An integral experiment relating to calibration and interpretation of plutonium solid waste measurements at Dounreay nuclear power development establishment

The measurement of plutonium in solid wastes which arise from PFR fuel reprocessing has been achieved by the use of non-destructive analysis (NDA) techniques at selected points on the various waste routes. These systems are calibrated by using both synthetic standards, which closely approximate the waste streams in matrix composition and plutonium content, and by mathematical modelling which uses a classical theoretical approach. This report represents collaborative work carried out by UKAEA Dounreay, Joint Research Centre Ispra and Lyon University France which relates to the characterisation and sampling of two selected solid waste streams in the PFR fuel reprocessing operation at DNPDE. This paper, gives details of the sampling procedures, historical data and destructive analysis techniques which were applied to high α, β, γ (leached hulls) and high α low β γ waste streams arising from PFR fuel reprocessing. The work was carried out after two PFR fuel reprocessing campaigns had been completed thus providing adequate statistical data. The levels of plutonium, which were found in these streams was much lower than had been anticipated at the plant design stage. This required some modification of the destructive analysis approach. These procedures must be repeated at intervals in order to establish a meaningful statistical pattern. If necessity the frequency of these checks must recognise the cost of such an approach and the interruption to the reprocessing operation