Calorimetric measurements inside the vacuum vessel of TFR, using water-cooled shields, give accurate values of the transmission and neutralisation efficiency of the neutral beam injection lines. Measurements during plasma operation give the value of the shine-through fraction of the injected power. The comparison with calculations indicates that the results are close to the expected ones if the usual value of the beam stopping cross-section is slightly increased ( approximately=15%). For TFR experimental conditions, the fast neutral ionization profile throughout the plasma is almost unaffected by this correction and full beam input accountability is experimentally assessed.