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Main text Since 1976, 23 laboratories have submitted 44 samples of 134Cs to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Cs-134. In the last few years, the POLATOM (Poland), the NRC (Canada), the LNMRI-IRD (Brazil) and the PTB (Germany) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR or linked to the SIR from the APMP.RI(II)-K2.Cs-134 comparison and the updated KCRV have been calculated and the results are given in the form of a table. A graphical representation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Three new participations in the BIPM.RI(II)-K1.I-131 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the CCRI(II)-S6.I-131 comparison piloted by the International Atomic Energy Agency (IAEA) in 2006, based on the participation of CMI-IIR in both comparisons. One NMI used the S6 comparison to update its degree of equivalence. The results of two NMIs in the CCRI(II)-S6.I-131 comparison were superseded by a more recent APMP.RI(II)-K2.I-131 comparison. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for the latest results in the BIPM.RI(II)-K1.I-131, and the linked CCRI(II)-S6.I-131, APMP.RI(II)-K2.I-131 and EURAMET.RI(II)-K2.I-131 comparisons. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1976, 15 laboratories have submitted 39 samples of 88Y to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Y-88. Recently, the LNE-LNHB (France) and the BEV (Austria) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1977, 23 laboratories have submitted 45 samples of 133Ba to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ba-133. Recently, the NRC (Canada), the TENMAK-NÜKEN (Türkiye), the NMISA (South Africa) and the NIST (United States) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between the updated KCRV and each equivalent activity measured in the SIR or linked to the SIR from the APMP.RI(II)-K2.Ba-133 comparison have been calculated and the results are given in the form of a table. A graphical representation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1976, 13 laboratories have submitted 27 samples of 139Ce to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ce-139. Recently, the NMISA (South Africa) and the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1979, 8 laboratories have submitted 20 samples of 201Tl to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifer BIPM.RI(II)-K1.Tl-201. The NIST (United States) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1975, 7 laboratories have submitted 13 samples of 113Sn to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Sn-113. Recently, the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been updated to take account of the change of the 113Sn half-life value used for the SIR. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Three new participations in the BIPM.RI(II)-K1.Co-57 comparison have been added to the previous results and this has produced a revised value for the key comparison reference value (KCRV), calculated using the power-moderated weighted mean. A link has been made to the CCRI(II)-S6.Co-57 comparison piloted by the International Atomic Energy Agency (IAEA) in 2008 for which one sample of the 57Co radioactive solution was sent to the SIR. Two NMIs used the S6 comparison to update their degree of equivalence. The degrees of equivalence between each equivalent activity measured in the International Reference System (SIR) and the KCRV have been calculated and the results are given in the form of a table for the remaining seven NMIs in the BIPM.RI(II)-K1.Co-57 comparison and the three eligible participants in the CCRI(II)-S6.Co-57 comparison. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

International audience; This work investigates a compact Compton Suppression System (CSS) based on a High-Purity Germanium (HPGe) diode as a primary spectrometer. From a wide range of potential materials for the guard detector, including plastic scintillator, Thallium doped Sodium Iodide (NaI(Tl)), and Lanthanum III bromide (LaBr3), a bismuth germanate crystal (BGO) is selected on account of a high photon mass-attenuation coefficient, thus allowing more compactness. The authors then describe the complete design study of an HPGe/BGO CSS based on the post-processing of Monte Carlo particle track history files (MCNP6.1/PTRAC). The calculation program, simulating the filtering of coincident events on both primary and secondary detectors, is validated through a series of experimental measurements using Am-241, Cs-137, and Co-60 sources in various configurations. On the basis of this empirically validated calculation, an optimization study of the BGO-active shield is performed over two factors of merit: Compton Suppression Factor (CSF) and Full-Energy Peak Efficiency. Optimization steps subsequently involve the scaling of BGO internal and external radii, the thickness of the entrance window, and the diameter of a collimation hole. Eventually, performance figures of the CSS are illustrated in a case study involving the characterization of large waste containers, carrying low levels of uranium activity to seek among natural radiological background. Calculation results show a lowering of minimal detectable activities (MDA) by a factor of 2.5 based on the signature of 1001-keV gamma rays from U-238.

This work aims at proposing ways to robustly predict gaseous fission product behavior in fast spectrum and subsequently improve the nuclear instrumentation dedicated to clad failure detection. The goal is, first to estimate concentrations and expected activities in the fuel at any time and second, the fraction released through the clad when a failure takes place.

Main text Since 2014, 3 laboratories have submitted 3 samples of 223Ra to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ra-223. The NPL (United Kingdom), the PTB (Germany) and the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been calculated for the first time. The degrees of equivalence between each equivalent activity measured in the SIR and the KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1975, 10 laboratories have submitted 28 samples of 85Sr to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Sr-85. Recently, the PTB Germany) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text In 2019, the IRA (Switzerland) submitted a sample of 161Tb to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Tb-161. As IRA is the first participant in the comparison no key comparison reference value (KCRV) and no degrees of equivalence can be calculated. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Metrological non-destructive characterization of intense ( α , n) neutron sources (emission rate between 107 and 3 × 108 s−1 into 4 π sr solid angle) is a challenge for nuclear applications. In this article, we will present the design, development and in situ validation of two measurement cells especially dedicated to this characterization. The main goal consists in determining the absolute neutron emission rate of this type of neutron sources with relative uncertainties less than 5% (k=1). Another purpose is related to the qualitative and quantitative analysis of fission products present in irradiated neutron sources. Because of experimental constraints, acquisitions were carried out underwater which required a full remote control of the measurement cells. Neutron emission rate is assessed using three different non-destructive techniques: (i) global neutron counting, (ii) neutron activation using gold dosimeters and (iii) gamma-ray spectrometry. We will successively present the design step and associated constraints, main characteristics of measurement cells and associated laboratory characterization as well as experimental results obtained during the final in situ measurement campaign. The latter shows an excellent agreement regarding the neutron emission rate values provided by the three different non-destructive techniques and a relative combined standard uncertainty less than 5% (k=1) for the investigated neutron sources.

Main text Since 1978, 10 laboratories have submitted 17 samples of 67Ga to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ga-67. The PTB (Germany) and the NIST (United States) participated in the comparison. The key comparison reference value (KCRV) has been re-calculated using the power-moderated weighted mean. The degrees of equivalence between each equivalent activity measured in the SIR and the KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1976, 29 laboratories have submitted 73 samples of 60Co to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Co-60. Recently, the VNIIM (Russian Federation) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1988, 3 laboratories have submitted 5 samples of 153Gd to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Gd-153. Recently, the NIST (United States) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text In 2019, the PTB(Germany) has submitted a sample of 225Ac to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ac-225. As PTB is the first participant in the comparison no key comparison reference value (KCRV) and no degrees of equivalence can be calculated. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database https://www.bipm.org/kcdb/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text A comparison of the activity concentration of an 55Fe solution was organized by the POLATOM under the auspices of the CCRI(II). The solution was sent to thirteen laboratories; ready-to-measure sources were also prepared using the same 55Fe solution in diffusive (polyethylene) vials and sent to twelve laboratories. Twelve measurement reports were received. The results, as well as relevant information on the measurement techniques, are presented and analysed in this paper. The differences in the results obtained from measurements in non-diffusive (glass) and diffusive vials are indicated. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1983, 6 laboratories have submitted 7 samples of 110mAg to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)-K1.Ag-110m. Recently, the PTB (Germany) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Main text Since 1976, 28 laboratories have submitted 72 samples of 60Co to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Co-60. Recently, the PTB (Germany) and the TAEK (Turkey) participated in the comparison and the key comparison reference value (KCRV) has been updated to include the PTB result. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The responses of the three photomultiplier tubes (PMTs) in a triple-to-double coincidence ratio (TDCR) liquid scintillation (LS) system are often not identical. Such asymmetries can have a significant influence on activity determinations. The problem is often solved by means of a minimization algorithm which can easily be applied when analytical methods are used for the efficiency calculation, as is usually done for pure beta emitters. However, for radionuclides with more complex decay schemes, the counting efficiencies are often calculated with stochastic methods and the computation of the required corrections becomes very challenging. This paper presents a new numerical method to overcome the asymmetry problem for such complex decays and a comprehensive study on 55Fe is described in detail. For the measurements, the asymmetry was varied by means of grey filter films which were placed in front of one of the photomultiplier tubes. In the case of the pure electron-capture (EC) radionuclide 55Fe, the asymmetry can also be taken into account with a very simple correction which is derived assuming monoenergetic emissions. This work is also of great importance for the planned extension of the International Reference System (SIR) at the BIPM which will be used for international comparisons in radionuclide metrology.

CEA LIST is working of the development of a high-sensitivity thermal neutron counter, based on the insertion of gadolinium in spherical plastic scintillators. As the radiation sensor comprises one or several volumes of scintillating polymers, it is, by nature, sensitive to both neutron and gamma radiations. This property allows the development of a versatile detector, provided that it is possible to algorithmically separate the signature of both types of radiations. The technologically building brick is, moreover, to be implemented in a transportable ( 15 kg) system, handled by a first intervention task force in an exposed area. The aim of this paper is to study, both through Monte Carlo simulation and experimentally, an algorithmic architecture of the measurement chain discriminating neutron and gamma events. The presentation is subdivided in three main sections. First, we detail a comparative study between the outputs of a numerical modeling tool, developed to simulate the total response of the sensor to varying radiation sources and the results of a series of experiments carried out in a controlled environment. Second, we describe the building and numerical pre-validation of a simulation code dedicated to the study of consolidated algorithmic architecture, namely γ – γ quasi-coincidence on two adjacent plastic scintillators. Third, we comment on an experimental study of γ – γ quasi-coincidence, Gd-based neutron detection and a comparison between the results and the estimated of the numerical study. We conclude with the presentation of first estimates of neutron sensitivity), gamma-background vulnerability, and n/ γ discrimination ratio for the scaled and assessed, material and algorithmic architectures.

Since 1976, 13 laboratories have submitted 29 samples of 22Na to the International Reference System (SIR) for activity comparison at the Bureau International des Poids et Mesures (BIPM), with comparison identifier BIPM.RI(II)- K1.Na-22. Recently, the LNE-LNHB (France) participated in the comparison and the key comparison reference value (KCRV) has been updated. The degrees of equivalence between each equivalent activity measured in the SIR and the updated KCRV have been calculated and the results are given in the form of a table. A graphical presentation is also given. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

The principle of the proposed method is based on a simple and efficient way to estimate the muon energy deposition in a cylindrical sensor. Muon initial energy is randomly sampled from experimental distributions and the traveled distance through the scintillator volume is assessed from a Monte-Carlo model in cylindrical coordinates. Energy deposition is estimated by solving Bethe-Block formula thanks to digital Euler approximation. This model has been experimentally tested in our laboratory using NaI(Tl) scintillator apparatus. Results from this comparison show good agreement and confirm the potential of the model. Sources of discrepancy are emphasized, while explaining peak shift between experimental results and theoretical calculations.

Pulse shape analysis is commonly implemented into nuclear detection systems notably dealing with phoswich structures addressingfor instance beta or neutron discrimination from gammarays. Particle transport codes such as MCNP, TRIPOLI or GEANT are useful toolsto help designing phoswich systems. However, the basic calculation is focused on the estimation of the deposited energy per particlehistory into scintillator parts. The new model proposed by the CEA LIST enables to process scintillation light production, collection, conversion, and thereafter pulse shape simulation at the output of a photomultiplier.

The approach of the scheme is to pile-up X-ray photons on the scintillator to generate a high energy peak in the spectrum. The system includes a miniature X-ray generator, a brass disk with a thin slit rotated by a motor and placed in front of the X-ray window, and a collimator placed in front of the scintillation detector to reduce the time of alignment between the scintillation detector and the X-ray generator. The rotating brass disk placed between the X-ray source and the collimator is deployed as a high-frequency obturator. If, during a time duration lower than the integration time of the scintillation detector, a large number of photons interact with the scintillator, the energy is added and the spectrometer records this energy as the contribution of a high energy single photon. Experimental results underlines a tangible proof of concept for a selfcalibration device, which will be valuable for the correction of the temperature drift in the scintillator-photomultiplier pair.

International audience; CEA LIST has investigated different schemes enabling neutron detection thanks to the implementation of gadolinium converters. The fine analysis of the prompt gamma ray signature has permitted us to propose and test dedicated designs such as Gd-doped plastic scintillator, large spherical scintillators or compensated CdZnTe diodes.

La realisation du programme d’experimentations nucleaires en Polynesie francaise a ete accompagnee par la mise en place d’un dispositif de surveillance radiologique de l’environnement, qu’il s’agisse du milieu physique ou biologique, continental ou marin, vegetal ou animal, afin de s’assurer de l’absence de risque pour les populations. Ce dispositif a pris toute son importance avec les essais realises dans l’atmosphere entre 1966 et 1974. Sa mise en œuvre a necessite des moyens importants en materiel et en personnel avec l’intervention d’organismes civils et militaires ou parfois mixtes. La surveillance a naturellement ete exercee de facon tres complete dans les zones voisines des sites de tir, mais aussi sur l’ensemble du territoire polynesien, notamment les atolls les plus peuples. Elle a porte egalement, mais de facon plus allegee, sur des zones lointaines, comme les pays andins, en raison de leur situation geographique. Les resultats obtenus par les differents laboratoires impliques etaient rassembles et interpretes afin d’assurer l’information des responsables et des autorites, notamment en Polynesie, et a travers eux la population. Ils ont ete chaque annee transmis au comite scientifique des Nations-Unies pour l’etude des effets des rayonnements ionisants (UNSCEAR). Le dispositif de surveillance est ainsi decrit, en dehors des zones proches des zones de tir, avec la presentation des differents organismes impliques et celle des differents programmes de surveillance.

Conference of 4th International Conference on Advancements in Nuclear Instrumentation Measurement Methods and their Applications, ANIMMA 2015 ; Conference Code:121554; International audience; Radionuclide identification and quantification is a serious concern for many applications as safety or security of nuclear power plant or fuel cycle facility, CBRN risk identification, environmental radioprotection and waste measurements. High resolution gamma-ray spectrometry based on HPGe detectors is a performing solution for all these topics. During last decades, a great number of software has been developed to improve gamma spectra analysis. However, some difficulties remain in the analysis when full energy peaks are folded together with a high ratio between their amplitudes, when the Compton background is much larger compared to the signal of a single peak and when spectra are composed of a great number of peaks. This study deals with the comparison between a conventional analysis method and an innovative approach, called SINBAD ("Spectrométrie par Inférence Non paramétrique BAyesienne Déconvolutive"), for radionuclide identification and quantification. For many years, SINBAD has been developed by the CEA LIST for unfolding complex spectra from HPGe detectors. Contrary to the conventional method using fitting procedures, SINBAD uses a probabilistic approach with nonparametric Bayesian inference to process spectrum data. The conventional fitting method founded for instance in Genie 2000 is compared with the nonparametric SINBAD approach regarding some key figures of merit as the peak centroid estimation (identification step) and net peak area determination (quantification step). Complex cases are studied for nuclide detection with closed gamma-rays energies and high full energy peak intensity differences. Tests are performed with spectra from the International Atomic Energy Agency (IAEA) for gamma spectra analysis software benchmark and with spectra acquired in our laboratory. It appears that SINBAD results are better than GENIE 2000 ones in most of the cases even if hard deconvolutions can be achieved thanks to GENIE 2000 at the cost of expert parameters fine tuning which has to be compared with the user-friendly SINBAD operating.

International audience; In the context of failed fuel detection in Sodium-cooled Fast Reactors (SFR), Delayed Neutrons Detection (DND) systems are implemented. This study deals with the design optimization of such a system by Monte-Carlo particle transport simulation (MCNP). During a clad failure, neutron precursor fission products (mainly halogen ones: 137 I, 87 Br, 88 Br) escape into the primary coolant. The detection of these precursors through their delayed neutrons ensures a diagnosis on clad failures events. In DND systems, 3 He proportional counters are chosen as the best available technology for neutron detection purposes. Associated with 3 He counters, polyethylene blankets are required in order to thermalize neutrons. Feedbacks from past SFR have shown an important noise coming from photoneutrons mitigating the signal-to-noise ratio. These photoneutrons originate from the 2 D(γ,n) reaction in polyethylene (in natural abundance) and is due to the 24 Na activity. Another material avoiding photoneutrons production is considered in this paper as moderator. Indeed, the graphite appears as a good candidate, sufficiently light for neutron thermalization and with a C(γ,n) reaction threshold higher than energies considered here. The first simulations run with MCNPX code provide satisfactory results for a low-noise DND system based on graphite thermalizing.

Les etudes et recherches relatives a l'environnement, c'est-a-dire la radioecologie, ont debute en France au milieu des annees 1950, essentiellement au Commissariat a l'energie atomique. La mise en ?uvre de programmes nucleaires militaires, d'abord a l'etranger puis en France, a conduit a developper ces etudes, en raison des retombees dues aux essais atmospheriques americains et russes mais aussi des rejets des installations produisant les matieres fissiles necessaires (en France, le centre de Marcoule). Par la suite, le developpement des utilisations civiles de l'energie nucleaire a conduit a en faire une branche importante de la radioprotection. L'emergence de ces etudes, l'action des premiers acteurs, l'adaptation des structures, sont les elements de l'histoire de cette discipline ; elles l'ont amenee, au milieu des annees 1960, a son rythme de croisiere. On presente l'histoire de la radioecologie durant cette periode (1955-65), illustree par les premieres grandes etudes realisees alors.

Five ultrasound laboratories from Obstetrics and Gynecology departments of Belgian university hospitals or affiliated institutions conducted a prospective study from 1984 to 1992 in which the results of prenatal ultrasound examinations were compared to examination reports of the neonates. The results of the period 1984–89 (PI) have been published previously, and those of the period 1990–92 (PII) are presented here. Some very minor congenital anomalies, as listed. and defined in the EUROCAT Register, were excluded. Of 26 147 pregnant women at normal risk for congenital anomalies, 25 046 had at least one ultrasound scan (96%). A total of 616 fetuses were structurally abnormal (prevalence 2.42%), and 685 abnormalities were recorded. The sensitivity of the ultrasound test was 40.4% in PI and 51.1% in PII for abnormal fetuses (p < 0.05) and 45% (PI) and 64% (PII) for abnormalities (p < 0.01). The specificity was 99.9%) and the positive and negative predictive values were 94.2% and 98.6%, respectively; these values did not differ significantly between the two periods. The sensitivity for the detection of anomalies before 23 weeks increased from 21% in PI to 41% in PII, indicating an improvement in the early detection of fetal abnormalities. Copyright © 1995 International Society of Ultrasound in Obstetrics and Gynecology

This work deals with the use of gamma spectrometry to monitor the fourth generation sodium fast reactor (SFR) power. Simulation part has shown that power monitoring in short response time and with high accuracy is possible measuring delayed gamma emitters produced in the liquid sodium. An experimental test is under preparation at French SFR Phenix experimental reactor to validate simulation studies.

A (sub)millimetric source is obtained by difference-frequency mixing in a nonlinear crystal. It allows investigation of spectral absorption between 4 and 40 cm−1 with a new two-beam spectroscopic mounting. The complete mounting is described. The measurement method is given in detail. Compressed gaseous nitrogen-induced absorption measurements are used to calculate relaxation times and spectral moments. Comparisons are made with other measurements in close frequency regions, and theoretical models and an empirical line-shape model.

United States and European consensus views differ on the place of routine ultrasound scans during pregnancy and the validity of such scans as screening tests for fetal malformations in the general population is still under debate. Four ultrasound laboratories from Obstetric and Gynecology departments of Belgian University hospitals and affiliated hospitals have conducted a prospective study from 1984 to 1989 to compare the anomalies discovered in ultrasonic screening of the fetus with the anomalies of the neonates. Of 16,370 pregnant women at normal risk for congenital anomalies attending the antenatal clinics of these hospitals, 16,072 have had at least one ultrasound screening for congenital anomalies (98.5%). Congenital anomalies, single or multiple and 'minor' or 'major', were clearly defined in order to allow comparisons. The excluded congenital anomalies were listed as defined in the Eurocat Register. A total of 381 fetuses (2.3%) were structurally abnormal. Of the 381, 154 were correctly detected by ultrasound (sensitivity 40.4%). Altogether 15,972 fetuses were true negatives (specificity 99.9%). Eight (0.05%) were false positive for congenital anomalies. The positive predictive value was 95.1% and the negative predictive value was 98.6%. Ultrasound diagnoses were correctly achieved before 23 weeks of gestation for 21% of the anomalies. The gestational age, operator and technical dependence of ultrasound screening for congenital anomalies is discussed.

A four stage study of the life cycle inventories of polyvinyl chloride (PVC) resin manufacturing, compounding, part fabrication and disposal was conducted by IBM to evaluate the environmental burdens associated with the use of PVC in structural applications for personal computer products. The overall project was performed in two phases. The first phase developed inventories for the various processes involved in the manufacture of a typical PVC housing. These processes included suspension polymerization of PVC, production of a commercially formulated PVC compound, part molding, the use of copper paint for metallization (electromagnetic shielding) of the part, an alternative metallization technology (the use of a discrete steel liner inside the PVC part), and the use of a waterborne paint for decorative finishing of the PVC part as opposed to integral finish obtained from the mold. This manufacturing phase of the study provided a comparison of shielding technologies as well as an assessment of the relative and cumulative burdens of the part manufacturing processes. Phase two of the project provided ecoprofiles of three disposal alternatives for a clean PVC plastic part at end-of-life: landfilling, incineration with heat recovery, and a closed loop recycling option. This paper presents the manufacturing phase data (phase one) of the project and their relationship to the end-of-life conclusions, In addition, the work provides recommendations for environmentally preferable design guidelines and recycling applications.

Hewlett-Packard's Inkjet Business Unit (HP IJBU) designs and manufactures inkjet print cartridges for a wide variety of computer printers, plotters, facsimile machines and related equipment sold by Hewlett-Packard and other companies. In September 1994, HP IJBU undertook a comprehensive life cycle assessment (LCA) of it's highest selling print cartridge. The project was conducted with the assistance of Ecobalance, Inc., the US branch of a worldwide LCA consulting firm. After six months of extensive work involving many of HP's primary suppliers and over 100 HP people spread over the USA, Europe, and Asia, the project was completed. To the authors' knowledge, this in-depth LCA of a consumable is one of the first in the computer industry. This paper covers the reasons for undertaking the study, the project findings, and how this information is being used.

In Europe, Life Cycle Assessment (LCA) has proven to belong to that category of tools providing quantitative objective and scientific analysis on some environmental impacts of industrial systems. The reason for this is that an LCA is a detailed and quantitative balance-sheet of energetics and material inputs and outputs of a carefully defined system describing a product, an activity, or a set of processes. In the case of a product Life Cycle Assessment, the system encompasses the entire "life cycle" of the product, from raw material extraction to the different end of life management alternatives (landfilling, incineration, recycling, reusing, etc.), including the manufacturing stages, transportation, distribution, use and waste collection. One of the most important applications of LCAs is that it highlights this pollution displacement which then in turn can be better managed and controlled. By providing an unbiased analysis of entire industrial systems, LCA has shown that the reality behind widely held beliefs regarding "green" issues such as reusable vs. one way products, recycling vs. incineration, "natural" vs. synthetic products were far more complex than expected and not as "green" as assumed. >

This joint study between Environment Canada and Northern Telecom aimed at carrying out an LCA on a manufactured product, the Nortel M7310 business telephone, in order to identify improvement strategies. The telephone, invented a century ago, by Alexander Graham Bell in Canada, is emblematic of a sophisticated but common everyday product. As such, this study provides an excellent demonstration of the benefits of design-for-environment. This paper describes the details of the methodology.

IBM is evaluating the environmental burdens associated with the use of polyvinyl chloride (PVC) in major structural parts for information technology equipment. The evaluation involves developing life cycle inventories of the following four stages: (I) production of PVC from raw materials, (II) PVC compounding, (III) molding, finishing (for electromagnetic compatibility (EMC) and decorative appearance) and (IV) the end-of-life disposal options This paper presents a study of the life cycle inventories of the end-of-life disposal options of Stage IV. The work compares landfilling, incineration with heat recovery, and an experimental closed loop PVC recycling process implemented by IBM in conjunction with its cathode ray tube (CRT) recycling process. Sensitivity and scenario analyses were used to test the influence of key parameters in each disposal system. This study demonstrates the utility of life cycle assessment for decision-making on waste management alternatives and defines criteria that constitute an environmentally positive profile for a closed-loop recycling process for business machine applications.

Market pressures and regulations are increasingly driving businesses to consider environmental issues during product development, promoting the idea of design for environment (DfE). A number of different approaches to DfE have emerged as this concept takes hold, which cover the spectrum from life cycle assessment (LCA) to guidelines for design to design for disassembly. Conducting a full LCA is very difficult for those who are not familiar with the method, such as design teams charged with the development of complex products (e.g., electronic devices or cars). Other approaches to DfE address specific concerns but have limitations in scope and applicability. To fully address the concept of DfE, most companies require an integrated approach that provides life cycle data for their products and addresses regulatory and consumer concerns. This paper presents how each of these different DfE approaches falls short with respect to the requirements of a product design team. It presents how these methodologies can be combined to provide a robust life cycle design tool, and outlines how it would meet the needs of a typical design team.

Global companies are beginning to recognize the health, safety, environmental and economic benefits of resource management programs that lead to a position of sustainable development. As a result, many such companies are developing and beginning to implement design practices that consider environmental aspects across all life stages of their products (raw material acquisition, manufacturing, packaging/distribution, use/service, and end-of-life management). The Ecobilan Group's Environmental Information & Management Explorer (EIME) tool was developed to enable eco-design practices in the electronics industry. To illustrate the utility of EIME, a case study performed by the Eastman Kodak Company (Kodak) during pilot testing of the software is presented and discussed. Pilot study experience indicates that several enhancements to the tool are necessary for broad use. The Ecobilan Group is working in partnership with Kodak and potentially other stakeholders to further enhance the EIME tool. Enhancements that have been identified include expanding the capability to model product end-of-life alternatives, incorporating a single-figure eco-efficiency index for scoring environmental performance of products, expanding the current life cycle inventory database, and developing connectivity between EIME and predict data management libraries.