Effects Of Radiation Environment Research Articles

Autonomous search investigation for radioactive leaked source based on an updated infotaxis method during nuclear emergency rescue

Identifying leakage locations is one of the key issues for off-site decision workers in nuclear accident conditions, especially for performing early emergency rescue. To rapidly reduce the environmental radiation level of serious accidents in nuclear facilities caused by external events and identify radioactive residues outside containment, an autonomous search method for residue leakage source in nuclear emergency rescue based on the updated Infotaxis method was proposed. It takes into account radioactive decay and wet settlement caused by high-pressure sprinkling or precipitation. The sampling rate function was updated by the radioactive decay term and washing factor in the Infotaxis method, which improves the dilution effect of environmental radiation and provides more accurate entropy information. The search trajectories were investigated under multiple scenarios, such as different source emission rates and wet deposition due to high-pressure sprinklers or precipitation. The results showed that the proposed method could improve search efficiency by adding a washing term, especially for improvement of the success rate in search of leakage source under higher source emission rates, and it helps nuclear emergency decision-makers trace the location of leakage source accurately during the rescue process to provide more scientific information for early emergency response and consequence assessment.

Radiation Belt Daily Average Electron Flux Model (RB‐Daily‐E) From the Seven‐Year Van Allen Probes Mission and Its Application to Interpret GPS On‐Orbit Solar Array Degradation

AbstractWe use NASA's Van Allen Probes data to build a 3‐dimensional Radiation Belt Daily Average Electron flux model (RB‐Daily‐E) covering 25 differential energies (33–7,700 keV), 17 pitch angles, and a variable number of L shells from 2 to 7. RB‐Daily‐E can be used to deduce the fluences observed by any satellite that flew within Van Allen Probes' 7‐year mission lifetime. We supplement Van Allen Probes fluxes with THEMIS average fluxes to cover higher L shells when applying the model to a secondary satellite. RB‐Daily‐E agrees with both the Arase high‐energy electron experiment (XEP) flux data and the GPS Combined X‐ray Dosimeter (CXD) electron flux approximately within a factor of two or better, and comparisons with AE9 are as expected. The RB‐Daily‐E Model has applications for when actual fluxes on day‐timescales are required for post‐anomaly investigations, including long‐term radiation environment effects such as solar cell and solar array degradation. We therefore applied the model to two GPS satellites to determine electron fluence inputs to the Equivalent Flux (EQFLUX) solar cell degradation model. The modeled voltage degradation well‐matched the voltage degradation trends identified in the GPS telemetry data, suggesting that the radiation environment is the primary cause of the voltage degradation. The current degradation was largely underestimated, suggesting that current degradation is influenced by other sources.

Effect of Environmental Radiation on Public Health

A reviewoneffect of environmental radiation on public health is described. Radiation is energy that comes from different sources and exists in different forms in the environment. This energy has an electric field and a magnetic field associated with it, and has electromagnetic properties. The author is discussed about the environmental radiation and its effect on public health.

Sir Frederick Edward Warner. 31 March 1910—3 July 2010

Frederick Edward (‘Ned’) Warner's childhood home was a London County Council flat in north London. He won a scholarship to Bancroft's School, where he was successful in both academic and sporting activities and was awarded an Exhibition to read chemistry at University College London. Following this chemistry degree he took a diploma in chemical engineering. Sport, debates and left-wing politics dominated his student years. Warner was at the forefront in developing health, safety, risk assessment and environmental policies, particularly in their implementation to chemical process plant; early professional experience in several chemical manufacturing companies and extensive wartime work associated with acid manufacture had driven this commitment. He was a leading figure in the creation of the consulting company Cremer and Warner, and was appointed court expert to the Court of Enquiry following the Flixborough explosion in 1974. As treasurer of the Scientific Committee on Problems of the Environment, he chaired three of its major projects: Environmental Consequences of Nuclear War; Pathways of Artificial Radionucleotides; and Radiation from Nuclear Test Explosions. His expertise in the environmental effects of radiation put him in a position to lead the first international team to Chernobyl after the reactor meltdown in 1986. Warner served on many governmental, professional and academic bodies, particularly the Institution of Chemical Engineers, of which he was president in 1966–1967. He was knighted in 1968 for services to chemical engineering, was elected to the Royal Society in 1976 and was a founder fellow of the Fellowship of Engineering (now the Royal Academy of Engineering). He died in 2010, aged 100.

Environmental radiation on large Japanese field mice in Fukushima reduced colony forming potential in hematopoietic progenitor cells without inducing genomic instability

Purpose To study the environmental radiation effects of wild animals after the Fukushima Dai-ichi nuclear power plant accident, we assessed effects on hematopoietic progenitor cells (HPCs) in large Japanese field mice (Apodemus speciosus). Materials and methods A. speciosus were collected from three contaminated sites and control area. The air dose-rates at the control and contaminated areas were 0.96 ± 0.05 μGy/d (Hirosaki), 14.4 ± 2.4 μGy/d (Tanashio), 208.8 ± 31.2 μGy/d (Ide), 470.4 ± 93.6 μGy/d (Omaru), respectively. We investigated possible DNA damage and pro-inflammatory markers in the bone marrow (BM) cells. The colony-forming potential of BM cells was estimated by the number of HPC colony-forming cells. Radiation-induced genomic instability (RIGI) in HPCs was also analyzed by quantifying delayed DNA damage in CFU-GM clones. Results Although no significant differences in DNA damage and inflammation markers in BM cells from control and contaminated areas, the number of HPC colonies exhibited an inverse correlation with air dose-rate. With regard to RIGI, no significant differences in DNA damage of CFU-GM clones between the mice from the control and the three contaminated areas. Conclusions Our study suggests that low dose-rate radiation of more than 200 Gy/d reduced HPCs, possibly eliminating genomically unstable HPCs.

A Compact Model to Evaluate the Effects of High Level C++ Code Hardening in Radiation Environments

A high-level C++ hardening library is designed for the protection of critical software against the harmful effects of radiation environments that can damage systems. A mathematical and empirical model to predict system behavior in the presence of radiation induced faults is also presented. This model generates a quick evaluation and adjustment of several reliability vs. performance trade-offs, to optimize radiation hardening based on the proposed C++ hardening library. Several simulations and irradiation campaigns with protons and neutrons are used to build the model and to tune it. Finally, the effects of our hardening approach are compared with other hardened and non-hardened approaches.

Investigating Space Radiation Environment Effects on Communication of Razaksat-1

This study attempted to identify whether space radiation sources could have affected the communication on RazakSAT-1 that was orbiting in a Low Earth Orbit-Near Equatorial (LEO-NEqO). Data on galactic cosmic rays (GCR), trapped protons, trapped electrons, and solar energetic particles (SEPs) obtained from Space Environment Information System (SPENVIS)are considered. The effects of these radiation sources are analyzed using the linear energy transfer (LET), total ionizing dose(TID), and solar cell degradation. Flux data from National Oceanic and Atmospheric Administration (NOAA) 15, 16, and 17 satellites, and the geomagnetic conditions during the time when RazakSAT-1’s missing is also analyzed. Another two satellites, Satelite de Coleta de Dados (SCD-2) and Advanced Land Observation Satellite (ALOS), are compared with the performance of RazakSAT-1. Results showed that GCR dominated at a high energy range of 103 MeV and above in the LEO-NEqO, whereas the energies of the trapped protons and trapped electrons are less than 400 MeV and 4 MeV, respectively. There are no SEPs estimated during the mission period (2009 – 2011). Based on the SPENVIS, SCD-2 and ALOS are more exposed to higher radiation damage than RazakSAT-1. Thus, an analysis of space radiation environment effects on the RazakSAT-1 communication lost after one year of operation will be discussed further, as a platform to fi nd the best strategy for future missions.

Effect of environmental radiation on the long-wave infrared signature of cruise aircraft

In the long-wave infrared radiation band (8–12 μm), the environmental radiation greatly affects the infrared signature of aircraft. The main aim of this paper is to assess the effects of atmospheric and ground radiance on the infrared signature of a cruise aircraft flying at high altitude. Firstly, the computation method of infrared signature is presented. The reverse Monte Carlo ray tracing method is applied to evaluate the effect of environmental radiation on the infrared signature of aircraft. The MODTRAN code is used to compute the atmospheric/ground radiance and atmospheric transmittance. Then, this method is validated with experimental data. Finally, the effect of environmental radiation on infrared signature of aircraft is discussed with the consideration of atmospheric condition, flight altitude, flight speed, and the emissivity of the airframe skin. The results show that the infrared signature of the lower surface of the aircraft is sensitive to the environmental radiation whose reflection contributes more than 20% to the total radiation at Mach 0.9. Increasing flight altitude, reducing atmosphere temperature and reducing flight speed will increase the ratio of reflected environmental infrared radiation intensity to total infrared radiation intensity of the aircraft. After considering the environmental radiation, the reduction amplitude of infrared signature of the aircraft by reducing the surface emissivity is decreased. The infrared signature of the aircraft lower surface is still significant compared to environment, even though the emissivity of the aircraft surface is reduced.

In vivo 3D analysis of systemic effects after local heavy-ion beam irradiation in an animal model.

Radiotherapy is widely used in cancer treatment. In addition to inducing effects in the irradiated area, irradiation may induce effects on tissues close to and distant from the irradiated area. Japanese medaka, Oryzias latipes, is a small teleost fish and a model organism for evaluating the environmental effects of radiation. In this study, we applied low-energy carbon-ion (26.7 MeV/u) irradiation to adult medaka to a depth of approximately 2.2 mm from the body surface using an irradiation system at the National Institutes for Quantum and Radiological Science and Technology. We histologically evaluated the systemic alterations induced by irradiation using serial sections of the whole body, and conducted a heart rate analysis. Tissues from the irradiated side showed signs of serious injury that corresponded with the radiation dose. A 3D reconstruction analysis of the kidney sections showed reductions in the kidney volume and blood cell mass along the irradiated area, reflecting the precise localization of the injuries caused by carbon-beam irradiation. Capillary aneurysms were observed in the gill in both ventrally and dorsally irradiated fish, suggesting systemic irradiation effects. The present study provides an in vivo model for further investigation of the effects of irradiation beyond the locally irradiated area.

Effects of environmental radiation on testes and spermatogenesis in wild large Japanese field mice (Apodemus speciosus) from Fukushima.

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident that occurred after the Great East Japan Earthquake in March 2011 released large quantities of radionuclides to the environment. The long-term effects of radioactive cesium (Cs) on biota are of particular concern. We investigated the accumulation of radioactive Cs derived from the FDNPP accident, and chronic effects of environmental radionuclides on male reproduction, in the large Japanese field mouse (Apodemus speciosus). In 2013 and 2014, wild mice were captured at 2 sites in Fukushima Prefecture and at 2 control sites that were distant from Fukushima. Although the median concentrations of 134Cs and 137Cs in the mice from Fukushima exceeded 4,000 Bq/kg, there were no significant differences in the apoptotic cell frequencies or the frequencies of morphologically abnormal sperm among the capture sites. Thus, we conclude that radiation did not cause substantial male subfertility in Fukushima during 2013 and 2014, and radionuclide pollution levels in the study sites would not be detrimental to spermatogenesis of the wild mice in Fukushima.

Effect of a fluid layer on the sound radiation of a plate and its active control

In this paper, a baffled plate facing a layer of fluid is used to investigate the effects of the radiating environment on the plate׳s sound radiation and its active control. By varying the thickness of the fluid layer, different radiation environments are presented to the plate, resulting in a variation in the efficiencies and shapes of the radiation modes of the plate. As the design of feed-forward control of the radiated sound power and of feedback control of the vibration velocity or volume velocity is limited by the properties of the secondary control path (an open-loop frequency response function), the performance of the control system may be deteriorated if a controller optimally designed for one radiation environment is used for a different environment. The effects of radiation environment on the properties of the secondary control path and performance of active control are investigated.

Atmospheric Radiation Environment Effects on Electronic Balloon Board Observed During Polar Vortex and Equatorial Operational Campaigns

Atmospheric Radiation Environment Effects on Electronic Balloon Board Observed During Polar Vortex and Equatorial Operational Campaigns

Numerical Simulation of Supersonic Aircraft Surface Aerodynamic Heating and Infrared Radiation Characteristics

The aerodynamic heating and infrared radiation characteristics of BrahMos supersonic cruise missile were investigated. The aerodynamic heating was simulated using finite volume method, and the infrared radiation characteristics were simulated by reverse Monte Carlo method. Infrared radiation characteristics of missile surface were analyzed in different surface emissivity and flight altitudes, and the effects of environmental radiation and atmospheric attenuation were considered. The results show 8~14μm and 3~5μm environment radiation were approximately 10% and 2.4% of total radiation respectively, when the surface emissivity is 0.3. The proportion of environmental radiation reduces nearly half when the surface emissivity increases by 0.2.

Numerical Simulation of Supersonic Aircraft Surface Aerodynamic Heating and Infrared Radiation Characteristics

The aerodynamic heating and infrared radiation characteristics of BrahMos supersonic cruise missile were investigated. The aerodynamic heating was simulated using finite volume method, and the infrared radiation characteristics were simulated by reverse Monte Carlo method. Infrared radiation characteristics of missile surface were analyzed in different surface emissivity and flight altitudes, and the effects of environmental radiation and atmospheric attenuation were considered. The results show 8~14μm and 3~5μm environment radiation were approximately 10% and 2.4% of total radiation respectively, when the surface emissivity is 0.3. The proportion of environmental radiation reduces nearly half when the surface emissivity increases by 0.2.

Modified wind chill temperatures determined by a whole body thermoregulation model and human-based facial convective coefficients

Wind chill equivalent temperatures (WCETs) were estimated by a modified Fiala's whole body thermoregulation model of a clothed person. Facial convective heat exchange coefficients applied in the computations concurrently with environmental radiation effects were taken from a recently derived human-based correlation. Apart from these, the analysis followed the methodology used in the derivation of the currently used wind chill charts. WCET values are summarized by the following equation:[Formula: see text]Results indicate consistently lower estimated facial skin temperatures and consequently higher WCETs than those listed in the literature and used by the North American weather services. Calculated dynamic facial skin temperatures were additionally applied in the estimation of probabilities for the occurrence of risks of frostbite. Predicted weather combinations for probabilities of "Practically no risk of frostbite for most people," for less than 5 % risk at wind speeds above 40 km h(-1), were shown to occur at air temperatures above -10 °C compared to the currently published air temperature of -15 °C. At air temperatures below -35 °C, the presently calculated weather combination of 40 km h(-1)/-35 °C, at which the transition for risks to incur a frostbite in less than 2 min, is less conservative than that published: 60 km h(-1)/-40 °C. The present results introduce a fundamentally improved scientific basis for estimating facial skin temperatures, wind chill temperatures and risk probabilities for frostbites over those currently practiced.

The radiation environment near the lunar surface: CRaTER observations and Geant4 simulations

At the start of the Lunar Reconnaissance Orbiter mission in 2009, its Cosmic Ray Telescope for the Effects of Radiation instrument measured the radiation environment near the Moon during the recent deep solar minimum, when galactic cosmic rays (GCRs) were at the highest level observed during the space age. We present observations that show the combined effects of GCR primaries, secondary particles (“albedo”) created by the interaction of GCRs with the lunar surface, and the interactions of these particles in the shielding material overlying the silicon solid‐state detectors of the Cosmic Ray Telescope for the Effects of Radiation. We use Geant4 to model the energy and angular distribution of the albedo particles, and to model the response of the sensor to the various particle species reaching the 50 kilometer altitude of the Lunar Reconnaissance Orbiter. Using simulations to gain insight into the observations, we are able to present preliminary energy‐deposit spectra for evaluation of the radiation environment's effects on other sensitive materials, whether biological or electronic, that would be exposed to a similar near‐lunar environment.

Environmental radiation effects from muon and tau colliders and their impact on facility licensing

Although contemporary accelerators only affect their local radiation environment, muon and tau colliders produce radiation profiles that extend far beyond their site boundaries. These radiation profiles affect the licensing and siting of these planned accelerators. The analysis presented herein suggests that a linear collider concept with the lepton beams collided in air offers a means to limit the environmental radiation effects from these accelerators.

Does Melanoma Begin in a Melanocyte Stem Cell?

What is the cellular origin of melanoma? What role do melanocyte stem cells (MSC) and other melanocyte precursors play in the development of melanoma? Are MSCs and other latent melanocyte precursors more susceptible to solar radiation? These and many other questions can be very effectively addressed using the zebrafish model. Zebrafish have a robust regenerative capability, permitting the study of how MSCs are regulated and recruited at specific times and places to generate the pigment pattern following fin amputation or melanocyte ablation. They can be used to determine the effects of environmental radiation on the proliferation, survival, repair, and differentiation of MSCs. Our lab is using zebrafish to investigate how UVA- (320–400 nm) and UVB- (290–320 nm) induced damage to MSCs may contribute to the development of melanoma. A review is given of MSCs in zebrafish as well as experimental techniques and drugs for manipulating MSC populations. These techniques can be used to design experiments to help answer many questions regarding the role of MSCs or melanocyte precursors in the formation of melanoma stem cells and tumors following exposure to UVA/UVB radiation.

Microorganisms Associated with Feathers of Barn Swallows in Radioactively Contaminated Areas Around Chernobyl

The Chernobyl catastrophe provides a rare opportunity to study the ecological and evolutionary consequences of low-level, environmental radiation on living organisms. Despite some recent studies about negative effects of environmental radiation on macroorganisms, there is little knowledge about the effect of radioactive contamination on diversity and abundance of microorganisms. We examined abundance patterns of total cultivable bacteria and fungi and the abundance of feather-degrading bacterial subset present on feathers of barn swallows (Hirundo rustica), a colonial migratory passerine, around Chernobyl in relation to levels of ground level environmental radiation. After controlling for confounding variables, total cultivable bacterial loads were negatively correlated with environmental radioactivity, whereas abundance of fungi and feather-degrading bacteria was not significantly related to contamination levels. Abundance of both total and feather-degrading bacteria increased with barn swallow colony size, showing a potential cost of sociality. Males had lower abundance of feather-degrading bacteria than females. Our results show the detrimental effects of low-level environmental radiation on total cultivable bacterial assemblage on feathers, while the abundance of other microorganism groups living on barn swallow feathers, such as feather-degrading bacteria, are shaped by other factors like host sociality or host sex. These data lead us to conclude that the ecological effects of Chernobyl may be more general than previously assumed and may have long-term implications for host-microbe interactions and overall ecosystem functioning.

Space radiation environment effects on X-ray CCD background

Charge coupled devices (CCDs) are often employed as the detector of choice for observing X-rays in space. The instrument background experienced in orbit has a major impact on the overall sensitivity of the camera system. The instrument background for the European Space Agency X-ray Multi Mirror (XMM-Newton) mission was found to be much greater in orbit than that originally predicted pre-launch, the reasons for which still being up for discussion. The Geant4 toolkit provides a framework for Monte Carlo simulations in a variety of areas in science and is used here to simulate the instrument background for several CCD based detectors in-orbit in order to gain a further insight into the formation of the instrument background continuum. The missions discussed in this paper include the ESA XMM-Newton mission, the NASA Swift mission and the Japanese Space Agency Suzaku mission. These three missions allow a comparison between the effects of both the mission orbit and the detector construction on the instrument background count-rate. Analysis of the results from the simulation lead to the conclusion that knock-on electrons, produced when protons pass through the shielding, dominate the instrument background continuum at the XMM-Newton Highly Elliptical Orbit (HEO) with a perigee and apogee of approximately 7000 and 120 000 km respectively, forming an additional background component not considered in the pre-launch study. The surface properties of the detector and shielding have the greatest impact on the level of the instrument background due to the interaction length of the knock-on electrons produced. At the Low Earth Orbit (LEO) of Swift and Suzaku at approximately 600 km, the impact of the knock-on electrons is reduced due to the differing in-flux of protons, and the form of the instrument background can vary greatly with the detector construction. The inconsistencies between this study and the pre-launch simulations are discussed. Sensitivity considerations regarding the instrument background are deliberated with a view towards future missions.