Influence of the Nb and V Addition on the Microstructure and Corrosion Resistance of the Fe-B-Co-Si Alloy

The paper presents a comparison of the results of the corrosion resistance for three Fe-B-Co-Si-based newly developed alloys with the addition of Nb and V. The corrosion performance differences and microstructure variations were systematically studied using scanning electron microscope, electric corrosion equipment, X-ray diffractometer, and differential calorimeter. It has been shown that each alloying addition increased the corrosion resistance. The highest corrosion resistance obtained by potentiodynamic polarization was found for the alloy with both Nb and V addons (Fe57Co10B20Si5Nb4V4) and lowest in the case of the basic four-element Fe62Co15B14Si9 material. This shows that the proper choice of additions is of significant influence on the final performance of the alloy and allows tailoring of the material for specific applications.

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.

Comparison of the Responses of New Reduced-Size Calorimetric Cells Made of Different Structure Materials for High Energy Deposition

This paper concerns experimental and numerical works on a new differential calorimeter called CALORRE and validated recently under irradiation conditions in MARIA reactor at low nuclear absorbed dose rate level. Works focus on a specific configuration of CALORRE which was designed especially for the measurement of high nuclear energy deposition rates inside Material Testing Reactors. Due to the high level, a new calibration system was fabricated in order to determine the response of the new configuration under laboratory conditions for a very wide range of electrical power never applied in the literature. The response of the new configuration can be considered linear for this very wide range of electrical power. An analytical calculation shows the contribution of each heat transfer in specific zones. 3D thermal simulations performed by means of COMSOL Multiphysics under irradiation conditions give the predictions of the calorimeter behavior under real conditions (up to 20W.g−1).

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.

THERMAL PROCESSES MODELING IN QUASI-DIFFERENTIAL CALORIMETER

The model of the quasi-differential calorimetric system based on the electrothermal analogy method is proposed. Using the model, the dynamics of average temperatures and heat flow changes in the system elements, the temperature perturbations and the technological parameters spread influences on the measurement error are researched.