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The Fork detector is widely used by the safeguards inspectorate of the European Atomic Energy Community (EURATOM) and the International Atomic Energy Agency (IAEA) to verify spent nuclear fuel. Fork measurements are routinely performed for safeguards prior to dry storage cask loading. Additionally, spent fuel verification will be required at the facilities where encapsulation is performed for acceptance in the final repositories planned in Sweden and Finland. The use of the Fork detector as a quantitative instrument has not been prevalent due to the complexity of correlating the measured neutron and gamma ray signals with fuel inventories and operator declarations. A spent fuel data analysis module based on the ORIGEN burnup code was recently implemented to provide automated real-time analysis of Fork detector data. This module allows quantitative predictions of expected neutron count rates and gamma units as measured by the Fork detectors using safeguards declarations and available reactor operating data. This paper describes field testing of the Fork data analysis module using data acquired from 339 assemblies measured during routine dry cask loading inspection campaigns in Europe. Assemblies include both uranium oxide and mixed-oxide fuel assemblies. More recent measurements of 50 spent fuel assemblies at the Swedish Central Interim Storage Facility for Spent Nuclear Fuel are also analyzed. An evaluation of uncertainties in the Fork measurement data is performed to quantify the ability of the data analysis module to verify operator declarations and to develop quantitative go/no-go criteria for safeguards verification measurements during cask loading or encapsulation operations. The goal of this approach is to provide safeguards inspectors with reliable real-time data analysis tools to rapidly identify discrepancies in operator declarations and to detect potential partial defects in spent fuel assemblies with improved reliability and minimal false positive alarms. The results are summarized, and sources and magnitudes of uncertainties are identified, and the impact of analysis uncertainties on the ability to confirm operator declarations is quantified.

A project to research the application of nondestructive assay (NDA) to spent fuel assemblies is underway. The research team comprises the European Atomic Energy Community (EURATOM), embodied by the European Commission, DG Energy, Directorate EURATOM Safeguards; the Swedish Nuclear Fuel and Waste Management Company (SKB); two universities; and several United States national laboratories. The Next Generation of Safeguards Initiative–Spent Fuel project team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. This study focuses on spectrally resolved gamma-ray measurements performed on a diverse set of 50 assemblies [25 pressurized water reactor (PWR) assemblies and 25 boiling water reactor (BWR) assemblies]; these same 50 assemblies will be measured with neutron-based NDA instruments and a full-length calorimeter. Given that encapsulation/repository and dry storage safeguards are the primarily intended applications, the analysis focused on the dominant gamma-ray lines of 137 Cs, 154 Eu, and 134 Cs because these isotopes will be the primary gamma-ray emitters during the time frames of interest to these applications. This study addresses the impact on the measured passive gamma-ray signals due to the following factors: burnup, initial enrichment, cooling time, assembly type (eight different PWR and six different BWR fuel designs), presence of gadolinium rods, and anomalies in operating history. To compare the measured results with theory, a limited number of ORIGEN-ARP simulations were performed.

This research focused on the analysis of a set of stationary passive gamma measurements taken on the spent nuclear fuel assemblies from a boiling water reactor (BWR) using pulse height analysis data acquisition. The measurements were performed on 25 different BWR assemblies in 2014 at Sweden’s Central Interim Storage Facility for Spent Nuclear Fuel (Clab). This study was performed as part of the Next Generation of Safeguards Initiative–Spent Fuel project to research the application of nondestructive assay (NDA) to spent fuel assemblies. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay (NDA) measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins, (3) estimate the plutonium mass, (4) estimate the decay heat, and (5) determine the reactivity of spent fuel assemblies. The final objective of this project is to quantify the capability of several integrated NDA instruments to meet the aforementioned goals using the combined signatures of neutrons, gamma rays, and heat. This report presents a selection of the measured data and summarizes an analysis of the results. Specifically, trends in themore » count rates measured for spectral lines from the following isotopes were analyzed as a function of the declared burnup and cooling time: 137Cs, 154Eu, 134Cs, and to a lesser extent, 106Ru and 144Ce. From these measured count rates, predictive algorithms were developed to enable the estimation of the burnup and cooling time. Furthermore, these algorithms were benchmarked on a set of assemblies not included in the standard assemblies set used by this research team.« less

The purpose of the Next Generation Safeguards Initiative (NGSI)–Spent Fuel (SF) project is to strengthen the technical toolkit of safeguards inspectors and/or other interested parties. The NGSI–SF team is working to achieve the following technical goals more easily and efficiently than in the past using nondestructive assay measurements of spent fuel assemblies: (1) verify the initial enrichment, burnup, and cooling time of facility declaration; (2) detect the diversion or replacement of pins; (3) estimate the plutonium mass [which is also a function of the variables in (1)]; (4) estimate the decay heat; and (5) determine the reactivity of spent fuel assemblies. Since August 2013, a set of measurement campaigns has been conducted at the Central Interim Storage Facility for Spent Nuclear Fuel (Clab), in collaboration with Swedish Nuclear Fuel and Waste Management Company (SKB). One purpose of the measurement campaigns was to acquire passive gamma spectra with high-purity germanium and lanthanum bromide scintillation detectors from Pressurized Water Reactor and Boiling Water Reactor spent fuel assemblies. The absolute 137Cs count rate and the 154Eu/137Cs, 134Cs/137Cs, 106Ru/137Cs, and 144Ce/137Cs isotopic ratios were extracted; these values were used to construct corresponding model functions (which describe each measured quantity’s behavior over various combinations of burnup, cooling time, and initial enrichment) and then were used to determine those same quantities in each measured spent fuel assembly. The results obtained in comparison with the operator declared values, as well as the methodology developed, are discussed in detail in the paper.

The details of two product concepts and the hardware realization aspects for low profile Ku-/Ka-band land mobile terminals for high data rate satellite communications are described. Beside the competitive low cost approach, the non-obstructive design and lower weight are key issues for many applications to achieve a broad customer acceptance. The introduction of a proprietary planar antenna technology opens the possibility to meet these requirements.

This paper presents a new architecture for low-cost mobile terminal antennas suitable for linear-polarized satellite communications systems. It is based on a sparse phased array that uses 1-bit phase controls. In this way it is possible to reduce the array cost by employing simpler and fewer controls. Measurements of a prototype demonstrate the feasibility of the approach.

A project to research the application of non-destructive assay (NDA) techniques for spent fuel assemblies is underway at the Central Interim Storage Facility for Spent Nuclear Fuel (for which the S ...

A recent type of receptor modelling technique the Positive Matrix Factorization (PMF) has been applied to a geochemical dataset obtained by XRF analysis on sediments from 11 alpine lakes located in Italy. Also, two usual pattern recognition techniques, Principal Component Analysis (PCA) and Cluster Analysis (CA), were investigated. Four interpretable factors were identified through PMF analysis, in connection with the mineralogical/chemical features of lake sediments in the catchment areas: phosphate and sulphur source, carbonates, silicates and heavy metal-bearing minerals. Also, to properly modify individual uncertainty estimates, a new PMF factor was identified, explaining a possible Pb contamination source.

Waste-to-energy solid-recovered fuels (SRFs) are prepared from non-hazardous waste. Their use is regulated under European Union (EU) legislation and requires specifications for commercial or regulatory purposes. SRFs are seen as important contributors to a sustainable EU waste management. Directive 2001/77/EC includes in its scope the production of electricity from biomass, being defined as the biodegradable fraction of products, waste and residues from agriculture, forestry and related industries, as well as the biodegradable fraction of industrial and municipal waste. In this context, the European Commission (EC) gave a mandate to the European Committee for Standardisation (CEN) to develop and validate Technical Specification (TS) concerning SRF for energy recovery and to transform these TS into European Standards. To meet these requests, a holistic validation programme covering quality management and the validation exercises for the pre-standards of CEN's Technical Committee on Solid Recovered Fuels (CEN TC 343) was designed and carried out by various members of CEN TC 343, interested non-governmental organisations (NGOs) and the EC's Joint Research Centre (JRC). This paper gives an overview about the validation programme called QUOVADIS (from QU ality Management O rganisation, VA lidation of Standards, D evelopments and I nquiries for S olid-Recovered Fuels) and the partnership behind it, and highlights some particular aspects in performing the necessary validation work.

International safeguards inspectorates (e.g., International Atomic Energy Agency {IAEA}, or Euratom) rely heavily on neutron assay techniques, and in particular, on coincidence counters for the verification of declared nuclear materials under safeguards and for monitoring purposes. While 3He was readily available, the reliability, safety, ease of use, gamma-ray insensitivity, and high intrinsic thermal neutron detection efficiency of 3He-based detectors obviated the need for alternative detector technologies. However, the recent decline of the 3He gas supply has triggered international efforts to develop and field neutron detectors that make use of alternative materials. In response to this global effort, the U.S. Department of Energy’s (DOE) National Nuclear Security Administration (NNSA) and Euratom launched a joint effort aimed at bringing together international experts, technology users and developers in the field of nuclear safeguards to discuss and evaluate the proposed 3He alternative materials and technologies. The effort involved a series of two workshops focused on detailed overviews and viability assessments of various 3He alternative technologies for use in nuclear safeguards applications. The key objective was to provide a platform for collaborative discussions and technical presentations organized in a compact, workshop-like format to stimulate interactions among the participants. The meetings culminated in a benchmark exercisemore » providing a unique opportunity for the first inter-comparison of several available alternative technologies. This report provides an overview of the alternative technology efforts presented during the two workshops along with a summary of the benchmarking activities and results. The workshop recommendations and key consensus observations are discussed in the report, and used to outline a proposed path forward and future needs foreseeable in the area of 3He-alternative technologies.« less

This paper discusses the possibility of using sparse array antennas for low-cost mobile terminal antennas in satellite communication systems. Compared to uniform antenna arrays, sparse arrays may offer advantages in cost, wide angle scanning, and power handling. The paper focuses on the implementation and testing aspect of the sparse array prototype.

24-h simultaneous samplings of PM10 and PM2.5 particulate matter (PM) have been carried out during the period December 1997–September 1998 in the central urban area of Milan. The mass concentrations of the two fractions showed significant daily variations linked to different thermodynamic conditions of the planetary boundary layer (PBL) and characterised by higher values during wintertime. The elemental composition, determined by energy dispersive X-ray fluorescence technique, was quite different in the two fractions: in the finer one the presence of elements with crustal origin is reduced while the anthropogenic elements, with a relevant environmental and health impact, appear to be enriched. The composition data allowed a quantification of two major components of the atmospheric particulate: sulphates (mainly of secondary origin) and particles with crustal origin. An important but unmeasured component is likely constituted by organic and elemental carbon compounds. The multivariate analysis of elements, gaseous pollutants and mass concentration data-sets leads to the identification of four main sources contributing to PM10 and PM2.5 composition: vehicles exhaust emissions, resuspended crustal dust, secondary sulphates and industrial emissions. The existence of a possible background component with non-local origin is also suggested.

Reference LEMA-ARTICLE-1998-006View record in Web of Science Record created on 2006-11-30, modified on 2016-08-08

This paper presents two electronically steered phased array approaches allowing to reduce the number of phase shifter bits required to control steering and polarization. The first approach is based on particular combination of the phase shifters arrangement and elements rotation, while the second introduces a different approach with a combination of simplified phasing approach and aperiodic lattice allowing the number of bits to be reduced to one only. Both approaches have been validated through full scale implementation and measurements results are presented in this paper.

A semiconductor detector coupled with a neutron converter is a good candidate for neutron detection, especially for its compactness and reliability if compared with other devices, such as (3)He tubes, even though its intrinsic efficiency is rather lower. In this paper we show a neutron detector design consisting of a 3 cm × 3 cm silicon pad detector coupled with one or two external (6)LiF layers, enriched in (6)Li at 95%, placed in contact with the Si active surfaces. This prototype, first characterized and tested at INFN Laboratori Nazionali del Sud and then at JRC Ispra, was successfully shown to detect thermal neutrons with the expected efficiency and an outstanding gamma rejection capability.

Reference LEMA-ARTICLE-2004-003doi:10.1002/mop.11353View record in Web of Science Record created on 2006-11-30, modified on 2016-08-08

Chemical composition data for the Danube River and its tributaries sediments were analyzed using positive matrix factorization (PMF). The objective was to identify both natural and anthropogenic sources affecting Danube Basin. During the Joint Danube Survey 2 (JDS2) campaign 148 bottom sediments samples were collected. The following elements were analyzed using the X-ray fluorescence technique: Al, As, Ca, Cd, Cl, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Si, Ti, V and Zn. Mercury was determined by cold vapour atomic absorption spectrometry. Three factors were obtained considering the whole dataset (Danube and tributaries), identified as: (i) carbonate component characterized by Ca and Mg; (ii) alumino-silicate component dominated by Si and Al content and the presence of some metals attributed to natural processes; (iii) anthropogenic source identified by Hg, S, P and some heavy metals load. To better characterize the role of tributaries, the Danube and tributaries datasets, were also analyzed separately. The same three factor structures were identified in the Danube dataset. For the tributaries, a four-factor source model gave one further factor dominated by S and P, which could be attributed to the use of fertilizers in agriculture.

This paper presents the development of a low profile, low-cost, switched-beam antenna array terminal for mobile satellite applications. An original aperture topology is presented, which is inspired from the so-called trihexagonal tiling of the plane. The array consists of three interlaced sub-arrays based on series feeding, which are combined in various ways to produce the twelve sector beams that cover the whole field of view. Simulation results showed that a directivity of 11 dB is achieved over almost the whole expanse of each of the twelve beams.

The active components (phase shifters, LNAs) of a Ku-band direct radiating array are a major part of its cost. A way to reduce this cost is to use simpler control elements. In the frame of ESA project BEST (BEam Switching Transmit-receive mobile user terminal antenna), we have designed, built and measured a receive-only, Ku-band demonstrator using 1-bit phase controls. These controls have been implemented using discrete switches.

This paper describes a demonstrator with a small size, incorporating the concepts developed in the ESA-funded project NATALIA. This demonstrator is a smaller version (16 patches) of the final prototype (156 patches). The small prototype is described in detail and measurement results of the farfield, nearfields, power consumption and thermal behaviour are presented. It is shown that the performance is according to expectation and that the design is very robust. The outcome of all experiments verifies the NATALIA concepts.

GNSS is entering into a period of intense change over the next 5–10 years which will impact on users and operators of high-end GNSS equipment. For many years, GPS and GLONASS existed as the only systems. However, all is set to change with the advent of new global and regional systems (Galileo, Compass, IRNSS, GINS and QZSS), augmentation services and test satellites offering combined new and improved performance. Furthermore, GPS and GLONASS are also going through their own phases of modernisation with the GPS III programme and the GLONASS M and K programmes. With such a diverse range of developments and future possibilities it is difficult to see how the traditional hardware receiver solutions can keep pace with the speed of changes demanded by users and operators. The PRECISIO project is aiming to address this challenge by developing a high-end prototype multi-constellation, multi-frequency receiver based on a Software Defined Radio (SDR) approach. The purpose of this paper is to describe the current status of the PRECISIO project.

This paper presents two different Ku-Band Low-Profile antenna concepts for Mobile Satellite Communications. The antennas are based on low-cost hybrid mechanical-electronic steerable solutions but, while the first one allows a broadband reception of a satellite signal (Receive-only antenna concept), the second one provides transmit and receive functions for a bi-directional communication link between the satellite and the mobile user terminal (Transmit-Receive antenna). Both examples are suitable for integration in land vehicles and aircrafts.

This paper deals with the Galileo 1 /GPS Tracking for GNSS stations. This study has been done under a European Space Agency contract: “Evolutionary Navigation Systems”, for which EADS Astrium was prime. Francisco Amarillo Fernandez was the ESA project technical manager.

Macroinvertebrates are one of the key components of lake ecosystems and are required to be monitored alongside other biological groups to define ecological status according to European Union legislation. Macroinvertebrate communities are highly variable and complex and respond to a diverse series of environmental conditions. The purpose of this study was to examine the relative importance of environmental variables in explaining macroinvertebrate abundance. A total of 45 sub-alpine lakes were sampled for macroinvertebrates in the shallow sublittoral. Environmental variables were grouped into four types: (1) aquatic physical and chemical parameters, (2) littoral and riparian habitat, (3) lake morphometric parameters and (4) sediment chemical characteristics. Nonparametric multiplicative regression (NPMR) was used to model the abundance of individual macroinvertebrate taxa. Significant models were produced for nine out of the 24 taxa examined. Sediment characteristics were the group most frequently included in models and also the factors to which taxa abundance was the most sensitive. Aquatic physical and chemical variables were the next group most frequently included in models although chlorophyll a was not included in any of the models and total phosphorus in only one. This indicates that many taxa may not show a direct easily interpretable response to eutrophication pressure. Lake morphometric factors were included in several of the models although the sensitivity of macroinvertebrate abundance tended to be lower than for sediment and aquatic physical and chemical factors. Habitat factors were only included in three models although riparian vegetation was found to have a significant influence on the abundance of Ephemera danica indicating that ecotone integrity is likely to play a role in its ecology. Overall, the models tended to be specific for species with limited commonality across taxa. Models produced by NPMR indicate that the response of macroinvertebrates to environmental variables can be successfully described but further research is required focussing in more detail on the response of key taxa to relevant environmental parameters and anthropogenic pressures.

This paper presents three different concepts of Ku-band low profile antennas for mobile satcom. First, a low profile fully active phased array aiming to Ku-Band broadcast reception is presented. Two other hybrid phased arrays are presented, one aiming to receive only applications and one for Tx/Rx operations. All the three presented antennas are low profile and suitable for in-vehicle integration.

Multivariate factor analytical techniques are widely used for the approximation, in terms of a linear combination of factors, of multivariate experimental data. The chemical composition of soil samples are multivariate in nature and provide datasets suitable for the application of these statistical techniques. Recent developments of multivariate factor analytical techniques have led to the approach of Positive Matrix Factorization (PMF), a weighted least squares fit of a data matrix in which the weights are determined depending on the error estimates of each individual data value. This approach relies on more physically significant assumptions than methods like Principal Components Analysis which is frequently used in the analysis of soil datasets. In this paper we apply PMF to characterise the pollutant source in a set of geographically referenced soil samples taken within a 200 m radius of a site characterised by a high concentration of heavy metals. Each sample has been analysed for major and minor elements (using wavelength-dispersive X-ray fluorescence spectrometry), carbon, hydrogen and nitrogen (using a CHN elemental analyzer) and mercury (using cold-vapour atomic absorption spectrometry). Analysis of the soils using PMF resulted in a successful partitioning of variances into sources related to background soil geochemistry, organic influences and those associated with the contamination. Combining these results with a geostatistical approach successfully demarcated the main source of the combined organic and heavy metal contamination.

Phased array technology is becoming a commercially important market for mobile telecommunication applications, e.g. mobile satellite terminals. Such systems, either for maritime, aeronautical or land applications, must be able to receive satellite broadcasting services on-the-move. Multimedia is here the driving force to develop cost-effective compact commercial terminals, favourably for various classes of applications, such as general or customised broadcasting services, for example. Such terminals are of special interest to the automotive industry because the terminals currently on the market for such applications are still partly based on mechanical moving parts, thus maintenance intensive, heavy and bulky, and subject to G-forces. These properties are not very appealing to the automotive industry where car aesthetics are ever so important. Far more favourable are the fully electronically steerable solutions that can be very compact and have very low maintenance. However, one of the major limitations and biggest design challenges of this type of phased array systems is the relatively high price due to its electronic complexity. The NATALIA project (New Automotive Tracking Antenna for Low-cost Innovative Applications) funded by ESA, is investigating the possibility of realizing a compact cost-effective solution for a receive- only full electronically steerable antenna for cars in Ku-band. The key items for the design of this antenna system are not only low-cost but also small size (around 20 cm in diameter and a height of a few em's) so that the antenna can easily be integrated into or onto the structure of the car. Different concepts for the NATALIA antenna have been investigated such as RF-phase shifters in (M)MIC technology and different configurations of beam forming/switching networks, all evaluated with respect to complexity/costs, performance (G/T) and size, resulting into a first baseline design. (5 pages)

A semiconductor detector coupled with a neutron converter is a good candidate for neutron detection, especially for its compactness and reliability if compared with other devices, such as 3He tubes, even though its intrinsic efficiency is rather lower. In this paper we show a neutron detector design consisting of a 3 cm × 3 cm silicon pad detector coupled with one or two external 6LiF layers, enriched in 6Li at 95%, placed in contact with the Si active surfaces. This prototype, first characterized and tested at INFN Laboratori Nazionali del Sud and then at JRC Ispra, was successfully shown to detect thermal neutrons with the expected efficiency and an outstanding gamma rejection capability.