Halden experience with in-reactor material property assessment

An overview of the experimental work scope at the Halden reactor is provided, together with the most important achievements related to fuel and materials safety and reliability. The most important characteristics of the Halden tests consists in the in-reactor monitoring capability, which provides unique on-line data on specific performance items, such as for instance fuel temperature, fission gas release and pellet-cladding mechanical interaction for fuel rods and crack growth, creep and stress/strain relaxation for structural materials. The type of measurements, the techniques involved, the data and their relevance for the nuclear community are presented and discussed. In particular, licensing items related to high burn-up fuel, such as overpressure criteria and response to LOCA, are addressed. Considerations are also given to the long term availability of the Halden reactor as a key support tool for the nuclear industry in the decades ahead. (author)