Netwerkers in the Tabloo team
- Marijke Beel: Tabloo project leader
- Ward Vangenechten: project engineer civil
- Jan Versmissen: project employee automation – preceded and now replaced by Yves Surmont
- Stephan Vanderhoydonk: safety coordinator – assisted by Anne-Lies Martens
- Stef Van Dyck: security specialist
- Dirk Maes: Property management NIRAS (important for cadastres, properties, plot boundaries, etc.)
- Marleen Elsen: Financial management cAt site and therefore important for coordinating budgets
- Elisabeth Van Gucht: Responsible for Reception & Guide Operations
After years of preparation and negotiations, the first proverbial shovel went into the ground on January 14, 2019. And it didn’t stop at that one shovel! After years of hard work, a table suddenly appeared in Dessel. This table, Tabloo, is the visitor center that NIRAS built in preparation for the surface disposal project for low-level radioactive waste.
Is it a visitor center, a monument, or a meeting center?
Yes.
In addition, the building also includes a bistro, an exhibition space, an office building, and tourist information.
Tabloo, table in Esperanto, embodies the consultation between all partners, gives a sense of security, and invites participation. From the opening on March 1, 2022, it should therefore become a hotspot in the Kempen.
The entire project was realized through intensive cooperation between NIRAS, Mona, and Stora. The latter two are local associations that represent the residents of Dessel and Mol in this project. The entire site is a co-design of the three partners, with the input of the local population not least. In this way, this collaboration is seen as unique in the world.
In addition to a few offices (NIRAS, Mona, Stora) and meeting rooms, there is a bistro, a theater hall, and a permanent exhibition. This exhibition gives the visitor a clear picture of nuclear energy, radioactive radiation, and the disposal of waste. From the Big Bang to pressed barrels, from the first protest to a fruitful collaboration. The aim of the exhibition is to clearly frame what exactly will happen on the site over the next 300 years.
Technical challenges
In addition to the theoretical data, we are of course also more than interested in the technical side of this project. What are the biggest engineering challenges? Where did it go wrong? What did this project cost and was it within the proposed budget?
Concrete
The table is completely cast in concrete. Because concrete is an enormously honest product, it was very important to map all factors that can influence the quality. Nothing can be changed about weather conditions, but all other factors were covered. For example, three approach routes were calculated from the nearest concrete plant so that the concrete would never sit in a mixer for too long.
The entire table, with a tabletop of 45 x 45 meters, rests on only 9 columns, which posed a nice challenge for the stability engineers.
In addition, the concrete table consists of an insulated double-walled concrete wall, with the outer wall suspended from the whole. The gigantic surfaces, both horizontally and vertically, that bridge large distances, made many a project employee frown.
To make the whole thing “bearable”, the floors were made according to a weight-saving method.
Certain diagonal reinforcement bars are 6 meters long, which posed a difficult challenge for the contractor. That is why they were delivered in pieces and joined together with coupling sleeves. Given the tensile forces that would act on the sleeves, separate studies were carried out for this. Only when all tests gave positive results were they implemented.
A beautiful but complex terrazzo floor was laid for the finishing of the center square. The enormous surface area of this cast floor requires an ultra-stable base layer.
And fortunately, the site manager who was responsible for the concrete work was kind enough to postpone his retirement for a while and carry eggs to the Clarisses: not a single day of weather downtime!
Wood
The interior is entirely made of wood. For example, all stairs, interior spaces, and the elevator shaft were made of wood. Even the theater hall is entirely constructed of wood, which required an exceptionally good approval process in the fire safety permit.
In addition to a warm experience, this woodwork is also partly a conceptual elaboration. Tabloo is primarily a monument to remind us and future generations of the disposal site for low-level radioactive waste. For the monument, the half-life of the radioactive radiation and the guarantee of the disposal were taken as a benchmark. And the date for that is 2321. 300 years into the future! The interior, on the other hand, has a more temporary function of, say, 50 years. The future vision is therefore that in 300 years only a beautiful park and a gigantic table will remain.
Success story
The project as a whole was a success.
Of course, there were small hick-ups here and there, but the general line was positive. No sinecure and a lot of credit for the project leader on duty. By always keeping the end goal in mind and bringing everyone back to constructive cooperation every time, this project was delivered both within the proposed budget of 16.5 million euros and (almost) within the planned timeframe.
Not a single day of weather downtime, but unfortunately a temporary stop during the first lockdown of the COVID-19 pandemic, in the spring of 2020. A very unreal moment to completely close the site and send the entire team home.
The entire building is equipped with a building management system to support maintenance and to regulate the building. In this way, heat is controlled remotely, defects are automatically reported, and light and light intensity can be regulated centrally.
In addition to enormous insulation of the walls, double walls with insulation that meets contemporary standards, cold-heat storage and concrete core activation are used. For this, an underground heat and cold basin is used.
In the tabletop, an exhibition is housed about radioactivity and radioactive waste. An experiential whole, with interaction based on high-quality technical gadgets, a combination of materials, and integrated multimedia.
Exclusive tour
We were lucky enough to be guided around by colleague Marijke. After 5 years, Marijke knows the project through and through, both in terms of content and practical matters. She knows what happens behind every door, why which finish was chosen, and which juicy details the concrete will preserve forever. An afternoon on the road through the table, it was an experience.
From March 1, however, the building is open to everyone. More than worth the effort to visit the exhibition, walk through the park, and do justice to the bistro.
We left outside, with a broad view of the table. Only then did the grandeur of the building strike us. And that’s just what you see above ground! Each table leg has its own foundation. In total, 4,400 m³ of concrete was used…
Through the front door to the inside, onto the center square. This central heart of the center is considered a village square, a market square. You will also find entrances to the reception (Halloo), the bistro (Bistroo), the expo (Expoo),… The double oo from Tabloo is consistently repeated in a playful but consistent way.
We cross the square and go to the theater hall. A beautiful wooden hall with good acoustics, a multifunctional stage, and a promise of many beautiful lectures.
We cross the square again and end up in the bistro. It is worth mentioning that the bistro, but also the rest of the building, was furnished in consultation with the local associations. This bistro is therefore intended to provide cyclists, walkers, and local associations with food and drinks.
After the bistro, we walk back across the center square and pass the unmanned tourist office. Unmanned, but don’t let it be unloved: thanks to a combination of various interactive information pillars, visitors can discover all the tourist hotspots of Dessel, Mol, and by extension the entire Kempen in various languages.
To reach the expo, we take the elevator. This elevator, in a wooden elevator shaft, takes us to the middle of the tabletop. First, we pass by the lab, a professionally equipped workspace where pupils and students can carry out all kinds of tests with radioactivity under expert guidance. The purpose of the lab and the expo is therefore purely educational and fully focused on radioactivity, radiation, and the disposal of radioactive waste.
For the expo, 3.5 million euros, the most modern techniques are used in the field of projection, interactivity, and total experience. From the Big Bang over the table of Mendeleev to the disposal process: every aspect is touched upon and explained.
With the virtual elevator, we go 250 meters underground, but then we take the real stairs to the balcony. From here we have a beautiful view of the landscape park-with-5km-walking route and the future disposal site.
Time has flown by, and we are completely in awe of this beautiful building. As a company, we are very proud that Tabloo came about in part thanks to our Netwerkers.
Yep, even in Dessel they know what always a great job really means!
