Profile

Main field of activity is the development of magnetic field sensing methods and their applications. I participated in two other major European projects: the MANODET project based on combination of the magnetic field imaging with the eddy current method; the NANOMAGDYE project targeted the development nanoparticle based magnetic dye and its sensing technology. I contribute to the NOMAD project with the Magnetic Adaptive Testing method.

Abstract

NDE characterization of embrittlement by means of magnetic methods

The safety of the nuclear power plants (NPPs) long term operation is a very important aspect, especially if the extension of their lifetime has been accepted. This requires the development of reliable tools are for estimating the remaining lifetime of NPP components. Reactor pressure vessel (RPV) is the most import-ant, irreplaceable part of NPPs. The main ageing process of RPVs is the irradiation embrittlement.

This embrittlement, generated by long-term and high-energy neutrons, causes mechanical property changes: increase of hardness, yield stress, and tensile strength, and also decrease of toughness. However, testing and the evaluation of the embrittlement is a difficult task, since it is not one simple degradation mechanism but the sum of several quite different processes.

In the second generation of the NPPs, surveillance specimens are placed inside of the vesseland are withdrawn after certain periods for destructive tests. These testings consume the samples. Therefore, several efforts were performed to apply nondestructive methods to measure the rate of the embrittlement, like using the measurement of the Seebeck coefficient or application of the well-known ultrasonic technique. The most of the presently operating nuclear reactors are Pressurized Water Reactor (PWR) are made from low al-loyed steels, thus magnetic methods (hysteresis measurements, Barkhausen noise measurement, magnetoacoustics emission) can be successfully applied on them.

I summarize the novel achievements of the NOMAD project having the focus on the Micromagnetic Multiparameter Microstructure and Stress Analysis (3MA) method and on the Magnetic adaptive testing (MAT) method.