CEDMCS Flashcards

1
Q

To where does CEDMCS send signals on a Reactor Trip?

A
Main Turbine for tripping
DFWCS for RTO
SBCS for QOB
ERFDADS for indications
SRP Downtown
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2
Q

How long does it take to drop rods 90%?

A

4 seconds

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3
Q

What powers the CEDMCS cooling fans?

A

NGN-L17

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4
Q

How many CEAs are in a subgroup?

A

4

Except the one that has 5

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5
Q

What does the Plant Computer supply to CEDMCS?

A
Upper Group Stop
Lower Group Stop
Sequential Permissive
Upper Sequencing Limit
Lower Sequencing Limit
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6
Q

What does RRS provide to CEDMCS?

A

Rate and Direction Signals

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7
Q

How many reed switch assemblies and voltage ladders are there per CEA?

A

2

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8
Q

How far apart are the reed switches on a CEA?

A

1.5 inches

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9
Q

How far is one step for a CEA?

A

0.75 inches

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10
Q

At how many steps does the Upper Electrical Limit occur?

A

200 steps

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11
Q

At how many steps does the Lower Electrical Limit occur?

A

1 step

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12
Q

What functions does the Dropped Rod Contact serve in CEDMCS?

A
  • The rod bottom light on B04

- Tells the Plant Computer to zero the pulse counters.

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13
Q

If the Upper Latch Coil on a CEA is at a reduced voltage, is it holding or latching/moving?

A

Holding

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14
Q

What does CWP stand for?

A

CEA Withdraw Prohibit

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15
Q

What does AMI stand for?

A

Automatic Motion Inhibit

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16
Q

What does AWP stand for?

A

Automatic Withdraw Prohibit

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17
Q

Which rod inhibition can be bypassed?

A

CWP

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18
Q

When is a CWP enacted?

A
2/4 High Pressurizer Pressure Pre-Trip
2/4 Low DNBR Pre-Trip
2/4 High LPD Pre-Trip
RPCB
CEA Misalignment from CPCs/CEACs
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19
Q

When is an AMI enacted?

A
  • > 5% deviation between redundant indicators for TLI, Reactor Power, and Tave when AVERAGE is selected on RRS
  • Whenever Reactor Power < 15%
  • When TLI < 15% and Reactor Power is below the lesser of
    - SBCS availability + TLI or…
    - AMI threshold setpoint.
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20
Q

When is an AWP enacted?

A
  • Tave > Tref by 6F
  • Tc > 575F
  • SBCS Demand
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21
Q

What are the power supplies to the CEDMCS MGs?

A

NGN-L03

NGN-L10

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22
Q

What is the voltage output of the CEDMCS MGs?

A

240V

23
Q

Is one CEDMCS MG enough for control rod operation in Manual Group?

A

No. But it is enough for Manual Individual operation

24
Q

When does SPS open the CEDMCS MG output contactors and open the Trip Circuit Breakers?

A

2409 psia

25
Q

Where can you see Trip Circuit Breaker position indication?

A

PPS
SPLA Cabinet
Locally

26
Q

Are the Trip Circuit Breakers safety related?

A

Yes, but power through them is not

27
Q

From where can you open the Trip Circuit Breakers?

A
  • B05
  • Locally
  • PPS Cabinets (testing)
  • SPLA Cabinets (testing)
28
Q

From where can you close the Trip Circuit Breakers?

A
  • PPS Cabinets (normal)
  • Locally (testing)
  • SPLA Cabinets (not OPS)
29
Q

What, specifically, happens to the Trip Circuit Breakers on a trip?

A

They are tripped by the concurrent actuation of both shunt trip (energize to trip) and under voltage (de-energize to trip) devices.

30
Q

What is the purpose in the CEDMCS MG flywheels?

A

They provide stored energy for 1 second of operation with no power.

31
Q

What causes the Continuous Gripper High Voltage alarm?

A

A loss of subgroup logic power

32
Q

If a Continuous Gripper High Voltage alarm is received, what must be done?

A

The affected subgroup must be placed on the hold bus within 10 minutes or the CEDM coil could burn up resulting in a dropped CEA

33
Q

What results from any CEA subgroup being placed on the Hold Bus?

A
  • CEDMCS Trouble Alarm

- Rods on Hold Bus won’t move in Manual or Auto

34
Q

When rods move IN in MANUAL, what speed do they move?

A

30”/min

35
Q

When rods move OUT in MANUAL, what speed do they move?

A

30”/min

36
Q

When rods move IN in AUTO, what speed do they move?

A

3”/min or 30”/min

37
Q

When rods move OUT in AUTO, what speed do they move?

A

3”/min

38
Q

What is the trip logic for the Undervoltage Relays which monitor the CEDMCS bus voltage?

A
  • 2/4 logic

- each relay will trip at 180V

39
Q

When the trip logic is met for the CEDMCS UV Relays, what happens?

A
  • Turbine Trip to EHC
  • RTO to DFWCS
  • PC and RK annunciators
  • Sequential Trip/Coastdown Trip signal to Main Generator
  • QOB to SBCS for X valves on Low Tave and RX TRIP combo
40
Q

From where do the Digital Group and Individual Position Indication on B04 come?

A

Pulse counts

41
Q

What does Manual Sequential require to work?

A

The Plant Computer

42
Q

What alarm will be received if an Out of Sequence from the Plant Computer is detected?

A

CEA TECH SPEC VIOLATION

43
Q

What will bring in the CEDMCS TRBL alarm?

A
  • CGHV
  • MG Set Overload
  • Continuous CEA motion
  • Any Subgroup on the Hold Bus
  • local alarms
44
Q

What will bring in the Continuous Motion Alarm?

A

30 seconds in high speed

60 seconds in low speed

45
Q

What will bring in the CEA TECH SPEC VIOLATION alarm?

A
  • Major/Minor deviations in CEA positions

- Out of Sequence condition

46
Q

What happens to CEDMCS on a loss of PNA or PNB?

A

The associated RTCBs open (A and C or B and D) but power is maintained to the CEAs

47
Q

What happens to CEDMCS on a loss of PNC?

A
  • RTCBs A and C open
  • Pac-Man on Core Mimic
  • Pulse Counters for the lit Rod Bottom Lights will zero
  • MI only method available for moving the remaining 1/4 of the rods
48
Q

What happens to CEDMCS on a loss of PND?

A
  • RTCBs B and D open
  • Reverse Pac-Man on Core Mimic
  • Pulse Counters for the lit Rod Bottom Lights will zero
  • MI only method available for moving the remaining 3/4 of the rods
49
Q

What happens to CEDMCS on a loss of NNN-D11 or NNN-D12?

A

Nothing

50
Q

What happens to CEDMCS on a loss of NNN-D11 and NNN-D12?

A
  • All CEAs will drop into the core.
  • No Core Mimic, UEL, or LEL lights (during a Station Blackout, theres no easy way to verify that the rods are on the bottom)
51
Q

What happens to CEDMCS on a loss of the Plant Computer?

A
  • Only methods available for moving rods are MI and MG.
  • Rods will not automatically stop at UGS and LGS
  • Pulse counters are lost
  • PDIL alarms are lost (out-of-sequenc, deviation, and exercise limit)
52
Q

What happens to CEDMCS on a loss of CEDM Cooling?

A

CEDM Coils may be damaged if cooling is not restored or the coils de-energized within 40 minutes if RCS temperature is > 300F

53
Q

What happens to CEDMCS on a loss of Aux Building HVAC?

A

Could cause rods to slip, drop, or move around randomly as the CEDMCS Cabinet Room heats up.

54
Q

What does LCO 3.1.5 say?

A
  • All full strength rods have to be operable
  • All full and part strength rods aligned within 6.6” in their group - of not, then reduce power and restore alignment
  • if 2 or more CEAs are > 9.9” = Trip immediately
  • if 1 or more CEAs are untrippable = M3 in 6 hrs