U-235 Enrichment Determination Via Gamma Spectroscopy Improved Calibration and

An improved method of calibrating NDA gamma spectroscopic instrumentation for U-235 enrichment determination is presented. The calibration utilizes a chi-squared minimization method to fit two coefficients to the data. Sources of uncertainty in the initial data are used to "weight" the fit; uncertainties are computed for the two fitting coefficients. The calibration procedure and calculation of "unknown" enrichments is demonstrated. Only simple counting instrumentation is needed; calculations can be readily handled by small computers. An example calculation and program listings are included.