INRAT-H case studies
INRAT-H · Put your knowledge to work in context.
INRAT-H, also described as the Human Factors paper within the International Nuclear Reactor Operator License Examination family, is a professional knowledge assessment focused on how people actually perform inside a nuclear control room. It is aimed at licensed operators, senior reactor operators, shift supervisors, simulator instructors, human factors practitioners, and regulator or utility staff who review operating events and crew performance. The INRAT-H case studies are 5 cases and about 2,447 words.
1Night Shift Alarm Flood After a Sensor Drift
At 02:40 on the third consecutive night shift, the unit is at 92% power. A feedwater flow transmitter has been drifting for two weeks, and maintenance deferred recalibration because the spare was on backorder.
496 words, about 2 min2Handover Omission During a Load-Following Maneuver
A control room is executing a planned power reduction from 100% to 70% for grid demand. The maneuver is routine and the outgoing shift lead gives a five-minute verbal handover in a noisy room while the incoming lead is still logging in.
488 words, about 2 min3Procedure Use When the Step Does Not Fit the Plant State
An emergency operating procedure instructs the operator to reset a specific signal and then verify a valve lineup. During a transient, the operator finds the signal already reset by an automatic action and the valve in a position the procedure does not describe.
486 words, about 2 min4Training Records Show Competence the Simulator Does Not
A licensed reactor operator has a complete training file: all required simulator hours signed off, annual requalification passed, and no failed evaluations in six years. During a routine simulator session observed by a new training instructor, the operator performs well on scripted evolutions but freezes when the instructor introduces an unscripted compound failure-loss of a feedwater pump combined with a stuck-open relief valve.
488 words, about 2 min5Near-Miss Reporting After a Maintenance Error
During a refueling outage, a technician installs a temporary blind flange on the wrong line. The error is caught 20 minutes later by a second technician doing an independent walkdown.
489 words, about 2 min