Duong Duc Thang

• Master of Science
• Researcher at Vietnam Atomic Energy Institute

This study was carried out to investigate background levels of plutonium (239+240Pu), strontium (90Sr), and cesium (137Cs) in the soil in some provinces in northern Vietnam. Thirty-one soil samples were collected from October 2020 to January 2022. These samples were analyzed by gamma spectrometry, alpha spectrometry, beta counting, and radiochemica...

A comparison between the MCNP simulated gamma spectrums based on the nuclear data from NuDat with the current version 3.0 and Nucléide-Lara against measured spectra based on the IAEA reference samples has been performed to assess the influence of nuclear data of photon decay processes and cross-section of photon interactions on the quality of the s...

Transfer of natural radionuclides from soil to water spinach (Ipomoea aquatica Forssk) in Hanoi, Vietnam have been investigated using a low background gamma spectrometer with an HPGe detector (Model-GC5019). Twenty pairs of soil and water spinach samples in two environmental conditions, i.e., flooded and unflooded, were collected for measuring the...

This paper presents the assessment of the distribution and characteristics of 137 Cs activity in surface soil in the middle of Laos. Measurement has been conducted for 212 soil samples distributed evenly in the middle of Laos using low background gamma spectrometers. It is found that the activity concentrations of 137 Cs vary in the range of 0.50-7...

The Red River is one of the largest rivers that plays an important role in the economic development of North Vietnam. There are many radionuclides bearing rare earth, uranium ore mines, mining industrial zones and magma intrusive formations along this river. The contamination and accumulation of radionuclides could exist at high concentration in su...

Coastal wetlands rely on sediment for exchange and development, and a study on the temporal trend of sedimentation can provide a tool for comprehensive interpretation of how the wetland will evolve. To reveal long-term sedimentation processes in the Xuan Thuy Natural Wetland Reserve in Vietnam, five sediment cores were taken for sediment chronology...

Sediment cores were taken in the coastal area of Ba Lat estuary (Red River), in the Xuan Thuy national park. Each core was cut into slices of 4 cm in thickness, numbered from top to bottom and then analyzing for radionuclides (226Ra, 137Cs and 210Pb). Computational dating models were used to determine the age and sedimentation rate for each sedimen...

Assessment of the characteristics of natural radionuclides and 137Cs in soil in Phonsavan district, Xiengkhouang province, Laos has been conducted using a standard electrode coaxial Ge (SEGe) detector. Soil samples were collected at 20 locations close to the populated and agricultural area in Phonsavan district. The average activity concentrations...

This paper presents the results of the first observation of airborne trace elements using Barbula Indica moss in Hai Phong city, one of the two largest seaport cities in Vietnam. A total of 39 moss samples were collected at 39 different locations in January 2020 in Hai Phong. Neutron activation analysis method was used to analyze the concentration...

An important task for future planning and management is predicting how the coastal wetland will develop. In order to calculate the rates of sediment accumulation, five sediment cores A, B, C, D, and E were taken from the Xuan Thuy National Park. Results show that the wetland experienced two to three sedimentation periods of different sedimentation...

This paper presents the results of the first observation of airborne trace elements using Barbula Indica moss in Hai Phong city, one of the two largest seaport cities in Vietnam. A total of 39 moss samples were collected at 39 different locations in January 2020 in Hai Phong. Neutron activation analysis method was used to analyze the concentration...

The baseline data of radioactivity levels in food is one of the main factors for the assessment of resident's health risk. Gross beta and alpha activity was identified for selected commercial freshwater fish species, including 29 types of fish species by a gas-flow proportional detector. The samples were collected from wholesale markets in Hanoi ci...

Evaluating measurement uncertainty of a physical quantity is a mandatory requirement for laboratories within the recognition ISO/IEC 17025 certification to access reliability of measured results. In this work, the uncertainty of ionizing radiation measurements such as air-kerma, personal dose equivalent Hp(d) was evaluated based on GUM method and M...

In this study, a method to estimate the baseline of ambient dose equivalent rate (ADER) of the Lang Son radioactive monitoring station was presented. The warning level is calculated from the arithmetic mean and standard deviation of the terrestrial background value. The terrestrial background value estimated from the Radon peak removal algorithm is...

The 226Ra, 232Th (228Ra), 40K activity concentrations in soil distributed in 67 points belonging to different geological formations in Khammouan, Laos were measured using HPGe detector. The results showed that the activity concentration varies from (6.0 ± 0.61) Bq/kg to (68.5 ± 8.0) Bq/kg, (8.7 ± 1.0) Bq/kg to (78.9 ± 8.3) Bq/kg, (32.1 ± 3.1) Bq/kg...

Understanding concentration and mobility behavior of radionuclides in soil and plant plays an important role and application. In this study, radionuclides in 28 soil layers and tea plant parts samples at Hoa Binh, Vietnam were investigated by gamma spectrometry. The results showed that the 137Cs concentration significantly decreased with the depth,...

Calculating gamma radiation dose rate from online real-time environmental gamma spectrum using NaI(Tl) detector has been developed into a software named RADAPROC V.1 in the Center for Operating the National Network of Environmental Radiation Monitoring And Warning (CONNERMAW). Currently, hundreds of online gamma spectra per day from online monitori...

Abstract: We simultaneously collected 85 pairs of 24-h PM1.0 and PM2.5 samples from a new urban area in Hanoi, Vietnam, and analyzed their chemical compositions with particle-induced X-ray emission (PIXE) and ion chromatography (IC) to obtain input data for source apportionment via positive matrix factorization (PMF). Sulfate, ammonium, and black c...

In this study, ARGOS software was used to simulate the atmospheric radioactive emissions from Fangchenggang nuclear power plant to Viet Nam. The simulated cases are hypothetical accidents with hypothetical source terms equivalent to level 6 of the International Nuclear and radiological Event Scale (INES). The results show the possibility of using A...

226Ra, 238U, 40K, and 232Th (228Ra) activity concentrations of 61 soil samples distributed surrounding the rare earth element mine (NORM), MH, Lao Cai, Vietnam have been measured by HPGe detector. The activity concentrations of 226Ra, 238U, 40K, and 232Th (228Ra) range from 1179 to 6291 Bq/kg, from 1024 to 8351 Bq/kg, from 260 to 3519 Bq/kg, and fr...

Recovery efficiency of 137Cs in seawater samples with different volumes of 40, 50, 60, 80 and 100 liters using co-precipitation method by ferrocyanide compounds has been determined. 134Cs nuclide was used as a tracer to determine recovery efficiency. The results showed that the recovery efficiency of 134Cs ranged from 92.62% to 99.26% with mean val...

This paper presents the evaluation of natural radioactivity and radiological hazards of the terrestrial naturally occurring radionuclides of \(^{226}\hbox {Ra}\), \(^{232}\hbox {Th}\) and \(^{40}\hbox {K}\) in Savannakhet province, Laos. The activity concentrations of \(^{226}\hbox {Ra}\), \(^{232}\hbox {Th}\) and \(^{40}\hbox {K}\) are in the rang...

FLEXPART software simulates atmospheric emissions based on wind-field movements and random disturbances. To simulate random processes, FLEXPART uses a certain number of simulation particles. Changing the number of simulation particles causes a change in the simulated results of the dispersion concentration of the radionuclides. The larger number of...

The aims of this study are to determine the activity concentration of naturally occurring radionuclides in soils and the extent of their exposure to the population. The radioactivity concentrations of 226Ra, 232Th and 40K in the surface layers (5‑30 cm depth) collected from Khammoune province, Laos, were 32.57 ± 3.35 Bq.kg-1, 41.10 ± 3.04 Bq.kg-1 a...

In this study, aerosol samples at Hanoi, Vietnam from February 2017 to January 2018 collected on the glass fiber filter were analyzed for 210Pb by using HPGe spectrometry. 210Pb weekly activity concentrations were in the range of 0.12 mBq.m-3 to 2.87 mBq.m-3 with an average value of 0.92 mBq.m-3and 210Pb monthly activity concentrations were in the...

The paper presents the evaluation of gamma contribution in a neutron calibration field of a 241Am-Be source. The characterization of gamma flux spectra and gamma ambient dose equivalent rates has been performed using a portable NaI(Tl) gamma spectrometer. For obtaining the gamma ambient dose equivalent rates from the measured spectra, two approache...

FLEXPART is a Lagrangian transport and dispersion model suitable for the simulation of a large range of atmospheric transport processes. FLEXPART has been researched and applied in simulation of the long-range dispersion of radioactive materials. It can be applicable to the problem of radioactive materials released from the nuclear power plants imp...

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC), our research concentrates in assessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 under the scenario of normal operation using software package NRCDose72 provided by the USNRC. The datab...

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC)~our~research~concentrates on assessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 to the environment under scenario of an INES-level 5 nuclear accident caused by two incidents of the stat...

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC) our research concentrates on assessing radiation doses caused by radioactive substances released from the Ninh Thuan 1 nuclear power plant (NPP) to the environment under scenario of an INES-level 6 nuclear accident caused by the Station Black Out (SB...

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC), our research concentrates in assessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 under the scenario of normal operation using software package NRCDose72 provided by the USNRC. The datab...

Based on guides RG 1.109, RG 1.111 published by United States Nuclear Regulatory Commission (USNRC) our research concentratesinassessing radiation doses caused by radioactive substances released from the nuclear power plant (NPP) Ninh Thuan 1 under the scenario of normal operation using software package NRCDose72 provided by the USNRC. The database...