A method of removing a radioactive material from a gas includes directing the gas through a bed of salt, wherein the gas includes water vapor and the radioactive material. The salt constitutes more than 50 percent by weight of the bed. The method additionally includes condensing the water vapor in the bed and dissolving a portion of the salt to form a salt solution. The method further includes absorbing the radioactive material into the salt solution while a remainder of the gas passes through the bed. A salt filtration system configured to perform the method may be implemented as a pre-filter (or post-filter) to an existing filter unit or as a standalone filter.