Mass-spectrometric analysis of transplutonium element nanogram quantities in spent WWER fuel

Deseription and results of mass-spectrometric isotopic analysis of nanogram quantities of transplutonium elements (TPE) in spent WWER type reactor fuel are presented. Fuel samples containing TPE have been preliminarily purified by the method of partition chromatography, ltnthanum fluoride precapitation and electromigration on paper and have been electrolytically applied on evaporator tape of an ion source. Mass part of americium and curium is determined by the method of isotopic dilution. When determining the relative isotopic composition of TPE samples with the content 10-8-10-9 g and 10-10-10-11 g using mass spectrometer MI-1201 the use of recording system, based on counting separate ions and multiple scanning of mass spectrum with electric field, permitted to obtain the root-mean-square deviation for isotopic ratios of 1-2% and 5-10% respectively