Gross alpha-beta measurement is a worldwide applied technique to determine activity concentration in drinking water. Laboratories have implemented standard methods where standard sources measurements ...and routine methods are applied to achieve good analytical results. Proficiency testing is among the most used methods to assess the accuracy of the analytical data produced by laboratories, as this also represents a requirement for laboratories which have ISO 17025 and a quality assurance system implemented. The results presented in this paper show the performance of two laboratories for proficiency tests organized by IAEA, to which SALMROM laboratory and Personal Dosimetry Monitoring Laboratory (LDPM) have participated in 3 years. The feedback from the final reports from IAEA reports demonstrates the performance of the laboratories where 17 out of 18 results pass the acceptance criteria. Only one reported result has a warning which means that it did not pass all acceptance criteria. The results served as a basis to improve the laboratory analysis and to optimize accuracy measurements. The overall results of the PTs point out the reliability and traceability of the systems used for drinking water measurements.
This paper presents complex studies on establishment of derived emission limits for potential radionuclides emitted as gaseous and liquid effluents, during the decommissioning activities (2nd and 3rd ...phases) of a nuclear research reactor, cooled and moderated with distilled water, type VVR-S, owned by the IFIN-HH. In the present paper there are described: the analysis methods and equipment used, the methodologies for calculating doses and the Derived Emission Limits (DEL), the experimentally measured activities of the representative radionuclides found in gaseous and liquid effluents resulted from decommissioning activities, as well as the effective derived limits of liquid and gaseous effluents, applying the calculation methodologies, specific to critical categories of exposed subjects. A constraint effective dose limit for a person from the critical group of 50 μSv/year was considered in calculations. From the comparison of the two series of values, measured released activities and DELs, there has been concluded that for the gaseous effluents they comply with the DELs, while in the case of liquid effluents they are higher and consequently they must be treated as liquid radioactive wastes.
•The DELs for gaseous and liquid effluents in decommissioning were studied.•The impact on the environment and critical group was assessed.•Gamma-ray spectrometry was used to determine the radionuclide composition.•Based on the dosimetry models, the values of conservative DELs were calculated.•The DELs are compliant for gases, not for liquids; require the treatment as rad-waste.
A low-background radiation laboratory was constructed and fully commissioned in 2006 in the former Unirea (Slanic-Prahova) salt mine at 208
m below surface (estimated to 560
m water equivalent). ...Preliminary measurements showed a global reduction of the absorbed dose due to natural factors of about 39 times compared to level on the surface, reaching inside the mine 1.17±0.14
nGy/h. The total gamma background spectrum between 40
KeV and 3
MeV was 100 times smaller at laboratory level with respect to the same spectrum recorder at surface, in open field. All these experimental facts recommend the Slanic-Prahova low-background radiation laboratory, at present time fully operational, as very suitable for various measurements needing a low background.
This paper presents the measurement of the dose equivalent Hp(10) to low (0.005–1)
mSv and high (20–1000)
mSv doses by exposure at
241Am and
173Cs radiation sources of the halide film with FB-III-D ...dosimeter system. Accuracy of measurements, standard error of the dose mean value (SEM) and some comments about ability to reread of dosimetric films were determined. A good accuracy was obtained over the important dose ranges. In the low dose range, under 0.1
mSv, the SEM values of the
241Am doses, recorded on the film under plastic filter, are between −21.36% and +47.51%. For 0.1–500
mSv
137Cs dose range the SEM values are from −9.55% to +7.24%.
This paper presents one part of the activities deployed by the Laboratory for Environment and Personnel Dosimetry (LDPM) of IFIN-HH, namely the radiological monitoring of the environment within the ...Institute's area and its surrounding influence zone, according to the program approved by the National Regulatory Body for Nuclear Activities, CNCAN. The representative reports regard the radioactive content of soil, surface and underground water, cultivated and spontaneous vegetation, aerosols and atmospheric fallout, sediments. The common requirement is that the measured quantities be precise and the reported values be reliable and credible. This goal is achieved by maintaining a Quality System, verified within the obtaining and maintaining of the laboratory accreditation, according to the international standard ISO/IEC 17025:2005.The LDPM is accredited by the Romanian accreditation body, RENAR, member of the European Accreditation, EA and is designed by CNCAN as a notified testing laboratory. Many measurements were performed in collaboration with the Radionuclide Metrology Laboratory (RML) from IFIN-HH, RENAR accredited and CNCAN notified for calibration and for testing in the field of radioactivity measurement. This paper proposes a short presentation of the important aspects in our activity:i.description of equipment, sampling methods, processing and measurement of environmental samples;ii.validation of equipment and methods by participation in international and national proficiency tests;iii.a five year follow chart, containing the results in measurement of samples;iv.a recent application, with a wide impact in Romanian mass media: the credible daily report on the possible influence of Fukushima accident over the Romanian environmental radioactivity.
► The equipment and associated methods, ensuring quality performance management. ► It is very important the implementation of necessary corrections to results. ► By measuring the frequency was not detected any effect of activity IFIN-HH. ► The Fukushima nuclear accident had no radiological impact on the area from IFIN-HH
The aim of the paper is to present a special application of the Romanian thermoluminescent dosemeters system, based on the use of the LiF:Mg,Cu,P, commercial GR-200A detectors, for the measurement of ...the ultra-low-level ambient dose equivalent rate values, situated within the interval of 1-100 nSv h(-1). The paper briefly describes the system and presents in detail the experimental procedure, including the corrections to be applied to the experimental values. The final characterisation of a Romanian salt mine, proposed to be used as an underground accelerator laboratory, is given. The comparison with the previous measurement results in the Slanic Prahova former salt mine and with the results obtained using the gamma-ray spectrometry method validates the results reported in this paper. The conclusion is that the system provides reliable results in the measurement of the ultra-low-level radiation background.
Purpose The purpose of this study is to investigate the thermoforming process of 3D-printed parts made from polylactic acid (PLA) and explore its application in producing wrist-hand orthoses. These ...orthoses were 3D printed flat, heated and molded to fit the patient’s hand. The advantages of such an approach include reduced production time and cost. Design/methodology/approach The study used both experimental and numerical methods to analyze the thermoforming process of PLA parts. Thermal and mechanical characteristics were determined at different temperatures and infill densities. An equivalent material model that considers infill within a print is proposed. Its practical use was proven using a coupled finite-element analysis model. The simulation strategy enabled a comparative analysis of the thermoforming behavior of orthoses with two designs by considering the combined impact of natural convection cooling and imposed structural loads. Findings The experimental results indicated that at 27°C and 35°C, the tensile specimens exhibited brittle failure irrespective of the infill density, whereas ductile behavior was observed at 45°C, 50°C and 55°C. The thermal conductivity of the material was found to be linearly related to the temperature of the specimen. Orthoses with circular open pockets required more time to complete the thermoforming process than those with hexagonal pockets. Hexagonal cutouts have a lower peak stress owing to the reduced reaction forces, resulting in a smoother thermoforming process. Originality/value This study contributes to the existing literature by specifically focusing on the thermoforming process of 3D-printed parts made from PLA. Experimental tests were conducted to gather thermal and mechanical data on specimens with two infill densities, and a finite-element model was developed to address the thermoforming process. These findings were applied to a comparative analysis of 3D-printed thermoformed wrist-hand orthoses that included open pockets with different designs, demonstrating the practical implications of this study’s outcomes.
Bimetallic nanostructures have the potential to become the new generation candidates for applications in catalysis, electronics, optoelectronics, biosensors and also for surface-enhanced Raman ...Spectroscopy (SERS). The bimetallic nanocrystals offer additional properties over the single metal components such as improved electromagnetic properties and corrosion protection. This work presents a simple and inexpensive method to fabricate large area biplasmonic (bimetallic) substrates, employing DC magnetron sputtering, picosecond laser pulses and a digital galvanometric scanner. The aim of this study was to achieve large area homogeneous substrates while having a good and predictable signal amplification by SERS effect. Gold thin films with 200 nm thickness were deposited on optical polished substrates and then irradiated in atmospheric air with λ = 1064 nm wavelength laser pulses with 8 ps pulse duration and 500 kHz fixed repetition rate. Various laser fluences and laser irradiation speeds were employed in order to optimize the Laser-Induced Periodic Surface Structures (LIPSS) formed on the substrate. The results are presented comparatively for the standalone Cu substrates and for the Cu-Au substrates using Raman spectral analysis on a single signal peak of a Rhodamine 6G solution.
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