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EDF and Veolia, through respective subsidiaries Cyclife Holding and Asteralis, have created joint entity Graphitech. The company will focus on decommissioning technologies and innovations that could have wider applications and benefits beyond nuclear reactors that incorporate graphite technology. 

With only two graphite reactors dismantled to date, and around 60 requiring decommissioning globally, Graphitech hopes to capitalize on EDF’s nuclear expertize with Veolia’s nuclear-environment robotics capability.

“Graphitech will be responsible for the technological development and engineering studies required, in preparation for decommissioning of nuclear reactors that use graphite technology,” Graphitech chairwoman Estelle Desroches told Nuclear Energy Insider.

“The venture will develop remote-operated tools to break up complex, large-scale concrete and metal structures, as well as tools to remotely extract activated graphite bricks and piles. It will also design systems and articulated arms to enable deployment of those tools.”

Graphitech's first objective will be to provide EDF with an optimized scenario for decommissioning the Chinon A2 reactor in 2028 and to offer a testing program to evaluate the technological solutions needed to complete the project.

Full-scale models

The Chinon A2 program will begin in 2022 with a development and qualification phase using full-scale models. This scalable facility will enable operators from all potential stakeholders to:

• Check the feasibility of new decommissioning scenarios, including alternative solutions to face unexpected situations
• Allow intense use of realistic 3D modelling based on on-site 3D scanning
• Train workers to cope with scenarios, use selected tools and most suitable techniques
• Increase safety, control delays and costs through effective tools determination, improvement of dismantling pace, limitation and control of secondary waste volumes or releases, limitation of dose rate exposure, optimization of final waste packaging, full scale test of control and handling procedures
• Implement remote handling tools and test the efficiency of cutting tools on real scale mock-ups

Desroches added that decommissioning of graphite reactors is challenging mostly because of their design and characteristics, hence the need for full-scale mockups.

“Those reactors are huge, almost 2 to 3 times the height of pressure vessel reactors, 3 to 4 times larger in diameter and 20 times heavier,” said Desroches. “They are compact, and full of a stack of graphite layers inside, accounting for tens of thousands of bricks. The volume of materials to be removed is therefore relatively high.

“There is almost no useful return on experience of similar operations currently available at this scale: so far only a couple of small graphite power reactors have been dismantled.”

All of France’s gas-cooled graphite reactors are shut down, as are most worldwide, with 14 AGRs in the UK set to close between 2023 and 2030.

Veolia will provide its know-how and experience in robotics and remote handling technologies with a view to designing and delivering innovative solutions to access the cores of gas-cooled reactors and to cut up and extract components under optimum safety and security conditions.

“In the longer term, the new learnings should improve decommissioning practices in relation to other reactor types,” François Parot, COO Continental Europe Veolia Nuclear Solutions, told Nuclear Energy Insider.

“Development of remote handled tools and systems, as well as mechanical platforms and tools, will certainly generate a reasonable amount of innovation that will tend to standardize those technologies and make them more accessible for other dismantling operations. The possible standardization of those remote operations might also become a reference in terms of nuclear safety and radiation protection.”

Scott Birch