Radioactive Emissions Research Articles

Влияние радиоактивных выбросов полигона «Капустин яр» на экологическую обстановку близлежащих районов

This paper discusses the environmental problems of Kazakhstan and ways to solve them on the territory of test sites in the West Kazakhstan region. The article aims to evaluate the effect of radioactive waste of the landfill on the environment Bokeiorda and Zhangala areas of West Kazakhstan region. As a result of spacecraft launches, the environment of these areas was polluted by the decay products of various types of rocket fuel, nitrogen compounds, heavy metals and other toxic substances. The article provides a theoretical analysis of statistical data on the assessment of the environmental situation in the surrounding areas relative to the Kapustin Yar landfill. Thus, in the areas of the West Kazakhstan region adjacent to the Kapustin Yar landfill, indicators were found for the analyzed period that differ from the national average or control values, which in turn indicates an adverse impact on the environment and human health of radioactive emissions from the Kapustin Yar landfill.

Estimation and Prediction of the Population Irradiation Dose in the Vicinity of NPP with VVER-1200

The dose loads from the natural and technogenic background to the population living in the vicinity of NPP with VVER-1200 in Kaliningrad Oblast were estimated on the basis of radioecological inspection data. The average yearly effective population irradiation dose from natural and technogenic radionuclides present in the environment is equal to 2.42 mSv. The population radiation impact from atmospheric emissions is predicted. The maximum dose load is ~1 μSv/yr and does not exceed the quota for radioactive emissions from NPP 10 μmSv/yr.

Laser Spectroscopy for Monitoring of Radiocarbon in Atmospheric Samples.

In-situ monitoring of radiocarbon emissions is challenging due to the lack of a suitable method for sensitive online detection of this isotope. Here we report on a complete system for automatized continuous on-site monitoring of radiocarbon gaseous emissions from nuclear facilities. By combining radiocarbon detection using mid-infrared cavity ring-down spectroscopy and an advanced sampling system, an elevated amount of radiocarbon in an atmospheric-like gas matrix was detected. Radiocarbon was detected in the form of 14CO2 after extraction of the carbon dioxide from the air sample. The system is also able to discriminate between radiocarbon in organic or inorganic molecular form by converting 14CH4 into 14CO2. This work lays the groundwork for further use of this technology in nuclear facilities for online on-site monitoring of radioactive gaseous emissions as well as future work on in-situ monitoring of atmospheric radiocarbon.

X-Ray and Gamma-Ray Emission from Core-collapse Supernovae: Comparison of Three-dimensional Neutrino-driven Explosions with SN 1987A

Abstract During the first few hundred days after the explosion, core-collapse supernovae (SNe) emit down-scattered X-rays and gamma-rays originating from radioactive line emissions, primarily from the 56Ni → 56Co → 56Fe chain. We use supernova (SN) models based on three-dimensional neutrino-driven explosion simulations of single stars and mergers to compute this emission and compare the predictions with observations of SN 1987A. A number of models are clearly excluded, showing that high-energy emission is a powerful way of discriminating between models. The best models are almost consistent with the observations, but differences that cannot be matched by a suitable choice of viewing angle are evident. Therefore, our self-consistent models suggest that neutrino-driven explosions are able to produce, in principle, sufficient mixing, although remaining discrepancies may require small changes to the progenitor structures. The soft X-ray cutoff is primarily determined by the metallicity of the progenitor envelope. The main effect of asymmetries is to vary the flux level by a factor of ∼3. For the more asymmetric models, the shapes of the light curves also change. In addition to the models of SN 1987A, we investigate two models of SNe II-P and one model of a stripped-envelope SN IIb. The Type II-P models have observables similar to those of the models of SN 1987A, but the stripped-envelope SN model is significantly more luminous and evolves faster. Finally, we make simple predictions for future observations of nearby SNe.

ON THE IDENTIFICATION OF THE SOURCE OF EMISSION ON THE PLANE

We consider the problem of identification of the position and the moment of the beginning of a radioactive source emission on the plane. The acts of emission constitute inhomogeneous Poisson processes and are registered by $ K $ detectors on the plane. We suppose that the moments of arriving of the signals at the detectors are measured with some small errors. Then, using these estimate, we construct the estimators of the position of source and the moment of the beginning of emission. We study the asymptotic properties of these estimators for large signals and prove their consistency.

CHARACTERISTICS OF RADIONUCLIDES ON THORIUM-CYCLE EXPERIMENTAL POWER REACTOR SPENT FUEL.

CHARACTERISTICS OF RADIONUCLIDES ON THORIUM-CYCLE EXPERIMENTAL POWER REACTOR SPENT FUEL. There are several options of nuclear fuel utilisation in the HTGR-based Experimental Power Reactor (Reaktor Daya Eksperimental/RDE). Although mainly RDE utilises low enriched uranium (LEU)-based fuel, which is the most viable option at the moment, it is possible for RDE to utilise other fuel, for example thorium-based and possibly even plutonium-based fuel. Different fuel yields different spent fuel characteristics, so it is necessary to identify the characteristics to understand and evaluate their handling and interim storage. This paper provides the study on the characteristics of thorium-fuelled RDE spent fuel, assuming typical operational cycle. ORIGEN2.1 code is employed to determine the spent fuel characteristics. The result showed that at the end of the calculation cycle, each thorium-based spent fuel pebble generates around 0,627 Watts of heat, 28 neutrons/s, 8.28x1012 photons/s and yield 192.53 curies of radioactivity. These higher radioactivity and photon emission possibly necessitate different measures in spent fuel management, if RDE were to use thorium-based fuel. Tl-208 activity, which found to be emitting potentially non-negligible strong gamma emission, magnified the requirement of proper spent fuel handling especially radiation shielding in spent fuel cask.Keywords: RDE, spent fuel, thorium, HTGR, Tl-208.

A systems biology approach to propose a new mechanism of regulation of repetitive prophylaxis of stable iodide on sodium/iodide symporter (NIS)

Our group showed that repetitive dose of potassium iodide (KI) for eight days offers an efficient protection for exposure to repeated radioactive emissions without adverse effects on adult rats. However, differential expression of genes implicated in Wolff-Chaikoff effect was observed. To understand the Wolff-Chaikoff regulation and its molecular constituents during repetitive administration of KI, a biochemical reaction network was constructed as a “geographical” map of the thyrocyte depicting iodide and thyroid hormone synthesis. Path analysis of the network has been performed to investigate the presence of a regulatory circuit of the node iodide to the node “nis transcription”. NIS is responsible for the uptake of KI and plays an important role in the Wolff-Chaikoff effect. The map is a source for the most updated information about iodide and thyroid hormone metabolism. Based on this map, we propose a hypothesis that shows a putative mechanism behind NIS regulation and KI uptake.

Assessment of the health damage costs of radionuclides releases from Muğla provinces lignite-fired power plants

Abstract The health impacts and corresponding damage costs of radioactive emission of Muğla province lignite-fired power plants have been assessed by using the simplified impact pathway approach. Radiation dose and risk calculations have been carried out by the code CAP88-PC around the power plants. Specific isotopes, 238U, 232Th, 226Ra and 40K in the flying ash samples are considered as radioactive sources. Power plants intersecting regions are also considered in the collective dose calculation. The estimated total collective dose around Muğla province due to Yatağan, Yeniköy and Kemerköy power plants is 5.25 × 10−2 man.Sv/year. The total health effects damage cost around the Muğla province due to the radioactive emissions from the power plants is 2504.3 US $ 2000/year. The results obtained from the calculations are under the dose limits of International Commission of Radiation Protection and it does not any risk for public health around the plant environment.

Performance Review of Venturi Scrubber

Radioactive emissions are released from the molten core into reactor containment during the failure of nuclear power plant (NPP) due to severe accident. The technology called “Filtered Vented containment system (FVCS)” is the necessity in nuclear power plant for the removal of gaseous pollutants. The Self – Priming venturi scrubbers are the most efficient scrubbing device for the collection of gaseous pollutants and fine particles. Venturi Scrubbers frequently collect gaseous pollutants and particulate matter from the contaminated gas stream in the form of droplets formed due to liquid atomization. The main purpose of this literature review regarding the Venturi Scrubber to make modified optimum design to improve the performance of Venturi Scrubber as per the required safety regulation standards.

WATER POLYUTANTS - RADIOACTIVE SUBSTANCES

Radioactive hazardous solid waste occurs with the use of radioisotopes in medical centers and industry, and there are certain amounts of radioactive lightning rods in our country, but more specific knowledge about the quantities of this waste is not known. There are no official collection systems for radioactive waste and there are no disposal facilities. Radioactive waste is small and consists of radioactive materials, usually subject to several legal provisions such as: collection, disposal and finally disposal of radioactive materials in human environment, regulations for the circulation and use of radioactive materials through a certain limit, X-ray devices and other devices that generate ionizing rays and protective measures from these rays. Priorities regarding radioactive waste management are: development of capacity for permanent storage of low and intermediate level radioactive emissions sources in accordance with the existing legal provisions for control and management of radioactive emissions and exposure of the public to them. This paper will describe in detail the radioactivity, radioactive waste, the increase in water temperature as a result of the use of nuclear reactors, the impact of nuclear reactors on water, as well as the way of storing and delaying radioactive waste, as well as the negative consequences caused by the radioactive waste.

Radioactive Gamma-Ray Emissions from Neutron Star Mergers

Abstract Gravitational waves and electromagnetic radiations from a neutron star merger were discovered on 2017 August 17. Multiband observations of the optical transient have identified brightness and spectrum features broadly consistent with theoretical predictions. According to the theoretical model, the optical radiation from a neutron star merger originates from the radioactive decay of unstable nuclides freshly synthesized in the merger ejecta. In about a day the ejecta transits from an optically thick state to an optically thin state owing to its subrelativistic expansion. Hence, we expect that about a day after the merger the gamma-ray photons produced by radioactive decays start to escape from the ejecta and make it bright in the MeV band. In this paper, we study the features of the radioactive gamma-ray emission from a neutron star merger, including the brightness and the spectrum, and discuss the observability of the gamma-ray emission. We find that more than 95% of the radiated gamma-ray energy is carried by photons of 0.2–4 MeV, with a spectrum shaped by the nucleosynthesis process and the subrelativistic expansion of the ejecta. Under favorable conditions, a prominent pair annihilation line can be present in the gamma-ray spectrum with the energy flux about 3%–5% of the total. For a merger event similar to GW170817, the gamma-ray emission attains a peak luminosity of ≈2 × 1041 erg s−1 at ≈1.2 days after the merger and fades by a factor of two in about 2 days. Such a source will be detectable by satellite-ETCC if it occurs at a distance ≲12 Mpc.

Um questionário conceitual sobre radiações: processo de elaboração e análise dos distratores

Considerando a relevância do tema radiações no escopo da Física Moderna e Contemporânea e a pertinência em pensar e propor estratégias para investigar a compreensão conceitual de estudantes a respeito dos conteúdos de ensino, apresentamos o processo de elaboração de treze questões múltipla escolha que abarcam tópicos como raios X, emissões radioativas, radiações ionizantes e radiações não ionizantes. Concomitantemente à apresentação das questões, discutimos os raciocínios que poderiam levar os estudantes a assinalar os distratores propostos. Dada a escassez de artigos científicos sobre o assunto, especialmente no âmbito da literatura brasileira, esperamos que este trabalho possa de alguma forma inspirar o desenvolvimento e a publicação de investigações que visem a pensar aspectos associados à elaboração, à utilização e à análise de questionários conceituais de física.

Tellurium radionuclides produced by major accidental events in nuclear power plants

Environmental contextHistorical accidents in nuclear power plants have released radionuclides of several elements, including tellurium, to the environment. Although tellurium radionuclides are significant radioactive emission products, and show medium-term persistence in the environment, the mechanisms behind their widespread dispersion are unknown. Future research into the biogeochemical behaviour of stable tellurium is proposed as an appropriate approach to develop tellurium dispersion scenarios fundamental for post-accident management. AbstractTellurium (Te) is a technology critical element (TCE) and a non-negligible fission product in nuclear facilities. This work compiles the environmental releases of Te radionuclides registered after two nuclear power plant (NPP) major accidental events in human history (Chernobyl and Fukushima Daiichi). Despite the registered non-negligible activities and environmental persistence, Te radionuclides are scarcely monitored, which limits the current understanding of their biogeochemical behaviour, dispersion and fate in all environmental compartments. This lack of knowledge implies an underestimation of the role of Te radionuclides during and after accidents and its consideration in dispersion scenarios, which are fundamental for post-accidental risk assessment and management.

Relative Risk Assessment for Hypothetical Radioactivity Emission at a Snow Climate Site

Relative Risk Assessment for Hypothetical Radioactivity Emission at a Snow Climate Site

Radiofármacos e suas aplicações

Radiopharmacy was developed from the necessity of human body studies by images with greater precision, sensibility and diagnosis early to a strong request of Nuclear Medicine. Historically the radiopharmacy is associated with the discovery of radioactivity and also with the pioneer studies related with this subject by Henri Becquerel, Pierre Curie and Marie Curie. The radiopharmaceuticals are complex compounds constituted by a radionuclide (radioactive isotope) responsible by radioactivity emission bound to non-radioactive molecule that exhibits biological affinity for an organ or system, aiming diagnostic or therapeutic purpose. The diagnostic using images by radiopharmaceuticals administration is a consolidated area of this science, representing approximately 95% of all nuclear medicine procedures. The images are acquired by means of the radiation emitted by radiopharmaceutical inside in the body unlike conventional images techniques. The acquisition of the images by radiopharmaceuticals allow morphological and functional evaluation of target organs. According to radionuclide emission type of interest, the molecular bases imaging obtained with use of radiopharmaceuticals can be performed by two basic techniques, SPECT and PET, which allow investigating, qualitatively and quantitatively, the metabolic activity or function of a particular organ or system. In summary, SPECT and PET images constitute a diagnostic procedure safe, minimally invasive, and of high value to study of different systems, contributing to many benefits to the patient.

Методический аппарат для разработки типовых сценариев развития запроектных аварий на АЭС с реакторами ВВЭР при планировании и проведении защитных мероприятий для населения

To develop a simple methodological apparatus for constructing typical scenarios of accidents and estimate of emissions of radioactive substances from nuclear power plants with VVER reactors in the planning and implementation of protective measures for the population.Material and methods_ To build the model of release of radionuclides into the environment in case of an accident used literary experimental data of outputs of the radioactive substances from the fuel when it is heating and melting, the destruction of the fuel rod cladding, the use of technical means retention of radioactive substances in the containment of the reactor and their behaviour in the containment (sedimentation, sorption, etc.).Results_ Mathematical apparatus has been developed to quantify the magnitude of emissions of radioactive substances at nuclear power plants with VVER reactors depending on the time for dose-forming radionuclides in the instantaneous rupture of cooling pipelines in the presence of additional failure of NPP safety systems. The amount of emission of each deterministic of an accident correspond to the level 4 to 7 of the INES scale. Radionuclide release into the environment was calculated in the following physical and chemical processes_ heating and melting of fuel, depressurization of fuel rod claddings, peculiarities of the behavior of radionuclides in the containment shell (deposition, etc.) and operation of technical means to ensure radiation safety, structural leakages of the buildings. As an example, the assessment of the release of radionuclides into the environment depending on the time for level 5 of the INES accident scale is given. Conclusion_ Methodical apparatus can be used in the construction of typical scenarios for the development of basis accidents and assessment of radioactive emissions at nuclear power plants with VVER reactors in the planning and implementation of protective measures for the population and emergency exercises and training_

Optimization of mechanical properties of chitosan/phenol formaldehyde composite

The Frechet distribution which has a scale and shape parameters, has been found to have wide application in modelling extreme events such as radioactive emission, flood, rainfall, seismic analysis, wind speed, etc. In this research paper, the Bayesian analysis of scale parameter of Frechet distribution was considered. It is necessary to know the best combination of prior distribution and loss function for the parameter estimation. Posterior distribution was derived by uniform and Jeffrey’s prior under the square error, Precautionary, Quadratic and Weighted balance loss function. Bayes estimation and their corresponding risk was obtained by the above stated priors and loss function. Monte Carlo simulations was conducted to compare the performance of the estimators. It is evident that weighted balance loss function when used with uniform prior provides the least posterior risk.Keywords: Frechet Distribution, Non-Informative Prior, Bayesian Estimation, Loss Functions, Monte Carlo Simulations

Evaluation of doses in coupled rooms in case of beyond design accident basis

An object of research in this study are radioactive substances and its expansion in adjacent spaces. An objective of the study - to develop an assessment algorithm of the doze budget from the radioactive sources in adjacent spaces considering the convective transfer of radioactive substances. The universal scale of installation-420 (hereinafter-UGU-420) space is installed, the location is on the site of “JIPNR– Sosny” of NAS of Belarus (hereinafter – the Institute) in the software package simulations of COMSOL Multiphysics 3.5 a (hereinafter-COMSOL). According to the results of the test calculation of the relative concentration distribution radioactive substances in the volume of the space, taking into account barriers and ventilation pipeline, the dose budget on the employees of the Institute with possible release of radioactive 60Co was determined. The comparative analysis on the calculation results of radioactive substances and dose budget expansion was performed with the help of the developed software module for evaluation spread of radioactive emissions.

A Sensitive, Nonradioactive Assay for Zn(II) Uptake into Metazoan Cells.

Sensitive measurements of cellular Zn(II) uptake currently rely on quantitating radioactive emissions from cells treated with 65Zn(II). Here, we describe a straightforward and reliable method employing a stable isotope to sensitively measure Zn(II) uptake by metazoan cells. First, biological medium selectively depleted of natural abundance Zn(II) using A12-resin [Richardson, C. E. R., et al. (2018) J. Am. Chem. Soc. 140, 2413] is restored to physiological levels of Zn(II) by addition of a non-natural Zn(II) isotope distribution comprising 70% 70Zn(II). The resulting 70Zn(II)-enriched medium facilitates quantitation of Zn(II) uptake using inductively coupled plasma-mass spectrometry (ICP-MS). This sensitive and reliable assay assesses Zn(II)-uptake kinetics at early time points and can be used to delineate how chemical and genetic perturbations influence Zn(II) uptake. Further, the use of ICP-MS in a Zn(II)-uptake assay permits simultaneous measurement of multiple metal ion concentrations. We used this capability to show that, across three cell lines, Zn(II) deficiency enhances selectivity for Zn(II) over Cd(II) uptake.

Environmental correction of gamma ray logs by geometrical / empirical factors

This paper presents a series of empirical expressions to correct the total natural gamma ray log due to well environmental factors. This correction is focussed on improving the quantification of 40 K, given its application in the computation of the clay content of the different layers crossed during drilling.To date, there are no analytical relationships that make this correction and continuously consider the different diameters of the many existing sondes. There are also no functions that continuously take into account the different combinations of media interspersed between the well walls and the sonde (casing, drill pipe, gravel pack, cement, etc.) for different measurement modes and systems, such as wireline, while drilling.To solve these shortcomings, the relationships developed in this work have cited, in addition to the different well diameters and mud densities, the diameter of the sonde and the environmental parameters as variables with any value and in any possible combination. The obvious advantage of these parametric equations is that they can easily be entered as a subroutine into any code.Unlike the existing correction methods, i.e., empirical charts and curves obtained by simulation codes based on the Monte Carlo method, the relationships developed take into account the variation of the build-up effect that the radiation undergoes as it travels from layers with a certain radioactive emission to the sonde. In addition, another difference is that the relationships generated in this work include the internal diameter of the sonde between its outer walls and the cylindrical radiation detector glass.Starting from the general relationships that consider the attenuation and build-up effects of gamma radiation when passing through a medium, the methodology consisted of establishing an effective distance for the cylindrical geometry in which the source is the well wall, particularized for each effect and each type of tool (centred and eccentred).The resulting correction factors have been contrasted with the most recognized experimental charts in the field of well logging, obtaining a very high correlation and an average deviation of around 1.5%.