Developments in autoradiography measurements for DDandR applications
Résumé
The localization, and the characterization, of surface contamination by radioactive substances are two recurring necessities of the dismantling process. Firstly, the estimation of the nature and the activity of the contamination is a mandatory step of the initial state characterization of any nuclear installation. Secondly, during the dismantling process, there is a strong need for wastes characterization in order to adapt the final repository accordingly. For long range radiations, such as gamma rays, various detection systems and cameras are available on the market and can be used in dismantling facilities for such purposes. However, there is currently no industrial device capable of measuring and localizing precisely the contamination of short range radiations both for beta emitters (such as 3H, 14C…) and alpha emitters (such as 241Am, 238U, 239Pu…).
Since 2010, a CEA laboratory has been studying the applicability of autoradiography measurements for dismantling applications. Mainly developed in biology with radioactive tracers, this method is able to provide accurate imaging of radioactivity on a surface of different matrices. Very promising results have been obtained in various dismantling facilities using Phosphor film [1,2,3] but the autoradiography method requires more developments in order to become a viable industrial solution for dismantling application.
First, we will report the results previously obtained with autoradiography Phosphor films in dismantling applications. We will discuss the strengths, but also the limitations, of the current solution and the improvement required for dismantling purpose. Subsequently, we will present the new generation of autoradiography detector which is currently developed by the MAUD (a national research project) collaboration. This project, supported by the French waste management agency Andra, is aiming at developing an industrial autoradiography solution adapted to dismantling applications. The First results are very promising and have led to the submission of a patent.
We would like to express our gratitude to Andra and CEA for the financial support.