As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
HAD INDICATION OF NR 1 ENGINE FIRE AT FL 250. ACCOMPLISHED ENGINE FIRE CHECKLIST IAW QRH. SHUTDOWN ENGINE, ACTIVATED FIRE EXTINGUISHER, DUMPED FUEL AND RETURNED TO ZSPD. FOUND PRESSURE RELIEF VALVE (PRV) WILL NOT STAY CLOSED. REMOVED AND REPLACED PRV AND LEAK AND OPERATIONALLY CHECKED GOOD IAW AMM 36-11-03.