Operational Experience with an in-Line Enrichment Monitor for International Safeguards.

摘要

A liquid-phase UF sub 6 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 continuously measures the percent exp 235 U in a constant volume of liquid UF sub 6 by counting the 186 keV gamma rays interacting with the NaI(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 from 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 in progress demonstrates that the system can provide very useful information in the safeguarding of enrichment plants. (ERA citation 07:046052)