EDF has completed building a one-third scale reactor containment facility which will verify construction methods and study ageing of the materials used in the structure. Construction of the double-walled containment building - Vercors (Verification Réaliste du Confinement des Réacteurs) - started in August 2013 at EDF's research and development laboratory at Renardières in Seine-et-Marne, near Paris. It is 30 metres high with a diameter of 16 metres and required 5,000t of concrete for its construction. It is equipped with 700 sensors and 2km of optical fibre have been positioned in the concrete and on both the rebar and prestressing cables to measure temperature, deformation and water content of the concrete.
EDF said that during construction, hourly measurements were taken from the sensors immediately after concreting. Hundreds of samples of concrete will be prepared and tested to determine their material behaviours and parameters, including strength, drying, shrinkage, creep and leak tightness.
The scaled-down size of the containment building causes accelerated ageing of the materials used in its construction. Thousands of data readings collected in real time will help researchers better understand how the materials used in the structure evolve over time. The model will enable researchers and engineers to investigate and model the phenomena of ageing and leaking through the concrete, to check the robustness of the works and demonstrate the safety of nuclear power plants for extended periods of operation, EDF said.