Assessing Radiological Dose to Members of the Public and Workers during Used Nuclear Fuel Transportation

Large scale transportation of Canada’s inventory of used nuclear fuel is still several decades away. However, the impact of the used fuel transportation program is actively being evaluated. This assessment examines the potential radiological dose that may be received by members of the public and transportation workers resulting from the transportation of used nuclear fuel by road using the Used Fuel Transportation Package (UFTP) illustrated in Figure 1.As transportation of used nuclear fuel willoccur in the public domain, members of thepublic and transportation workers may be inthe proximity of passing UFTP shipments.Thus, the radiological impact of used fuelshipments on residents along transportroutes, individuals in vehicles sharing thetransport routes, individuals at rest stops,cyclists, UFTP transport crew,transportation inspectors, roadside workers,etc. is examined.Using dose rates at various distances fromthe UFTP, and estimated exposure time,distance and frequency data gathered byresearchers from Carleton University, dosesto individuals are calculated and annualized.These doses are compared to the regulatorydose limits defined in the RadiationProtection Regulations published by theCanadian Nuclear Safety Commission(CNSC). Activities including packageloading, preparation for shipment, and securing onto the transport trailer are typically conducted by workers at a licensed facility and arethus outside the scope of this assessment.Annual radiological dose to individuals is calculated to range from 1.3 x 10-6 mSv for a hitchhikeralong the transport route (equivalent to 1 second in an airplane at altitude) to 0.35 mSv for thetransport crew of used fuel shipments (equivalent to 90 hours in an airplane at altitude). All dosesto members of the public and transportation workers are calculated to be below the annual regulatorypublic dose limit of 1 mSv per year, therefore no individuals including transportation workers requiredesignation as a Nuclear Energy Worker (NEW). However, dose rates and resulting occupationaldoses received by workers have been calculated and are not based on measured values. Dosemonitoring of occupational activities and NEW designation requirements for workers will beestablished when the radiation protection program is developed, prior to the operational startup of theused fuel transportation program.