What was found
(CAN) A STRONG SMELL OF RAW KEROSENE PERMEATED THROUGH THE FLIGHT DECK AND CABIN AFTER BOARDING FLIGHT. CAPTAIN DEPLANED PASSENGERS AS A PRECAUTION ALLOWING MAINTENANCE TIME TO INVESTIGATE THE ROOT SOURCE OF FUEL SMELL. THE F/O AND THE S/D COMPLAINED OF HEADACHES AS A RESULT OF THE EXPOSURE TO THE FUMES. MAINTENANCE PERFORMED INSPECTION OF ACFT AND DETERMINED THE ACFT WAS SERVICEABLE. ALL THE OPERATING CREW TERMINATED FLYING. DISCUSSIONS WITH DUTY PILOT/MOC AND OPERATING FLIGHT CREW WERE CONDUCTED. APU AND PACKS RUN FOR SEVERAL HOURS. UNABLE TO DUPLICATE. ENGINE RUNS CARRIED OUT. UNABLE TO DUPLICATE. NO KEROSENE/FUEL ODOR PRESENT ON AIRCRAFT. CONSIDERED SERVICEABLE.