Spent sealed radioactive sources conditioning technology for the disposal at the national repository Baita-Bihor

A spent sealed radioactive source(SRS) is a high integrity capsule which contains a small amount of concentrated radionuclide with an activity which ranges from a few MBq up to levels of hundreds TBq. Presently, there are now many spent and unusable SRS in Romania, which have been used a long time in various industrial applications (smoke detectors, weld testing etc.). Considering the activity of the Radioactive Waste Treatment Plant (STDR) at the Institute for Nuclear Research Pitesti regarding radioactive source collecting from various economic agents, several radioactive sources are held in the intermediate storage deposit facility on the institute platform awaiting conditioning for the final disposal. This paper presents the conditioning technology for this sources, which has as ultimate purpose to completion of a product which matches the waste acceptance requirements imposed by the National Authority Control of Nuclear Activities, CNCAN, for the disposal site DNDR Baita - Bihor. The technology used for obtaining the final product allows two options for the immobilization of the sources in the 218 L steel drum and these are: Sources placed in the original packages and which can not be dismantled will be isolated by encapsulation in 10 litters metal capsules and then conditioned in 218 l steel drum, with a concrete biological shielding; Sources removed from the initial package are isolated in stainless steel capsules, which are to be conditioned in the same 218 L steel drum. The final product obtained as a result of the concrete conditioning operations of the spent SRS in 218 L steel drum is the steel drum - concrete - low radioactive waste assembly which presents itself as a concrete block which includes one or more capsules containing SRS. (author)