| Event, or operator comment | Underlying cognitive processes (inferred by analysis) |
| feed-flow/ steam-flow mismatch in Steam Generator 'A' | INFORMATION AVAILABLE |
| COGNITIVE INFERENCES BY OPERATORS | |
| air radiation alarms, plus rapid decrease of pressuriser level and pressure, plus mismatch, unequivocally confirm rupture, probably in Steam Generator 'A' | Interpretation |
| pressuriser level and pressure will continue
to decrease. low pressuriser pressure will cause :- automatic reactor trip (shut-down)- automatic safety water injection | Expectations |
| minimise effect of reactor trip on power grid (sudden pull-off of power not desirable) | Intention |
| notify grid controller of planned reduction. commence load reduction. | ACTIONS |