FACULTY OF PHYSICS & ENGINEERING PHYSICS

DEPARTMENT OF NUCLEAR PHYSICS - NUCLEAR ENGINEERING - MEDICAL PHYSICS

Nguyen Anh TUAN and Chau Van TAO

Nuclear Technology & Radiation Protection: Year 2020, Vol. 35, No. 1, pp. 36-41

Abstract:

An electron beam from the UELR-10-15S2 accelerator (average energy of 9.92 ± 0.48 MeV) was applied to irradiate food and medical items at the Research and Development Center for Radiation Technology, Vietnam Atomic Energy Institute, Vietnam. The materials are under an electron beam window, such as irradiation products, conveyor, magnet and shielding mate- rial for the magnet coil, bombarded by electrons and generated X-ray (bremsstrahlung effect). In this article, X-ray conversion efficiency from polypropylene, aluminum, iron, and lead bombarded by an electron beam from the UELR-10-15S2 accelerator is measured by the film dosimeter and simulated by the MCNP4c2 code, and there is good agreement between the calculation and measurement results. The results show that X-ray conversion efficiency is the highest from lead (4.3 %), so the gamma - neutron reaction (Q-value of –6.74 MeV for 207Pb) has to be studied in food and medical items irradiated by a 10 MeV eelectron beam.

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Nguyen Huu Quyet, Le Hong Khiem, Trinh Thi Thu My, Nguyen Thi Bao My, Marina Frontasieva, Inga Zinicovscaia, Nguyen An Son, Tran Thien Thanh, Le Dai Nam, Khuat Thi Hong, Nguyen Ngoc Mai, Trinh Dinh Trung, Duong Van Thang, Nguyen Thi Thuy Hang

Environmental Engineering and Management Journal

Abstract:

Atmospheric deposition of chemical elements in the Hanoi region has been investigated in this study based on moss biomonitoring. Twenty-seven Barbula indica moss samples were collected from the end of 2016 to the beginning of 2017, and the concentrations of 33 chemical elements in the samples were determined by instrumental neutron activation analysis. The results show that Hanoi’s air is highly polluted with Zn, Ba and Ta, and slightly polluted with Al, Cl, Sc, Ti, V, Cr, Mn, Fe, Ni, Co, As, Cd, Sb, La, Ce, Sm, Gd, Tb, Yb, Hf, Th and U. A determination of the possible pollution sources has been made for the analyzed elements; namely: coal and oil combustion are the main sources of V, Ni, Co and As; vehicle exhaust and non-exhaust sources, as well as industrial emissions, are the main sources of Mn, Co, Cd and Ba; construction dust is the source of Ca, Mg and Sb; various industries are the sources of Cr and Ni; the dust from cement kilns and ash from biomass burning is responsible for K and Cl; two-stroke motor vehicles, galvanizing factories and tire wear are the sources of Zn; and Br may be emitted from burning wastes.

 

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Background Radiation in some Quarries and Quarry Lakes in Binh Duong Province, Vietnam

Van Thang Nguyen, Nguyen Phong Thu Huynh, Huynh Thi Yen Hong, Truong Huu Ngan Thy, Huynh Truc Phuong, Cong Hao Le

Journal of Radioanalytical and Nuclear Chemistry(2022)

Abstract:

Operation of some quarries can release radioactive materials from the deep soil to other environments that potentially impact human health. The present study investigated concentrations of radon and other radionuclides in surface soil, air, and water around two quarries in the south of Vietnam. Indoor radon concentrations ranged between 6.19 Bq m-3 and 20.6 Bq m-3. In surface soil, the average concentrations of 40K, 226Ra, and 232Th were 387, 36.5, and 44.5 Bq kg− 1, respectively. In surface soil, the average values of radioactivity found for 40K, 226Ra, 238U, and 232Th were 2.65, 1.23, 1.12, and 1.22 mBq l-1, respectively. The results show that the radioactive levels in the quarry region are found higher than in the nearby area. However, these levels are not enough for a recommendation for public health.

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Phan Long Ho, Le Dinh Hung, Vu Tuan Minh, Dang Van Chinh, Tran Thien Thanh, Chau Van Tao

Science of The Total Environment, Available online 18 June 2020, 140291

 
Abstract:
This paper presents information on the concentration of radioactivity and chemicals at 12 water stations that used groundwater as their raw water supply source. The groundwater's radioactivity was higher than the treated, tap, and surface water, but lower than the national and international recommendations. At five stations (41.7%), the gross alpha contents were higher than the levels advised by Vietnam's regulations, but met the WHO and IAEA's recommendations. The mean active (Bq L−1) gross alpha, gross beta, Ra-224, Ra-226, and Ra-228 were 0.093 ± 0.012, 0.221 ± 0.020, 0.031 ± 0.004, 0.028 ± 0.004, and 0.035 ± 0.001, respectively. The contribution of Ra-226 to the gross alpha was in a range of 23%–60% (r = 0.91, p value <.001), and the ratio of Ra-226/Ra-228 ranged from 0.49–1.06. For the treated and tap water, each age groups' annual committed effective dose was lower than the international regulations. The concentration of the total dissolved solids, sulfate, chloride, sodium, barium, and manganese met the national regulations. However, during the rainy season, the surface water in the area was affected by saltwater intrusion, with salinity up to 4.1‰. Discriminant analysis was applied to study the differences among the water groups. As a result, the treated and tap water were separated from the others.
 
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L. H. Khiem, K. Sera, T. Hosokawa,N. H. Quyet, M. V. Frontasyeva, T. T. M. Trinh, N. T. B. My, N. T. Nghia, T. D. Trung, L. D. Nam, K. T. Hong, N. N. Mai, D. V. Thang, N. A. Son, T. T. Thanh,  D. P. T. Tien

Journal of Radioanalytical and Nuclear Chemistry,  published online: 21 February 2020

Abstract:

The concentration of 22 metal elements including Mg, Al, Si, P, S, Cl, K, Ca, Ti, Cr, Mn, Fe, Ni, Cu, Zn, As, Br, Rb, Sr, Zr, Ba and Pb in Barbula Indica moss samples collected in 12 di erent sites in Ha Noi in July of 2018 were determined by Proton Induced X-ray Emission. The obtained results has been used for assessment of heavy metal pollution in the air in Ha Noi region. The factor analysis was applied to the concentration data of 11 interested elements and the possible sources of air pollution have been suggested. The study showed that the PIXE technique is e cient to environmental pollution analysis since it precise, fast and low-cost.

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 Assessment of annual effective dose from radium isotopes in groundwater samples in households along the lower Mekong River

Phan Long Ho, Vu Tuan Minh, Le Dinh Hung, Do Quoc Trung, Dang Van Chinh, Tran Thien Thanh, Chau Van Tao

Abstract

In this study, the 224Ra, 226Ra, 228Ra in groundwater samples at Long Phu district were determined by HPGe detector with co- precipitation method. The median concentrations were 0.040 ± 0.005 Bq L−1, 0.039 ± 0.004 Bq L−1, and 0.049 ± 0.004 Bq L−1. Highest MDC values were 0.028 Bq L−1, 0.010 Bq L−1, 0.018 Bq L−1, respectively. It’s a strong relationship between 224Ra, 228Ra versus conductivity, salinity, TDS, SO42−. The annual e ective dose of the age groups was lower than the WHO rec- ommended value except for infants exceeding around 1.5 times. Besides, the 226Ra minimum recovery obtained was 90% with trueness 9.9% and relative percentage di erence 6.1%.

Keywords Radium isotopes · Groundwater · Co-precipitation method · Gamma spectrometry · Annual e ective dose · Pearson correlation

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DOI:  https://doi.org/10.1007/s10967-019-06699-z

 

 

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