INVENTORY DETERMINATION OF LOW AND INTERMEDIATE-LEVEL RADIOACTIVE-WASTE OF PAKS NUCLEAR-POWER-PLANT ORIGIN

In the execution of disposal of low and intermediate level radioactive wastes, it is important to evaluate accurately the kind and quantity of each radionuclide in the wastes. For such an evaluation, correlatio n of non-gamma-emitting nuclides based on gamma-emitting nuclides is r ecommended and regarded as a practical method. This method necessitate s a completion of a highly accurate and reliable nondestructive assay system of gamma-emitting nuclides for practical use. In 1992, in suppo rt of the new waste disposal program in Hungary, Paks NPP initiated a waste characterization program to determine the radiological propertie s of its radwastes. A segmented gamma scanning system has been set up to measure the gamma-emitting nuclides in 200 litre low level drums fo llowing in-drum compaction. In the framework of the program a radioche mical analysis sub-program was started to determine the long-lived non -gamma emitting radionuclides, mainly those listed in the US regulator y document (10CFR61). The radionuclides of interest have been H-3, C-1 4, Sr-90, Fe-55, Ni-59, Tc-99, I-129 and TRUs. Sample preparation tech niques and measurement methods have been selected and used. Newly deve loped or adopted methods have been tested on real liquid radwaste stre ams such as concentrates, ion-exchange resin and sludge. The measureme nts taken so far have revealed brand new information and data on radio logical composition of waste of WWER-type reactors. In the next stage of the characterisation program attempt will be made for providing cor relation factors between the gamma and non-gamma-emitting radionuclide s in different waste streams. Short description of the methods and res ults on waste inventory are given by highlighting the problem areas.