The Karlsruhe Nuclear Center is studying the conceptual design of a helium-cooled poloidal ceramic blanket with beryllium multiplier for the Next European Torus. To maintain the tritium losses from the plant below 10 Ci/day, a separate helium purge flow is required. In the case of a high-pressure purge flow, tritium containment requires an oxidizing atmosphere in the purge flow region. The consequences of the resulting T2O partial pressure on Li2O are assessed. A purge flow at 1 bar does not require an oxidizing atmosphere.