Construction of the Pallas research reactor in the Netherlands advances steadily, with commercial operation planned before 2032

Recently, the second-phase construction of the Pallas research reactor project in Petten, the Netherlands, has made significant progress, with construction of the underground walls and the Aircraft Protection Shell (APS) advancing steadily. As a key new-build project to replace the aging High Flux Reactor (HFR) currently in service, Pallas is scheduled to complete civil construction around 2030 and achieve full commercial operation before 2032.

In terms of engineering and construction details, with the smooth completion of the floor slab on underground level -3, the construction team has fully launched segmented pouring operations for the walls on each underground level and the APS protective shell. On level -3, the APS protective wall is being concreted in 12 successive segments, of which the first two were completed in September, using a total of 275 cubic meters of concrete. To precisely control the heat of cement hydration and prevent thermal stress cracking, the construction team has deployed a dedicated pipe network cooling system inside the reinforcement mesh to dynamically regulate temperature differences during concrete pouring, thereby ensuring the integrity and durability of the large nuclear safety-related building structure.

It is understood that the project will start construction of the inner walls of the reactor building and the first round of reinforcement work for the reactor foundation in October 2026. This foundation will simultaneously support the reactor pool and the service pool. At the same time, multiple key core components, including the heavy water storage tank, are being manufactured in parallel at the factory. In terms of supporting facilities, water quality investigation and discharge permit approval for the foundation pit of the secondary cooling system building are progressing in an orderly manner, and contract preparation and permit applications for horizontal directional drilling for the intake pipeline have also been fully launched, with the relevant pipelines having arrived on schedule at a temporary staging area south of Petten.

According to the established roadmap, the Pallas project will enter its third phase from 2027 to 2030, when construction will extend from the ground floor to the roof, focusing on the structural integration of hot cells and complex secondary cooling infrastructure; subsequently, from 2030 to 2032, the fourth phase of commissioning and startup will be carried out, ensuring the safe and stable entry into service of this medical isotope and cutting-edge research reactor through phased loading, power escalation, and comprehensive regulatory verification.