Year
1982
Abstract
A liquid-phase UFg enrichment measurement instrument for International Safeguards monitors enrichment plant output by giving the inspectorate an accurate real time indication of product enrichment. This provides 1) an immediate indication of enrichment levels greater than declared and 2) information which can be coupled with weight data for material accountancy. The basic monitor, developed by Los Alamos National Laboratory, continuously measures the percent 235U in a constant volune of liquid UFg by counting the 186 keV gamma rays interacting with the Nal(Tl) detector. This count and the background count are multiplied by calibration constants to arrive at the percent enrichment. This basic monitor has been adapted to international safeguards applications by reducing the size of the electronics package and adding tamper protection. Physical tamper protection is provided by an anodized tamper indicating container. Data tamper protection results frcm using an encryption algorithm which authenticates both the data content and source. It also allows both the inspectorate and the operator access to the data. A prototype of this monitor is operating at the Oak Ridge Gaseous Diffusion Plant (ORGDP) together with a computerized data collection system for gathering data during the operational evaluation. This evaluation, which remains in progress, demonstrates that the system can provide very useful information in the safeguarding of enrichment plants.