scholarly journals Analytical model for determining the leakage albedo component for a direct cylindrical channel passing through the nuclear reactor protective layer

2021 ◽  
Vol 7 (2) ◽  
pp. 91-95
Author(s):  
Kirill S. Kupriyanov ◽  
Vladimir V. Pereverzentsev
Keyword(s):  
Ionizing Radiation ◽  
Nuclear Reactor ◽  
Radiation Flux ◽  
Gamma Quantum ◽  
Protective Layer ◽  
Radiation Environment ◽  
Line Of Sight ◽  
Dose Rates ◽  
Radiation Fluxes ◽  
Quantum Flux

The task of determining the radiation situation, including neutron and gamma-quantum flux density, radiation spectrum, specific volumetric activity of radioactive gases in the air, etc. behind the protective composition having inhomogeneities, has always been important in matters of radiation safety. One of the ways to solve the problem of determining gamma radiation fluxes was to divide the total ionizing radiation flux into four components: line-of-sight (LOS), leakage, line-of-sight albedo, and leakage albedo, and obtain an analytical solution for each component. The first three components have been studied in detail in relation to simple geometries and there are analytical solutions for them, but there is no such a solution for the last component. The authors of this work have derived an analytical representation for the leakage albedo component, which, in contrast to numerical methods (such as Monte Carlo methods), makes it possible to analyze the effect of inhomogeneities in protective compositions on the radiation environment as well as to quickly obtain estimated values of fluxes and dose rates. Performing a component-by-component comparison, it becomes possible to single out the most significant mechanisms of the dose load formation behind the nuclear reactor protection, to draw conclusions about the effectiveness of design solutions in the protection design and to improve the protection at significantly lower computational costs. Finally, the authors present calculations for the four components of the total ionizing radiation flux for various parameters of the cylindrical inhomogeneity in the reactor protection. Based on the obtained values, conclusions are made about the importance of taking into account the leakage albedo component in the formation of the radiation situation behind the core vessel.

The ionizing radiation environment on the moon

2007 ◽  
Vol 40 (3) ◽  
pp. 338-341 ◽  
Author(s):  
J.H. Adams ◽  
M. Bhattacharya ◽  
Z.W. Lin ◽  
G. Pendleton ◽  
J.W. Watts
Keyword(s):  
Ionizing Radiation ◽  
Radiation Environment ◽  
The Moon

scholarly journals Investigation of dose-rate effects and cell-cycle distribution under protracted exposure to ionizing radiation for various dose-rates

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Yusuke Matsuya ◽  
Stephen J. McMahon ◽  
Kaori Tsutsumi ◽  
Kohei Sasaki ◽  
Go Okuyama ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Ionizing Radiation ◽  
Dose Rate ◽  
Cell Cycle Distribution ◽  
Dose Rates ◽  
Dose Rate Effects ◽  
Rate Effects

scholarly journals Change in local regulation of hemopoiesis under the chronic exposure to ionizing radiation

2009 ◽  
Vol 8 (4) ◽  
pp. 52-59
Author(s):  
Ya. V. Porovsky
Keyword(s):  
Ionizing Radiation ◽  
Chronic Exposure ◽  
Vessel Wall ◽  
Nuclear Reactor ◽  
Blood System ◽  
Tissue Samples ◽  
Local Regulation ◽  
Actual Material ◽  
Inflammatory Changes ◽  
Number Of Cells

Results of annual examinations of peripheral blood and single examinations of bone marrow after 11, 14, 15, and 22 years of the chronic exposure to ionizing radiation in total doses of 24.25, 103.96, 111.84, and 74.09 mSv, respectively, are presented along with the results on the morphology of microvasculature vessels in skin tissue samples of two men and two women working at a nuclear reactor. Changes in the content of hemoglobin, total number of leucocytes, population of erythrocytes, neutrophils, reticulocytes, and in the composition of maturating and mature myeloid and erythroid cells accompanied by an increase составе in the number of cells of the lymphoid and monocytic pool as the intensity of inflammatory changes in microvasculature vessels increases from productive panvasculitis to panvasculitis with sclerosis of vessel wall were noticed. The presented actual material indicates that damages in the blood system can be connected with the intensity of pathological changes in microvasculature vessels, which represent one of the local components of hemopoiesis-inducing microenvironment responsible for hemopoiesis regulation.

scholarly journals EVALUATION OF RADIATION DOSE RATE OF RSG-GAS REACTOR

2018 ◽  
Vol 24 (3) ◽  
Author(s):  
Amir Hamzah ◽  
Hery Adrial ◽  
Subiharto Subiharto
Keyword(s):  
Radiation Dose ◽  
Radiation Exposure ◽  
Dose Rate ◽  
Nuclear Reactor ◽  
Area Measurement ◽  
Radiation Dose Rate ◽  
Safety Level ◽  
Modeling And Analysis ◽  
Dose Rates ◽  
Limit Value

EVALUATION OF RADIATION DOSE RATE OF RSG-GAS REACTOR. The RSG-GAS reactor has been operated for 30 years. Since the nuclear reactor has been operated for a long time, aging process on its components may occur. One important parameter for maintaining the safety level of the RSG-GAS reactor is to maintain radiation exposure as low as possible, especially in the working area. The evaluation results should be able to demonstrate that the radiation exposure of the RSG-GAS is still safe for workers, communities and the surrounding environments. The purpose of this study is to evaluate radiation exposure in the working area to ensure that the operation of RSG-GAS is still safe for the next 10 years. The scope of this work is confirming the calculation results with the measured radiation dose in the RSG-GAS reactor working area. Measurement of radiation exposure is done by using the installed equipments at some points in the RSG-GAS working area and a portable radiation exposure measurement equipment. The calculations include performance of a modeling and analysis of dose rate distribution based on the composition and geometry data of RSG-GAS by using MCNP.  The analysis results show that the maximum dose rate at Level 0 m working area of RSG-GAS reactor is 3.0 mSv/h with a deviation of 6%, which is relatively close to the measurement value. The evaluation results show that the dose rate in RSG-GAS working area is below the limit value established by the Nuclear Energy Regulatory Agency of Indonesia (BAPETEN) of 10 mSv/h (for the average effective dose of 20 mSv/year). Therefore, it is concluded that the dose rate in RSG-GAS working area is safe for personnel..Kata kunci: dose rates, RSG-GAS, radiation safety, MCNP.

scholarly journals MATERIAL ISSUES FOR CURRENT AND ADVANCED NUCLEAR REACTOR DESIGNS

2014 ◽  
Vol 5 (1) ◽  
Author(s):  
Peter Hosemann ◽  
Jasmina Vujić
Keyword(s):  
Nuclear Reactor ◽  
Prolonged Exposure ◽  
Liquid Metals ◽  
Radiation Environment ◽  
High Radiation ◽  
Nuclear Systems ◽  
Temperature And Pressure ◽  
Pressure Stress ◽  
Liquid Salts ◽  
Lifetime Extension

In all engineering applications, design and materials together determine the functionality and reliability of a device. This is particularly important in nuclear systems where the materials are pushed to their limits and phenomena not present anywhere else occur. In nuclear systems a combination of high temperature and pressure, stress, corrosive environment and high radiation environment combined causes significant materials challenges. Majority of commercial LWRs today are licensed for 40 years of operation, but many of them undergo lifetime extension to 60 or possibly 80 years. Materials degradation has always been a significant issue. However, due to the lifetime plant extension, finding materials that could sustain prolonged exposure to these extreme conditions has become a significant problem. In addition to the materials challenges in current LWRs, advanced reactors usually deal with even more difficult issues due to their operational requirements. Unusual heat transport media, such as liquid metals, liquid salts or other types of coolants, lead to a whole new set of material challenges. While corrosion has been the main issue, much higher operating temperatures create additional difficulties. In this paper, we present an overview of materials issues for current and advanced nuclear reactor designs.

The DRESOR Method for a Collimated Irradiation on an Isotropically Scattering Layer

2006 ◽  
Vol 129 (5) ◽  
pp. 634-645 ◽  
Author(s):  
Qiang Cheng ◽  
Huai-Chun Zhou
Keyword(s):  
Heat Transfer ◽  
Monte Carlo ◽  
Radiative Heat ◽  
Radiation Flux ◽  
Solid Angle ◽  
Heat Transfer Process ◽  
Arbitrary Direction ◽  
Scattering Layer ◽  
Radiation Fluxes ◽  
Angle Space

Forward and backward Monte Carlo methods may become inefficient when the radiant source is collimated and radiation onto a small, arbitrary spot and onto a small, arbitrary direction cone is desired. In this paper, the DRESOR method was formulated to study the radiative heat transfer process in an isotropically scattering layer exposed to collimated radiation. As the whole spherical solid angle space was uniformly divided into 13,316 discrete solid angles, the intensity at some point in up to such discrete directions was given. The radiation fluxes incident on a detector inside the layer for varying acceptance angles by a step of 2deg were also measured, which agreed well with those in literature. The radiation flux across the top and the bottom boundaries were also provided.

scholarly journals The most problematic variable in the course of human-biometeorological comfort assessment — the mean radiant temperature

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Noémi Kántor ◽  
János Unger
Keyword(s):  
Thermal Comfort ◽  
Short Wave ◽  
Urban Environments ◽  
Outdoor Thermal Comfort ◽  
Radiation Environment ◽  
Wave Radiation ◽  
Mean Radiant Temperature ◽  
Radiation Fluxes ◽  
The Mean ◽  
Radiant Temperature

AbstractThis paper gives a review on the topic of the mean radiant temperature Tmrt, the most important parameter influencing outdoor thermal comfort during sunny conditions. Tmrt summarizes all short wave and long wave radiation fluxes reaching the human body, which can be very complex (variable in spatial and also in temporal manner) in urban settings. Thermal comfort researchers and urban planners need easy and sound methodological approaches to assess Tmrt. After the basics of the Tmrt calculation some of the methods suitable for obtaining Tmrt also in urban environments will be presented.. Two of the discussed methods are based on instruments which measure the radiation fluxes integral (globe thermometer, pyranometer-pyrgeometer combination), and three of the methods are based on modelling the radiation environment with PC software (RayMan, ENVI-met and SOLWEIG).

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