Abnormal and emergency operations
Abnormal and emergency operations
This domain tests recognition, classification, immediate actions, and use of abnormal and emergency procedures. The exam expects you to act on symptoms, not wait for a diagnosis, when an immediate action is required.
Core rules
- Enter the correct procedure at the correct entry condition. A reactor trip, safety injection, or containment isolation has immediate actions that come before troubleshooting.
- Protect critical safety functions: reactivity control, reactor coolant inventory and pressure, core heat removal, containment integrity, and electrical availability.
- Do not reset a trip or isolate a safety system until the cause is understood and the procedure authorizes it.
- Use the command structure: announce actions, use repeat-backs, and keep the supervisor informed.
Worked example
Indications show falling reactor coolant pressure, rising containment pressure, and rising containment radiation. Treat this as a possible loss-of-coolant accident. Perform the immediate actions in the plant emergency procedure: trip the reactor and turbine if not already tripped, start safety injection as directed, start auxiliary feedwater, and verify containment isolation. Diagnose only after immediate actions are complete; do not delay safety injection to find the leak.
Traps
Resetting alarms to clean up the board; applying an abnormal procedure after an emergency procedure entry condition exists; assuming one instrument is correct; and taking manual control before verifying the automatic action.