The interaction of alpha -particles in JET tritium discharges with global Alfven waves via inverse Landau damping is analysed. It is found that alpha -particle driven eigenmodes were stable in the PTE1 and should also be stable in a future 50:50 deuterium-tritium mix discharge aiming at QDT identical to 1 provided the same ion density as in the discharges with the best deuterium-deuterium performance is maintained.