SYSTEM OF NUCLEAR MATERIAL MEASUREMENTS AT LUCH

The Program of NM Measurements was developed within the framework of Control and Accounting System at Luch establishing the requirements to all its elements. On its basis, the Program of NM parameter measurements was approved for each MBA taking into account their work specificity. Types of MC&A measurements: • Weight measurements; • Measurements of NM solution volume; • Destructive mass-spectrometric and non-destructive gamma-spectrometric measurements of enrichment; • Destructive chemical measurements of uranium content: by gravimetry and potentiometric titration by Davies Gray method; • Gamma-spectrometric measurements/estimations of holdup in the equipment. Measuring instruments: • Finnigan mass spectrometer MAT 262; • Mettler Toledo automatic system based on the titrator DL-25 for uranium analysis; • Mettler Toledo electronic scales; • Gamma spectrometer U-Pu InSpector Canberra for enrichment measurement; • Gamma spectrometer “Kupol” of SNIIP-AUTOMATIKA, Moscow, Russia, for holdup measurements. Measuring instruments are certificated for measurements. Specialized organizations of Russian GOSSTANDART calibrate the equipment for destructive measurements. Reference scale AX-205, weight comparators PR 2004 and KA 32-3 and reference weights were acquired for calibration test of scales. Techniques of measurements have a level of standards or instructions of Russian Ministry of Atomic Energy and metrological certificate. The measurement system is provided with both Russian (state and branch) and American standard samples. The enterprise standard samples made and certificated at Luch are used for routine chemical analysis of uranium content and for non-destructive measurements. About 60 working weight standards are used for weight equipment calibration. The system of measurements quality control is based on the regular measurements of standard samples. Only trained and certified personnel having appropriate qualification are attracted for control and accounting measurements. The comprehensive database on measurements was accumulated according to the coordinated procedures of monitoring within the framework of Program of NM consolidation and conversion in association with USA. The comparison of results of mass-spectrometric and gamma-spectrometric measurements of enrichment, gravimetric and potentiometric measurements of uranium content during long period is presented in the report.