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1
Q

LCO 3.3.1 “Reactor Protective System (RPS) Instrumentation” requirements

A

4 RPS trip units, associated instrument channels, and associated Zero Power Mode (ZPM) Bypass removal channels for each Low Steam Generator Level Trip and each Low Steam Generator Pressure Trip shall be operable.

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2
Q

LCO 3.3.1 “Reactor Protective System (RPS) Instrumentation” applicability

A

Modes 1 & 2, and Modes 3-5 with more than 1 full-length control rod capable of being withdrawn and PCS boron concentration less than refueling boron concentration.

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3
Q

LCO 3.3.1 “Reactor Protective System (RPS) Instrumentation” required actions if 1 or more ZPM Bypass Removal channels inoperable.

A

IMMEDIATELY
Remove the affected ZPM Bypasses
OR
Declare affected trip units inoperable

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4
Q

LCO 3.3.1 “Reactor Protective System (RPS) Instrumentation” required actions if 1 or more functions with 2 RPS trip units or associated instrument channels inoperable.

A

WITHIN 1 HOUR

Place one unit in trip

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5
Q

LCO 3.3.3 “Engineered Safety Features (ESF) Instrumentation” requirements

A

4 ESF Bistables and associated instrument channels for each Steam Generator Low Pressure Signal shall be operable

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6
Q

LCO 3.3.3 “Engineered Safety Features (ESF) Instrumentation” applicability

A

Modes 1-3
Not required in Modes 2 & 3 when all MSIVs are closed and deactivated, and all MFRVs and MFRV Bypasses are either closed and deactivated, or isolated by closed manual valves.

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7
Q

LCO 3.3.4 “Engineered Safety Features (ESF) Logic and Manual Initiation” requirements

A

2 ESF Manual Initiation and 2 ESF Actuation Logic channels and associated bypass removal channels shall be operable for each Steam Generator Low Pressure Signal

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8
Q

LCO 3.3.7 “Post Accident Monitoring (PAM) Instrumentation” requirements

A

The PAM instrumentation for each Steam Generator Water Level and Pressure shall be operable

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9
Q

LCO 3.3.7 “Post Accident Monitoring (PAM) Instrumentation” applicability

A

Modes 1-3

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10
Q

LCO 3.3.8 “Alternate Shutdown System” requirements

A

The Alternate Shutdown System function Steam Generator Pressure and Wide Range Level shall be operable

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11
Q

LCO 3.3.8 “Alternate Shutdown System” applicability

A

Modes 1-3

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12
Q

LCO 3.7.1 “Main Steam Safety Valves (MSSVs)” requirements

A

23 MSSVs shall be operable with lift settings of 1000 psia, 1020 psia, and 1040 psia

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13
Q

LCO 3.7.1 “Main Steam Safety Valves (MSSVs)” applicability

A

Modes 1-3

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14
Q

LCO 3.7.2 “Main Steam Isolation Valves (MSIVs)” requirements

A

2 MSIVs shall be operable

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15
Q

LCO 3.7.2 “Main Steam Isolation Valves (MSIVs)” applicability

A

Mode 1

Modes 2 & 3 except when both MSIVs are closed and de-activated

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16
Q

LCO 3.7.4 “Atmospheric Dump Valves (ADVs)” requirements

A

1 ADV per steam generator shall be operable

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17
Q

LCO 3.7.4 “Atmospheric Dump Valves (ADVs)” applicability

A

Modes 1-3

Mode 4 when steam generator is being relied upon for heat removal

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18
Q

What is the purpose of the MSIVs?

A
  • Isolates steam generators to prevent uncontrolled release of radioactivity to environment in the event of a steam generator tube rupture
  • prevent blowing down the good steam generator into containment in the event of a steam line rupture in containment
  • prevent uncontrolled cooldown of the PCS
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19
Q

What are the power supplies for the MSIVs?

A

Left channel solenoids - D11-1
Right channel solenoids - D21-1
Each MSIV has 2 solenoids (1 air supply, 1 vent) from each channel

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20
Q

What is the process for latching the MSIVs?

A
  • Handswitch in control is taken to open, which de-energizes the solenoids, allowing manual latching of MSIV.
  • Both handswitches need to be in open to open MSIV. This allows latching all vents closed and air supplies open
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21
Q

What happens when either MSIV handswitch is taken to close?

A

Both MSIVs close because solenoids energize, causing air supplies to close, and vents to open

22
Q

What is a precaution to be taken after an MSIV handswitch is taken to close?

A

Take handswitch back to open to de-energize the solenoids to prevent them from burning up. Solenoids won’t reposition at this point because they are unlatched.

23
Q

What are the automatic actions that occur on steam generator low pressure, and what is the setpoint?

A
  • 500 psia (2/4 logic) in either steam generator
  • causes both MSIVs to close
  • MFRV and MFRV Bypass on only the affected steam generator go closed
24
Q

When can MSIV closure on low steam generator pressure be blocked?

A

When 3 of 4 steam generator pressure channels between 512 and 548 psia

25
Q

Why is MSIV closure on low steam generator pressure block used?

A

Allows the MSIVs to remain open while using the TBV to cool down and conserves water inventory that is lost to atmosphere when the ADVs are used

26
Q

When does MSIV closure block clear?

A

When 2 of 4 channels are above 550 psia steam generator pressure

27
Q

How can the TBV be used to cool down when the MSIVs are closed?

A

In an emergency, MSIV Bypass Valves can be opened

28
Q

How does the main steam system respond to CHP?

A
  • 2/4 logic closes both MSIVs
  • if only 1 channel actuates, only its associated MFRV and MFRV Bypass close (left channel closes A S/G feed valves, right channel closes B S/G feed valves). So you need both channels to actuate to isolate feed to both S/Gs
29
Q

What is the function of the ENABLE/DEFEAT keyswitch next to the MSIV control switches?

A

Allows you to disable the turbine trip on MSIV out of position

30
Q

What are the MSIV Bypass Valves used for?

A
  • normal use is for secondary side warm up and pressurization during plant startup
  • can be used in an emergency to cool down using the TBV instead of the ADVs
31
Q

When must the MSIV Bypass Valves be closed, and why?

A

Above 2% reactor power because there is no auto closure for these valves on CHP or S/G low pressure

32
Q

What are the power supplies for the MSIV Bypass Valves?

A

MCC-3 for both

33
Q

What is the steam flow capacity of the ADVs?

A

7.5% total steam flow per valve (30% total)

34
Q

What is the motive force for operation of the ADVs?

A
  • instrument air
  • air accumulator
  • nitrogen backup from bulk nitrogen tank
35
Q

What are the power supplies for the ADV solenoids?

A

CV-0779/0781 - D11-1
CV-0780/0782 - D21-1
Each DC power supply powers 1 valve on each steam line

36
Q

How do the ADVs fail on a loss of DC power?

A

closed, and light indication goes away

37
Q

How are the ADVs controlled?

A

All 4 ADVs are controlled by 1 controller in the control room, which sends its signal to C-33 through 2 controllers to the ADVs

38
Q

Where are the ADV controllers powered from?

A

All 3 powered from Y-10

39
Q

What are the modes of operation for the ADV controller?

A

Auto - upon turbine trip, contacts close in the ADV circuitry, then the controller modulates ADVs based on Tave.
Manual - operator controls output with slide bar

40
Q

How does the ADV quick open mode operate?

A

With a turbine trip and Tave > 556.9 F, ADVs and TBV get a quick open signal and stay full open until Tave < 556.9 F

41
Q

How does the ADV modulate mode operate?

A

With a turbine trip and Tave < 556.9 F, ADVs and TBV throttle based on Tave.
556.9 F = full open
535 F = full closed
If below 535 and rising, valves will start throttling open at 540 F

42
Q

What is the power supply for the TBV?

A

Controller is from Y-01

Solenoid valves are from D11-1

43
Q

What is the steam flow capacity of the TBV?

A

4.5% total steam flow

44
Q

What controls the TBV?

A

Receives signal from ADV controller and its own controller. The controller that is putting out the largest open signal will control the TBV

45
Q

What are the modes of operation for the TBV controller?

A

Manual - operator controls output with slide bar
Auto - controls S/G pressure at a selected setpoint (normally 900 psia). Valve is full open when S/G pressure is 5 psia above setpoint, and full closed when 5 psia below setpoint. TBV doesn’t need a turbine trip to operate, but S/G pressure is about 770 psia at full power, so TBV is receiving a full closed signal

46
Q

What is the TBV interlock with condenser vacuum?

A

TBV will auto close, or will not open if condenser vacuum < 5” Hg

47
Q

How does the TBV fail?

A

Fails closed on loss of air or D11-1

48
Q

What function does the TBV accumulator serve?

A

Allows TBV to quick open without air pressure, but it won’t be able to modulate

49
Q

How many code safeties do we have?

A

24 (12 per steam generator)

50
Q

What are the code safety lift setpoints?

A

4 @ 1000 psia
4 @ 1020 psia
4 @ 1040 psia

51
Q

Why are the code safety lift setpoints staggered?

A

To prevent chatter

52
Q

Where in the system are the main steam line rad monitors located?

A

Located between the MSIVs and ADVs, so they won’t be able to detect releases from the ADVs

Advanced Systems (36 decks)

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