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Abstract A prototypal system for the separation of CO 2 from air and concentration in small volume containers was developed and tested at ENEA in the frame of two European research projects (MetroRWM and MetroDECOM), funded by the European Metrology Research Programme (EMRP). The aim of the proposed system is to separate and concentrate in an effective way the CO 2 content from radioactive air stream in nuclear installations or nuclear waste repositories during normal operation or decommissioning phase, by using a cryogenic process. This system is intended to be used as preparatory stage of the CO 2 samples to be analysed by a radioactive gas-in-air monitor using a standardised 14CO 2. Connecting the ENEA cryogenic system to the monitor will enable a sample of air to be processed and measured, and its 14CO 2 activity concentration calculated, from knowledge of the volume of air sampled by the cryogenic system and the response of the monitor. Our work demonstrates the feasibility of a14C monitoring based on cryogenic method, according to which the components of a gaseous mixture can be separated on the basis of the differences between the phase transition properties of each gas components. The initial design was made considering the readily-available commercial instruments and devices and combining them in an optimum way. System testing showed almost 100% CO 2 separation and recovery. Highlights • A prototypal system for separation of CO 2 from air was developed and tested. • Gas mixture components separated on the basis of different transition gas properties. • Application in 14C monitoring in nuclear installations or waste repositories. • Method feasibility experimentally demonstrated. • Almost 100% CO separation and recovery obtained. [ABSTRACT FROM AUTHOR]

In this paper, the application of the efficiency transfer method to the evaluation of the surface beta contamination is described. Using efficiency transfer factors, the reference calibration factor of contamination monitors is corrected, to obtain the calibration factor for an actual contamination source. The experimental part of the paper illustrates the applicability of the method to the direct measurement of the surface beta contamination. [ABSTRACT FROM AUTHOR]

Characterization and calibration measurements were carried out at the National Institute of Ionizing Radiation Metrology of ENEA on the TAp WAter RAdioactivity (TAWARA) Real Time Monitor system recently developed for real time monitoring of radioactive contamination in water processed at water treatment facilities. Reference radiations and radionuclides were chosen in order to reflect energy ranges and radiation types of the major water radioactive contaminants possibly arising from environmental, industrial or terroristic origin. The following instrument parameters were tested: sensitivity, selectivity, background, short/long term stability, linearity with respect to activity. [ABSTRACT FROM AUTHOR]

The determination of characteristic limits in the measurement of radioactive materials is an important aspect of low-level measurements and the underlying principles are well understood by scientists working on such measurements. ISO 11929:2010 provides a rigorous basis for the systematic calculation of detection limits, but may be difficult to interpret for the routine user. This paper attempts to simplify some of the more arcane aspects of this standard. [ABSTRACT FROM AUTHOR]

A novel method has been developed for the activity measurement of large-area beta reference sources. It makes use of two emission rate measurements and is based on the weak dependence between the source activity and the activity distribution for a given value of transmission coefficient. The method was checked experimentally by measuring the activity of two ( 60 Co and 137 Cs) large-area reference sources constructed from anodized aluminum foils. Measurement results were compared with the activity values measured by gamma spectrometry. For each source, they agree within one standard uncertainty and also agree within the same limits with the certified values of the source activity. [ABSTRACT FROM AUTHOR]

This paper is concerned with the modeling of the transmission of beta rays through thin foils in planar geometry based on the plane source concept, using Monte Carlo simulation of electron transport and least squares fitting. Applications of modeling results for calculating the efficiency of large-area beta sources, transmission coefficient of beta rays through thin foils and the beta detection efficiency of large-area detectors used in surface contamination measurements are also presented. [ABSTRACT FROM AUTHOR]

Abstract: The importance of determination of the blank indication for active radon monitors is discussed. Two new blank chambers were developed at ENEA-INMRI that allows such determination with an uncertainty lower than a few Bq/m3. Results are reported and that show the large blank variability between radon active monitors and its growth with time when such monitors are used at high radon concentrations. [Copyright &y& Elsevier]

Abstract: A set of 60 spiked simulated air filter sources was developed for the 2004–2005 proficiency test of the Italian radioactivity surveillance network. Each simulated filter source was prepared by reproducible volumetric dispensing of 19 drops of a mixed radioactive solution containing Co-57, Cs-134, Cs-137, Co-60 and Eu-152. The spiking pattern was investigated and optimized by numerical simulations. The filter sources were checked by double counting on HPGe and NaI(Tl) detectors. The standard deviation (SD) of activity values was 1.5%. [Copyright &y& Elsevier]

Abstract: Using a simple gas-gain model, the efficiency sensitivity of gas-flow proportional counters to changes in the influence quantities (applied anode voltage, gas purity, gas-flow rate, ambient pressure and temperature) was analyzed and applied for the absolute standardization of large-area reference sources. Thus, the uncertainty of measurement was evaluated by taking into account the fluctuations of these quantities in normal conditions of counter operation. It was shown that the uncertainty is small in these conditions but accidental and large changes in the influence quantities may give rise to large errors of measurement. In addition, a cleaning procedure and a simple way of stabilizing the gain of gas-flow proportional counters were used to improve the absolute standardization of large-area reference sources. As a result, measurements were performed with uncertainties smaller than 0.55% and the reproducibility better than 0.42%. [Copyright &y& Elsevier]

Short-lived radionuclides, γ, β+ and/or β- emitters, such as 18F, and 99mTc, particularly useful for nuclear medicine applications, both diagnostic and in radiotherapy, can be produced with high-specific activity in a small biomedical cyclotron or by a radionuclide generator. While [18F]Fludeoxyglucose ([18F]FDG) is a widely used radiopharmaceutical for positron emission tomography, the development of innovative diagnostic techniques and therapies involves the use of new radio-labelled molecules and emerging radionuclides, such as 64Cu and 124I. During the last 3 years, an extensive supply of [18F]FDG was started by many production sites in Italy, and new radiopharmaceuticals are being studied for future nuclear medical applications. Therefore, a special nuclear medicine research programme for primary standard development and transferral to the end-users has been carried out by the ENEA-INMRI. Because of the short half-lives of these nuclides, a portable well-type ionisation chamber was established as a secondary travelling standard. This device has been calibrated and transported to the radiopharmaceutical production centres in Italy where the local instrumentation, typically radionuclide calibrators, has been calibrated by a simple comparison, with an uncertainty level lower than 2%. [ABSTRACT FROM AUTHOR]

Abstract: A 64Cu national primary standard, was developed by the National Institute for Ionising Radiation Metrology (INMRI) of the ENEA (ENEA-INMRI) using the CIEMAT/NIST method of 4πβ liquid scintillation spectrometry with 3H-standard efficiency tracing. Relatively short 64Cu half-life is required for the work to be performed at the production site. It was produced at the Scanditronix MC40 Cyclotron of the Joint Research Centre (JRC) of the European Commission (Ispra, Italy) through the 64Zn(d,2p) 64Cu reaction. Significant efforts were made to identify and quantify the impurities of 61Cu and 65Zn in the mother solution, which were activated through the 64Zn(d,αn) 61Cu and 64Zn(d,p) 65Zn reactions, respectively. To this purpose, a new procedure for the determination of pure β-emitter impurities by the CIEMAT/NIST method has been applied. A transfer standard portable well-type ionisation chamber was also calibrated with minimum uncertainty. [Copyright &y& Elsevier]

We perform a comparison of two jet clusterization algorithms. The first one is the standard Durham algorithm and the second one is a global optimization scheme, Deterministic Annealing, often used in clusterization problems, and adapted to the problem of jet identification in particle production by high energy collisions; in particular we study hadronic jets in WW production by high energy e+e− scattering. Our results are as follows. First, we find that the two procedures give basically the same output as far as the particle clusterization is concerned. Second, we find that the increase of CPU time with the particle multiplicity is much faster for the Durham jet clustering algorithm in comparison with Deterministic Annealing. Since this result follows from the higher computational complexity of the Durham scheme, it should not depend on the particular process studied here and might be significant for jet physics at LHC as well. [Copyright &y& Elsevier]

166Ho (T 1/2 ≈ 26.8 h) is an emerging theragnostic radionuclide of interest in nuclear medicine due to its peculiar decay scheme, featuring high-energy β− emission (≈ 1.8 MeV) coupled with the main gamma-ray emission (≈ 80.6 keV). Using the new 166Ho activity standard and the well-calibrated, high-energy resolution HPGe detector, both available at ENEA-INMRI, a new determination of several 166Ho gamma-ray emission intensities, I γ , was performed with low uncertainty. The new I γ values contributed to the Decay Data Evaluation Project. • 166Ho and its use in nuclear medicine as theragnostic radionuclide. • Absolute activity measurements by Triple-to-Double Coincidence Ratio (TDCR) technique. • Hidex and portable ENEA-INMRI TDCR counters. • Gamma-ray spectrometry technique. • 166Ho gamma-ray emission intensities. [ABSTRACT FROM AUTHOR]

Abstract: A 177Lu primary standard was developed at the ENEA-INMRI in the frame of an international comparison organized by BIPM and piloted by NIST (USA). The CIEMAT/NIST method with 3H standard source as tracer was used for standardizing a solution of 177Lu. The activity value was compared also with the measurements of the same mother solution carried out by the 4πγ integral counting method. Particular efforts were made to identify and quantify the long–lived 177mLu impurity in the mother solution. The results obtained by the two methods are in good agreement within their standard uncertainties. The arithmetic mean of the two values is in good agreement with the Comparison Reference Value (CRV). By the new primary standard two well-type ionization chambers (ICs), one fixed and the other one portable, were calibrated with an uncertainty lower than 2%. These ICs are used for routinely applications in the activity measurements of short-lived radionuclides particularly useful for medical applications. [Copyright &y& Elsevier]

Abstract: We reviewed the calibration procedures of gamma-ray spectrometry with particular emphasis to factors that affect accuracy, detection limits and background radiation in field measurements for dosimetric and radon potential mapping. Gamma-ray spectra were acquired in western Liguria (Italy). The energy windows investigated are centred on the photopeaks of 214Bi (1.76MeV), 208Tl (2.62MeV) and 40K (1.46MeV). The inferred absorbed dose rate and the radon flux are estimated to be lower than 60nGyh−1 and 22Bqm−2 h−1, respectively. [Copyright &y& Elsevier]

Abstract: The sum-peak counting method was applied for 125I absolute activity measurement. Count rate-dependent corrections for random summing and dead time effects were experimentally determined at different count rates and in several experimental conditions. Two NaI(Tl) crystals of different volumes were used. They were connected to pulse recording systems with different characteristics, with or without pile-up rejection live-time corrector circuits (PUR/LTC). A theoretical model was proposed to explain the different behaviours found experimentally. It is shown that count rate-dependent effects are drastically reduced by the use of PUR/LTC. [Copyright &y& Elsevier]

A preliminary intercomparison on gamma-ray spectrometry determination of natural radionuclides in building materials was carried out in 1999–2002. Samples measured were fly ash, sand and tuff. Laboratories used different experimental equipment and procedures. Corrections for blank, spectral interference, self-absorption and coincidence summing effects were applied in most cases. The agreement between results was within 15–20%, most often within the reported uncertainties. Several general conclusions can be drawn regarding procedures correctness, uncertainty budget, secular equilibrium condition, and radionuclide representativeness in each natural series. Further studies are needed to draw more specific conclusions. [Copyright &y& Elsevier]

Abstract: Experimental tests are described to check solid 241Am radioactive sources used to monitor operation of liquid xenon detectors. In particular, radioactive leakage was tested in extreme temperature conditions following immersion in liquid nitrogen for different time periods. No radioactivity loss was detected from the sources considered. The paper describes the source characteristics, test methods and results obtained. [Copyright &y& Elsevier]

Measurements of neutron streaming through penetrations in biological shields are being carried out at JET fusion device by means of thermoluminescence (TL) detectors with the objective to validate the neutronics codes and nuclear data widely applied in ITER nuclear analyses in a real fusion environment. TLDs response due to the neutron component of the radiation field is related to the neutron fluence in a well-defined neutron energy spectrum. Therefore, a TLDs calibration in real fusion radiation fields is necessary to allow neutron fluence from TL measurements at JET to be more precisely calculated. Hence, a MCP-N and MCP-7 TLDs produced at the IFJ PAN in Kraków were calibrated at the ENEA facilities of Frascati and Casaccia laboratories. The obtained results have been analysed and new calibration factors are proposed. The detection system based on TLDs developed and calibrated for JET experiments can then be generally applied not only to fusion neutron fields, but also to ITER to monitor the neutron fluence outside the biological shield. [ABSTRACT FROM AUTHOR]

The EMRP project MetroDECOM was concerned with research addressing all aspects of nuclear decommissioning in order to deliver integrity and cost-effectiveness in support of clearance and disposal processes as well as improving safety and accuracy. One of the work packages was focused on the characterisation of materials present on decommissioning. Within this work package, work on scaling factors was aimed at applying the principles set out in ISO 21238:2007 to the measurement of contaminated areas in decommissioning sites. In this paper, we report the progress made under MetroDECOM in identifying decommissioning matrices of specific relevance to nuclear decommissioning within the EU and selecting priority hard-to-measure radionuclides for further study. [ABSTRACT FROM AUTHOR]

This paper addresses the measurement facilities for pre-selection of waste materials prior to measurement for repository acceptance or possible free release (segregation measurement system); and free release (free release measurement system), based on a single standardized concept characterized by unique, patented lead-free shielding. The key objective is to improve the throughput, accuracy, reliability, modularity and mobility of segregation and free-release measurement. This will result in a more reliable decision-making with regard to the safe release and disposal of radioactive wastes into the environment and, resulting in positive economic outcomes. The research was carried out within “Metrology for Decommissioning Nuclear Facilities” (MetroDecom) project. [ABSTRACT FROM AUTHOR]

Reliable measurement of Naturally Occurring Radioactive Materials is of significance in order to comply with environmental regulations and for radiological protection purposes. This paper discusses the standardisation of three reference materials, namely sand, tuff and TiO 2 to serve as quality control materials for traceability, method validation and instrument calibration. The sample preparation, material characterization via γ, α and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and the assignment of values for both the 4n (Thorium ) and 4n+2 (Uranium ) decay series are described. [ABSTRACT FROM AUTHOR]

Over the last years 177 Lu has received considerable attention from the clinical nuclear medicine community thanks to its wide range of applications in molecular radiotherapy, especially in peptide-receptor radionuclide therapy (PRRT). In addition to short-range beta particles, 177 Lu emits low energy gamma radiation of 113 keV and 208 keV that allows gamma camera quantitative imaging. Despite quantitative cancer imaging in molecular radiotherapy having been proven to be a key instrument for the assessment of therapeutic response, at present no general clinically accepted quantitative imaging protocol exists and absolute quantification studies are usually based on individual initiatives. The aim of this work was to develop and evaluate an approach to gamma camera calibration for absolute quantification in tomographic imaging with 177 Lu. We assessed the gamma camera calibration factors for a Philips IRIX and Philips AXIS gamma camera system using various reference geometries, both in air and in water. Images were corrected for the major effects that contribute to image degradation, i.e. attenuation, scatter and dead- time. We validated our method in non-reference geometry using an anthropomorphic torso phantom provided with the liver cavity uniformly filled with 177 LuCl 3 . Our results showed that calibration factors depend on the particular reference condition. In general, acquisitions performed with the IRIX gamma camera provided good results at 208 keV, with agreement within 5% for all geometries. The use of a Jaszczak 16 mL hollow sphere in water provided calibration factors capable of recovering the activity in anthropomorphic geometry within 1% for the 208 keV peak, for both gamma cameras. The point source provided the poorest results, most likely because scatter and attenuation correction are not incorporated in the calibration factor. However, for both gamma cameras all geometries provided calibration factors capable of recovering the activity in anthropomorphic geometry within about 10% (range −11.6% to +7.3%) for acquisitions at the 208 keV photopeak. As a general rule, scatter and attenuation play a much larger role at 113 keV compared to 208 keV and are likely to hinder an accurate absolute quantification. Acquisitions of only the 177 Lu main photopeak (208 keV) are therefore recommended in clinical practice. Preliminary results suggest that the gamma camera calibration factor can be assessed with a standard uncertainty below (or of the order of) 3% if activity is determined with equipment traceable to primary standards, accurate volume measurements are made, and an appropriate chemical carrier is used to allow a homogeneous and stable solution to be used during the measurements. [ABSTRACT FROM AUTHOR]

In 2014, the first three comparisons of activity measurements of 18 F were carried out at the VNIIM, NPL and the ENEA-INMRI using the BIPM’s Transfer Instrument of the International Reference System. The transfer instrument and the NMIs primary measurement methods are briefly described. The degrees of equivalence with the key comparison reference value defined in the frame of the corresponding SIR comparison have been evaluated. World-wide consistency of activity measurements of 18 F is demonstrated. [ABSTRACT FROM AUTHOR]

A severe supply crisis of 99 Mo, precursor of 99m Tc a diagnostic radionuclide largely used in Nuclear Medicine, occurred in 2008–2009 due to repeated shut-down of the two main (aged) fission reactors. An alternative route for producing 99 Mo by 100 Mo(n,2n) 99 Mo reaction was investigated at ENEA. The experiment, designed according to Monte Carlo simulations performed with the Fluka code, produced 99 Mo by irradiating a natural Molybdenum powdered target with 14 MeV neutrons produced at the Frascati Neutron Generator. The 99 Mo specific activity was measured at metrological level by γ-ray spectrometry. [ABSTRACT FROM AUTHOR]

This paper presents the results of the tests of High Purity Germanium (HPGe) based gamma spectrometers employed for radioactivity control carried out on a daily basis in steel factories. This new application of this type of detector is part of the Joint Research Project (JRP) MetroMETAL supported by the European Metrology Research Programme (EMRP). The final purpose of the project was the improvement and standardisation of the measurement methods and systems for the control of radioactivity of recycled metal scraps at the beginning of the working process and for the certification of the absence of any radioactive contamination above the clearance levels (IAEA-TECDOC-8S5) in final steel products, Clearance levels for radionuclides in solid materials: application of exemption principles). Two prototypes based on HPGe detectors were designed and assembled to suit the needs of steel mills which had been examined previously. The evaluation of the two prototypes, carried out at three steel factories with standard sources of 60 Co, 137 Cs, 192 Ir, 226 Ra and 241 Am in three different matrices (slag, fume dust and cast steel) and with samples provided on-site by the factories, was successful. The measurements proved the superiority of the prototypes over the scintillation detectors now commonly used regarding energy resolution and multi-nuclide identification capability. The detection limits were assessed and are presented as well. [ABSTRACT FROM AUTHOR]

During their entire lives, people are exposed to the pollutants present in indoor air. Recently, Electronic Nicotine Delivery Systems, mainly known as electronic cigarettes, have been widely commercialized: they deliver particles into the lungs of the users but a “second-hand smoke” has yet to be associated to this indoor source. On the other hand, the naturally-occurring radioactive gas, i.e. radon, represents a significant risk for lung cancer, and the cumulative action of these two agents could be worse than the agents separately would. In order to deepen the interaction between radon progeny and second-hand aerosol from different types of cigarettes, a designed experimental study was carried out by generating aerosol from e-cigarette vaping as well as from second-hand traditional smoke inside a walk-in radon chamber at the National Institute of Ionizing Radiation Metrology (INMRI) of Italy. In this chamber, the radon present in air comes naturally from the floor and ambient conditions are controlled. To characterize the sidestream smoke emitted by cigarettes, condensation particle counters and scanning mobility particle sizer were used. Radon concentration in the air was measured through an Alphaguard ionization chamber, whereas the measurement of radon decay product in the air was performed with the Tracelab BWLM Plus-2S Radon daughter Monitor. It was found an increase of the Potential Alpha-Energy Concentration (PAEC) due to the radon decay products attached to aerosol for higher particle number concentrations. This varied from 7.47 ± 0.34 MeV L −1 to 12.6 ± 0.26 MeV L −1 (69%) for the e-cigarette. In the case of traditional cigarette and at the same radon concentration, the increase was from 14.1 ± 0.43 MeV L −1 to 18.6 ± 0.19 MeV L −1 (31%). The equilibrium factor increases, varying from 23.4% ± 1.11% to 29.5% ± 0.26% and from 30.9% ± 1.0% to 38.1 ± 0.88 for the e-cigarette and traditional cigarette, respectively. These growths still continue for long time after the combustion, by increasing the exposure risk. [ABSTRACT FROM AUTHOR]

Abstract: The discipline of radionuclide metrology at national standards institutes started in 1913 with the certification by Curie, Rutherford and Meyer of the first primary standards of radium. In early years, radium was a valuable commodity and the aim of the standards was largely to facilitate trade. The focus later changed to providing standards for the new wide range of radionuclides, so that radioactivity could be used for healthcare and industrial applications while minimising the risk to patients, workers and the environment. National measurement institutes responded to the changing demands by developing new techniques for realising primary standards of radioactivity. Looking ahead, there are likely to be demands for standards for new radionuclides used in nuclear medicine, an expansion of the scope of the field into quantitative imaging to facilitate accurate patient dosimetry for nuclear medicine, and an increasing need for accurate standards for radioactive waste management and nuclear forensics. [Copyright &y& Elsevier]

Abstract: In 2011 the joint research project Metrology for Radioactive Waste Management (MetroRWM) 1 [1] This joint research project is financially supported by the European Commission in the frame of the European Metrology Research Programme EMRP (www.emrponline.eu) undertaken by several EU Member States under the Article 169 initiative, JRP contract identifier EMRP ENV09 MetroRWM. of the European Metrology Research Programme (EMRP) started with a total duration of three years. Within this project, new metrological resources for the assessment of radioactive waste, including their calibration with new reference materials traceable to national standards will be developed. This paper gives a review on national, European and international strategies as basis for science-based metrological requirements in clearance and acceptance of radioactive waste. [Copyright &y& Elsevier]

Abstract: The effect of radon diffusion and distribution between a 226Ra matrix and the top air gap inside sample containers for gamma-ray spectrometry was studied. Containers filled at almost 100% or just 70% of total capacity yielded correction factors of about 7% and 20% respectively. Applying these correction factors allowed activity values calculated from 226Ra or radon decay products to agree within 2%. [Copyright &y& Elsevier]

Abstract: The second part of an intercomparison of the coincidence summing correction methods is presented. This exercise concerned three volume sources, filled with liquid radioactive solution. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing corrective factors for several energies of 152Eu and 134Cs, and different source-to-detector distances. They are presented and discussed. [Copyright &y& Elsevier]

Abstract: An international Key Comparison of 177Lu has recently been carried out. Twelve laboratories performed assays for radioactivity content on aliquots of a common master solution of 177Lu, leading to eleven results submitted for entry into the Key Comparison Database of the Mutual Recognition Arrangement. A proposed Comparison Reference Value (CRV) was calculated to be 3.288(4)MBq/g using all eleven results. Degrees of equivalence and their uncertainties were calculated for each laboratory based on the CRV. Most of the values reported by the participating laboratories were within 0.6% of the CRV. [Copyright &y& Elsevier]

Abstract: A comparison of the coincidence summing correction methods is presented. Since there are several ways for computing these corrections, each method has advantages and drawbacks that could be compared. This part of the comparison was restricted to point sources. The same experimental spectra, decay scheme and photon emission intensities were used by all the participants. The results were expressed as coincidence summing correction factors for several energies of 152Eu and 134Cs, and three source-to-detector distances. They are presented and discussed. [Copyright &y& Elsevier]

Abstract: Following the approach of the National Primary Laboratory of the UK (NPL) for the calibration of radionuclide calibrators, but using a commercially available instrument with no data available in the literature, the radionuclide calibrator response was investigated as a function of different measurement geometries at the “Regina Elena” National Cancer Institute (IRE) in Rome. Working with Italian National Metrology Institute for ionising radiation quantities (ENEA-INMRI), specific calibration factors with traceability to national primary standards were determined for different types of glass vials, solid capsules and plastic syringes, investigating three radionuclides with different energy spectra (Tc-99m, In-111, I-131). For each kind of syringe, calibration correction factors for different filling volumes were calculated. For Tc-99m and I-131 the difference between measured and true activity was in the range 2–7%, depending on measurement geometry. For In-111 a large percentage deviation from the true activity value was found in each geometry considered, reaching 35%. The magnitude of this difference is particularly dependent on the energies of the emitted photons. [Copyright &y& Elsevier]

In 2002 the Italian Standardisation Organisation (UNI) - Nuclear Energy Commission (UNICEN) - appointed a working group with the main task of writing a set of standards on drinking water measurements. To date two standards have been designed, namely, for total alpha- and beta-activity, and 222Rn. Further procedures are under development for measuring 226Ra and U isotopes, and gamma-emitting radionuclides in water. The paper gives an overview of these standards, both developed and under study, with special attention to the validation of the methods. [ABSTRACT FROM AUTHOR]

Describes an improvement of the neutron activation system in operation on the Frascati Tokamak Upgrade tokamak for the measurement of the total neutron yield. Measuring system; Calibration sources; Efficiency calibration curve for the well-type detector.

Every year millions tons of steel are produced worldwide from recycled scrap loads. Although the detection systems in the steelworks prevent most orphan radioactive sources from entering the furnace, there is still the possibility of accidentally melting a radioactive source. The MetroMetal project, carried out in the frame of the European Metrology Research Programme (EMRP), addresses this problem by studying the existing measurement systems, developing sets of reference sources in various matrices (cast steel, slag, fume dust) and proposing new detection instruments. This paper presents the key lines of the project and describes the preparation of radioactive sources as well as the intercomparison exercises used to test the calibration and correction methods proposed within the project. [ABSTRACT FROM PUBLISHER]