Study review of the CALORRE differential calorimeter: definition of designs for different nuclear environments

This paper deals with the CALORRE differential calorimeter patented by Aix-Marseille University and the CEA in 2015. Firstly, the paper focuses on the presentation of the first prototype of CALORRE calorimeter qualified under real conditions during the MARIA irradiation campaign in 2015. Then, a review of the studies restricted to one CALORRE calorimetric cell realized thanks to experimental characterizations under laboratory conditions is detailed. Several configurations were studied to determine the influence of the cell height, its horizontal fin geometry and the nature of the material of its structure on its response for a calibration protocol: linearity, sensitivity, range, reproducibility, response time and absolute temperatures. Finally, within the framework of the new CALORI project, an optimization of the calorimeter assembly and its design were carried out in order to remove contact thermal resistances and provide a new configuration of CALORRE calorimeter suited for the in-core water loop of the MIT reactor (2 W.g-1). The response of this new calorimeter is estimated thanks to thermal simulations.

Electrochemical Isoperibolic Calorimetry for D2O Electrolysis

Equations developed for isoperibolic electrochemical calorimetry were tested for the electrolysis of D2O in an open calorimetric cell. The derivatives of these equations gave correct values within the experimental error range for the important rate of change of the cell temperature with time (dT/dt). In addition, these calorimetric equations were also tested directly in determining the enthalpy change (ΔH) for the D2O electrolysis reaction. The mean experimental value at 298.15 K was ΔH = 294.4 ± 0.3 kJ/mole. This compares favorably (within 0.10%) with the literature value of ΔH = 294.600 kJ/mole. The accuracy of these ΔH measurements could be even further improved by more accurate cell voltage and cell temperature measurement. <br>

Electrochemical Isoperibolic Calorimetry for D2O Electrolysis

Equations developed for isoperibolic electrochemical calorimetry were tested for the electrolysis of D2O in an open calorimetric cell. The derivatives of these equations gave correct values within the experimental error range for the important rate of change of the cell temperature with time (dT/dt). In addition, these calorimetric equations were also tested directly in determining the enthalpy change (ΔH) for the D2O electrolysis reaction. The mean experimental value at 298.15 K was ΔH = 294.4 ± 0.3 kJ/mole. This compares favorably (within 0.10%) with the literature value of ΔH = 294.600 kJ/mole. The accuracy of these ΔH measurements could be even further improved by more accurate cell voltage and cell temperature measurement. <br>

Study of the Flow Temperature and Ring Design Influence on the Response of a New Reduced-Size Calorimetric Cell for Nuclear Heating Quantification

This paper concerns experimental studies of different designs of a new compact calorimetric cell under laboratory conditions. This kind of cell is used for the measurement of the nuclear heating rate inside Material Testing Reactors thanks to differential calorimetry. The results, obtained by applying an operating protocol corresponding to a preliminary out-of-pile calibration step, are presented for three designs. The influence of the horizontal-fin design is shown on the calibration curve and the sensor sensitivity. The influence of the external fluid flow temperature is given for the quarter design. The different responses of the calorimetric cell are explained by taken into account a 1D analytical thermal model coupling thermal conductive and radiative transfers.

Review of Nuclear Heating Measurement by Calorimetry in France and USA

This paper gives a short review of sensors dedicated to measuring nuclear heating rate inside fission reactors in France and USA and especially inside Material Testing Reactors. These sensors correspond to heat flow calorimeters composed of a single calorimetric cell or of two calorimetric cells at least with a reference cell to obtain a differential calorimeter. The aim of this paper is to present the common running principle of these sensors and their own special characteristics through their design, calibration methods, and in-pile measurement techniques, and to describe multi-sensor probes including calorimeters.