Investigation of radioactive reactor graphite by gamma-spectrometric method

Abstract

In this research radioactive contamination of graphite of the 4th block of the Leningrad NPP was determined using the method of gamma-spectrometric analysis. The obtained results of the specific activity of isotopes were compared with the contamination of the graphite masonry of industrial uranium-graphite reactors. It was found that in comparison with graphite of industrial uranium-graphite reactors, the LAES-4 masonry has less contamination with decay products and actinoids, which indicates that, unlike industrial reactors, there were no incidents of fuel Rod destruction in power plants. But at the same time, it was noted that the RBMK masonry has an increased content of60Co. It was determined that this is due to the increased content of iron and cobalt impurities in unradiated graphite for RBMK. This research is important in terms of confirming the view that spent graphite from each specific uranium-graphite reactor has important features that need to be taken into account when planning decommissioning measures.