Support activities in Namie Town, Fukushima undertaken by Hirosaki University

2021 ◽  
pp. 014664532110068
Author(s):  
Shinji Tokonami ◽  
Tomisato Miura ◽  
Naofumi Akata ◽  
Hirofumi Tazoe ◽  
Masahiro Hosoda ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Indoor Radon ◽  
Germanium Detector ◽  
Dose Assessment ◽  
Radiological Protection ◽  
Radiation Doses ◽  
Gamma Ray Spectrometer ◽  
High Purity Germanium ◽  
Thoron Progeny

This paper does not necessarily reflect the views of the International Commission on Radiological Protection. Several radiation monitoring research projects are underway on dose assessment, biological analysis, and risk communication under an agreement with Namie Town. Indoor radon and thoron progeny concentrations have been measured using passive-type monitors to estimate internal doses due to inhalation. In addition, airborne radiocaesium concentrations at five points in Namie Town have been analysed using a high-purity germanium detector to estimate internal doses for comparison with radon. External radiation doses from natural and artificial radionuclides have also been estimated using an in-situ gamma-ray spectrometer. Other support activities are mentioned briefly in this article,

Gamma-ray spectrometer calibration for field analysis of thorium, uranium and potassium

1970 ◽  
Vol 7 (4) ◽  
pp. 1093-1098 ◽  
Author(s):  
P. G. Killeen ◽  
C. M. Carmichael
Keyword(s):  
Regression Analysis ◽  
Gamma Ray ◽  
Laboratory Analysis ◽  
In Situ Analysis ◽  
Field Analysis ◽  
Gamma Ray Spectrometer ◽  
Nonlinear Relation ◽  
Using Data ◽  
Spectrometer Calibration

The calibration of a portable three-channel gamma-ray spectrometer for in situ analysis of thorium, uranium, and potassium is discussed. A method of regression analysis is suggested as the best means of including all of the data available from the calibration stations. Calibration indicates a nonlinear relation between count rates obtained in the field and concentrations in parts per million obtained from laboratory analysis. The range of radioelement content must be taken into consideration and appropriate sets of calibration constants applied. As an example of the method, calibration constants are calculated for a portable gamma-ray spectrometer using data for the Blind River uranium region of Ontario.

scholarly journals Determination of 137Cs in Sea Water Samples Using Gamma Spectrometry

2020 ◽  
Vol 13 ◽  
pp. 247
Author(s):  
N. Evaggeliou ◽  
Ch. Lykomitrou ◽  
A. Zafiropoulou
Keyword(s):  
Gamma Spectrometry ◽  
Comparative Evaluation ◽  
Sea Water ◽  
Germanium Detector ◽  
Advantages And Disadvantages ◽  
High Purity Germanium ◽  
Co Precipitation ◽  
Radioanalytical Procedures

In the present study a comparative evaluation of two methods for 137Cs determination (pretreatment for gamma spectrometry) is attempted. One of them is the conventional AMP (ammonium molybdophosphate, (ΝΗ4)3Ρ(Μo3O10)4) method (radiochemical treatment based on coprecipitation) and the other one is a method based on pre-concentration of cesium in situ by using the Mark III Centrifugal Pump. The pump, which is described analytically in the study, is composed of a mo­tor (pump), four cartridge housings (containing the scavengers), a flow meter and a pressure tube (containing the battery pack and the timer board). For justification, this method is compared with the AMP co-precipitation one. Following up the radioanalytical procedures, the gamma spectrometry system (relative efficiency of high purity germanium detector 90%) is also demonstrated, as conformed to mea­ suring obtained parameters. Finally, the advantages and disadvantages of these two methods are recorded and the application of each one is suggested.

Comet nucleus gamma-ray spectrometer penetrator - An in situ nucleuscomposition experiment

1985 ◽  
Author(s):  
B. SWENSON ◽  
A. MASCY ◽  
L. EDSINGER ◽  
S. SQUYRES ◽  
C.P. MCKAY
Keyword(s):  
Gamma Ray ◽  
Comet Nucleus ◽  
Gamma Ray Spectrometer

scholarly journals Low-background, digital gamma-ray spectrometer with BEGe detector and active shield: commissioning, optimisation and software development

2019 ◽  
Vol 322 (3) ◽  
pp. 1311-1321
Author(s):  
Krzysztof Gorzkiewicz ◽  
Jerzy Wojciech Mietelski ◽  
Renata Kierepko ◽  
Kamil Brudecki
Keyword(s):  
Gamma Ray ◽  
Germanium Detector ◽  
Low Background ◽  
Gamma Ray Spectrometer ◽  
Annihilation Peak ◽  
The Mean ◽  
Plastic Scintillators ◽  
Set Up ◽  
Active Shield ◽  
Broad Energy

Abstract This paper presents results of the development process of low-background, digital gamma-rays spectrometer equipped with Broad Energy Germanium detector (CANBERRA BE5030), multi-layer passive shield and cosmic veto system that consists of five plastic scintillators (SCIONIX EJ-200). Data acquisition is performed using digitizer CAEN DT5725 with CoMPASS software. Output data analysis is carried out with purposely written and developed code VETO. On the basis of conducted tests, acquisition parameters were set up and tuned as well as time delays between all detectors were established. As a result of the configuration process, the mean background counts reduction of 64% in the whole spectrum and 65% in annihilation peak were achieved. This procedure allowed diminishing detection limits of selected isotopes 37% on average.

Numerical investigation of radon dispersion and dose assessment for typical ventilation schemes with an air purifier

2020 ◽  
Vol 30 (1) ◽  
pp. 114-128
Author(s):  
Dong Xie ◽  
Chenhua Wang ◽  
Chuck W Yu ◽  
Hanqing Wang
Keyword(s):  
Mechanical Ventilation ◽  
Effective Dose ◽  
Natural Ventilation ◽  
Indoor Radon ◽  
Radioactive Decay ◽  
Dose Assessment ◽  
Radiological Protection ◽  
Ventilation Condition ◽  
Air Supply ◽  
Air Purifier

Radon is a radioactive pollutant that could pose hazards to the surrounding environment and people due to its radioactive decay progenies. In this study, numerical simulations of radon dispersion were conducted under natural and mechanical ventilation with an air-purifier for radon. Factors such as the air supply speed, position and air supply angles of the purifier were considered. Results showed that the increase in the air supply speed from the purifier was an effective solution to reduce indoor radon pollution. The effect was better when the purifier was in the middle of the room. The purification effect was similar when the air supply changed under natural ventilation, while purification function was more effective when the air supply angle was 60° under the mechanical ventilation condition. An effective dose estimation involving typical ventilation schemes with radon purifier was evaluated. Using this approach, the radiation effect on occupants was computed. The calculated effective dose was 0.9 mSv y−1 when the air supply speed of the purifier was 0.2 m s−1 under natural ventilation. As a result, the effective dose calculated was under the annual effective dose limit of 3–10 mSv y−1 recommended by the International Commission on Radiological Protection (ICRP) for public exposure.

scholarly journals Assessment of Natural Radioactivity Level and Annual Effective Dose of Amber Rice Samples Cultivated in the South of Iraq

2019 ◽  
Vol 122 ◽  
pp. 05004
Author(s):  
Abdulridha S. Younis ◽  
Nada F. Tawfiq
Keyword(s):  
Effective Dose ◽  
Gamma Ray ◽  
Annual Effective Dose ◽  
Radioactive Material ◽  
Radiological Protection ◽  
Gamma Ray Spectrometer ◽  
Activity Concentrations ◽  
Rice Consumption ◽  
Rice Samples ◽  
South Of Iraq

In this work, the activity concentrations of naturally occurring radioactive material including 238U, 232Th, and 40K were measured of some amber rice samples cultivated in southern Baghdad and Al Najaf governorate and used in Baghdad governorate, Iraq in 2018, using gamma-ray spectrometer with NaI (Tl) detector. The results show that the activity concentrations for 238U ranged from (2.68 to 10.81) Bq/kg with average 5.94 Bq/kg, 232Th ranged from (B.D.L to 3.37) Bq/kg with average 2.65 Bq/kg, and for 40K ranged from (4.48 to 35.7) Bq/kg with average 16.84 Bq/kg. The annual effective dose from rice consumption by adults for 238U, 232Th, and 40K ranged from (0.41 to 1.6) x10-5 Sv/y with average 0.9 x10-5 Sv/y, (B.D.L to 0.42) x10-5 Sv/y with average 0.2 x10-5 Sv/y, and (0.17 to 1.2) x10-5 Sv/y with average 0.45 x10-5 Sv/y respectively. All values of the average specific activities are less than the global average values of ICRP, and the annual effective dose from rice consumption by adults was lower than the permissible limit of (1 m Sv/y) recommended by the International Commission on Radiological Protection.

THE NATURAL GAMMA‐RAY FLUX: IN‐SITU ANALYSIS

Geophysics ◽  
1968 ◽  
Vol 33 (2) ◽  
pp. 311-328 ◽  
Author(s):  
Ronald Doig
Keyword(s):  
Gamma Ray ◽  
Background Radiation ◽  
In Situ Analysis ◽  
Rock Outcrops ◽  
Large Sample ◽  
Gamma Ray Spectrometer ◽  
Natural Gamma ◽  
Major Project ◽  
Quantitative Evaluations

A fully portable transistorized gamma‐ray spectrometer has been constructed, and used to investigate the nature of the gamma ray activity at the surface of rock outcrops. Gamma‐ray photopeaks of [Formula: see text] and members of the U and Th series have been identified, along with strong fallout activity dominated by the 0.75 Mev activity of [Formula: see text]. A method has been devised for measuring, in situ, the K, U, and Th contents of rocks. Calibration accounts for the interference between the radioelements, and for background radiation. The following estimates of accuracy and sensitivity are for five‐minute counting intervals: 5 percent plus 0.1 percent K, 10 percent plus 0.2 ppm U, 10 percent plus 0.5 ppm Th. The main advantages of the method are its speed and versatility and the very large sample analyzed. A number of surveys have been performed to demonstrate some of the applications of the instrument. The major project of this series is detailed mapping of the K, U, and Th distribution in the Preissac granite of northwestern Quebec. In addition to its use as a petrologic tool, the technique is eminently suited to prospecting for U and Th, and the quantitative evaluations of occurrence of these elements.

scholarly journals Measurment of radon, thoron and their progeny in indoor environment of Mohali, Punjab, Northern India, using pinhole dosimeters

2016 ◽  
Vol 31 (3) ◽  
pp. 299-305 ◽  
Author(s):  
Vimal Mehta ◽  
Deep Shikha ◽  
Pal Singh ◽  
Pal Chauhan ◽  
Singh Mudahar
Keyword(s):  
Indoor Radon ◽  
Area Measurement ◽  
Indoor Environments ◽  
Indoor Radon Concentration ◽  
Annual Dose ◽  
Northern India ◽  
Decay Products ◽  
Radon Monitor ◽  
Thoron Progeny

The health hazards of radon and its decay products above certain levels are well known. However, for any preventive measures to be taken, we have to be aware of radon levels of that particular area. Measurement of radon and its decay products in indoor environments is an important aspect of assessing indoor air quality and health conditions associated with it. Keeping this in mind, measurements of radon, thoron and their progeny concentrations were carried out in Mohali, Northern India, using pinhole-based twin cup dosimeters. Radon exhalation rates of soil samples in the dwellings/areas were measured via an active technique of a continuous radon monitor. The indoor radon concentration in Mohali varied from 15.03 ? 0.61 Bq/m3 to 39.21 ? 1.46 Bq/m3 with an average of 26.95 Bq/m3 ,while thoron concentration in the same dwellings varied from 9.62 ? 0.54 Bq/m3 to 52.84 ? 2.77 Bq/m3 with an average of 31.09 Bq/m3. Radon progeny levels in dwellings under study varied from 1.63 to 4.24 mWL, with an average of 2.94 mWL, while thoron progeny levels varied from 0.26 to 1.43 mWL , with an average of 0.84 mWL. The annual dose received by the inhabitants of dwellings under study varied from 0.78 to 2.36 mSv, with an average of 1.61 mSv. The in situ gamma dose rate varied from 0.12 to 0.32 mSv/h.

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