Nondestructive determination of nuclear fuel enrichment by Ge(Li) spectrometer

A non-destructive method is described of the determination of the enrichment of uranium with 235U within the region of 0.7 to 90% by means of a comparison of the spectra of 235U and sup(234m)Pa. The gamma spectrum of these isotopes was scanned with a coaxial Ge(Li) detector with a volume of 77 cm3. The time of measurement was between 1 to 2 hrs; the statistical error for the 1001.4 keV line was in all cases less than 1.5%. The described method allows for the measurement of uranium samples with arbitrary enrichment and various chemical composition and geometry without necessitating comparison with the standard. (J.B.)