Hungary for ESS

The Hungarian site

• Neutron science in Hungary
  
• The Hungarian site
  
• Economic conditions, socio-economic impact
  

The site secured for the ESS by the City of Debrecen is 25 % larger than required and of very advantageous shape. This will keep open a large variety of options for a potential up-grade of the facility in the decades after its completion, including the opportunity of adding a second target station and/or extending the length of the linear accelerators without substantial restriction in the availability of space. This location is within 10-15 minutes from the city centre by car, within 2 km from the international airport and accessible for the heaviest classes of road transport via a major high-way. All utilities are available at the level required by the ESS.

The geological properties of the fully flat site are most adequate and allow for the cost effective realization of the ESS without special measures. Soil is cheaply available in the area (under 4 €/m3). This makes it possible to build the accelerator above ground level, which is a most economical solution. The approximately 6 m thick coverage used for shielding purposes above the accelerator tunnel can be produced by excavation on site. Building the linear accelerator above ground level (e.g. as it was done at J-PARC or partially at LANL) also offers the advantage of further reducing the irradiation of rain and ground water way below environmental requirements, maximally satisfying the ALARA (“as-low-as-reasonably-achievable”) principle. The site is not part of an area of drinking water collection. The geological conditions have been thoroughly explored (borehole excavations and CPT/Cone Penetration Tests). In the absence of bedrock within reasonable reach underground, the stability of the facility will be achieved by the combination of piles reinforcement (~800 mm diameter and 20-25 m depth) and letting the buildings differentially settle according to their weight per m2. The process is not influenced by the natural annual variation of the ground water level and the time it needs does not impact the construction schedule of the facility.