Abstarct: A new BNCT beam line has been designed baxsed on the use of the TRR medical room using MCNPX Monte Carlo code. The medical room is located behind the east wall of the reactor pool. In the first step, the feasibility study of using medical room has been performed. The results showed that by considering the special in-pool Beam Shaping Assembly (BSA) an appropriate epithermal neutron beam could be achieved. The designed BSA including Moderator, reflector, neutron and gamma filter is considered between the reactor core and the medical room wall. It is found that the final designed BSA could be provided 2/96×109 n/cm2.s epithermal neutron flux with acceptable beam contaminations. The capability of new BNCT facility for deep-seated brain tumor treatment has been assessment by considering proper head phantom as well. The obtained results show that the new setup could be treated deep-seated brain tumor, which was located up to 5 cm of the brain surface. Moreover, computational investigation of the medical staff effective dose during BNCT has been performed in different situations using MCNP4C Monte Carlo code and two ICRP 110 voxel baxsed male phantoms. The results show that the medical staff effective dose is highly dependent on the position of the medical staff.