Terrestrial Gamma Radiation in Phuket Island, Thailand

The aim of this study was to evaluate the level of terrestrial radioactivity on Phuket Island, which used to be the richest tin province in Thailand. We measured 124 survey points of terrestrial gamma dose rate at one meter above the surface of local soil along roads in the environs of Phuket Island. Another 31 survey points were examined inside an old ore-dressing plant. The terrestrial gamma dose rate of the Island (excluding the abandoned area of the old dressing plant) ranges from 20 to 900 nGy h-1, while the geometric mean Island value was 190 nGy h-1. Soil samples were also collected from selected areas having high gamma dose rates to analyze for activity concentrations of 226Ra, 232Th and 40K. Based on these soil activities, the calculated terrestrial gamma dose rate found to range between 25 and 520 nGy h-1. The corresponding annual effective doses varied between 0.03 and 0.6 mSv y-1. The results of the terrestrial gamma dose rate obtained from direct measurement in the old tin dressing plant ranged from 110-17,170 nGy h-1 with a mean value of 1410 nGy h-1. The terrestrial gamma dose rate calculated from soil samples in the dressing plant ranged from 590 to 206,080 nGy h-1 which corresponding to annual effective dose of 0.7-250 mSv y-1. Thus, the dose rates on much of Phuket Island are within typical background values while the dose rates within the old tin dressing plant are elevated by as much as 16 times background

Generic cost estimates, site screening, and site design of low- and intermediate-level waste system

Most of the wastes produced in the developing countries are low- and intermediate-level wastes. These wastes are initially stored on-site. Since applications using of the radioactive materials is increasing, in some countries, the radioactive wastes are accumulating to the point that the initial on-site storage has to be expanded. In order to increase interim storage capacity, existing capacity must be increased or replaced with a new permanent facility. The waste management system cost must be considered to achieve the most cost effectiveness. The management of radioactive waste includes every step in the system from the waste generator to the final disposal. The major costs in the waste system are: processing costs, transportation costs, and burial costs. However, modification of one step to reduce its cost may impact other costs in the system and even increase total costs as well. Computer models have been developed that simulate the entire system so that interactive may be evaluated to determine for estimating the generic total waste system cost and average unit disposal cost. The radioactive waste materials produced in Thailand are used as input data to test the models. The preliminary site screening and site design study to identify the potentially suitable site areas are also performed in this study. The sensitivity analyses obtained from the disposal model show that the rate of return or interest rate, the operating cost and the capital costs affect the disposal unit cost. The development, and postoperating period do not affect on the disposal unit cost. The results obtained from system cost model show that type of waste, volume reduction factor, and treatment technology affect the waste management system cost.Digitization note: p. 135 missing from paper original and microfilm versions

Development and evaluation of an impactor sampler for radioactive aerosol particles.

IRPA1

Territorial Gamma Radiation Dose Rate in Phuket island: Thailand

7th International Conference on High Levels of Natural Radiation and Radon Areas(7HLRRA

A Simple Technique for Determining the Equiliburium Equivalent Toron Concentration Using a CR-39 Detector

International Conference on Radioecology & Environmental Radioactivit

Distribution of rare earth elements, thorium and uranium in Gulf of Thailand\u27s sediment

Distribution of rare earth elements (REEs), thorium and uranium in fifty-four marine sediments collected from five selected areas along the Gulf of Thailand are discussed in this paper. These areas have been selected as potential sites to set up thermal and nuclear power plants. Concentration of elements was determined using inductively coupled plasma mass spectrometry (ICP-MS). Absolute concentrations of REEs, Th and U show a sample-to-sample variation and may be due to different geological characteristic of area as well as grain size effect. Total REE concentrations (not including Y) range between 9 μg/g and 210 μg/g. The chondrite-normalized REEs patterns of all samples are similar to Post Archaean Australian Shale (PAAS) and average Upper Continental Crust (UCC), with LREEs enrichment relative to HREEs (LaN/YbN = 6.5 – 29.3), fairly flat HREEs patterns (GdN/YbN = 1.0 – 3.8) and ubiquitous negative Eu-anomaly (Eu/Eu* = 0.3 – 0.7). Th concentrations (1 – 28 μg/g) are relatively higher than those of uranium (0.4 – 4 μg/g). Th/U ratios (1.5z – 9.9) are higher than the average upper crust. These results are consistent with terrigenous sediments that formed from the weathering and erosion of felsic rocks

Development of a simple technique for measuring the activity size distribution of attached radon and thoron progeny for dose assessment

International Symposium on Natural Radiation Exposures and Low Dose Radiation Epidemiological Studie