What was found
(CAN) CREW DID AN EMERGENCY DESCENT DUE ECAM WARNING EXCESSIVE CABIN ALTITUDE WITH CPC NR 1 FAULT. THE EMERGENCY DESCENT STARTED FROM FL320 TO FL090. THE CABIN ALTITUDE REACHED 12000 FT. DURING THE DESCENT THEY GOT MESSAGE "CABIN PR SAFETY VALVE OPEN". DURING TROUBLESHOOTING NR 1 CPC INTERROGATION WAS SHOWING NR 1 DELTAP SYS. SYS RESET AND ALL INDICATION TESTED SERVICEABLE. AFTER RETURN FLIGHT TO BASE, BOTH SAFETY VALVES WERE REPLACED AS PRECAUTIONARY.