LYRA and other projects on RPV steel embrittlement: Study and mitigation of the AMES Network

Within the framework of the European Network Ageing Materials Evaluation and Studies (AMES), a number of experimental works on RPV materials embrittlement are carried out at the Institute for Advanced Materials (JAM) of the Joint Research Centre (JRC) of the European Commission (EC). The objectives of AMES are mainly the understanding of the property degradation phenomena of RPV western reference steels like JRQ and HSST, eastern RPV steels like 15X2MFA and 15H2X15, and annealing possibilities. In order to conduct a very high quality irradiation programme, an AMES dedicated irradiation rig, LYRA facility, has been designed and developed at the high flux reactor (HFR) Petten. Another dedicated rig, named LIMA, has been developed at the HFR Petten in order to irradiate RPV steels, internals and in-core materials under typical BWR/PWR conditions. The samples can be irradiated in pressurised water up to 160 bar, 320°C, and the water chemistry fully controlled. For irradiation of standard or miniaturised LWR related materials samples, another group of well experienced irradiation devices with inert gas or liquid metals environment are employed. These devices are tailored to their various specific applications. This paper is intended to give information about the structure and the objectives of the existing European network AMES, and to present the various AMES main and spin-off projects, including a brief description on the modelling activities related to RPV materials embrittlement.