Rod Ctrl Flashcards
What is the C-1 Conditional?
Intermediate Range Rod Stop
- Stops AUTO and MANUAL Rod Withdraw
- 1/2 - IRNI > 18% (16%)
- Manually blocked above P10 (≥ 10% PR)
- Unblocked below P10
What is the C-2 Conditional?
Power Range Rod Stop
- Stops AUTO and MANUAL Rod Withdraw
- 1/4 PR > 103%
- Blocked when ROD STOP BYPASS selected to alarming channel
What is the C-3 Conditional?
OTΔT Rod Stop
- 2/4 PRNI 3% < trip setpoint
- Stops AUTO and MANUAL rod withdraw
- No Block!
What is the C-4 Conditional?
OPΔT Rod Stop
- 2/4 PRNI 3% < trip setpoint
- Stops AUTO and MANUAL rod withdraw
- No Block!
What is the C-5 Conditional?
Turbine Power Interlock
- MPC-253 < 15%
- Stops AUTO ONLY rod withdraw
- No Block!
What is the C-11 Conditional?
Control Bankd D Rod Stop
- Ctrl Bank D at 229 steps
- Stops AUTO ONLY rod withdraw
- No Block!
What are the Rod Ctrl Inputs?
- Auctioneered High Tave
- Auctioneered High PR NI
- MPC-253, Turbine 1st Stage Impulse #
What is the Rod Control System designed to do?
Maintain Tavg within 5°F of program and restore Tavg within 1°F following:
- 10% step load change
- 5%/min ramped load change
- 50% step load change with steam dumps (40% dumps)
Where are the MG Sets powered from?
11/21A and 11/21D busses
What will trip the CRD MG Set Output Bkrs?
- Overvoltage
- Overcurrent
- Reverse Current
- Supply Bkr Open
What will trip the CRD MG Set Supply Bkrs?
- Load Con
- Overcurrent
If there is an urgent failure in the power cabinet, what is affected?
Rod Control
Rod groups for that cabinet
If there is an urgent failure in the logic cabinet, what is affected?
ALL RODS
What happens if you have an urgent failure on a Logic or Power Cabinet?
Stops all rod motion by de-energizing lift coil and energizing stationary and movable gripper
During a power escalation, Control Bank C – Group 1 Rod B-8 dropped. At the time the event occurred, reactor power was 48% and Rod B-8 was fully withdrawn.
While recovering the rod per 1-OHP-4022-012-005, Attachment B, “Recovery By Positioning Single Rod,” a Rod Control Urgent Failure alarm occurred.
Why was this alarm actuated?
All Control Bank C – Group 2 rod lift coil disconnect switches are open.
Given the following conditions:
* Unit 1 is at 100% power
* A loss of power to CRP-3 occurs
What is the effect on the Rod Position Indication (RPI) system and the procedural action necessary, if any?
RPI indications are lost. Dispatch an operator to manually align backup power supply (via ELSC) to energize the RPI Cabinets. Operation is allowed since RPI has been restored.
What does the Variable Gain Unit do?
Increases the output at low power because reactivity change at lower power has a smaller effect on power than at high power