Gamma-Spectrometric Determination of the Plutonium Mass in Containers

Abstract

A method is proposed for determining the mass and isotopic composition of the plutonium warehoused in containers at the RT-1 plant of the Industrial Association Mayak. A single measurement system with a detector based on ultrapure germanium is used for the measurements. The mass is determined according to the pulse count rate in ²³⁹Pu peaks. The correction for self-absorption of radiation in a container is determined by measuring the transmission of radiation emitted from an external source and by Monte Carlo calculations. Estimates show that the total error in determining the plutonium mass by the new method is 11% (P = 0.95). The method can be used to perform confirmatory measurements in the accounting and control system for nuclear materials.