As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
A DIESEL ODOR WAS IN THE CABIN SHORTLY AFTER TAKEOFF AND THE ACFT RETURNED TO FIELD. MX PERFORMED TSM 05-50-00-810-831-A AND FOUND FUEL LEAKING FROM THE RT CENTER FUEL TANK DRAIN VALVE. CLEANED RESIDUAL FUEL FROM FUSELAGE AREA AND APU INTAKE AREA. RAN APU AND BOTH PACKS NO ODORS NOTED. REPLACED THE SUMP DRAIN VALVE.