Radiation Map Research Articles

Radiation map for King Abdulaziz University campus and surrounding areas

ABSTRACTKing Abdulaziz University (KAU) buildings are expanded to accept more students and research centers. Many of the new buildings were constructed using granitic rocks as building materials. G...

Paracetamol micro-structure analysis by optical mapping

Domain structure of paracetamol - popular antipyretic analgesic - was investigated by infrared (IR) spectroscopy using synchrotron radiation. Absorbance and retardance maps reveal molecular orientation inside the micro-domains of the paracetamol form II which has a better water solubility and compressibility compared to the commercially used forms I. The developed method of analysis representing orientation of optical slow(fast)-axis is compared with azimuthal orientation of the absorbance at several specific IR bands using vector maps. High brightness of synchrotron radiation and hyper-spectral mapping of structural domains in paracetamol clearly reveals the domain boundaries and can potentially be used to observe in situ intra-phase transformations of paracetamol forms-I, II, III and melting, which are important for making medical tablets and powders by an industrial process.

MODELING STUDIES AND CODE-TO-CODE COMPARISONS FOR PRESSURE TUBE HEAVY WATER REACTOR CORES

Preliminary, conceptual studies have been performed previously using deterministic lattice physics (WIMS-AECL) and core physics codes (RFSP) to estimate performance and safety characteristics of various thorium-based fuels and uranium-based fuels augmented by small amounts of thorium for use in pressure tube heavy-water reactors (PT-HWRs). To confirm the validity of the results, the WIMS-AECL/RFSP results are compared against predictions made with the stochastic neutron transport code MCNP. This paper describes the development of a method for setting up an MCNP core model of at PT-HWR for comparison with WIMS-AECL/RFSP results, using a core with 37-element natural uranium fuel bundles as a test case for sensitivity studies. These studies included evaluating the sensitivity of the bias of the effective neutron multiplication factor (keff), a source convergence study, uncertainties correction with multiple independent simulations, the impact of irradiation map binning methods, and the impact of reflector models. A Python-based software scripting tool was developed to automate the creation, execution, and post-processing of reactor physics data from the MCNP models. The software tool and algorithm for creating an MCNP core model using data from the WIMS-AECL and RFSP models are described in this paper. Based on the preliminary evaluations of the simulation parameters with the base model, reactor physics analyses were performed for PT-HWR cores with thorium-based fuels in a 35-element bundle type. Code-to-code results demonstrate good agreement between MCNP and RFSP, giving confidence in the method developed and its applicability to other fuels and core types.

Decreasing trend of ambient dose equivalent rates over a wide area in eastern Japan until 2016 evaluated by car-borne surveys using KURAMA systems

As part of the investigation of the distribution of ambient dose equivalent rates around the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), car-borne surveys using Kyoto University RAdiation MApping (KURAMA) systems have been conducted over a wide area in eastern Japan since 2011. The enormous volume of measurement data collected until 2016, including those until 2012 which were reported in the previous paper, was analyzed, and dependencies of the decreasing trend of the dose rates in regions within 80 km of the FDNPP on land-use categories, evacuation order areas and magnitude of the dose rates were examined. The air dose rates within 80 km of the FDNPP tended to decrease considerably with respect to the physical decay of radiocaesium. The decrease of the dose rate in the “forest” was slower than its decrease in other regions, while that in “urban area” was the fastest. The decrease in the air dose rate from 2011 was the fastest outside the evacuation order area until 2015, and it was the slowest in the “difficult-to-return zone”. However, the decreasing trend starting from 2013 showed that the decrease in the “zone in preparation for the lifting of the evacuation order” and in the “residence restriction area” was the fastest. It was found that the air dose rates decreased depending on the magnitude of the dose rates and elapsed time from the FDNPP accident, i.e. the decrease in air dose rates in areas with relatively low dose ranges (such as 0.2–0.5 μSv/h) was the largest during a period relatively early after the accident, and the decreasing rate in the dose rate ranges of 1.9–3.8 and 3.8–9.5 μSv/h were the fastest after 2013. The averaged ratios were analyzed to obtain the ecological half-lives of the fast and slow decay components, and those in whole area within 80 km of FDNPP were estimated to be 0.44 ± 0.05 y and 6.7 ± 1 y, respectively. The ecological half-lives with respect to the land use categories, evacuation order areas and magnitude of the dose rates were also evaluated. The decrease in the dose rates obtained by the car-borne survey was larger than that obtained on flat ground with few disturbances using the NaI(Tl) survey meter during approximately 1.5 y after the FDNPP accident. Thereafter, the difference of decreasing tendencies in the air dose rates between both the measurements was negligibly small, with the ratio of dose rates by the car-borne survey to those by the fixed-point measurement of 0.72–0.77.

Spatiotemporal patterns of street-level solar radiation estimated using Google Street View in a high-density urban environment

This study presents a method for calculating solar irradiance of street canyons using Google Street View (GSV) images and investigates its spatiotemporal patterns in a high-density urban environment. In this method, GSV images provide a unique way to characterize the street morphology from which the diurnal solar path and solar radiation exposure can be estimated in a street canyon. Verifications of our developed method using free-horizon HKO observations and street-level field measurements show that both the calculated clear-sky and all-sky solar irradiance of street canyons well capture the diurnal and seasonal cycles. In the high-density urban areas of Hong Kong, we found that (1) the lowest monthly averaged solar irradiations in winter are 6.6 (December) and 4.6 (February) MJ/m2/day, and the highest values in summer are 17.3 (July) and 10.8 (June) MJ/m2/day for clear-sky and all-sky calculations, respectively; (2) The spatial variability of solar irradiation is closely related to sky view factor (SVF). In summer, the irradiation in a low-rise region (SVF≥0.7) on average is about three times that in a high-rise region (SVF≤0.3), and they differ by about five times in winter; (3) Street orientation has a significant impact on the solar radiation received in a high-density street canyon. In general, street canyons with West-East orientation receive higher solar irradiation during summer and lower during winter compared to those with South-North orientation. The generated maps of street-level solar irradiation may help researchers investigate the interactions between solar radiation, human health and urban thermal balance in high-density urban environments.

Large-scale Compression Acceleration during Magnetic Reconnection in a Low-β Plasma

Abstract In solar flares and other astrophysical systems, a major challenge for solving the particle acceleration problem associated with magnetic reconnection is the enormous scale separation between kinetic scales and the observed reconnection scale. Because of this, it has been difficult to draw any definite conclusions by just using kinetic simulations. A particle acceleration model that solves the energetic particle transport equation can capture the main acceleration physics found in kinetic simulations and thus provide a practical way to make observable predictions and directly compare model results with observations. Here we study compression particle acceleration in magnetic reconnection by solving the Parker (diffusion–advection) transport equation using velocity and magnetic fields from two-dimensional magnetohydrodynamics (MHD) simulations of a low-β high-Lundquist-number reconnection layer. We show that the compressible reconnection layer can give significant particle acceleration, leading to the formation of power-law particle energy distributions. We analyze the acceleration rate and find that the acceleration in the reconnection layer is a mixture of first- and second-order Fermi processes. When including a guide field, we find that the spectrum becomes steeper and both the power-law cutoff energy and maximum particle energy decrease as plasma becomes less compressible. This model produces a 2D particle distribution that one can use to generate a radiation map and directly compare with solar flare observations. This provides a framework to explain particle acceleration at large-scale astrophysical reconnection sites, such as solar flares.

Solar map of India under clear sky conditions

ABSTRACTThis paper focusses on generation of solar irradiation map under clear sky conditions using r.sun model. Direct Irradiation, diffuse irradiation and global irradiation maps are plotted using programme which was developed in C language. This programme calculates different components of solar irradiation using clear sky model (r.sun). Further Surfer software was used to plot different irradiation maps. All three values (Direct Irradiation, Global Irradiation and Diffuse Irradiation) were compared by IMD values for performing statistical analysis i.e. Mean Bias Error (MBE), Root Mean Square Error (RMSE) and standard deviation. MBE was found within ±10%, RMSE lies within <20% and standard deviation was found to have very low value which indicated good fitting between model results and calculated values. Therefore the r.sun model is good model and can be used for computing solar irradiation for India.

Faceted structure: a design for desired illumination and manufacture using 3D printing

A new optical component of transmissive faceted structure that allows the reshaping of collimated white light beam is depicted and realized. After being illuminated, each facet element in the structure can slightly tilt along its own axes to deflect the incident light. The calculation of the tilt angles is made by a numerical approach, which is the inverse solution of the analytical relationships between the two-dimensional tilt angles of the facet element and the local coordinates of the outgoing ray on the target plan. For a predefined illumination pattern on a fixed screen, the numerical computation of the 2D tilt angle matrix of the faceted structure is described. In the meantime, a Monte Carlo ray tracing program is created to calculate and verify the irradiance map, all compared with well-recognized commercial illumination software programs. Afterwards, the component is fabricated using an innovative additive technology, inspired by 3D printing and proposed by Luximprint.

Radiological comparison of a FDNPP waste storage site during and after construction

The clean-up effort that is occurring across the region affected by the 2011 Fukushima Daiichi Nuclear Power Plant accident is unprecedented in its magnitude as well as the financial cost that will eventually result. A major component of this remediation is the stripping of large volumes of material from the land surface, depositing this into large waste storage bags before placing these 1 cubic meter bags into specially constructed stores across Fukushima Prefecture.In this work, using an unmanned aerial vehicle to perform radiological surveys of a site, the time-resolved distribution of contamination during the construction of one of these waste storage sites was assessed. The results indicated that radioactive material was progressively leaching from the store into the surrounding environment. A subsequent survey of the site conducted eight months later revealed that in response to this survey and remedial actions, the contamination issue once existing on this site had been successfully resolved. Such results highlight the potential of low-altitude unmanned aerial systems to easily and rapidly assess site-wide changes over time – providing highly-visual results; therefore, permitting for prompt remedial actions to be undertaken as required.Use of UAV radiation mapping and airborne photogrammetry to produce a time-resolved assessment of remediation efforts within a Fukushima temporary storage facility.

Producing Global Solar Radiation maps in Iraq Using Geographic Information Systems

The design and operation of any solar energy system requires a good knowledge of the solar radiation data in a location. This data finds application in agriculture, climatology, meteorology, etc. Since the solar radiation reaching the earth’s surface varies with climatic conditions of a place, a study of solar radiation under local climatic condition is essential. Global solar radiation is of economic importance as renewable energy alternatives. In this research 14 Iraqi climatic stations radiation data were used for the years 2013 to 2015. Data have been designed and calculated by using Excel. ArcGIS 10.2 is used for spatial interpolation and mapping activities. Surface radiation map have been generated by using ordinary kriging interpolation technique. Different models are tested, namely Spherical, Gaussian and Circular model. Creation of digital grid maps makes it possible to obtain climatic information at any point, whether there is a weather station or not. Results show that the spherical model outperforms Gaussian and circular models.

Producing Global Solar Radiation maps in Iraq Using Geographic Information Systems

The design and operation of any solar energy system requires a good knowledge of the solar radiation data in a location. This data finds application in agriculture, climatology, meteorology, etc. Since the solar radiation reaching the earth’s surface varies with climatic conditions of a place, a study of solar radiation under local climatic condition is essential. Global solar radiation is of economic importance as renewable energy alternatives. In this research 14 Iraqi climatic stations radiation data were used for the years 2013 to 2015. Data have been designed and calculated by using Excel. ArcGIS 10.2 is used for spatial interpolation and mapping activities. Surface radiation map have been generated by using ordinary kriging interpolation technique. Different models are tested, namely Spherical, Gaussian and Circular model. Creation of digital grid maps makes it possible to obtain climatic information at any point, whether there is a weather station or not. Results show that the spherical model outperforms Gaussian and circular models.

Validation of a novel radiation mapping platform for the reduction of operator-induced shielding effects

With extensive remediation currently ongoing because of the Fukushima Daiichi Nuclear Power Plant accident, there exists the even greater need to provide a system with which the distribution of radiation (specifically radiocesium) can be rapidly determined across extensive areas, yet at high (metre or sub-metre) spatial resolutions. Although a range of potential survey methods have been utilised (e.g. fixed-wing aircraft, helicopter, vehicular and more-recently unmanned aerial vehicle) to characterise the distribution of radiological contamination, ground-based (on-foot) methods that employ human operatives to traverse sites of interest remains one of the primary methods through which to perform routine radiological site surveys. Through the application of a newly-developed platform carried as a backpack-contained unit, it was possible to map sites at twice the rate previously possible—reducing not only the exposure time of the operator to ionising radiation, but also dramatically reducing the level of radiation attenuation (introduced by the operator) onto the detector. Like magnetometry platforms used during geological ore prospecting, this system was similarly boom-based, extending sideways away from the central operator. While conventional radiological survey platforms require a correction be performed on the data to account for the carrier (aircraft, vehicle or human) interception and attenuation incident radiation—this system is shown to not require such a retrospective correction.

High-performance, robustly verified Monte Carlo simulation with FullMonte.

We introduce the FullMonte tetrahedral 3-D Monte Carlo (MC) software package for simulation, visualization, and analysis of light propagation in heterogeneous turbid media including tissue. It provides the highest computational performance and richest set of input, output, and analysis facilities of any open-source tetrahedral-mesh MC light simulator. It also provides a robust framework for statistical verification. A scripting interface makes set-up of simulation runs simple, including parameter sweeps, while simultaneously providing customization options. Data formats shared with class-leading visualization tools, VTK and Paraview, facilitate interactive generation of publication-quality fluence and irradiance maps. The simulator can read and write file formats supported by other similar simulators, such as TIM-OS, MMC, COMSOL (finite-element simulations), and MCML to support comparison. Where simulator features permit, FullMonte can take a single test case, run it in multiple software packages, and load the results together for comparison. Example meshes, optical properties, set-up scripts, and output files are provided for user convenience. We demonstrate its use in several test cases, including photodynamic therapy of the brain, bioluminescence imaging (BLI) in a mouse phantom, and a comparison against MCML for layered geometries. Application domains that can benefit from use of FullMonte include photodynamic, photothermal, and photobiomodulation therapies, BLI, diffuse optical tomography, MC software development, and biophotonics education. Since MC results may be used for preclinical or even clinical experiments, a robust and rigorous verification process is essential. Being a stochastic numerical method, MC simulation has unique challenges associated with verification of output results since observed differences may be due simply to output variance or actual differences in expected output. We describe and have implemented a rigorous and statistically justified framework for comparing between simulators of the same class and for performing regression testing.

Solar radiation map of Jordan governorates

The solar energy potential in Jordan is enormous as it lies within the solar belt of the world with average solar radiation between 4 and 8 KWh/m2, which implies a potential of 1400-2300 GWh per year annually. Electricity demand in Jordan plays a significant role in the high amount of energy consumption to cover the needs of heating, cooling, lighting, etc. For that, the availability of the solar radiation infor-mation becomes essential to help in the design and building of the solar energy application. In this study, a solar radiation map is provided of all Jordan governorates.

Simulation analysis on the propagation of the optical partial discharge signal in I-shaped and L-shaped GILs

When partial discharge (PD) occurs in the gas-insulated transmission line (GIL), accompanied by the occurrence of sound, light, electricity and thermal phenomena, the propagation characteristics of the optical PD signal are the basis for the arrangement of the optical sensors and PD source location. To study the propagation characteristics, simulation models of GIL are established. The total irradiance map (TIM) and the average value of the relative irradiance (AVRI) for the optical PD signal on each detection plane are observed under different PD source positions, detection distances and L-shaped angles. The simulation results indicate that 1) when the PD occurs near the inner conductor or the tank inner surface, it is more difficult to detect than other places. Taking the distance between the detection plane and the PD source (DDP), which is 60 cm, as an example, when the position of the PD source (PPS) is Up-50 mm, the AVRI is 79.56% of that when the PPS is Up-140 mm. 2) In the process of the L-shaped angles increasing, the value of relative irradiance has a certain increase. Taking the PPS below-95 mm as an example, when the L-shaped angle is 165°, the relative irradiance is 29.92% larger than that when the L-shaped angle is 90°. These findings can provide some reference for the optical PD detection in GIL.

Decreasing trend of ambient dose equivalent rates over a wide area in eastern Japan until 2016 evaluated by car-borne surveys using KURAMA systems

As part of the investigation of the distribution of ambient dose equivalent rates around the Fukushima Dai-ichi Nuclear Power Plant (FDNPP), car-borne surveys using Kyoto University RAdiation MApping (KURAMA) systems have been conducted over a wide area in eastern Japan since 2011. The enormous volume of measurement data collected until 2016, including those until 2012 which were reported in the previous paper, was analyzed, and dependencies of the decreasing trend of the dose rates in regions within 80 km of the FDNPP on land-use categories, evacuation order areas and magnitude of the dose rates were examined. The air dose rates within 80 km of the FDNPP tended to decrease considerably with respect to the physical decay of radiocaesium. The decrease of the dose rate in the “forest” was slower than its decrease in other regions, while that in “urban area” was the fastest. The decrease in the air dose rate from 2011 was the fastest outside the evacuation order area until 2015, and it was the slowest in the “difficult-to-return zone”. However, the decreasing trend starting from 2013 showed that the decrease in the “zone in preparation for the lifting of the evacuation order” and in the “residence restriction area” was the fastest. It was found that the air dose rates decreased depending on the magnitude of the dose rates and elapsed time from the FDNPP accident, i.e. the decrease in air dose rates in areas with relatively low dose ranges (such as 0.2–0.5 μSv/h) was the largest during a period relatively early after the accident, and the decreasing rate in the dose rate ranges of 1.9–3.8 and 3.8–9.5 μSv/h were the fastest after 2013. The averaged ratios were analyzed to obtain the ecological half-lives of the fast and slow decay components, and those in whole area within 80 km of FDNPP were estimated to be 0.44 ± 0.05 y and 6.7 ± 1 y, respectively. The ecological half-lives with respect to the land use categories, evacuation order areas and magnitude of the dose rates were also evaluated. The decrease in the dose rates obtained by the car-borne survey was larger than that obtained on flat ground with few disturbances using the NaI(Tl) survey meter during approximately 1.5 y after the FDNPP accident. Thereafter, the difference of decreasing tendencies in the air dose rates between both the measurements was negligibly small, with the ratio of dose rates by the car-borne survey to those by the fixed-point measurement of 0.72–0.77.

Implementing an Energy Calculator in a Mobile Based Application for Solar Potential Measurement

Solar photovoltaic (PV) technology has matured to become a technically viable large scale source of sustainable energy. Understanding the rooftop PV potential is critical for utility planning, accommodating grid capacity, deploying financing schemes and formulating future adaptive energy policies. The NIWE (National Institute of Wind Energy) under MNRE (Ministry of New and Renewable Energy) is an esteemed institute dedicated to Indian wind and solar renewable energy generation and monitoring. The SRRA (Solar Radiation and Resource Assessment) is a division under NIWE that is responsible for solar energy monitoring throughout India. They have created the Solar Radiation Map of India using high quality, ground measured solar data. This asks the question, whether it is possible to get a quick estimate of a solar installation. Thus, the paper explains the problems in the field of solar potential measurement and the deployment of a calculator in a mobile front platform. The mobile app would quickly and effortlessly give a rough estimate on what a solar installation could save in power consumption costs.

A fast simulation method for radiation maps using interpolation in a virtual environment

In nuclear decommissioning, virtual simulation technology is a useful tool to achieve an effective work process by using virtual environments to represent the physical and logical scheme of a real decommissioning project. This technology is cost-saving and time-saving, with the capacity to develop various decommissioning scenarios and reduce the risk of retrofitting. The method utilises a radiation map in a virtual simulation as the basis for the assessment of exposure to a virtual human. In this paper, we propose a fast simulation method using a known radiation source. The method has a unique advantage over point kernel and Monte Carlo methods because it generates the radiation map using interpolation in a virtual environment. The simulation of the radiation map including the calculation and the visualisation were realised using UNITY and MATLAB. The feasibility of the proposed method was tested on a hypothetical case and the results obtained are discussed in this paper.

Short-term forecasts of GHI and DNI for solar energy systems operation: assessment of the ECMWF integrated forecasting system in southern Portugal

Solar energy is key factor in the demand for clean energy development and management. In particular, global horizontal irradiance (GHI) and direct normal irradiance (DNI) are the foremost important solar resource components that need to be well characterized in order to seek an efficient operation of photovoltaic and concentrated solar power plants, respectively. The objective of the present work is to assess the quality of short-term (24 h) forecasts from a global Numerical Weather Prediction (NWP) model regarding the GHI and DNI components for solar energy applications. Forecast accuracy for the Integrated Forecasting System (IFS), the global model of the European Centre for Medium-Range Weather Forecasts (ECMWF), was verified through the comparison of the predicted hourly values with the corresponding ground-based measurements in southern Portugal. In this study, results from one year of IFS data are analysed, yielding a general good agreement between model and four ground-based measuring stations. High correlations occur particularly for GHI whilst DNI simulations are predominantly hindered by cloud and aerosol representation (i.e. the radiative effects of clouds tend to be underestimated by the model and the radiative effects of the aerosols are overestimated by the model under very clear atmospheric conditions), being closely linked to the parameterization of absorption and scattering phenomena as function of cloud and aerosol type and dimension. Relative differences of annual availabilities for GHI are found between ∼0.16% to ∼2.12% whilst for DNI values ranging from ∼7% to ∼12% are found. The respective correlations coefficients are around 0.95 for GHI and between 0.65 and 0.77 for DNI. Regional irradiation maps of GHI and DNI are presented, showing that NWP predictions are an important tool for the operation of electricity generation systems based on solar energy.

Development and validation of a high-resolution mapping platform to aid in the public awareness of radiological hazards

The distribution, quantification and exposure-related effects of radiation in the environment, arising from both natural and anthropogenic sources, is of great (and growing) concern for global populations. Recent events at the Fukushima Daiichi Nuclear Plant (FDNPP) have further highlighted the importance of developing radiation mapping technologies that not only contribute to the continued assessment of contamination, but can serve as an educational tool for members of the public regarding both its behaviour and extent. With an even greater number of people possessing smart-phone technology, a lightweight and portable ‘connected system’ has been developed to demonstrate to users the calibrated radioactive dose rate in an area, viewable in real-time through a dedicated phone application. As well as allowing for system users to be alerted where variations in dose rate are experienced, the combined results from multiple systems are viewable through a custom-built desktop application—permitting the output obtained via any number of units to be similarly displayed in real-time. A successful initial trialling of the system is described at a former tin mine in Cornwall (south-west England)—known to exhibit low, but identifiable radiation anomalies in discrete areas. Additional applications outside of its educational usage are also discussed.