•233U/238U abundance sensitivity at the 5 × 10−11 level demonstrated at the 1 MV CNA AMS system.•232Th3+, 234U3+ and 235U3+ scattered molecular fragments determine the 233U background levels at the ...CNA.•IAEA reference materials (soils and sediments) studied at the 600 kV ETH and CNA facilities.
233U (T1/2 = 0.159 My) has aroused much interest in the last few years because of the potential of 233U/236U to inform about anthropogenic U sources. The reported 233U/238U atom ratios in general environmental samples are in the 10−12–10−6 range. We demonstrate that 233U/238U abundance sensitivities at the 5 × 10−11 level can be achieved at the 1 MV Accelerator Mass Spectrometry system at the Centro Nacional de Aceleradores (CNA, Seville, Spain). Unresolved 234U, 235U and 232Th molecular fragments are identified as the main233U background contributors and procedures to subtract them are proposed. 233U/238U and 236U/238U atom ratios were analysed in the IAEA reference materials coded Soil-6, 300, 385, 410, and 412 at the CNA and at the 600 kV ETH AMS system for intercomparison. 233U/238U atom ratios for samples 412 and 385 were only reported by the ETH.
We report an approach for the accurate and reproducible measurement of boron isotope ratios in natural waters using an MC‐ICP‐MS (Neptune) after wet chemistry sample purification. The sample matrix ...can induce a drastic shift in the isotopic ratio by changing the mass bias. It is shown that, if no purification is carried out, the direct measurement of a seawater diluted one hundred times will induce an offset of −7‰ in the isotopic ratio, and that, for the same concentration, the greater the atomic mass of the matrix element, the greater the bias induced. Whatever the sample, it is thus necessary to remove the matrix. We propose a method adapted to water samples allowing purification of 100 ng of boron with a direct recovery of boron in 2 ml of 3% v/v HNO3, which was our working solution. Boron from the International Atomic Energy Agency IAEA‐B1 seawater reference material and from the two groundwater reference materials IAEA‐B2 and IAEA‐B3, was chemically purified, as well as boron from the certified reference material NIST SRM 951 as a test. The reproducibility of the whole procedure (wet chemistry and MC‐ICP‐MS measurement) was ± 0.4‰ (2s). Accuracy was verified by comparison with positive‐TIMS values and with recommended values. Seawater, being homogeneous for boron isotope ratios, is presently the only natural water material that is commonly analysed for testing accuracy worldwide. We propose that the three IAEA natural waters could be used as reference samples for boron isotopes, allowing a better knowledge of their isotopic ratios, thus contributing to the certification of methods and improving the quality of the boron isotopic ratio measurements for all laboratories.
Nous présentons ici une approche permettant la mesure juste et reproductible des rapports isotopiques du bore dans les eaux naturelles par l’utilisation d’un MC‐ICP‐MS (Neptune) après purification chimique de l’échantillon. Comme nous le démontrons, la matrice de l’échantillon peut induire un fractionnement important des rapports isotopiques. La mesure directe d’une eau de mer non purifiée, simplement diluée cent fois, entraine une différence de −7‰ sur le rapport isotopique. Il est également montré, qu’à teneur identique, plus l’élément est de masse atomique élevée, plus le biais sera important. Quel que soit l’échantillon, il s’avère nécessaire de le purifier. Nous proposons une méthode adaptée aux eaux naturelles permettant la purification de 100 ng de bore avec une récupération directe du bore dans 2 ml de 3% v/v HNO3 qui est la solution utilisée en routine pour la mesure sur notre MC‐ICP‐MS. La purification chimique du bore a été réalisée sur une eau de mer (IAEA‐B1) et deux eaux souterraines (IAEA‐B2 et IAEA‐B3) ainsi que sur le matériau de référence NIST SRM 951. La reproductibilité de la procédure (purification chimique et analyse au NEPTUNE) est de ± 0.4‰ (2s). La justesse est vérifiée par comparaison avec des valeurs obtenues en P‐TIMS ainsi qu’avec les valeurs recommandées. L’eau de mer étant homogène pour les rapports isotopiques du bore, elle est actuellement la seule eau naturelle analysée couramment pour tester la justesse des mesures au sein de différents laboratoires. Nous proposons que les trois eaux naturelles de l’IAEA soient utilisées en tant que solutions de référence pour les isotopes du bore, permettant ainsi une meilleure connaissance de leur rapport isotopique, et par conséquent aidant à la certification des méthodes et améliorant la qualité de la mesure des rapports isotopiques du bore dans les différents laboratoires.
Purpose
The PTW microDiamond has an enhanced spatial resolution when operated in an edge‐on orientation but is not typically utilized in this orientation due to the specifications of the IAEA TRS‐483 ...code of practice for small field dosimetry. In this work the suitability of an edge‐on orientation and advantages over the recommended face‐on orientation will be presented.
Methods
The PTW microDiamond in both orientations was compared on a Varian TrueBeam linac for: machine output factor (OF), percentage depth dose (PDD), and beam profile measurements from 10 × 10 cm2 to a 0.5 × 0.5 cm2 field size for 6X and 6FFF beam energies in a water tank. A quantification of the stem effect was performed in edge‐on orientation along with tissue to phantom ratio (TPR) measurements. An extensive angular dependence study for the two orientations was also undertaken within two custom PMMA plastic cylindrical phantoms.
Results
The OF of the PTW microDiamond in both orientations agrees within 1% down to the 2 × 2 cm2 field size. The edge‐on orientation overresponds in the build‐up region but provides improved penumbra and has a maximum observed stem effect of 1%. In the edge‐on orientation there is an angular independent response with a maximum of 2% variation down to a 2 × 2 cm2 field. The PTW microDiamond in edge‐on orientation for TPR measurements agreed to the CC01 ionization chamber within 1% for all field sizes.
Conclusions
The microDiamond was shown to be suitable for small field dosimetry when operated in edge‐on orientation. When edge‐on, a significantly reduced angular dependence is observed with no significant stem effect, making it a more versatile QA instrument for rotational delivery techniques.
This article presents compared cost assessment of selected nuclear-driven hybrid thermochemical cycles using International Atomic Energy's (IAEA) Hydrogen Economy Evaluation Program (HEEP). Cost ...estimations are made and evaluated for capital, fuel, decommissioning, O&B, and consumables, in addition to thermal energy and electricity cost details. Thanks to the data obtained with these cost estimates, 4 different nuclear hydrogen production systems were evaluated comparatively. Hybrid thermochemical cycles are expected to decrease operational expenses for hydrogen production. However, the capital expenses might be higher than pure electrolysis since they require more components for balance of plant components (BoP). The results obtained indicated that the levelized cost of hydrogen is 10%–30% less in the case of selected hybrid thermochemical cycles than that of pure electrochemical cycle.
•Energy based down selection of hydrogen technologies.•Energy and cost feasibility of hybrid thermochemical cycles.•LCOH assessment via IAEA's HEEP software.•Nuclear HyS and CuCl are economically feasible among others.
•International Atomic Energy Agency (IAEA) guidelines for newcomers.•Overview of Saudi Arabia's nuclear energy ambition.•Regulatory framework for Saudi Arabia's nuclear energy program.
This research ...article explores the Kingdom of Saudi Arabia's (KSA) efforts to meet its increasing electricity demand and reduce its reliance on fossil fuels by integrating nuclear energy into its energy mix. KSA aims to achieve a clean energy mix of 50% by 2030, including nuclear energy. The paper discusses KSA's progress in developing its nuclear power infrastructure, including the establishment of the King Abdullah City for Atomic and Renewable Energy (KA-CARE), and Nuclear and Radiological Regulatory Commission (NRRC). KSA has followed the IAEA “Milestones Approach” and conducted the first Integrated Nuclear Infrastructure Review (INIR) to ensure compliance with international standards and regulations. The article highlights the Kingdom's commitment to fulfilling international conventions and treaties related to nuclear power generation and its determination to achieve its VISION 2030 nuclear power generation targets. The paper provides an overview of the progress made by KSA towards introducing nuclear energy and underscores the measures taken to ensure the safety and security of the nuclear program.
•In order to demonstrate the ability of CFD codes to predict the complex phenomena of mixing flow, the results of numerical simulations of the ROCOM PTS experiments, which the IAEA proposed as an ...international open reference, are presented in this paper. A comparison between the calculated results produced by the commercial code Ansys CFX. 2022.R1 and the measurements from the experimental setup was made.•In both normal operation and accident scenarios, the phenomenon of coolant mixing at various temperatures in the primary circuit of pressurized water reactors (PWR) is significant. In this study, we explore the pressurized thermal shock (PTS) phenomena, which refers to a situation that threatens the integrity of the reactor pressure vessel (RPV).•The sole mechanism capable of preventing a reactivity insertion brought on by a temperature perturbation introduced into one of the loops during an overcooling transient is the slug mixing phenomena. For Pressurized Thermal Shock (PTS) scenarios, mixing water slugs of various temperatures is also crucial.•As typical one-dimensional codes are unable to anticipate these phenomena with the appropriate accuracy and spatiotemporal resolution, three-dimensional CFD codes must be used in this study to predict the transient flows of the coolant mixing event associated to thermal stratification. The nuclear industry now acknowledges that CFD codes have matured to the point where they can be used in nuclear power station design.•In order to solve specific safety concerns in nuclear power plants, CFD is already well-established. Further modeling work on the intricate physical processes involved, as well as the development of effective numerical schemes required to solve the fundamental equations in an efficient manner, including advanced turbulence modeling, are required for the development, verification, and validation of CFD codes in relation to NPP design.
The current paper documents the Computational Fluid Dynamics (CFD) code validation activity, carried out at the Nuclear Research Center of Birine relevant of Atomic Energy Commission of Algeria as part of International Atomic Energy Agency (IAEA) Coordinated Research Project (CRP): Application of Computational Fluid Dynamics Codes for Nuclear Power Plant Design to assess the current capabilities of these codes and to contribute to technological progress in their verification and validation. A set of ROCOM CFD-grade test data of Pressurized Thermal Shock test (PTS) specifications was made available in the framework of this (CRP) by Helmholtz Zentrum Dresden-Rossendorf, (HZDR) Germany, to perform detailed calculations of the proposed test. The reference point is the injection of relatively cold core cooling water (ECC), which can induce buoyant stratification. The data obtained from the PTS experiment were compared with the results of Ansys-CFX calculations in this paper. Unsteady Reynolds-Averaged Navier-Stokes (URANS) model is used to examine the buoyancy-influenced flows in the reactor pressure vessel for condition where natural circulation is a dominant factor. The Shear Stress Transport (SST k-ω) turbulence model is used to take into account the turbulence effects on the mean flow. Calculation results show a good qualitative and quantitative agreement with the experiment data.
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