NRG PALLAS says construction works have been progressing on the site of the PALLAS reactor project in the Netherlands, near the town of Petten. Since the second half of 2022, the eastern side of the Energy & Health Campus has been transformed to allow for the construction of the PALLAS reactor and its surrounding buildings. As of March 2025, the supporting structure for the construction of the new reactor is being delivered and the PALLAS Programme organisation has been moving towards the start of the construction.
The 55MWt tank-in-pool” PALLAS research reactor will replace the existing 45MWt High Flux Reactor (HFR), which began operating in September 1960. It was originally used for materials testing but is currently used for fundamental research and the production of medical radioisotopes. The reactor is operated by NRG on behalf of the European Union’s Joint Research Centre. It supplies some 60% of Europe’s and 30% of the world’s use of medical radioactive sources. PALLAS will able to deploy its neutron flux more efficiently and effectively than the HFR.
It is two years since the first concrete was poured at the construction site of the PALLAS reactor and the construction pit is nearing completion. The space where the PALLAS reactor building will eventually stand, is 50 metres square and 17.5 metres deep. The construction pit is a vital supporting structure for the reactor building.
In the base of the construction pit, the total of 790 tonnes of steel reinforcement bars have been placed in layers. In the final step, a 1.5-metre-thick layer of concrete will be poured across the whole surface of the pit’s bottom in five stages to form the foundation floor of the PALLAS reactor building.
In February 2023, the Nuclear & Radiation Protection Authority (ANVS – Autoriteit Nucleaire Veiligheid en Stralingsbescherming) granted a construction licence for the reactor and Rijkswaterstaat issued the Water Act permit for the intake and discharge of cooling water. First concrete for the foundation was poured the following May and the Ministry of Health, Welfare & Sport instructed PALLAS to continue with project preparations to avoid unnecessary delays.
Belgian construction firm BESIX was awarded a contract for the construction pit in November 2022. The General Contractor for the project, Spanish construction firm FCC Construcción, was appointed in December 2023. FCC is responsible for constructing several buildings, including the reactor building. The design has been delivered by ICHOS – a long-term partner contracted for the design of the PALLAS-reactor. In 2025, FCC will take over the works from BESIX. The coming months will see installation of the construction staff office for 250 people, initial work on the PALLAS-reactor, and its secondary cooling system building.
Although funding has been allocated for the construction of the PALLAS reactor, the government has yet to make a final formal decision and will depend on the Dutch parliament approving the creation of a new state-owned company The European Commission has already approved, under EU state aid rules, a €2bn ($2.17bn) measure by the Netherlands government to support the PALLAS reactor project.
