Marcoule UP1 MAR200 Use of Remotely Handled Equipment Associated with Laser Cutting for Spent Fuel Dissolver Dismantling - 23128

The MAR 200 facility is part of the UP1 reprocessing plant located on the Marcoule site (France). UP1 is the first French spent fuel reprocessing plant. The UP1 plant operated by CEA was commissioned in 1958. The MAR 200 facility was designed to perform the continuous dissolution of spent fuel rods from NUGG (Natural Uranium Gas Graphite) reactors. It is fitted with two production lines, each composed of a dissolver, the associated off gas treatment and receiving tanks. MAR200 was shut down in 1997. As part of the decommissioning activities, the vessels have been emptied, thoroughly rinsed using various chemicals and cleaned up by high-pressure lancing. The components to be dismantled mainly consist of the process equipment (vessels, piping, etc.) contained in several blind cells of the MAR200 facility. The dissolvers are made of Uranus 65. Following rinsing operations some nuclear activity remains. Remotely operated equipment with laser cutting was selected in order to finish the D and D work under contamination risks. The Remotely-Operated Handling and Cutting Unit is equipped with a MAESTRO manipulator arm developed by CEA. Remotely operated dismantling activities of the 'A' dissolution line were completed at the end of 2017. The waste (residual and metal chunks from dismantling) was packaged in Intermediate Reinforced Boxes that were then shipped to ANDRA's surface storage. The dismantling equipment was decontaminated and stored in the facility before carrying on the dismantling of the dissolution line B. As of 2022, CEA is now conducting part of the B line dissolver dismantling activities. Even though the B line dissolver used to fulfill the same process functions as the A line's, the undissolved deposit has been characterized to be more radioactive. The waste processing and packaging is thus a new challenge. Cold dismantling in man accessible locations has been completed in order to make room prior to moving the Remotely-Operated Handling and Cutting Unit and the Waste Extraction and Conditioning Unit. Studies in order to address the differences between line A and line B dissolvers and to optimize the waste packaging have been completed. Design developments to factor lessons learned from the A line dissolver include new ventilation principles intended to facilitate ventilation filters declogging as well as a revised operations sequence to minimize contamination of the waste from dismantling. Recent activities have been impeded by suspected presence of asbestos in structural materials that has to be ruled out before moving forward. Structural material characterization for asbestos presence is underway. (authors)