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The « CAT »: a remotely-controlled crawler designed to decontaminate the PWR fuel transfer tube.

An addition to our extensive service offer in the field of nuclear pools decontamination

The « CAT »: a remotely-controlled crawler designed to decontaminate the PWR fuel transfer tube.


Onet Technologies’ wide range of services in the field of nuclear logistics includes the decontamination of nuclear fuel pits, an activity carried out by specialist teams from Techman Industrie.

To optimise such operations, Techman Industrie needed a customised tool that would enable to remotely decontaminate the fuel transfer tube between the reactor pit and spent fuel pool(PWR 900MW).

It therefore decided to develop its own device and called on Comex Nucléaire - Onet Technologies’ maintenance engineering department - to produce it.


Thanks to this innovation the company won the contract to decontaminate the nuclear pools of the 4 reactor units at Chinon NPP in 2011, at the same time enlarging Onet Technologies’expertise in this specialist field.



Service provided

The CAT enables to decontaminate the entire length of the tube through which fuel is transferred between the reactor and spent fuel buildings.

Equipped with a radiometric sensor, the tool produces a radiological map of the tube before and after the decontamination process.

The entire operation is remotely controlled and monitored using a camera device posed on the pool deck.


  • Mobilisation and preparation of the work zone, equipment installation,
  • Initial radiological mapping of the transfer tube
  • Diffusion of decontaminating foam throughout the entire tube
  • Low pressure and high pressure rinsing of the transfer tube
  • Final radiological mapping of the transfer tube
  • Demobilisation of the equipment
  • Site clearance and withdrawal

Description of the installation/equipment

  • Conception and manufacturing of the crawler, and on-board tool mounting
  • Testing and acceptance in Comex Nucléaire’s workshop
  • Theoretical and practical training of the personnel due to perform the decontamination operations
  • Qualification of the device in the mock-up transfer tube at the CETIC centre (centre for the testing and validation of techniques and methods due to be employed during maintenance interventions on nuclear power plants)
  • Drafting of the installation and operating manuals.


  • Country: France
  • Client: EDF
  • Date of project launch: 12/17/2010
  • Sites concerned: Chinon NPP , the device has also been employed on the sites of Saint-Laurent, Blayais et Gravelines.


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13258 Marseille Cedex 9 - France
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Fax: +33 (0)4 91 29 18 58
ONET SA - RCS B 059 801 324 Marseille
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