A probabilistic dose assessment for accident conditions was performed for the Muntok area in the western Bangka region. Source-term was obtained from the Three-Mile Island unit 2 (TMI-2) PWR-type SB-LOCA reactor accident. The isotopes used in the simulation were Xe-133, Kr-88, I-131 and Cs-137. The effluent was released from a 50m stack. The Lagrangian particle dispersion method (LPDM) in 3-dimensional mass-consistent wind-field was employed to obtain surface-level time-integrated air concentration and spatial distribution of ground-level total dose in dry and wet conditions. Site-specific meteorological data were from hourly records obtained during the Site Feasibility Study period in Muntok in 2014-2015. Effluent was released at a uniform rate during a 6-hour period and the dose was integrated for 12 hours from the beginning of the release until most of the plume left the model boundaries. Maximum dose may exceed the regulatory limit of 1mSv for the general public and the radioactive plume spread mostly to the SE-SSE inland and to W-WNW from the proposed plant location to the Bangka sea.