Tritium removal from codeposits on carbon tiles by a scanning laser

A novel method for tritium release has been demonstrated on codeposited layers on graphite and carbon-fiber-composite tiles from the Tokamak Fusion Test Reactor. A scanning continuous wave Nd laser beam heated the codeposits to a temperature of 1200-2300 degreesC for 10-200 ms in an argon atmosphere. The temperature rise of the codeposit was significantly higher than that of the manufactured tile material (e.g. 1770 degreesC cf. 1080 degreesC). A major fraction of tritium was thermally desorbed with minimal change to the surface at a laser intensity of 80 W/mm(2), peak temperatures above 1230 degreesC and heating duration 10-20 ms. In two experiments, 46% and 84% of the total tritium was released during the laser scan. The application of this method for tritium removal from a tokamak reactor appears promising and has significant advantages over oxidative techniques. (C) 2002 Elsevier Science B.V. All rights reserved.