Analytical needs and strategies dedicated to support decommissioning operators - 5154

All over the world, several nuclear facilities have been shut down few years ago and are now under dismantling or will be dismantled in the future. Dismantling project takes place according to three major phases: -) Study and definition of the dismantling scenario; -) Dismantling site operations; and -) Decommissioning and final state characterization. Each step is led in agreement with safety, security and waste management. Characterization appears as a graded and iterative process and is a key issue for decommissioning and dismantling (D/D) operations in term of efficiency and cost. It requires analytical tools appropriate to the aims and radiological environment. For instance, for safety, fissile products, explosives will be quantified while security requires quantification of radiological, carcinogenic, mutagenic and reprotoxic elements such as As, Se, Cr(IV), asbestos... in order to follow more and more strengthened rules. For waste management, radiological and chemical quantification are necessary but must be completed by determining physical and chemical properties such as reactivity, stability or dissolution of the waste... This short list points out the diversity of the analytical tools that must be mastered (physico-chemistry, elemental organic, nuclear, speciation...). Furthermore, the required level of knowledge, analytical deadline, uncertainties, limits of detection and matrix variety depend on the decommissioning phase. In order to fulfill the prerequisite needs with a minimal cost, the analytical expert has to select, implement and qualify the optimal detection technic. In order to face this huge analytical demand, Nuclab purposes have been recently redirected. The laboratory is under a CEA AREVA partnership and provides services to several industrial operators in the fields of analytical chemistry, radioactivity measurements, in situ-nuclear measurements, decontamination processes and industrial chemistry processes, waste treatments to meet the needs of decommissioning. After reviewing the characterization needs of D/D steps, the presentation will focus on the analytical strategy developed by the laboratory since few years, including sampling strategy, in-site, off-site measurements. Real case will be detailed