A non-destructive assay of plutonium based nuclear fuels by in-house developed small volume calorimeter

•In-house development of a small volume radioactive calorimeter for non-destructive assay of plutonium based nuclear fuel.•Calibration is established by both electrical and plutonium standards.•The results from calorimetry are found to be in good agreement with conventional potentiometric analysis. Conventionally, quantitative estimation of radionuclides is carried out by measuring the decay particles/radiation (alpha, beta, neutron/gamma) or electrochemical techniques (potentiometry). Calorimetry is an alternative non-destructive technique for quantitative estimation of radionuclides, especially plutonium-containing fuels. The measurement of total heat in terms of power associated with radioactive decay is the basis of this calorimetry technique. This technique is widely used in the nuclear industry to account for plutonium in fuel pellets, powders, and metals. In the present work, the design, in-house development, fabrication and testing of a cost-effective small volume radioactive calorimeter based on peltier sensing elements is described and its performance in measuring the plutonium concentration is discussed. The calorimeter was calibrated by both electrical and plutonium standards. The results from calorimetry were corroborated with conventional potentiometric analysis and found to be in good agreement, qualified through Bland and Altman analysis. [Display omitted]