spray system logic will automatically start the Diesel Generators and:


    A. Trip the drywell coolers and open the NSW to Vital Header valve, SW-V117.
    B. Trip the drywell coolers and close the NSW to Vital Header valve, SW-V117.
    C. Start the drywell coolers and open the NSW to Vital Header valve, SW-V117.
    D. Start the drywell coolers and close the NSW to Vital Header valve, SW-V117.
    A. Trip the drywell coolers and open the NSW to Vital Header valve, SW-V117.
  45. During normal power operation of Unit Two, an ECCS Division I Trip Cabinet Trouble alarm is received. Investigation shows that both power supplies to the trip cabinet (XU-63) have failed and all associated trip unit meters indicate downscale with no trip lights lit.

    A DBA LOCA then occurs resulting in Reactor water level rapidly dropping below the Top of Active Fuel and rapid Reactor depressurization.

    How will Core Spray 2A and RHR LPCI Loop 2A respond?

    A. Core Spray 2A initiates, LPCI Loop 2A fails to initiate.

    B. Core Spray 2A and LPCI Loop 2A both fail to initiate.

    C. Core Spray 2A fails to initiate, LPCI Loop 2A initiates.

    D. Core Spray 2A and LPCI Loop 2A will both auto initiate.
    D. Core Spray 2A and LPCI Loop 2A will both auto initiate.


    Since all initiation logic is one out of two twice initiation will occur (i.e. Core Spray initiation on level has two inputs from Div I and two from Div II trip cabinet) since power is not lost to the initiation logic which has a separate power supply. (Note - c would be correct if power were lost to the initiation logic rather than the trip cabinets) (NEW)
  46. With the Core Spray system in standby alignment, a break occurs in the injection line between the reactor vessel penetration and the core shroud. The break would expose the low pressure side of the Core Spray Sparger Line Break Detection instrument to the __________ pressure of the region outside of the shroud. The break would be sensed as a __________ differential pressure and would activate a Control Room annunciator.
    lower; less negative.

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