A case study of management and disposal of TENORMs: radiological risk estimation by TSD Dose and RESRAD-ONSITE

Naturally Occurring Radioactive Materials (NORMs) and Technologically Enhanced NORMs (TENORMs) are among the principal sources of radiation exposure for humans and for the environment. Therefore, the assessment of the impact of NORMs and TENORMs waste on human health is a key issue for their management and for acceptance of disposal sites. The radiological doses to workers and public due to TENORMs disposal depend on the waste inventory, on the usage of the site during operational activities and post closure phase and on the presence of dwelling areas in the vicinity of the disposal site. In the present study it is presented a methodology to preliminary assess the feasibility of a disposal of TENORMs, mainly constituted by phosphate sludges, originated from phosphoric acid industry activities. The hypothetical case study here presented is inspired by a real case study. Different possible scenarios have been considered. The potential doses to workers and to the public on-site have been estimated by the use of the TSD Dose and the RESRAD on-site codes both during the production life cycle of the site and once it ended. Sensitivity analyses were conducted to evaluate the impact of some key parameters, such the coverage thickness and wind velocity, on potential risk for workers and public.