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Radiation Protection Dosimetry

Amr Abdelhady
In this study, a hypothetical nuclear criticality accident has occurred in open pool type reactor due to ejection of the control rod during loss of coolant accident. Dose rate distribution was determined for prompt neutrons and gamma rays resulting from first radiation pulse of the criticality accident. MCNP code has been used to determine the dose rate in different positions that the worker may locate inside the reactor during the accident. The results show that the maximum radiation dose is 2.52 Sv which located at the center of the top of the main pool...
August 7, 2018: Radiation Protection Dosimetry
L E Lubis, I Bayuadi, Y A Bayhaqi, F Ardiansyah, A R Setiadi, R D Sugandi, L A Craig, A Nasir, R A Basith, S A Pawiro, D S Soejoko
Dose metrics on intraoral and panoramic dental radiography were analyzed to preliminarily indicate dose trend of dental radiology equipment in Indonesia. Measurements were performed in 71 healthcare institutions involving a total of 92 dental X-ray devices. Imaging modes are categorized into 'low dose' and 'high dose' based on the task. The 75th percentile for intraoral IAK was 2.8 and 4.3 mGy for 'low' and 'high' dose modes, respectively while for panoramic devices the 75th percentile of the KAP for 'low' and 'high' dose modes were 85...
August 7, 2018: Radiation Protection Dosimetry
K G Veinot, K F Eckerman, N E Hertel, M M Hiller
No abstract text is available yet for this article.
August 3, 2018: Radiation Protection Dosimetry
Omeje Maxwell, Joel S Emmanuel, Adewoyin O Olusegun, Ehi-Eromosele O Cyril, Araka T Ifeanyi, Zaidi Embong
Building materials of different brands were assessed for the concentrations of 226Ra, 232Th and 40K using HPGe detector. The activity concentrations in the measured samples ranged from 27 ± 8 to 82 ± 8 Bq kg-1 for 226Ra, 41 ± 4 to 101 ± 8 Bq kg-1 for 232Th and 140 ± 8 to 940 ± 19 Bq kg-1 for 40K, respectively. The Radium equivalent (Raeq) activity from the samples was found to be <370 Bq kg-1 as the recommended value for construction materials. This study will set a baseline data for significant standards on radiation exposure of the measured radionuclides in the selected building materials used in Nigeria...
August 2, 2018: Radiation Protection Dosimetry
Sergei Shikhantsov, Arno Thielens, Günter Vermeeren, Piet Demeester, Luc Martens, Guy Torfs, Wout Joseph
In this article, we study human electromagnetic exposure to the radiation of an ultra dense network of nodes integrated in a floor denoted as ATTO-cell floor, or ATTO-floor. ATTO-cells are a prospective 5 G wireless networking technology, in which humans are exposed by several interfering sources. To numerically estimate this exposure we propose a statistical approach based on a set of finite difference time domain simulations. It accounts for variations of antenna phases and makes use of a large number of exposure evaluations, based on a relatively low number of required simulations...
July 30, 2018: Radiation Protection Dosimetry
J Dubeau, S S Hakmana Witharana, J Sun, B E Heinmiller, W J Chase
The computer code VARSKIN, version 5.3, is widely used to calculate superficial dose caused by the routine handling of radioactive substances or in skin contamination incidents. It allows a variety of source configurations, points, volume, surface and syringe-like (cylindrical) and a variety of exposure situations such as direct skin contact or exposure through clothing. However, there is a need for more benchmarking data of VARSKIN, especially for beta particles, with complex irradiation geometries. Dose calculations using MCNP5 and VARSKIN 5...
July 25, 2018: Radiation Protection Dosimetry
Yao Yang, Chengguo Pang, Wuyuan Li, Junkui Xu, Youwu Su
The first Radioactive Ion Beam Line in Lanzhou was a projectile fragment separator located in the HIRFL. The process of production and separation of radioactive ion beams can induce a strong and complex radiation field. The neutron dose equivalent rates were measured in four positions with a 70 MeV/u 40Ar18+ beam. The results were compared with that simulated by the FLUKA code. New shielding walls were installed to reduce the neutron background for spectroscopy measurement in the experimental terminal. In addition, the induced radioactivity of accelerator components and corresponding residual dose rates were analyzed for the radiation safety of accelerator workers...
July 25, 2018: Radiation Protection Dosimetry
Junko Bamba, Hideki Ishida, Kazuyuki Araki
Two phantoms for a performance evaluation of cone-beam computed tomography (CBCT) were developed and their efficiency was tested. The first phantom, for low-contrast resolution, consisted of an acrylic circular plate with three 0.5-1.0 mm diameter rods. These rods enable the user to visually evaluate the limit of observation. The second phantom, for geometric distortion, especially focused on the z-axis and consisted of two tabular acryl plates crossed perpendicularly with 1.0 mm-wide grooves in a grating form every 10...
July 25, 2018: Radiation Protection Dosimetry
M Abo-Elmagd, Ahmed Saleh, G Afifi
The annual effective radon doses for residents of 92 dwellings in Jazan city located in Northern Saudi Arabia are calculated from the radon concentration and equilibrium factor F, measured using passive technique. The overall average (±1 SD) of radon concentration, equilibrium factor and annual effective dose are 118 ± 12 Bq m-3, 0.3 ± 0.02 and 2.32 ± 0.17 mSv, respectively. Although 93% of the dwellings have radon concentrations below the reference level, about 24% of the dwellings have annual effective radon doses within the range of recommended action level of 3-10 mSv...
July 25, 2018: Radiation Protection Dosimetry
Hanna Piwowarska-Bilska, Aleksandra Supinska, Jacek Iwanowski, Bozena Birkenfeld
Staff at nuclear medicine departments receive doses of ionising radiation higher than the staff of radiotherapy and radiology departments, with the exception of interventional radiologists. Due to the updated lower occupational exposure limit for the lens of the eye, we measured eye exposure in workers of the Nuclear Medicine Department, Pomeranian Medical University in Szczecin, Poland. EYE-D™ dosimeters were used for 3 months by 10 employees working with sources of ionising radiation. Personal dosimeters also measured the exposure of the whole body and hands...
July 20, 2018: Radiation Protection Dosimetry
Valentina Hartwig, Giorgio Virgili, Luca Fabiano Ferrante Vero, Daniele De Marchi, Luigi Landini, Giulio Giovannetti
Magnetic resonance imaging (MRI) is one of the most common sources of electromagnetic (EM) fields as a diagnostic technique widely used in medicine. MRI staff during the working day is constantly exposed to static and spatially heterogeneous magnetic field. Also, moving around the MRI room to perform their functions, workers are exposed to slowly time-varying magnetic fields that induce electrical currents and fields in the body. The development of new exposure assessment methodologies to collect exposure data at a personal level using simple everyday equipment is hence necessary, also in view of future epidemiological studies...
July 20, 2018: Radiation Protection Dosimetry
Ali B Alhailiy, Ernest U Ekpo, Elaine A Ryan, Peter L Kench, Patrick C Brennan, Mark F McEntee
This study aims to assess patient radiation dose from cardiac computed tomography angiography (CCTA) with the aim of proposing a national diagnostic reference levels (NDRLs) for CCTA procedures in Australia. A questionnaire was used to retrospectively gather baseline information related to CCTA scanning and patient parameters in CT centres across the country. The 75th percentile of both volumetric CT dose index (CTDIvol) and dose length-product (DLP) was used as DRL values for CCTA. A DRL for CT calcium scoring test was also determined...
July 19, 2018: Radiation Protection Dosimetry
K Fujii, K Nomura, Y Muramatsu, S Obara, T Goto, K Akahane, H Ota, S Tsukagoshi, M Kusumoto
The aim of this study is to estimate tube current modulation (TCM) profiles in paediatric computed tomography (CT) examinations with a TCM scheme (Volume-EC) and evaluate the estimation accuracy of TCM profiles. Another aim is to validate organ doses calculated using Monte Carlo-based CT dosimetry software and estimated TCM profiles by comparing them with those measured using 5-year-old and 10-year-old anthropomorphic phantoms and radio-photoluminescence glass dosemeters. Dose calculations were performed by inputting detailed descriptions of a CT scanner, scan parameters and CT images of the phantoms into the software...
July 19, 2018: Radiation Protection Dosimetry
Tomokazu Shohji, Atsushi Tachibana, Sousuke Higuchi, Norio Nakata, Daichi Hayashi, Yo Katoh
We aimed to develop a software for facilitating absorbed dose per pixel (pixel dose) calculation using a size-specific dose estimate (SSDE). We calculated the pixel dose at nine equal points inserted into the radiophotoluminescence glass dosimeter (RPLD) and compared the pixel dose with the measured doses using RPLD. With this method, the relative errors of average pixel dose was -0.1% for adults and 2.86, 3.36 and 1.17% for those aged 10, 5 and 1 years without tube current modulation, respectively. In contrast, the relative error of SSDE was 17...
July 16, 2018: Radiation Protection Dosimetry
Cetin Kurnaz, Begum Korunur Engiz, Ugur Kose
As a result of the drastic increase in the number of mobile device users, there is considerable public debate about possible health hazards especially due to base stations and Wi-Fi access points. For this reason, in this study the effects of the number of users in a base station and wireless fidelity (Wi-Fi) access point on electric field strength (E) levels were investigated using real-time measurements. Two-stage E measurements were performed on Ondokuz Mayıs University's (OMU) Kurupelit Campus with a PMM-8053 and SRM-3006 electromagnetic field (EMF) meter...
July 10, 2018: Radiation Protection Dosimetry
Sabrina Friedrich, Oliver Hupe
In Germany, authorised experts are required to measure around an X-ray facility to determine supervised and controlled areas within the scope of a legal regulatory procedure. For this purpose, they have to use area dosemeters which are nationally type-approved by the PTB according to the German measurement and verification act. To date, all available type-approved area dosemeters are only tested in continuous radiation fields, and therefore the technical data of the measuring instruments are valid only for continuous radiation...
July 4, 2018: Radiation Protection Dosimetry
Hiroshi Yasuda, Kazuaki Yajima
Annual per-capita aviation doses of the Japanese people from commercial flights were calculated for 6 years period from 2009 (solar minimum) to 2014 (solar maximum) using the flight routes provided by major Japanese airlines. For international flights, the area other than Japan was separated to nine regions and collective effective doses were estimated from the number of the Japanese flyers to those regions multiplied by the calculated aviation route doses to representing cities. Collective effective doses for domestic flights were estimated as the products of the collective distances (man km) and the unit-distance route dose determined from three major routes...
June 29, 2018: Radiation Protection Dosimetry
E Vagena, P Katsaras, K Theodorou, S Stoulos
Mapping of the photoneutron spectrum and flux performed at several positions over the treatment table of a 15 MV medical linac. Neutron activation technique has been applied to obtain the neutron spectra in the mixed γ -n field. Thick foils have been used due to the low neutron flux and the measurements were unfolded using the MINUIT minimizer. GEANT4 code simulations have been performed to reproduce the photoneutrons' spectrum and estimate the flux along the treatment table. The mixed radiation field around medical linear accelerator was evaluated and the variation of the ambient dose equivalent over the treatment table was estimated...
June 29, 2018: Radiation Protection Dosimetry
H Dombrowski
In radiation protection, the quantity ambient dose equivalent, in short H*(10), is very important in the field of area dosimetry, because this quantity is used to estimate the effective dose to human beings, whose permissible limits are restricted by law. The conversion coefficient from air kerma to H*(10), valid for a 137Cs photon field, is essential as it enters the realization of the quantity H*(10) as well as every (directly or indirectly) related calibration. The basic calibration factor of any dose rate instrument is usually related to a calibration in a 137Cs photon field, which underlines the importance of the conversion coefficient discussed in this article...
June 23, 2018: Radiation Protection Dosimetry
Malgorzata Wrzesien
The production of radiopharmaceuticals for the needs of positron emission tomography (PET), in particular 18F-FDG, is a multi-step process performed most often by physicists and chemists. The monitoring of occupational exposure of staff employed in radiopharmaceutical production centres includes the measurement of the Hp(10) and Hp(0.07) values. Occupational exposure to ionising radiation means that the thyroid may be, among others, affected by the radiation field. This work analyses the exposure of the thyroid gland of employees of centres that produce the isotopes for PET, in particular fluorine-18...
June 20, 2018: Radiation Protection Dosimetry
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