Data compatibility for various Charpy-tests

An approach is proposed for determination of mechanical properties alteration of the irradiated metals. It consists in comparing the metal condition before and after the irradiation. The base material is tested in so called 'cold' cells, while the irradiated samples - in 'hot' ones. As long as the tests could be carried out in different laboratories, having at their disposal different Charpy test machines (with different parameters), from metrological point of view it is necessary to perform benchmark investigations in order to verify the compatibility of data obtained. They should include: comparison of the results, obtained in different 'cold' cells or in different 'hot' cells; comparison of the results, obtained in 'cold' and 'hot' cells; comparison of the results, obtained with or without electron filtration after the amplifier; comparison of the on-line and off-line results. Such benchmark investigations would enable the utilization of the results accumulated in data bank from all available experiments for a further complete assessment and for analysis of the metal state of the reactor pressure vessel. (author)