Evaluation and experimental control of actinide evolution in high-temperature-reactor fuel

Under the aspect of experimental and calculational determination of heavy metal content in HTR-fuel depending on fuel enrichment and burn-up and for the prediction of useful data for reprocessing and waste management, alpha spectra of samples from four DRAGON irradiation experiments are taken. Using a laser-micro-boring preparation method, high resolution alpha-spectroscopy and sophisticated computer decomposition programs we identify qualitatively and quantitatively most of the important actinide isotopes in irradiated HTR-fuel. Additionally we use data, delivered by gamma- and mass-spectroscopy of the same fuel samples. The evaluated results are compared with calculational results from the burn-up code ORIGEN, using a HTR-neutron-cross-section library, corrected for each experiment. Correlations for Pu239, Pu total, Pu238, Pu239+Pu241/Pu total and U236 versus burnup were calculated. The influence of the different enrichments to actinide transmutation is given