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Exam 3 > Rod Control > Flashcards

Rod Control Flashcards

1
Q

State functions of the Rod Control System

A

Moves control rods in responds to signals from the Reactor Control Unit (RCU)
Maintians RCS Tave within +- 1.5F of programmed value when >15% turbine power (C-5) for the following:
+- 10% step load change
+- 5%/ minute ramp load changes
+- 50% step decrease with steam dumps

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2
Q

What happens when both bypass breakers are racked in and closed

A

Both breakers open tripping the reactor.

This is independent of RPS

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3
Q

State the inputs for the Rod Control Unit

A 
Tref - Tave
NI power vs actual turbine power - PMM
Total error = Tref - Tave + PMM
Tave varies with RX power (557 - 589.1)
Polarity of error determines direction
magnitude of error determines speed
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4
Q

State the speed of rods in manual

A

Shutdown: 64
Control: 48

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5
Q

State speed of rods in Auto

A

1.5F - 3F: 8 steps/min
>3F - 5F: 32 steps/min/F change
>5F: 72 Steps/min

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6
Q

State C-1

A

20% IR equiv. current (1 of 2)
Blocks manual and auto rod withdrawal
resets at 10% (2 of 2)

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7
Q

State C-2

A

103% power range (1 of 4)
Blocks manual and auto rod withdrawal
A channel can be bypasses (coincidence becomes 1 of 3) using Rod Stop Bypass Switches
resets at 101% (4 of 4)

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8
Q

State C-5

A

15% Turbine power (1 of 1)
Fed from PT-505
enables auto rod withdrawal above 15% turbine power
resets at 13%

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9
Q

State C-11

A

Stops AUTO rod withdrawal for Control Bank D at 223 Steps

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10
Q

State Rod Control response when PR channel Fails High

A

PR>Turbine power
PMM error inserts rods
Actual Tave decreases
Tref>Tave calls for rod withdrawal
C-2 high flux (103% power) stops rod withdrawal
Need to place rods in MAN to stop insertion

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11
Q

State Rod Control response when PR channel Fails Low

A

No effect NI input to PMM s auctioneered high

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12
Q

State Rod Control response when Loop Tave fails low

A

AveTave < Tref

Rods will withdraw if: Control bank D is below C-11 block of 223 or C-2 of 103%

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13
Q

State Rod Control response when PT-505 fails high

A

Turbine power > auctioneered high PR

PMM error withdrawals rods if: Bank D is below 233 (C-11) and Power remains below C-2 (103%)

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14
Q

State Rod Control response when PT-505 fails low

A 
Auctioneered high PR > Turbine power
PMM error inserts rods
Tref drops to no load value of 557
Rods inserts at 72 steps/min
need to place rods in manual to stop insertion
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15
Q

State Rod Insertion Limit (RIL) basis

A

Ensures adequate SDM
Ensures core power distribution limits are maintained
Ensures rod ejection accident remains within design analysis

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16
Q

State P/A converter relationship with regards to the RIL

A

Provides VAS alarm RIL low when within 10 steps
Provides VAS alarm RIL low-low when at or below RIL
Calculates the RIL based on Delta-T 0-60F (auctioneered high Delta-T) and 0-100% power

17
Q

State T.S. 3.1.1.1 (Boration Control) LCO and Action

A

The Shutdown margin for 4 loop operation shall be >= the limit specified in the COLR
MODE: 1-4
Immediately initiate and continue boration at >=30GPM until the SDM is restored

18
Q

State T.S. 3.1.1.2 (Boration Control - Shutdown) LCO and Action

A

The SDM shall be >= the limit specified in the COLR. Additionally, the RCS Boron concentration shall be >= the concentration of the COLR when the RCS loops are in a drained condition
MODE: 5
Immediately initiate and continue Boration at >= 30GPM until the SDM is restored

19
Q

State T.S. 3.1.3.1 (Group Height) LCO and Action

A

All control Rods shall be operable and positioned within +/- 12 steps (DRPI) of their groups step counter demand positions
MODE: 1 and 2
Verify SHUTDOWN MARGIN within 1hr and be in HOT STANDBY within 6 hours

20
Q

State T.S. 3.1.3.5 (Moveable Control assemblies) LCO and Action

A

All shut down rods shall be fully withdrawn as specified in the COLR
MODE: 1 and 2
With a maximum of 1 shutdown rod not fully withdrawn, within 1HR either:
- Fully withdraw the Rod or
- Declare the Rod inoperable and apply 3.1.3.1

21
Q

State the function of the slave cycler and where it sends signals to

A 
Provides the control signals, current orders, to gate its respective power cabinets SCR's
Provides demand signals to:
- MPCS
- MCB step Counters
- P/A converter
22
Q

Discuss Logic cabinet Urgent failure

A

Stops all rod motion
Protects against dropping a rod
Alarm must be manually reset

23
Q

Discuss Power Cabinet Urgent failure

A

Stops rod motion for that cabinet only
Protects against dropping a rod
Rods in the unaffected banks may be moved in individual bank mode

24
Q

Discuss components affected by Rod Control Start up switch

A 
Resets:
Master cycler counter
slave cycler counters
Bank overlap counter
P/A Counter
All internal memory and alarm circuits
25
Q

State the problem with pushing Rod Control Start up switch at power

A

Group step counters goto zero causing demand/DRPI rod deviattion alarms
Bank overlap units selects Bank A for Motion
RIL alarm on all banks

Exam 3 (7 decks)

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