A Summary of the Most Recent Results and Experimental Activity Performed in the Mass/Volume Laboratory at the JRC Ispra Establishment

The mass/volume laboratory at the JRC, Ispra Establishment is a unique large full scale facility incorporating a variety of tanks of different shapes and sizes which are typically found in nuclear facilities. The facility provides support to the nuclear inspectorates in the form of training courses for both the IAEA and Euratom. More recently these training courses have been extended to include inspectors and operators of the Commonwealth of Independent States under the TACIS programme of support of the European Commission. Results are reported on the laboratory activity which now operates in a multi-functional mode in providing these training courses; in providing back-up experimental activity for inspectors and operators on influencing factors and phenomena affecting liquid level measurements and thus accountability; in providing an experimental testing facility for portable process monitoring equipment systems developed at the JRC and currently employed in field trials in reprocessing facilities. Results will be presented demonstrating the effects of slow and fast bubbling rates in the dip-tube measurement system, their interpretation, and errors, on data acquisition and analysis, on continuous versus incremental calibration conditions, and evaporation. The feasibility of using in-situ pressure measurements via the portable acquisition systems for identifying reference points, such as discontinuities within tanks, which can subsequently be applied for tank re-calibrations will also be presented. This method offers the incentives of cost savings by reducing interference and downtime of reprocessing plant operation.