NEA LOFT Project

The Loss-of-Fluid Test (LOFT) Research Programme was originally set up by the US Nuclear Regulatory Commission. Part of the programme was later broadened into an international collaboration project under the aegis of the OECD Nuclear Energy Agency (NEA). This initial programme addressed several configurations of loss-of-coolant accident (LOCA) with large break tests and intermediate break tests carried out between 1978 and 1982.

The new programme, subject of the NEA LOFT Project, was designed to use the LOFT experimental nuclear test facility at the Idaho National Engineering Laboratory (INEL) in a programme of safety experiments. The initial proposal was developed from an initiative of the United States Department of Energy, who also provided continuing management support. The project successfully combined the abilities and objectives of an international team with those of the reactor operation and analysis staff at INEL to provide a significant addition both to the international database of large-scale experimental data on reactor safety and to the analysis and understanding of the test results.

The experimental program of the NEA LOFT Project comprised eight experiments, six thermal-hydraulic experiments, and two fission product release experiments as listed hereafter.

In summary, the project has achieved the following:

  1. It successfully ran an international project in which both managerial decisions and the detailed planning of the programme were organised by the collective decisions of members. The lessons learned from this aspect of the project should be of permanent value for future international initiatives.
  2. The detailed experimental results provided valuable new evidence on thermal-hydraulic issues and an important international database for computer code verification.
  3. It provided a valuable forum for the exchange of specialist views and for computer code comparisons.
  4. The two tests, LP-FP-1 and LP-FP-2, extended the use of LOFT to provide data on fission product release and transport from failed fuel. LP-FP-2 is also a major data source on severe core damage phenomena in a large fuel bundle and work on the assessment of data from this test can be expected to continue over a number of years.
  5. Effective measures were taken to make the data of long-term value by archiving in the NEA Data Bank, by making the data available as part of the NEA Committee on the Safety of Nuclear Installations (CSNI) Code Validation Matrix, and by linking further work based on the LOFT data with current international programs such as the CSNI Specialist Committees, the ICAP program, and the USNRC Severe Fuel Damage Program.
  6. There is general agreement that there are problems in retaining facilities and expertise in a number of areas of reactor safety and that the facilities offered by LOFT are irreplaceable. The NEA LOFT programme was able to successfully make use of LOFT but was not able to provide a route for its further retention.

Reports and data

An account of the NEA LOFT Project – OECD LOFT-T-3907, May 1990.

Project data is available to NEA member countries, data abstracts are public.


Austria, Finland, Germany, Italy, Japan, Spain, Sweden, Switzerland, the United Kingdom and the United States.

Project period

January 1983 to December 1989


~ USD 100 million

Related links

Last reviewed: 7 July 2014