Responses of Single-Cell and Differential Calorimeters: from Out-of-Pile Calibration to Irradiation Campaigns.

Abstract

Abstract-The nuclear radiation energy deposition rate (unit usually employed: W.g -1 ) is a key parameter for the thermal design of experiments on materials and nuclear fuel carried out in experimental channels of irradiation reactors, such as the French reactor in Saclay called OSIRIS or the Polish reactor named MARIA. In particular the quantification of nuclear heating allows the prediction of heat and thermal conditions induced in irradiated devices and/or structural materials. Various sensors are used to quantify this parameter, in particular radiometric calorimeters, also known as in-pile calorimeters. Two main kinds of in-pile calorimeter exist possessing two geometries and two measurement principles: the single-cell calorimeter and the differential calorimeter. The present work focuses on specific examples of these calorimeter types, from the step of their out-of-pile calibration (transient and steady experiments respectively) to the comparison between numerical and experimental results obtained from two irradiation campaigns (French and Polish reactors). The main aim of this paper is to propose a steady numerical approach to estimate the single-cell calorimeter response under irradiation conditions.

Nuclear instrumentation and measurement: a review based on the ANIMMA conferences

“…Moreover, Brun et al simulated CAR-MEN type calorimeter under laboratory conditions and under in-pile conditions corresponding to two irradiation campaigns into OSIRIS periphery. A very good agreement between experimental and numerical results was found [130], suggesting that such numerical simulations can be used to design new calorimeters and to predict their response (cf. section dedicated to single-cell calorimeter).…”

“…It allows a wide automatic displacement range from À139 to +906 mm. The second two-superposed-cell calorimeter was integrated into a multi-sensor device called CARMEN [20] developed in the framework of the joint IN-CORE research program between CEA and AMU in order to quantify several key parameters simultaneously such as thermal and fast neutron fluxes, photon fluxes and nuclear heating in periphery channels of OSIRIS reactor up to 2 W/g, by coupling a differential calorimeter [130], a gamma thermometer, ionization chambers, fission chambers, SPNDs, and Self-Powered Gamma Detectors (SPGDs).…”

“…The authors performed calculations for both cases of laboratory conditions in [131] and in-pile conditions in [126,[128][129][130]. For instance, Carcreff et al determined the numerical temperature field inside a CALMOS type calorimeter in order to check that the maximal temperature, reached for a nuclear heating equal to 13 W/g corresponds to a suitable value (lower than material fusion temperature) [126].…”

“…Brun et al listed the advantages associated to the use of differential or single-cell calorimeters [130]. One advantage of differential calorimeters is related to the heaters located inside the calorimetric cells which allow three measurement methods to determine the nuclear heating inside the irradiation channels.…”

“…The authors scheduled thermal conductivity measurements by a specialized laboratory (instead of theoretical law) in order to improve in the future the numerical estimation of the correction coefficient [129]. Brun et al proposed a correlation for a nonlinear response [130].…”