Determination of uranium, plutonium and selected fission products in the coolant of the KS-150 reactor

The method of monitoring of U, Pu and some fission products (sup(103,106)Ru, sup(134,137)Cs and sup(141,144)Ce) in gaseous CO2 coolant is described. The method is based on the retention of the radionuclides studied by membrane filters built in by-pass of the burst-cartridge detection (BCD) system. The purpose of the present study was the determination of U, Pu in CO2 and the verification of the possibility of the indirect monitoring of U and Pu contents in the coolant, using the gamma-spectrometric determination of selected fission products retained by the filter. For calibration of the proposed method after decomposition of the filters, uranium was determined spectrophotometrically using Arsenazo III, plutonium was determined radiometrically after its separation by extraction with 2-thenoyltrifluoracetone and the fission products were determined by gamma-spectrometry. From the results obtained it follows that a correlation exists between the U and Pu content in the coolant and the activity of certain fission products retained on the filter. (author)