Analysis of the fluctuations of the average monthly activity at a nuclear power plant with an RBMK-1000 reactor

The results of an analysis of the fluctuations of the relative activity of gaseous (inert) and the specific activity of volatile (iodine) fission prod ucts in the technological medium of the power-generating units of the Kursk and Smolensk nuclear power plants in 1996 and 1997 air presented. It is sh own that these quantities behave in time as fluctuation bursts against a qu aisistationary background. Using a large set of statistical data, it is sho wn that this character of the activity is a consequence of two processes: t he appearance of leaks in the fuel elements mid the unloading of fuel assem blies containing unsealed fuel elements. A relation, which is the Same for all power-generating units, between the number of bursts per year and the n umber of unloaded fuel assemblies is found. The amplitude distribution func tions of the bursts, indicating the existence of groups defects in RBMK-100 0 fuel elements, are obtained. The results obtained are discussed and concl usions are presented. 3 figures. 1 table. 1 reference.