In a Stamicarbon urea plant an unexpected damage occurred in a Pool Condenser. The tubesheet was damaged at the low pressure steam side by erosion corrosion due to improper quality of the steam condensate. The damage was discovered in time and a failure leading to loss of containment (LOC) was prevented. A unique and delicate repair was carried out in cooperation with Schoeller Bleckmann Nitec from Austria to restore the integrity of the tubesheet. In this paper the root cause of the damage will be discussed, the challenges faced during the repair and preventive actions.