[en] During the summer of 1980 the condenser tubes of Barsebaeck 2 were acid cleaned due to the following reasons: 1) significant heat transfer losses 2) possible passivation of attacks filled with corrosion products 3) encouraging experiences from acid cleaning of Danish units 4) less encouraging experiences from mechanical cleaning. Prior to the acid cleaning some laboratory experiments were performed to investigate the effect of pH-value and temperature on the time required for cleaning. In spite of practical problems including loss of acid and cavitating pumps the acid cleaning was performed in less than 24 hours/condenser section. The result of the acid cleaning was better than the result of mechanical methods employed earlier. There was a significant increase in heat transfer efficiency. In two of the condenser sections the tubes were completely free of corrosion products after acid cleaning and cleaning with the Taprogge system. In the two remaining condenser sections some corrosion products were observed in a few deep attacks. This is due to a higher pH-value suring the cleaning of these two sections than during the cleaning of the two first sections. There were no indications of any acid leaking to the steam side of the condenser. (Author)