IRE (Exam 2)

Question 1

How many control Rods?

Answer 1

53
5 shutdown banks, 4 control banks

Question 2

Shut down bank makeup

Answer 2

5 banks (28 Rods)
A - 2 groups
B - 2 Groups
C - 1 Groups
D - 1 Group
E - 1 Group

Question 3

Control bank makeup

Answer 3

4 banks (25 rods)
A - 2 Groups
B - 2 Groups
C - 2 Groups
D - 2 Groups

Question 4

Purpose of Logic cabinet

Answer 4

-Generates the signals to step the rods and send to the power cabinets
-Rod group, direction and rate of movement
-Maintains proper bank overlap and group alignment

Question 5

What are rod speeds for each bank select switch position?

Answer 5

Auto - Based on IRX Program
Manual - 48 steps/min
Selected bank (1AC,2AC,1BD,2BD) - 48 steps/min
Selected bank (SCDE) - 64 steps/min

Question 6

Rod Speed Program Speeds

Answer 6

-Determined from difference between Tavg and Tref
-8-72 steps/min
-Used when CRD bank select switch in auto
- 8 steps/min from 1.5F to 3F error
- rises linearly from 3F error to 5F error (8-72 steps/min)
- 40 steps/min at 4F error

Question 7

At what temperature error do rods start to move? When do they stop?

Answer 7

+-1.5F error
+-1F error

Question 8

What does the bank overlap unit do?

Answer 8

-Directs commands from the master cycler to the proper slave cycler
-Counts up and down pulses
-Remembers which group and bank moved and in which direction
-Interrupts power flow within non-sequenced power cabinets
-Bypassed when bank select switch is not in manual or auto

Question 9

What does the master cycler do?

Answer 9

-Selects which group in a bank will be moved
-Triggers the appropriate slave cycler for the group to be moved
-Tells bank overlap unit when a cycle is complete

Question 10

What do Logic Cabinet Alarms Cause?

Answer 10

Non-Urgent alarm - Rod motion not impacted
Urgent Alarm - Prevents any rod motion in auto or manual until problem is corrected and alarm reset button is pressed. Can move rods in individual bank position without resetting alarm.

Question 11

Logic Cabinet Alarm causes?

Answer 11

Non-urgent:
-Loss of 1 of the 6 internal DC power supplies
Urgent:
-Pulser/Oscillator failure
-Slave cycler failure (Go no cycle, cycle no go, go while cycle)
-Loose or removed circuit card

Question 12

What are rod control power and logic cabinet power supplies?

Answer 12

-MG Sets (Stepped down to 120VAC)
-120VAC RPB
**Auctioneered high supply is used
-120VAC converted to DC

Question 13

What DC hold power supplied to?

Answer 13

Stationary Gripper coils
-125VDC used to assure latching of the stationary gripper
-70VDC used to hold the gripper without overheating the coils

Question 14

What do Power cabinet alarms cause?

Answer 14

Non-Urgent:
-Rod motion not impacted
Urgent:
-Prevents any rod motion in the power cabinet with the urgent failure
-In cabinets without a failure, can move rods in the individual bank position (If rod control in auto or man at occurrence, must select a bank and depress alarm reset button)

Question 15

Power cabinet alarm causes?

Answer 15

Non-Urgent:
-Loss of 1 of the 4 internal DC power supplies
Urgent:
-Regulation Failure Detector
-Phase failure detector
-Logic error detector
-multiplexer error detector
-Loose or missing circuit card

Question 16

What is the gripper sequence for rod withdrawal?

Answer 16

1 - Movable gripper energizes and engages movable latch
2 - Stationary gripper deenergizes and disengages stationary latch
3 - Lift coil energizes and raises movable gripper and rod
4 - Stationary gripper energizes and engages stationary latch
5 - Movable gripper deenergizes and disengages movable latch
6 - Lift coil deenergizes and lowers movable gripper

Question 17

MG set power supplies?

Answer 17

A - LXC
B - LXD
**One mg set can handle full load

Question 18

Pulse to Analog convertor purpose

Answer 18

-Converts pulse data from the logic cabinet to an analog signal
-Analog signals used for rod insertion limit computer, OAC and C-11 rod stop
-Readout can be changed manually

Question 19

What do step demand counters Indicate? Does it tell you where the rod actually is?

Answer 19

-Indication is driven by pulses generated in the rod control logic cabinet. Pules are counted and increments the displays steps demanded up or down accordingly
-No, they only tell demand position based on pulses

Question 20

What rod speed demand is show on the gauge for shutdown banks C,D and E?

Answer 20

0 steps/min

Question 21

What does “Rod Pos Start Up” button reset?

Answer 21

-Demand position counters
-Master cycler
-Slave cycler
-BOU
-P/A Convertor

Question 22

At what step position will the next bank or rods start to move

Answer 22

116 Steps removed

Question 23

What is total overlap for 2 rod banks

Answer 23

Max out position -116 steps
**Typically 112 steps