Shielding analyses of the inboard blanket, the vacuum vessel and the Toroidal Field Coil (TFC) in International Thermonuclear Experimental Reactor OTTER) were performed by Monte Carlo and 2-dimensional discrete ordinate methods taking the radiation streaming through the 20 mm wide gap between the adjacent blanket modules into account, and their peak nuclear responses were evaluated The nuclear responses of the TFC could fully satisfy the radiation limits. On the other hand, the helium production rates of the branch pipe, the leg and the front surface of the vacuum vessel behind the gap were about 2-3 times higher than the radiation limit at the end of the operation, i.e. the neutron fluence of 3 MWa/m2. So the shielding module is required to be increased by 80 mm to satisfy the radiation limit. Also, shielding analyses for 20 - 100 mm wide gaps were performed, and it was found that the gap width could be increased by up to 50 mm from the TFCs protection for their peak nuclear responses point of view.