Halden Reactor Project - Fuels and Material
Joint project

The Halden Reactor Project has been in operation at the Institute for Energy Technology (IFE) in Norway since 1958 and is the oldest NEA joint project. It brings together a large international technical network in the area of nuclear safety ranging from fuel safety and operational margins in commercial reactors, including fuel and cladding performance and behaviour both at normal operation and transient conditions, with emphasis on extended fuel utilisation, ageing and degradation of BWR and PWR reactor core materials under the combined effects of water chemistry and nuclear environment and plant control/monitoring and human factors. The project programme of work is updated every three years and the current mandate is from January 2024 to December 2026 (extension to complete the programme of work).

Since January 2021, the project has been split into two separate projects: one addressing the nuclear fuels and material thematic area, and one addressing the human, technology and organisation (HTO) area.

The Halden fuel and materials project is currently supported by around 80 research, regulation and industry organisations in 17 countries.

From the very beginning, investigations in the fuel and material area were built around in-pile experiments at the Halden boiling water reactor and complementary out of pile investigations. Numerous valuable experiments have been performed in the frame of the Halden Reactor Project and have led to an improved understanding of the behaviour of nuclear fuels and materials in various conditions for the entire nuclear community.

Halden LOCA tests series have served, for example, to enhance knowledge regarding the critical safety issues of pellet-clad interaction in transients and fuel fragmentation, relocation and dispersal in LOCA transients. Halden tests data have also been extensively used in the validation of fuel performance codes and LOCA transient analysis codes with a number of completed international benchmarks under IAEA and NEA auspices: 

In June 2018, technical and financial challenges led to the decision by the board of directors of IFE to permanently close the Halden Reactor. The reactor was regarded in many countries as a strategic asset for testing fuel and components for commercial reactors. To sustain and develop such in-reactor testing capacities, the NEA has implemented the FIDES II (Second Framework for Irradiation Experiments) framework.

A revised nuclear fuels and materials work programme was developed for the 2018-2020 period which was continued for the 2021-2023 period. The work programme focuses on post‑irradiation examinations (PIE) and LOCA experiments in hot-cells, including hot cells at Studsvik in Sweden, in the areas of:

  • fuel safety and operational margins;
  • cladding performance and behaviour;
  • ageing and degradation of core material.

This programme aims at completing experimental investigations in the above areas. Some investigations are still pending in 2024 due to delays in transports of material to Studsvik.  

Another important aspect of this work programme was the compilation and preservation of the Halden fuel and material legacy data, as well as the development of an experimental database. This substantial effort for the project data preservation was completed by IFE at the end of 2023 and the legacy database was released to the project members and the NEA at the end of 2023. The NEA has now the possibility to provide access upon request to NEA member organisations to Halden legacy data sets.

The 2024-2026 programme aims at closing the Halden fuel and material project with the completion of PIE and LOCA testing at Studsvik and the development of synthesis reports in the following topical areas: fission gas release, dimensional changes and pellet-cladding mechanical interaction, loss-of coolant accident transients, cladding corrosion and creep and crack growth initiation and growth rate for core structure materials. Some activities are also planned to complete the legacy data base with adding latest reports and reports produced in the HTO area until 2021. A new version of the legacy data base will be released at the end of 2026 at the closure of the project. In 2024, IFE is organising a final conference for the project "The OECD Halden Reactor Project’s (HRP) final conference, Celebrating 65 years of safety research".

Some of the data sets from the Halden project are accessible to NEA member countries’ organisations upon request at International Fuel Performance Experiments (IFPE) database


Belgium, China, Czechia, Finland, France, Germany, Hungary, Japan, Korea, Netherlands, Norway, Russia (suspended), Slovak Republic, Sweden, United Arab Emirates, United Kingdom, United States and European Commission.

Project period

Current mandate: January 2024 - December 2026

Budget (2024 -2026)
~ EUR 3,862 million