LYRA irradiation experiments: neutron metrology and dosimetry

LYRA is a dedicated rig for materials irradiation in the High Flux Reactor in Petten, the Netherlands. The LYRA facility is located at the HFR's Pool Side Facility. The irradiation rig comprises a tungsten gamma shielding, and the irradiation capsule itself. The capsule is foreseen of a heater box that forming a small oven allows for irradiation of large number of samples at very low thermal gradients and if required in-pile annealing. LYRA has been designed for carrying out the irradiation programmes of the European Network AMES, with the purpose of studying the irradiation damage of nuclear reactor pressure vessel materials. LYRA began its operation in 1997 and has been now operated for 10 years, holding already 10 irradiation campaigns. Through this period the facility has hosted a considerable amount of different specimens covering a wide range of steels and weld metals. In this paper the different LYRA irradiation experiments, their results from the neutron metrology as well as the doses build-up point of view are presented. (author)