METHOD FOR CONTROLLING POWDERED URANIUM ENRICHMENT Russian patent published in 1997 - IPC

FIELD: process control of powdered uranium enrichment in the course of nuclear fuel production. SUBSTANCE: proximate control is made by measuring gamma-radiation spectrum of specimen of typical size affording self-absorption of gamma-rays in the range of 0-300 keV by means of spectrometer built around scintillation detector. Then spectrum is interpolated and step-by-step integrated so as to make maximum of main analytic peak get into desired channel having energy of 186 keV. Then spectrum is subjected to digital filtering involving separation in it of separate peaks of gamma-radiation, $$$, and thorium isotopes, as well as X-rays of common uranium. Areas of separated peaks are measured, areas of all mentioned peaks are normalized dividing them by area of main analytic peak to obtain normalized intensities $$$, and auxiliary parameter r is found from formula %%%. Then enrichment of specimen is determined by substituting r in calibration dependence between enrichment and r values the latter being determined together with parameters p and q during instrument adjustment. EFFECT: facilitated procedure. 3 dwg