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Pégase: Plutonium waste treatment unit

Design, construction, commissioning and operation of a plutonium waste treatment facility

Pégase: Plutonium waste treatment unit


“Pégase” is a decommissioned experimental reactor located on the site of the CEA in Cadarache. After its shutdown, the reactor’s buildings had been used to store 2714 drums of plutonium waste.

When the nuclear safety authorities asked the CEA to remove the drums from this temporary storage, they were not in a suitable condition to be transported or stocked elsewhere. In consortium with Robatel and Millenium, Onet Technologies was awarded the task of reconditioning the drums on the Pégase site. The mission called for the design of a dedicated facility that would be able to cope with tight space constraints as volume available within Pégase is extremely limited. Led by Onet Technologies, the group designed, built, qualified and operated the facility. Today, the last of these non-standard drums are being reconditioned.

Service provided

Five work zones were created in spaces available in the still-operating BNI 22, and a building was erected to house the mortar production.


For this turnkey contract, Onet Technologies conceived and took charge of:

  • The nuclear measure and characterization workshop
  • The security of handling operations
  • The waste treatment workshop
  • Transport to ANDRA
  • The overall operating of the facility


Pégase Atelier de controle et identification
Verification and characterisation workshop





Glove boxes

Key figures

  • 2 714 drums requiring reconditioning
  • 62 000 hours of design studies and site-work monitoring
  • 170 tonnes of mortar for 490 870 litre packages


  • Client: CEA Cadarache, France
  • Beginning of the contract: December 2007
  • Contract length: 5 years


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