Cea Saclay Hd 13 1

Nuclear decommissioning: Onet Technologies and CEA recognized by SFEN and WNE for remotely operated laser cutting

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The SFEN awarded its Technological Innovation Prize on June 23, 2016 to Onet Technologies and the CEA for remotely operated laser cutting, developed at CEA Saclay and Marcoule, implemented by Onet Technologies on a sanitation site in the CEA Marcoule. An innovation, hailed by the WNE, which could also be retained for cutting debris from molten fuel in the damaged reactors of Fukushima Dai-ichi.

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Remote-operated laser cutting, developed by the CEA and implemented by Onet Technologies, is particularly well suited to very thick cutting operations in hostile environments. Indeed, it is easily controlled remotely, has a large positioning tolerance for cutting heterogeneous layers of materials and generates less aerosols than most other available techniques. Implemented by Onet Technologies for a world first in december 2015, remotely operated laser cutting demonstrated all its performance within the framework of the current project to dismantle the MAR200 dissolvers, within the used fuel processing plant at the CEA site in Marcoule. This dismantling method, also recognized through a nomination at the WNE Awards, received the Technological Innovation Prize from the SFEN on June 23.

A major challenge: adapting current technology to the constraints of Fukushima Dai-ichi

This prize also rewards a promising technology that could be retained for cutting the debris from molten fuel in the damaged reactors of Fukushima Dai-ichi, a project in which Onet Technologies and the CEA have been actively involved since 2014. The current project consists of adapting this existing technology and robust to the very specific constraints of damaged reactors. The removal of fuel debris from reactor cores will be an essential step in this dismantling program.

The combination of high-level expertise and industrial reality

The implementation of remotely operated cutting requires in-depth knowledge in several fields, provided by the CEA and IRSN laboratories. CEA Cadarache studies in particular the fuel debris resulting from the melting of a nuclear reactor, and manufactures non-radioactive simulants, intended for the cutting tests associated with this project. IRSN, for its part, is working on the composition of the aerosols generated by cutting. The combination of the industrial experience provided by Onet Technologies, which has demonstrated its know-how through its involvement in high-activity decommissioning sites in France, and the expertise of the CEA are the essential keys to ensure the deployment of this type of complex technology, in an international context.

Key dates for cutting UP1 dissolvers in Marcoule

  • December 2015: First laser cutting active on UP1
  • Fall 2016: End of cutting dissolver A

Timeline of the current project for Fukushima

  • August 2016: End of the first phase focused on the manufacture of simulants and cutting performance
  • September 2016 – March 2017: Second phase of the project focused on cutting underwater at great depth and the characterization of the aerosols generated