As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING CLIMB, THE NR 1 THRUST REVERSER INTRANSIT LIGHT ILLUMINATED FOLLOWED BY A SEVERE AIRCRAFT YAW. THE CREW FOLLOWED COM PROCEDURE AND SHUT DOWN THE NR 1 ENGINE. FUEL WAS DUMPED AND THE AIRCRAFT RETURNED TO IAD LANDING WITHOUT INCIDENT. MAINTENANCE PLACED THE NR 1 THRUST REVERSER ON MEL 78-1A. AN EXCESSIVE MANEUVER/OVERLOAD CHECK WAS COMPLETED PER AMM 05-51-02 WITH NO DAMAGE NOTED.