Digital Autoradiography technique an efficient tool for sampling procedure

摘要

In France, several nuclear facilities (laboratories, NPP) have been shut down few years ago and are now under dismantling. Physical, radiological and non-radiological characterization prior to dismantling is a key element of all decommissioning projects. Gamma cameras or contamination meter are the instruments commonly used for nondestructive analysis and to investigate the facilities potentially contaminated with gamma radionuclides (1). But, when suspected contamination concerns pure beta emitters such as H-3 or C-14 or alpha emitters and more generally radionuclides difficult to measure, researches are still going on to provide in-situ suitable method. At CEA (French Alternative Energies and Atomic Energy Commission, France), some facilities, where beta or alpha emitters have been handled, are intended to be decommissioned or even demolished. Whatever the end-state defined, the radioactive level inventory of the building must be investigated. In order to fulfil the request for laboratories of several hundreds of square meter, the analytical technique of Digital Autoradiography (DA) well known for biological researches (2) has been developed (3-5). Easy to handle (4, 6), it has been appeared as an efficient technique to localize precisely fixed or non-fixed contamination on various materials (7). For all decommissioning facilities regardless of their size and use, after historical site assessment, targeted characterization are required on different matrices. This requires techniques being able to improve sampling protocol. Sampling is highly important in analytical laboratories performing digestion processes generally requiring less than 1 g of material that must be characterized.