2024
December 2024
380 foundation piles are filled with concrete, integrating them as permanent components of the structure. Piles, filled with concrete and connected to the (yet to be realised) bearing slab, provide critical support for the reactor building from below.
November 2024
After the top sections of the 380 foundation piles were cut off, the piles were opened and inspected. Steel reinforcement bars (rebars) have been installed in the piles to strengthen their connection with the bearing slab (foundation floor of the reactor building), which is the final step yet to be completed in the reactor building's foundation.
October 2024
With the fully pumped out construction pit, the works at the bottom of the pit have been underway. The top parts of 380 foundation piles remain sticking out from the concrete floor. These top parts are being cut off and in the next step, they will be opened and inspected. Placing rebars and filling piles with concrete follow.
September 2024
With the foundation piles drilled and the concrete floor fully hardened, the basic foundation of the construction pit was established, which meant the water could be pumped out. A total volume of 48,000 cubic metres – equivalent to the volume of 19 Olympic swimming pools – were eventually pumped out.
August 2024
For many months, the construction pit of the PALLAS-reactor resembled a swimming pool. Water in the pit balanced ground water pressure and prevented the uplift of the bottom. With all 380 foundation piles in place and the bottom concrete floor hardened, the water started to be pumped out of the pit. The water (of which quality was tested in the lab) is being disposed to surrounding landscape according to the approval given by the authorities. Groundwater level is monitored throughout the process to ensure the water does not exceed accepted levels.
July 2024
During a continuous 30-hour work, 4,000 cubic meters of concrete were poured under water at the bottom of the PALLAS-reactor construction pit to create a 1.5-meter-thick concrete layer. Prior to this, a layer of gravel had been applied in to the excavated pit to ensure a high-quality underground pour.
June 2024
On 8 June, the PALLAS construction site was opened for a visit of external and internal stakeholders as part of the initiative called ‘Dag van de bouw’ (construction day). Around 450 visitors had a chance to experience the preparatory works of the PALLAS-reactor up close.
May 2024
More than half of 380 foundation piles have been drilled in the ground of the reactor building.
April 2024 Energy & Health Campus luchtfoto's
April 2024
The drilling of the 380 foundation piles of the reactor building has been underway. Given that the piles are drilled under water and the quality of all work is not visible until the pit is fully pumped out, several diving inspections are conducted. A diver inspects the quality of the drilling process at the bottom of the pit.
March 2024
The drilling of 380 foundation piles of the reactor building to a depth of -47.0 NAP has started. To balance ground water pressure, there is still water in the pit. Therefore, the 33-meter-long piles are drilled from the pontoon, using the pile cleaning device (PCD) to accurately position the drilling pile on the bottom.
February 2024
After more than three months of digging (first by dry excavation, in the second phase by wet excavation), the pit excavation was completed. The pit is excavated and extracted sand, clay and peat have been disposed of at the sand depot. The pit is still filled with water up to the groundwater level.
January 2024
Foundation piles have been successfully tested in 5 rounds of quality tests. The tests are conducted to verify pre-determined parameters of drilling such as speed, torque, and flow speed of the grout.
