[en] The TFTR vacuum vessel is to be protected with tungsten plates from the effects of neutral beam impingement. A thermal analysis is performed to determine the maximum allowable beam intensity (power per unit area) under normal and faulted operating conditions. In order to permit a faulted pulse, or unattenuated injection, to occur after normal pulse series, the maximum neutral beam energy flux should be below 10 kW/cm² depending on the beam design configuration, to prevent the melting of the plates. The analyses were performed using an injection time of 0.5 second and a cycle time of 300 seconds