Fuel and Reactor Materials Department
The experts of the Fuel and Reactor Materials Department investigate the behaviour of nuclear fuel and different reactor components using experimental facilities, material testing methods and numerical modelling. The activities of the department focus on the topics related to VVER-440 reactors used at Paks NPP, but several projects deal with new reactor types and fusion technology. The fuel research covers normal operational conditions in the reactor, design basis and severe accidents, wet and dry storage of spent fuel assemblies: • The investigation of changes in the nuclear fuel during normal operation requires data on fuel irradiated in NPPs or in research reactors. Such information is accessible through international co-operations (Russian fuel supplier, OECD Halden Reactor Project). Irradiation of cladding materials can be carried out in the Budapest research reactor. • High temperature facilities have been built for the investigation of fuel behaviour during accidents. Integral tests with electrically heated fuel assemblies can be performed in the CODEX facility. Separate effect tests on the oxidation, embrittlement, hydrogen uptake, plastic deformation and burst of Zr cladding material are investigated in small scale facilities. Activity release from fuel at high temperature is modelled with inactive fission product simulants. • The experimental and numerical simulation of leaking fuel rods during their interim storage focus on the estimation of activity release. The simulation of nuclear fuel cycle is handled by numerical models. The analyses cover the reprocessing and final disposal of spent fuel from the existing and planned new units of Paks NPP. The Reactor Materials Research Group has completed numerous projects dealing with structural materials and structural integrity calculations. It performed the studies of the ageing of reactor pressure vessels and the reliability analyses for NPP Paks. In these tasks both the analysis of the ageing of structural materials and the (finite element) strength analysis taking into account elastic and plastic deformations played important role. The Reactor Materials Research Group has a wide range of experience in testing structural materials used in nuclear industry. Staff members include mechanical engineers, metallurgists, welder and materials testing engineers and physicists (see the attached lists including only the key experts). The laboratory is equipped with the necessary instruments for the ageing of structural materials (neutron irradiation channel in the Budapest Research Reactor, owens for thermal ageing etc.); mechanical testing, which is suitable for investigation of normal and neutron irradiated (radioactive) samples; metallography; scanning electron and tunneling microscopy; neutron radiography; etc. The Group employs qualified scientists and technical assistants for all kinds of inspections.