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The influence of beech-wood particle size on its gasification with O2 was investigated in Entrained Flow Reactor (EFR) conditions. Experiments were performed in two facilities at very different scales: a drop tube reactor (DTR), and a pilot-scale EFR, the biomass feeding rates being set at 1 g/min and 90 kg/h respectively. Numerical simulation was used to bring a better understanding of the process. In the DTR, the carbon conversion into gas sharply increased with temperature for the larger particle powder – D50/D95 = 1230/1570 µm – from about 20% at 800 °C to 80 % at 1400 °C. For the smaller particle powder - D50/D95 = 370/510 µm – the conversion was of 80 % or higher whatever the temperature. At 1400 °C, the same conversion of about 80 % was reached for both powders and the gas composition was quite similar. The difference of conversion between the two powders was attributed to heat transfer limitations in the solid, and to a shorter residence time of the larger particles in the reactor. In the pilot-scale EFR, the different powder sizes – the smaller one being similar to the one used in the DTR, and up to D95 of 1040 µm - led to very close results in terms of temperature reached into the reactor, carbon conversion into gas and gas composition. For equivalent ratios (O2/O2 for stoichiometric combustion) of 0.36 and 0.45, the carbon conversion into gas was close to 100 %.

Beech sawdust particle conversion in a drop tube furnace was studied between 800 and 1,400 °C. Particular attention was paid to the influence of temperature and to the presence of oxygen on the gasification process. As temperature increases, light hydrocarbon production decreases and the CO + H2 production (gas of interest for biofuel production) increases. Presence of oxygen in the gasification atmosphere allows consuming a high part of light hydrocarbons and enhancing carbon conversion into gas. However, high yields of CO2 and H2O were observed and the total yield of CO + H2 was lower than in pyrolysis conditions.

A bilateral comparison between ENEA-INMRI (Italy) and NCBJ RC POLATOM (Poland) of 131 I-solution activity measurements was organized in the year 2015 and piloted by POLATOM, which provided the sources for the comparison. The 131 I master solution was standardized independently at both institutes by using Liquid Scintillation Counting and ionization chamber techniques. The 131 I master solution was then sent by POLATOM to the BIPM International Reference System (SIR). The comparison was registered as an EURAMET.RI(II)-K2.I-131 key comparison allowing the ENEA-INMRI result to enter in the SIR database., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Two main non-destructive techniques can be used to measure standard 222 Rn gas ampoules: well-type ionization chambers and gamma-ray spectrometry, the former being used in the Système International de Référence (SIR) for international comparison purposes. The reliability of these techniques requires that the variability of the flame-sealed gas glass ampoules used have a negligible influence on the detector response. This variability is studied in this work by considering three parameters: the volume of the ampoule, the position of the sealing point and the thickness of the glass. Results showed that variability of the gas ampoules induced measurement bias larger than the uncertainty of the standard sources., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

In response to the CIPM MRA, and to improve radioactivity measurements in the face of advancing technologies, the CIPM's consultative committee on ionizing radiation developed a strategic approach to the realization and validation of measurement traceability for radionuclide metrology. As a consequence, measurement institutions throughout the world have devoted no small effort to establish radionuclide metrology capabilities, supported by active quality management systems and validated through prioritized participation in international comparisons, providing a varied stakeholder community with measurement confidence., (Published by Elsevier Ltd.)

The purposes of this study were to create national activity standards of (64)Cu, to make possible the definition of an international key comparison reference value and to determine the decay data in order to improve the decay scheme. Four laboratories measured the activity of a (64)Cu solution; these results were compared through the International Reference System. Moreover, the laboratories carried out new measurements of the photon emission intensities and of the half-life. A new decay scheme was derived from these new values and the previously published ones., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

A comparison exercise for data analysis was recently conducted by the Liquid Scintillation Counting Working Group (LSCWG) of the International Committee on Radionuclide Metrology (ICRM) to evaluate the uncertainties involved in applying different analysis methodologies (including computer programs) for the triple-to-double coincidence ratio (TDCR) method. The goals of the comparison were to (1) study differences in calculation results from different TDCR analysis programs, (2) investigate differences in analysis techniques and uncertainty assessment philosophies between laboratories, and (3) study the effect of not taking asymmetry of photomultiplier tube (PMT) efficiencies into account on the calculated activity. To achieve this, a single set of TDCR data for the pure beta emitter (99)Tc, was distributed to the participants, who analyzed the data according to their normal procedures and report the activity concentration of the (99)Tc solution from their results. The results indicate that the presently used programs are generally able to calculate the same activity values, assuming that the correct input parameters are used and that not taking PMT asymmetry into account in the calculations can lead to significant (0.6% for (99)Tc) errors in reported results. The comparison also highlighted the need for a more rigorous approach to estimating and reporting uncertainties., (Published by Elsevier Ltd.)

The results of an international comparison of activity measurements of a solution of (55)Fe organized by the BIPM in 2005 are reported and analysed. This exercise, which follows the procedures of the CIPM mutual recognition arrangement to update older comparisons, is a renewal of the comparison organized by the BIPM that took place in 1978. A EUROMET comparison was organized in 1996 specifically to compare activity measurements of a (55)Fe solution by means of liquid-scintillation techniques. Results of these three comparisons are presented and discussed in this paper. The radionuclide solution was provided by the NPL, which also distributed the samples to the participants. The activity of the ampoules was measured by 16 laboratories using 12 methods producing 25 results. Some general considerations on uncertainty assessments pertaining to the different techniques used are drawn. The outcome of four different estimators is compared from which the presence of at least one outlier can be confirmed. Further measurements should be made to try to reduce the discrepancy between the results. To date the outcome of the present comparison does not show an improvement to that of the 1996 comparison.

This paper reports contributions from participants in the EUROMET project (No. 416) which was entitled "237Np research into problems relating to purification, characterization and standardization". Primary standardizations were made by the defined low solid angle, coincidence, 4pi alpha, 2pi alpha and liquid scintillation counting methods. Secondary standardizations were made with calibrated gamma-ray spectrometers. Absolute X-ray, gamma-ray and alpha-particle emission probabilities were also determined. The results for the successful conclusion of both primary and secondary standardization are presented together with the values for alpha-particle and gamma-ray emission probabilities determined in this exercise. Several significant inconsistencies remain with the gamma-ray emission probabilities, and these are highlighted.

The harmonization of different National Measurement Systems depends on the ability to demonstrate Equivalence between them. The responsibility for establishing a procedure to achieve this lies with the International Committee of Weights and Measures (CIPM) and its associated Consultative Committees. In pursuit of these ends, a series of general recommendations and procedures have been developed by BIPM in order to achieve these objectives. Central to these recommendations is the concept of Key Comparisons which involve a series of comparison exercises both within and between the regional metrology organizations, such as EUROMET, NORAMET and APMP. Because of the unique nature of radioactivity standardization, this generalized procedure is, for practical purposes, impossible to apply in the field of radionuclide metrology. The remedy has been the development of a protocol which optimizes both the current effort available within existing National Metrology Institutes (NMIs) and the considerable amount of data from previous intercomparisons. This paper details this novel approach, provides practical examples, discusses potential problems and examines the way in which the programme will continue and expand.