scholarly journals Low Energy Beta Emitter Measurement: A Review

Chemosensors ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 106
Author(s):  
Hara Kang ◽  
Sujung Min ◽  
Bumkyung Seo ◽  
Changhyun Roh ◽  
Sangbum Hong ◽  
...  
Keyword(s):  
Radiation Detection ◽  
The Body ◽  
Low Energy ◽  
Internal Exposure ◽  
Beta Particle ◽  
Radiation Hazard ◽  
Nuclear Facilities ◽  
Beta Particles ◽  
Beta Emitter ◽  
Plastic Scintillators

The detection and monitoring systems of low energy beta particles are of important concern in nuclear facilities and decommissioning sites. Generally, low-energy beta-rays have been measured in systems such as liquid scintillation counters and gas proportional counters but time is required for pretreatment and sampling, and ultimately it is difficult to obtain a representation of the observables. The risk of external exposure for low energy beta-ray emitting radioisotopes has not been significantly considered due to the low transmittance of the isotopes, whereas radiation protection against internal exposure is necessary because it can cause radiation hazard to into the body through ingestion and inhalation. In this review, research to produce various types of detectors and to measure low-energy beta-rays by using or manufacturing plastic scintillators such as commercial plastic and optic fiber is discussed. Furthermore, the state-of-the-art beta particle detectors using plastic scintillators and other types of beta-ray counters were elucidated with regard to characteristics of low energy beta-ray emitting radioisotopes. Recent rapid advances in organic matter and nanotechnology have brought attention to scintillators combining plastics and nanomaterials for all types of radiation detection. Herein, we provide an in-depth review on low energy beta emitter measurement.

scholarly journals Plutonium dioxide particle imaging using a high-resolution alpha imager for radiation protection

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuki Morishita ◽  
Shunsuke Kurosawa ◽  
Akihiro Yamaji ◽  
Masateru Hayashi ◽  
Makoto Sasano ◽  
...  
Keyword(s):  
High Resolution ◽  
Real Time ◽  
Spatial Resolution ◽  
Optical Microscope ◽  
Exposure Dose ◽  
Alpha Particles ◽  
Internal Exposure ◽  
Beta Particle ◽  
Nuclear Facilities ◽  
Plutonium Dioxide

AbstractThe internal exposure of workers who inhale plutonium dioxide particles in nuclear facilities is a crucial matter for human protection from radiation. To determine the activity median aerodynamic diameter values at the working sites of nuclear facilities in real time, we developed a high-resolution alpha imager using a ZnS(Ag) scintillator sheet, an optical microscope, and an electron-multiplying charge-coupled device camera. Then, we designed and applied a setup to measure a plutonium dioxide particle and identify the locations of the individual alpha particles in real time. Employing a Gaussian fitting, we evaluated the average spatial resolution of the multiple alpha particles was evaluated to be 16.2 ± 2.2 μmFWHM with a zoom range of 5 ×. Also, the spatial resolution for the plutonium dioxide particle was 302.7 ± 4.6 µmFWHM due to the distance between the plutonium dioxide particle and the ZnS(Ag) scintillator. The influence of beta particles was negligible, and alpha particles were discernible in the alpha–beta particle contamination. The equivalent volume diameter of the plutonium dioxide particle was calculated from the measured count rate. These results indicate that the developed alpha imager is effective in the plutonium dioxide particle measurements at the working sites of nuclear facilities for internal exposure dose evaluation.

DETERMINATION OF THE TOTAL EFFECTIVE DOSE OF EXTERNAL AND INTERNAL EXPOSURE BY DIFFERENT IONIZING RADIATION SOURCES

2019 ◽  
Vol 187 (1) ◽  
pp. 129-137
Author(s):  
V A Kudryashev ◽  
D S Kim
Keyword(s):  
Ionizing Radiation ◽  
Effective Dose ◽  
Radiation Risk ◽  
Neutron Radiation ◽  
Radiation Shielding ◽  
The Body ◽  
Internal Exposure ◽  
Complex Method ◽  
Radiation Sources ◽  
Total Effective Dose

Abstract The purpose of the research is to develop an integrated technique for determining the effective dose (E) of external and internal exposure by different sources of ionizing radiation. The proposing technique for determining the total effective dose is based on three methods of calculation. The first one is multiplying the value of the individual dose equivalent $H_{p}(10)$ by the factor of 0.642 to account for radiation shielding by various organs and tissues and its backscattering. The second method is multiplying $H_{p}(10)$ by the conversion factor of air kerma in free air in a plate phantom, depending on the photon energy. The third method is multiplying $H_{p}(10)$ by the sum of the radiosensitivity coefficients of various organs and tissues. As a result of research, a complex method was developed for determining the total effective dose, composed of doses of cosmic radiation, external gamma-, beta- and neutron radiation, internal exposure from radionuclides, including CDP of radon and thoron, entering the body through the organs of digestion and respiration. The proposed technique for determining the total effective dose allows one to take into account the comprehensive effect of ionizing radiation sources on a person and to obtain a more accurate measure of radiation risk than the existing methods provide.

Radioguided surgery: physical principles and an update on technological developments

2020 ◽  
Vol 65 (1) ◽  
pp. 1-10
Author(s):  
Ali Pashazadeh ◽  
Michael Friebe
Keyword(s):  
Radiation Detection ◽  
Clinical Information ◽  
The Body ◽  
Radioguided Surgery ◽  
Gamma Cameras ◽  
Recent Advances ◽  
Efficient Detection ◽  
Technological Developments ◽  
And Performance ◽  
Real Time Information

AbstractRadioguided surgery (RGS) is the use of radiation detection probes and handheld gamma cameras in surgery rooms to identify radioactively labeled lesions inside the body with an aim to improve surgical outcome. In today’s surgery, application of these devices is a well-established practice, which provides surgeons with real-time information to guide them to the site of a lesion. In recent years, there have been several major improvements in the technology and design of gamma probes and handheld gamma cameras, enhancing their applications in surgical practices. Handheld gamma cameras, for example, are now moving from single-modality to dual-modality scanners that add anatomical data to the physiologic data, and with that provide more clinical information of the tissue under study. Also, in the last decade, a radioguided surgical technique based on the Cerenkov radiation was introduced, with more improved sensitivity in identifying radioactively labeled lesions. Additionally, recent advances in hybrid tracers have led to more efficient detection of lesions labeled with these tracers. Besides, it seems that combining medical robotics and augmented reality technology with current radioguided surgical practices potentially will change the delivery and performance of RGS in the near future. The current paper aims to give an overview of the physics of RGS and summarizes recent advances in this field that have a potential to improve the application of radioguided surgical procedures in the management of cancer.

Fluid Damping in Fuel Assemblies

2017 ◽  
Author(s):  
Pierre Moussou ◽  
Adrien Guilloux ◽  
Eric Boccaccio ◽  
Guillaume Ricciardi
Keyword(s):  
Fuel Assembly ◽  
Seismic Design ◽  
Flow Direction ◽  
Lift Coefficient ◽  
The Body ◽  
Natural Mode ◽  
Force Model ◽  
Nuclear Facilities ◽  
Fluid Force ◽  
Fuel Assemblies

Damping is known to be a major parameter in the seismic design of nuclear facilities. Of special interest is the case of fuel assemblies in PWR plants, which, unlike other components, are submitted to axial flows: it has been known since the late 80s that their frequency response to lateral excitations was largely dependent on the flow velocity, and the issue raised by this observation is to determine a consistent fluid force model which could be used in seismic design. In the scientific literature, the standard model of fluid forces exerted upon an oscillating slender body was originally derived by Lighthill, and it involves a lift coefficient which, up to a reference frame shift, describes the force generated by a small angle of inclination of the body axis against the flow direction. Recent works by Divaret et al. have provided a value of this lift coefficient equal to 0.11 for a single cylinder, and to 0.18 for a square array of 5 by 8 cylinders, the Reynolds numbers being in the range of 104. Sticking to the idea that the damping stems from the local angle of inclination of the structure against the flow direction, the present study revisits recent tests performed in the Hermes test rig of CEA Cadarache, where a fuel assembly was submitted to incipient flow velocities varying from 1.5 to 5m.s−1, and to a lateral force exerted upon the middle grid, generating displacements in the ranges of a few mm and of a few Hz. Under the assumption that the fuel assembly behaves in an approximately linear manner and that it undergoes harmonic deformations close to its first natural mode shape, the dissipative fluid force can be expressed by an adequate combination of the hydraulic cylinder force and of the structure displacements. A lift coefficient equal to 0.3–0.4 is obtained with this procedure, which stands for the overall fuel bundle, rods and grids included.

scholarly journals The Issue Of Linear No-Threshold Hypothesis

2018 ◽  
pp. 54-57
Author(s):  
A. V. Nosovskyi
Keyword(s):  
Ionizing Radiation ◽  
Nuclear Power ◽  
Nuclear Energy ◽  
Radiation Safety ◽  
Harmful Effect ◽  
Assessment Process ◽  
Radiation Hazard ◽  
Nuclear Facilities ◽  
Safety Standards ◽  
Safety Barriers

Some issues concerning the effect of ionizing radiation on the human body and methodological approaches to the development of radiation safety standards are considered. It is shown that the use of the linear no-threshold hypothesis (LNT hypothesis) in up-to-date radiation safety standards is inconsistent with experimental and epidemiological dose-response data, introduces essential excessive conservatism in the safety assessment process and causes additional problems concerning nuclear power engineering development. Due to the absence of convincing proofs for the existence of the dose threshold* nowadays, it is assumed that any ionizing radiation can lead to a certain risk of developing harmful effects and, therefore, the linear non-threshold dependence between the dose and the probability of the harmful effect is recommended. However, everyone understands that the use of the LNT hypothesis significantly overestimates the real danger. At the same time, the LNT hypothesis aggravates the existing high public fear of nuclear power, and the nuclear power industry pays extraordinary expenses to comply with radiation protection standards based on the LNT hypothesis. In order to comply with rules and regulations based on the LNT hypothesis, the nuclear energy industry invests financial resources in the creation of additional safety barriers for nuclear facilities, as well as new security and control systems. One of the reasons for increasing the cost for construction of a nuclear power plant is the increased design cost caused by enhanced safety requirements that are based on the LNT hypothesis. The traditional engineering approach to ensure the safety of nuclear facilities is based on the increase in the number of protective systems and devices that reduce the probability of severe accidents and reduce the radiation hazard of their consequences. Implementation of this approach in practice leads to a complication and a rise in the price of a nuclear facility. Obviously, it is possible to substantially enhance the safety level of nuclear facilities by creating new and new safety barriers around them, but sooner or later the nuclear energy production will become uncompetitive compared to the generation of other kinds of energy. It is concluded that up-to-date knowledge gives all the necessary grounds for eliminating the use of the linear no-threshold hypothesis and for revising the existing radiation safety standards of Ukraine for some isolated technological operations related to radiation hazardous activities. Such technological operations include activities related to the mitigation of radiation accident consequences, retrieval of nuclear materials and other activities related to the Shelter’s transformation into an environmentally safe system.

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