text: This article relates primarily to RPMs deployed for screening trucks at ports of entry. Over 1400 RPMs are deployed at US borders and a similar number at foreign locations for the purpose of interdicting illicit radiological and nuclear material. The US deployments cover all land border vehicles, all seaport containerized cargo, and all mail and express courier facilities. Efforts are also being made to deploy similar measures to other cross border vectors including:
  * Pedestrian radiation portal monitoring
  * Air freight radiation portal monitoring
  * Crane based radiation portal monitoring
  * Air luggage radiation portal monitoring
  * Railway radiation portal monitoring
  RPMs are also deployed at civilian and military nuclear facilities to prevent theft of radiological materials. Steel mills often use RPMs to screen incoming scrap metal to avoid radioactive sources illegally disposed in this way. Garbage incineration plants often monitor incoming material to avoid contamination.