Nuclear Decontamination and Dismantling

Published: May 2, 2012
  • ONDRAF-NIRAS   Building B5:22 – photo  Julien De Puyt ONDRAF-NIRAS Building B5:22 – photo Julien De Puyt
  • ONDRAF-NIRAS - Linking pipes & storage vessels (to be dismantled) – photo  Julien De Puyt ONDRAF-NIRAS - Linking pipes & storage vessels (to be dismantled) – photo Julien De Puyt
  • ONDRAF-NIRAS- Existing filtration, building B5:22– photo  Julien De Puyt ONDRAF-NIRAS- Existing filtration, building B5:22– photo Julien De Puyt


The multidisciplinary process of preparing a nuclear Decontamination & Dismantling project is complex – winning the ONDRAF/NIRAS – B5/22 Project confirms Tractebel Engineering’s position as Owner’s Engineer for complex projects.

Following the boom that launched nuclear as a global industry 40 to 50 years ago, many of the world’s nuclear installations are now reaching the end of their expected life-cycle. As development of new nuclear installations and technologies continues apace, the industry, in parallel, is entering an era which calls for equally dedicated expertise in the complex business of Decontamination & Dismantling of old nuclear facilities. Drawing on an established team of experts and multidisciplinary skills across the whole of the nuclear life-cycle, Tractebel Engineering is well-prepared to lead the way in this domain – as the recently hard-fought, and won, B5/22 Project contract illustrates:

The B5/22 Project is a 6 year Architect-Engineering (EPC-M) mission for ONDRAF/NIRAS – the Belgian Agency for Management of Radioactive Waste and Enriched Fissile Materials, in collaboration with Belgoprocess. The project focus is the preparation (design, procurement, erection and commissioning) of works needed to begin the final decontamination & dismantling of high level waste storage tanks in the former EUROCHEMIC experimental reprocessing plant located on the site of Belgoprocess, in Dessel, Belgium.

B5/22 Project History

1966 – 1974 EUROCHEMIC operated an experimental reprocessing plant for irradiated fuel from power & research reactors from several European countries. The plant was shut down in 1976 and dismantling– aiming to return the site to “green field” status, began in 1989. Today, only 2 (bunker) process buildings, B105 and B122 remain; each containing two “empty” tanks (respectively 2 x 40m³ for effluents from reprocessed Low Enriched Uranium fuel, and 2 x 212m³ for effluents from reprocessed High Enriched Uranium fuel). Although drained of radioactive liquid effluents, the 4 tanks still generate high radiation levels due to large amounts of solid deposits that remain inside. These tanks pose the final decontamination & dismantling challenge central to the B5/22 project.

The Technical Solution

The B5/22 Project will see entire new containment buildings erected over the existing tank bunkers to house ventilated process rooms/cells, airlocks to prevent radiation leaks, link systems and remote tools, cameras and equipment. When commissioned in 2017, these cells will allow the tanks to be safely accessed through holes drilled through the 1,4 m thick concrete ceilings. Following a fully remote decontamination process, hands-on activity can begin – cutting and removing all internal elements like cooling water coils and piping, as well as the tanks themselves, for safe disposal.

An Important Reference

Such a project demands the very latest engineering techniques and a lot of specialised expertise. From 3D modelling to expert civil works, electricity, I&C systems, mechanical equipment, ventilation and more; during contract negotiations Tractebel Engineering could show it had it all. Not that walking away with the contract was a walk in the park! ONDRAF/NIRAS launched the international public tender in June 2009 and the high level of competition for the contract was a clear indicator of the future value and importance of the decontamination & dismantling business in the nuclear industry. Winning the project after an intense 2-year bid process confirms Tractebel Engineering as a major nuclear player in its home market and internationally. To play a leading role in the anticipated boom in this field, we had to be there from the start – and we are!


June 2009 – International Tender Launch and Pre-qualification rounds
April 2010 – Technical proposal (based on Belgoprocess process proposal)
Dec 2010 – Technical proposal (based on chosen “Market 8” solution)
Jan 2011 – Commercial proposal
April 2011 – Alternative commercial proposal
July 2011 – Official notification of selection: Tractebel Engineering selected as best bidder!
August 2011 – Purchase order for Phase 1 EPC-M mission received – work begins!

4 main phases

The mission, started on 25 July 2011, comprises 4 main phases:
1. Basic design, detailed design and licensing;
2. Call for tenders for the supply contracts (Markets 1 to 7);
3. Follow up of supply (manufacturing & factory acceptance tests);
4. Supervision of erection, testing and commissioning (2017).

More information

Jean-Pierre Lahaye – B5/22 Project Technical Coordinator
Michel Detilleux – B5/22 Project Director
Pierre Cnapelinckx – B5/22 Project Sales & Marketing Manager
Pierre Debiève – B5/22 Project Manager
Dimitry Bayart – Head of Projects

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