Construction update PALLAS Project Q3 2026
The outer walls of the reactor building start taking shape
Following completion of the -3 floor of the reactor building, the teams advanced to work on the outer walls of the -3 level of the building. Aircraft protection shell (APS), a key structural element enhancing the reactor’s building security, started taking shape.
The walls are constructed in phases by installing formwork and reinforcement before pouring the concrete. At the -3 level, the aircraft protection walls are poured in twelve sections. Two of these were poured in September, using a total of 275 m³ of concrete. Each concrete pour is a continuous operation lasting several hours.
To minimise risks on cracks in the concrete, a system of cooling pipes is installed inside the reinforcement. The cooling system is a network of pipelines and a big "refrigerator" that will be switched on when the concrete is poured. The system helps reducing the raise of temperature due to the chemical reaction of the cement with water, and thus the expansion of the concrete. Once the concrete cools down, the shrinkage caused by this temperature decrease is also reduced. The cooling system is then switched off. The pipes will remain in the concrete, will be filled with mortar, and have no function anymore.
For more details on the pouring process, you can watch the latest video update.
In October, works will start on the reactor building's inner walls and on the first reinforcement for the reactor block foundation, which will accommodate both the reactor pool and the service pool. Several key reactor components are also being manufactured in parallel, including the Heavy Water Storage Tank.
Secondary cooling system building construction pit
The construction pit for the secondary cooling system building currently contains approximately 15,000 m³ of water. Before this water can be safely discharged, its quality must meet the required standards. The teams are working towards obtaining the necessary permit confirming that these requirements have been met. Once the water has been discharged, access to the pit can be installed and the next phase of construction can begin.
In parallel, licensing and contractual preparations are underway for the horizontal drilling required for the inlet pipes of the secondary cooling system. The pipes have already been delivered and are temporarily stored at the construction site on the Zuiderhazerdwarsdijk.
