In-reactor testing of ionic thermometers

Abstract

Ionic thermometers have been tested in a nuclear reactor with attention to the steepness of the ionic conductivity jump and the influence of a glass container on the accuracy of the temperature measurements. It was found that, at the neutron fluxes up to 1.5×1018 m−2 s−1 (thermal) and 3×1018 m−2 s−1 (fast) in a light water reactor, the change of conductivity jump slope is negligible or nil for an ionic thermometer filled by HgI2, i.e., at 256.0±0.2 °C. The need to use boron-free glass was confirmed. The impact on the accuracy of the temperature point indication in a nuclear reactor core is discussed, as well as obvious inertness of the melting process mechanism to the intense irradiation field.

Thermometric standard for continuous scale verification in thermal analysis

“…This instrument makes it possible to check the thermometers directly in situ, inside the industrial plant [5]. It has even been proved that these elements are usable as internal standards inside the core of the nuclear reactor, though of course with higher error [4]. The ITD could be placed inside the measuring block of the DTA or DSC without losses on the thermal balance side.…”