What was found
ON CLIMB OUT, PASSING 5K FEET, LEVEL 3, ENGINE 2 FIRE ALERTS WITH ALL LIGHTS, MASTER WARNING AND FIRE BELL. PHASE 1 COMPLETED. AFTER A FEW SECONDS LEVEL 3 ALERTS WENT AWAY AND LEVEL 1, FIRE DET 2 FAULT CAME ON. CONTINUED WITH QRH AND ENGINE SHUTDOWN PROCEDURE FOR ENGINE FIRE. DECLARED EMERGENCY AND RTB. REMOVED AND REPLACED THE #2 ENG UPPER RIGHT TURBINE RAIL ASSY GND OPS CHECK NORMAL. RAN ENG PER JRH AT SEVERAL POWER SETTINGS FOR 20 MIN TOTAL NO FIRE DET FAULTS OR FIRE INDICATIONS.