Three-dimensional neutronics and photonics analysis has been performed for the neutral beam injection system of TDF. Using tungsten shield in the 0.35 m space available between the corner of the central cell solenoid and the duct wall provides adequate protection for the magnet. The peak radiation damage and nuclear heating in the magnet are well below the specified design limits. Acceptable heat loads were obtained in the cryopanels and superconductive shield. The radiation dose absorbed in the MACOR insulator of the ion source implies that it will last approximately 2.8 full power years.