The effects of radiation streaming through the neutral beam injector (NBI) port and divertor throat of a tokamak fusion reactor, the INTOR-J, was evaluated using Monte Carlo and discrete ordinates methods. Radiation streaming through the NBI port is found to be tolerable when a thick drift tube support acts as an effective shield. Neutron streaming through the divertor throat, however, makes the shutdown dose too high for personnel access into the reactor room. The radiation levels in the reactor room resulting from leakage through the NBI room walls are far smaller than that from leakage through the bulk shield, except behind the NBI room. The Monte Carlo-Monte Carlo and discrete ordinates—Monte Carlo coupling techniques used in the present study are shown to be very effective for the radiation streaming calculations.