What was found
DURING CLIMB, RECEIVED ECAM WARNING NR 2 THRUST REVERSER PRESSURIZED. ECAM LASTED FOR SEVERAL SECONDS THEN WENT OUT, REAPPEARED. THROTTLE WAS BROUGHT TO IDLE IAW ECAM & WARNING AGAIN WENT AWAY. MANUAL THRUST USED & EACH TIME NR 2 THROTTLE WAS MOVED ABOVE IDLE, WARNING APPEARED. REFERRED TO QRH, DECLARED EMERGENCY & RETURNED TO DEPARTURE, LANDED UNEVENTFULLY. PRSOV WAS INSTALLED