Publication Type: The 42^nd Congress on Science and Technology of Thailand

Year: 2017

Abstract: Uranium isotope and thorium were separated in nitric acid form by using ion exchange column-resin. This experiment was tested in batch. Feed was prepared from uranium, thorium and rare earth elements (REE) in 80 ppb concentrations. Three types of Dowex-50 cation exchange resins (x2, x4 and x8) were used in this experiment for uranium isotope and thorium separation. Three nitric acid concentrations (1 M, 2 M, and 3 M) were used to elute uranium isotope, while thorium was eluted by 6 M, 7 M, and 8 M of Nitric acid. The results are shown that 1 M HNO₃ and 7 M HNO3 were appropriate condition for uranium and thorium separation respectively. In this study, the optimum extraction resin of uranium was x4 Dowex-50 and thorium in rare earth mixture was x2 Dowex-50. Uranium isotopes, thorium and other REE concentration were determined by inductively coupled plasma – mass spectrometry (ICP-MS). Furthermore, this work used to study problem of matrix effects of high counting signal from each elements which could be interfered with the signal of low concentration elements in sample mixture.

Publication Type: in RRFM 2018, IAEA

Year: 2018

Abstract: The National Nuclear Forensics Laboratory of Thailand was established in 2013 by Office of Atoms for Peace (OAP) under the Project No.30, “Network of Excellence for Nuclear Forensics in South East 

Asia Region (2013-2014)”, supported by EU CBRN CoE.  It is expected to develop The National Nuclear Forensics Library (NNFL) and increase the capability of the nation to overcome illicit trafficking of domestic radioactive and nuclear materials.  

The nuclear materials in only location outside facilities (LOF), from total 93 facilities, were created as database in 2016.  It was input as one of the information in the present developing Nuclear Forensics Database prototype.  The nuclear knowledge which are planned to include, are legislative work, IAEA documents, ISO details, Nuclear Forensics analytical reports, inspection reports, and other useful/concerning information.  The templates of each nuclear material/radioactive material are in ongoing modification following the structures and formats available for NNFL, related to IAEA concepts and requirements.  

The success of this nuclear knowledge management (NKM) will reduce the time wasting for nuclear forensics assessments whether the sized material is or is not consistent with the given process or activity.  The concerning illicit activities can also be deterred.  These attempts will assist the National Nuclear and Radiological Emergency Plan, as well as the country nuclear security and physical protection, related to SG/NPT, for the peaceful use of atomic energy. 

For full article, please visit https://drive.google.com/file/d/1M0KtrCqLagJugaWQIscMtOnkkkcUGfgi/view

Publication Type: The 2018 Pure and Applied Chemistry International Conference (PACCON 2018)

Year: 2018

Abstract: Matrix effect is one of major problem of Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) technique. It will make inaccurate results. In some case the ratio of uranium isotope is quite sensitive necessity such as ²³⁵U/²³⁸U ratio. Solid phase extraction by using UTEVA resin is to separate uranium (U), thorium (Th) and other elements before using ICP-MS measurement. This work tests the extraction process of 2 multi-element standard solution and 3 geological samples. The experiment focus on percent recovery of U, Th, resin recycling, and matrix effect of extracted-process. The results show that UTEVA resin is highly selectivity for U/Th with other elements, then matrix effect is reduced. The other benefit of this extraction process provides increase U and Th concentration in sample that can be measured by quadrupole mass spectrometer (or ppb detection limit) and to improved confidential result of unknown samples for nuclear forensics and safeguards aspect.

For full article, please visit https://drive.google.com/file/d/1mtSy_YbYoaT7SRo6Vo1fAk3aRVc_Qy5J/view

Publication Type: Kasetsart University Academic Conference  

Year: 2018

Abstract: Non-destructive analysis of geological samples is one of the most popular techniques used in forensic investigations to accurately analyze the radioisotope type, composition and determine the structure of the sample. The analyzed data were then compared to nuclear and radiation databases to find connections between people, places, etc. before and after nuclear and radiation-related events. In this work, 30 soil samples were analyzed using Gamma Spectrometry (GEM Series HPGe, High Purity Gemanium) and X-ray diffraction (XRD, D2 Phaser). Th-234, Ra-226 and Bi-214 naturally occurring radionuclides were detected. It was found that all samples had the main crystal structure of Quartz. In addition, the analysis by X-ray fluorescence spectrometer (XRF,S1 TITAN) showed that the main element was Si and Al is the main component.

Publication Type: Kasetsart University Academic Conference  

Year: 2018

Abstract: Non-destructive analysis of geological samples is one of the most popular techniques used in forensic investigations to accurately analyze the radioisotope type, composition and determine the structure of the sample. The analyzed data were then compared to nuclear and radiation databases to find connections between people, places, etc. before and after nuclear and radiation-related events. In this work, 30 soil samples were analyzed using Gamma Spectrometry (GEM Series HPGe, High Purity Gemanium) and X-ray diffraction (XRD, D2 Phaser). Th-234, Ra-226 and Bi-214 naturally occurring radionuclides were detected. It was found that all samples had the main crystal structure of Quartz. In addition, the analysis by X-ray fluorescence spectrometer (XRF,S1 TITAN) showed that the main element was Si and Al is the main component.

Publication Type: The 2019 Pure and Applied Chemistry International Conference (PACCON 2019)

Year: 2019

Abstract:  The analysis of ²³⁵U and ²³⁸U isotopes in three water types was studied using inductively coupled plasma mass spectrometry (ICP-MS). The waters from drinking water, radioactive waste, and surface water were collected and stabilized using concentrated HNO3 before measurement. The method validation was performed by spiking uranium isotopic standard in different concentrations for each kind of sample. The results of drinking water and radioactive waste were agreed to the percent recovery within the range of 80-110%. However, the recovery values obtained for most samples from the surface water were out of the recovery acceptable range. Trace elements of each sample were investigated, which were Cr, Mn, Fe, Cu, Zn, As, Se, Cd, Ba, and Pb. The concentrations of elements in surface water were found highest when compared with other samples. In order to determine high contaminated water, interference needs to be removed by using a column separation technique before measurement.  This method can be used for the analysis of the uranium isotopes in a low impurities sample for supporting the nuclear regulation which is safety, security, and safeguards.