Use of highly pressurized liquid nitrogen technology for concrete scabbling application at SICN nuclear facility - 59282

The decommissioning process is a quite long and complicated stage who may take few years or decades to be achieved. Generally, this process involves the implementation of a large number of technologies dedicated to cutting and decontamination operations. Based on this finding, the Clean- Up Business Unit of AREVA with Air Liquide decided to start the development of a new technology based on the use of liquid nitrogen (-140 deg. C / 3500 bar). The NitroJetR process is a quite interesting and promising technology. It can be used, as we described in this document, for concrete scabbling operations but also for decontamination and cutting applications. The Clean-Up Business Unit, with its partner Air Liquide, realized a complete study of this technology including several tests and optimizations to be able to handle it in a nuclear environment. Thus, we did: - increase of the reliability of the machine, - nuclearization of the system (including the development of efficient shroud system and efficient HP pipes insulation); - development of a dedicated bearer for automatic configuration; - optimization of parameters for D and D applications. As we already mentioned, NitroJetR technology showed promising perspectives as: - economic: increase of rate processing, decrease in site monitoring costs, - environmental: use of an inert gas, no secondary waste generation, non use of chemical, dry process, - social: less strenuous work, decrease of operator dosimetry compatible with ALARA principle The future for the NitroJetR technology will be its implementation in a real high level activity environment. This process will be used in spring 2012 in AREVA nuclear reprocessing facility of La Hague (France) to accomplish concrete scabbling applications. This test will be the last of a long development period before industrial exploitation. (authors)