Belgian National Agency for Radioactive Waste & Enriched Fissile Material, Ondraf/Niras (Organisme National des Déchets Radioactifs et des matières Fissiles enrichies/ Nationale Instelling voor Radioactief Afval en verrijkte Splijtstoffen) has appointed contractors to construct a surface disposal facility for low- and intermediate-level, short-lived waste at Dessel. NucleusSafe will be responsible for civil engineering and Denys for electromechanical work.
The Federal Agency for Nuclear Control (FANC – Federaal Agentschap voor Nucleaire Controle) granted a permit to Ondraf/Niras to construct the facility in 2023. Ondraf/Niras applied to FANC for the licence initially in 2013 but FANC requested additional clarifications.
Sigrid Eeckhout, spokeswoman for NIRAS said: “The realisation of the surface storage installation in Dessel will take place in phases and will take several decades. We hope for smooth cooperation with the contractors who always have the same goal in mind: to guarantee safety for people and the environment, now and in the long term. Works are scheduled to start after the summer.”
The Temporary Partnership NucleusSafe comprises Besix and its subsidiary Vanhout, Deckx and Stadsbader Contractors, each bringing complementary experience in complex infrastructure. “The civil engineering of a project like this requires implementation that meets the highest requirements in terms of technical complexity, quality and safety, said Bert Lenaerts, CEO of Vanhout.
“Building on our successful delivery of the foundation pit for the PALLAS reactor in the Netherlands, the used fuel storage facilities in Doel and Tihange in Belgium, and a state-of-the-art nuclear medicine radioisotope facility in Sydney, we are proud to once again support the development of essential infrastructure in the nuclear sector,” said Mark Beyst, General Manager of Besix Belgium-Luxembourg. “Together with our joint venture partners, and especially with our subsidiary Vanhout, we remain fully committed to delivering this project with the highest standards of safety, technical precision, and operational excellence.”
Geert Dhont, CEO Denys, noted: “In recent decades we have been able to contribute to many projects within the nuclear sector at home and abroad.” Denys has worked on the NPP sites of Doel and Tihange (Belgium), Flamanville (France), Borssele (Netherlands), Hinkley Point C (UK) and is involved in Sizewell C (UK). “We are now well aware of the unique needs of nuclear construction projects. Our knowledge of nuclear is one of the areas of expertise that we actively want to further deploy. We are therefore looking forward to participating in the development of the new storage installation in Dessel.”
The storage facility will be built in the nuclear zone on the territory of Dessel, near the border with the municipality of Mol. This is the first time that a radioactive waste storage facility has been built in Belgium.
The facility consists of several modules. Construction will take place in two phases: 20 modules in the first zone and 14 in the second zone, each divided into two rows. A module contains about 900 monoliths and measures 11 metres high and about 25 metres by 27. The modules will be constructed on an embankment composed of a layer of gravel 60 centimetres thick, covered with a mixture of sand and cement two metres thick. They will always be above water level and protected from ascending humidity.
An inspection gallery will separate two rows of modules. Under each module there will also be an inspection space and a drainage system. This makes it possible to detect any cracks or water infiltrations in time and to take the necessary measures. Inspections will be carried out by robotic devices.
During filling, a temporary steel roof will cover the modules to protect them from the weather. When a module is filled with monoliths, the remaining empty spaces will be filled with gravel, and then sealed using a concrete closing slab. Once all the modules in an area are filled, the installation will be closed and the steel roof replaced with a permanent cover made up of different natural and artificial protective layers. It will take approximately 50 years to complete the two zones.
One of the major functions of the permanent cover is to limit water infiltration. In addition, the role of the earth layers of the cover is to protect the concrete barriers from degradation. The cover will have a total thickness of more than 5 metres and will eventually give the storage modules of the two zones the appearance of two hills in the landscape.
The storage facility and its surroundings will be subject to permanent monitoring for 350 years. The entire storage comprises several stages: operating phase (years 0-95); closing phase (years 95-100); nuclear control phase (years 100-350).
