EDF, Chooz A decommissioning project


Chooz A is the first PWR reactor under decommissioning in France. Chooz A is formed by two large caverns, one for the reactor, primary loop and steam generators and the other one for the auxiliary equipment. It was shut down in 1991 after 22 years of operation. EDF began the decommissioning operations on site in 2007 and the reactor core components are currently dismantled.


The Neutron Shield Tank (NST) is a tank surrounding the PWR vessel of Chooz A with a former protective function for the concrete bioshield. Thus, the NST is partially highly activated and requires remotely operated cutting tasks to minimise the dose exposure during dismantling operations.

Our proposal

Cyclife Engineering has been tasked to perform the detailed design of the NST’s dismantling operations.

Cyclife has significantly improved the existing basic design scenario by proposing the use of a remotely operated wire saw cutting system integrated on a support structure preferred to the former complex system composed of a circular saw mounted on a hanging platform.

Customer benefits

  • Unlike with the former cutting solution, no liquid effluents are generated
  • The provided solution requires less human exposur and improves the overall occupational safety


  • Number of needed cuts divided by 7
  • Collective dose exposure reduced by 20%
  • Total estimated costs of the project and duration of the operations reduced by 30%