Das Projekt "Development and performance assessment of measurement systems for nuclear materials; destructive analysis, 1988-1991" wird vom Umweltbundesamt gefördert und von European Commission, Joint Research Centre (JRC). Institute for Transuranium Elements (ITU) durchgeführt. Objective: To develop methods for the destructive analysis of the samples taken from the open fuel cycle and, in particular, from reprocessing plants. General Information: Progress to end 1990. A device was developed to prepare targets for alpha-spectroscopy by a robot. Several techniques to dissolve fresh fuel samples for subsequent analyses by titration and K-edge densitometry using the robot were compared. The existing quality control scheme of the laboratory is being studied in order to serve as a basis for an expert system and to improve the overall accuracy of the analyses with the target set at 0.1 per cent . Detailed description of work foreseen in 1991 (expected results). A prototype of an alpha-spectrometer to be operated by a robot will be developed. A dissolution apparatus for fresh fuel based on microwave will be developed. An expert system will be developed for the programming of the robotized sample dissolution and titration. - The error sources of the existing method will be determined in greater detail with the aim to reduce the overall error to 0.1 per cent . An appropriate quality assurance will be set up. - The programming of an expert system for quality assurance and error detection will begin. Short description of evolution of work in 1992. It is foreseen that activities of this type will be continued in the new multi-annual specific JRC programme in order to maintain our competence in this field at a level which is necessary to back up ongoing service activities for DG I and Dg XVII in the safeguards field. Achievements: The analytical tools for safeguards analysis were further refined and progress was made in achieving the set goal of an overall error of less than 0.1 per cent . A set up to accelerate plutonium dissolution by applying a high frequency field (microwave) was successfully tested. The titration program was modified and extended. The data transfer between the mass spectrometer and the PDP computer was improved. Progress was made in the development of an expert system for quality assurance and error detection. An expert system for the programming of robotized sample dissolution was developed.