Analysis of calculation codes for metal tritium interaction and numerical evaluation of the tritium behaviour in the net first wall

Several calculation codes have been developed for the determination of permeation, recycling and inventory of hydrogen isotopes in the first wall of thermonuclear fusion reactors. An analysis of these codes has been performed in the first part of this report. Then the PIDAT code has been modified by introduction of a temperature gradient in the wall. This modified code has been used to calculate the tritium behaviour in the first wall of NET. The results confirm that tritium permeation and inventory are affected by the conditions at the inner and outer surface, by trapping and by the temperature gradient in the wall