2021-04-11T22:30:48Z
http://rpe.kntu.ac.ir/?_action=export&rf=summon&issue=6693
Radiation Physics and Engineering
RPE
2645-6397
2645-6397
2020
1
1
Measurement of naturally occurring radioactive materials concentration in Tehran’s water using Gamma spectrometry
Mehrnaz
Zehtabvar
Dariush
Sardari
Gholamreza
Jahanfarnia
The concentration of naturally occurring radioactive materials (NORM) in surface water and irrigation wells is measured using gamma ray spectrometry by HPGe detector. Measurement was carried out for samples that were collected over seventeen points in Tehran city and its suburbs. The samples were prepared in compliance with the principles from irrigation wells of city. The specific radioactivity of Ra-226, Th-232 and K-40 were measured and the results from different locations covered a range with the minimum being below "minimum detectable activity" up to maximum of 4.04, and 6.85 and 4.7 Bq per liter of water, respectively. The accumulation of radioactive materials in the samples from southern areas of Tehran was more than that of central areas. Also, concentration of Ra-226 in all the samples was less than the Derived Release Limit of Canada and Environmental Protection Agency standard threshold.
Naturally radioactive materials
Gamma ray spectrometry
HPGe detector
Tehran's water
2020
01
01
1
5
http://rpe.kntu.ac.ir/article_57882_28456f715939469b56483ca8f76c96b3.pdf
Radiation Physics and Engineering
RPE
2645-6397
2645-6397
2020
1
1
Introducing a novel FDG synthesis method in Iran based on alkaline hydrolysis
Parviz
Ashtari
18F-FDG PET/CT is commonly used for evaluation and diagnostic of many types of cancer, such as; tumor diagnosis, treatment monitoring, and radiation therapy planning. Accurate diagnostic is needed in meticulous patient preparation, including restrictions of diet and activity and management of blood glucose levels in diabetic patients, as well as an awareness of the effect of medications and environmental conditions. All of these conditions play important roles toward obtaining good-quality images, which are essential for accurate interpretation. This article introduces the new synthesis and quality control method for obtaining the best quality FDG which is used as radiopharmaceutical. All the reactions are carried out and completed in one reaction vessel without any replacement. The paper is including details of synthesis, quality control and transportation step. It is the first time that the alkaline FDG synthesis is introducing by details in Iran.
Alkaline Hydrolysis
Synthesis
FDG=[18F]Fluorodeoxyglucose
2020
01
01
7
11
http://rpe.kntu.ac.ir/article_57883_e9a35a4728a0959ba7c83509d60a1196.pdf
Radiation Physics and Engineering
RPE
2645-6397
2645-6397
2020
1
1
A Geant4 study on dosimetric comparison between three kinds of radioactive esophageal stents to be used in treatment of advanced esophageal cancers
Payam
Rafiepour
Shahab
Sheibani
Daryiush
Rezaey Uchbelagh
Hossein
Poorbaygi
Utilizing radioactive stents is a usual method for treatment of advanced esophageal cancer. It is necessary to investigate the dose distribution of radioactive esophageal stents before the clinical use. This study presents a dosimetric comparison between three radioactive esophageal stents: I-125 seed-loaded stent, iodine-eluting stent and double-layered iodine-eluting stent. Depth-dose and angular dose distributions were carried out using Geant4 toolkit. Moreover, the effect of interval distance between two adjacent seeds on the dose distribution was investigated. Esophageal stents loaded with I-125 seeds seems to be better than iodine-eluting stents, with the distance less than 15 mm between two adjacent seeds.
Advanced esophageal cancer
Radioactive stent
Brachytherapy
Dosimetry
Geant4
2020
01
01
13
18
http://rpe.kntu.ac.ir/article_57884_1402e5658ec4b5a1e0cc77a993af45dd.pdf
Radiation Physics and Engineering
RPE
2645-6397
2645-6397
2020
1
1
Three-dimensional solution of the forward and adjoint neutron diffusion equation using the generalized least squares finite element method
Farahnaz
Saadatian Derakhshandeh
Numerical solution of the multi-group static forward and adjoint neutron diffusion equation (NDE) using the Finite Elements Method (FEM) is investigated in detail. A finite element approach based on the generalized least squares method is applied for the spatial discretization of the NDE in 3D-XYZ geometry. A computer code called GELES was also developed based on the described methodology covering linear or quadratic tetrahedral elements generated via the mesh generator for an arbitrary shaped system. A number of test cases are also studied to validate the proposed approach. Moreover, to assess the output dependency to the number of elements, a sensitivity analysis is carried out at the end.
Neutron Diffusion Equation
Adjoint Flux
Generalized Least Squares
Finite Element Method
2020
01
01
19
27
http://rpe.kntu.ac.ir/article_57885_71a444fdd987dd8f87e77a18249cbddc.pdf
Radiation Physics and Engineering
RPE
2645-6397
2645-6397
2020
1
1
Calculation of dose uniformity ratio in irradiation cell of GC-220 using analytical method based on multipole moment expansion
Peiman
Rezaeian
Vahideh
Ataenia
Sepideh
Shafiei
In this paper, dose uniformity ratio in irradiation cell of GC-220 is specifiedutilizing an analytical method based on the multipole moment expansion. In this method, the values of monople, dipole and quadrupole moments for source arrangements of GC-220 are calculated by numerical integrating. Appling these values, the dose uniformity ratio in the irradiation cell of GC-220 is calculated equal to 1.92. Monte Carlo simulation is applied to validate calculations. There is a relative difference about 12% between the results obtained from the analytical calculation and Monte Carlo simulation, which confirm the used method. In comparison with Monte Carlo methods, this method is not time consuming, so, this method can be used for the conceptual designing and the source load planning of irradiators.
Dose Uniformity Ratio
Mutipole Moment Expansion
Monte Carlo Method
Gamma Cell 220
Source Load Planning
2020
01
01
29
32
http://rpe.kntu.ac.ir/article_57886_e0e15fa50bd27b21ce8cf778fe89cba4.pdf
Radiation Physics and Engineering
RPE
2645-6397
2645-6397
2020
1
1
Reduction of radiation exposure probability at Tehran research reactor equipped with a second shutdown system
Ehsan
Boustani
Samad
Khakshournia
A second shutdown system (SSS) is designed for the Tehran Research Reactor (TRR) completely independent and diverse from the existing First Shutdown System (FSS). Given limitations, specifications, and requirements of the reactor, the design of SSS is based on the injection of liquid neutron absorber. The plan has the ability to satisfy the major criterion of required negative reactivity worth, to transfer the reactor to subcritical state in needed time, with necessary shutdown margin and for the required duration. Design calculations are performed using the stochastic code MCNPX2.6.0, deterministic code PARET and Pipe Flow Expert software. The ORIGEN2 code and HotSpot health physics code are also used for simulation of environmental pollution release. The SSS chambers cause a decrease of about 5% and 15% in total and thermal neutron flux, respectively. To demonstrate the SSS role in enhancing reactor safety, the probable accident of core meltdown is investigated. As a consequence of this accident, the radioactive pollution in and out of reactor containment is released. Without existing the SSS and in case of failure of FSS, the residents within 58000 m2 of the reactor perimeter would receive about 1 mSv which is more than the annual limit of absorbed dose for the community.
Tehran research reactor
Safety
Second shutdown system
MCNPX code
ORIGEN2 code
PARET code
HotSpot code
2020
01
01
33
38
http://rpe.kntu.ac.ir/article_57887_06b31557b8cac998728cfa370544f9d2.pdf