Borehole Concept – Preliminary Safety Assessment using a Screening Tool

The adequate management of disused sealed radioactive sources (DSRS) is an important problem associated to its widespread generation from the nuclear applications and the high level activities for some DSRS on this specific wastes stream. The Borehole Design Concept (BDC) has been evaluated as feasible disposal solution to avoid the high costs linked to the implementation of the deep geological options. In this paper the results of the tool application (screening tool) for safety assessment to estimate the impact of the DSRS disposal from the nuclear program in Cuba using the BDC, are shown. The preliminary assessment was supported by the information associated to the facility design, site characterization results (mainly hydrogeology and geochemistry) and the DSRS inventories. Supported by the site documentation, also was studied the data variation to evaluate the role played for some parameters uncertainties on the estimated radiological impact. The outputs showed that the impacts were below to the target dose limit for both evaluated pathways; well water and house dweller. The radiological impacts are different for the evaluated scenarios and the higher doses are related to well water scenario. Also, the main radionuclides according its contribution to the final dose for the critical groups were identified. These preliminary results are relevant to support the planned next stages; definition of the waste acceptance criteria for the disposal facility and the radiological assessment for the predisposal operations. (author)