). The thoron emanation features were also calculated from the obtained results (2.9 to 21.2% with an average of 8.6%). The thoron exhalation and emanation properties were compared with the radon exhalation and emanation features determined in a previous study. It was found that there was no correlation between the radon and thoron emanation features, according to the obtained data. This can be explained by the different Ra-224 and Ra-226 distributions in the soil grains. As a result, the thoron emanation factor cannot be predicted from radon emanation and vice versa.
A pilot scale field test on passive treatment systems for metal and sulfate removal from ground water and surface runoff, is being conducted in Butte, Montana. This study is a collaborative effort between Montana Tech and the Atlantic Richfield Company (ARCO) to find solutions for treating metal contaminated water (e.g. Cu, Zn, Cd, and Fe). The field demonstration systems include anaerobic horizontal flow gravel bed wetlands with plants, horizontal flow gravel/organic substrate wetlands with plants, and vertical upflow gravel/organic substrate system without plants. The experimental design for sulfate and metal removal will be presented as well as the hydraulic design criteria used. Results from this test will be used to estimate system economics, long term performance and the life expectancy for these systems. Studies on mesoscale passive treatment systems such as 1.5 m high vertical upflow gravel/organic substrate columns are also presented. The parameters describing system performance are: hydraulic conductivity, volumetric sulfate-reduction rate, and metal immobilization rate.
Military, disaster management and in many cases civilian tasks include surveying of a given section of terrain that is likely to be contaminated with radioactive materials. Such a measurement series can form the basis for the complete recultivation and decontamination of large areas. This survey can take place after an emergency situation. This paper will use concrete surveys to illustrate the efficiency of new measurement technologies and developments. All these technologies aim to carry out radiation reconnaissance tasks as quickly and accurately as possible. Different hot spots were found during on-foot radiation reconnaissance. During in-situ measurements, a Bayesian-based isotope identifying algorithm was used and the measured data were validated with results from gamma spectroscopy in the laboratory. A rapid on-site quantitative analysis was also performed by evaluating the samples taken next to the hot spots. In addition to the measurement, the data were generated and stored in a standard N42 format ideal for data exchange. Many issues were solved like how the measurement data are associated with relevant additional information (e.g. time and coordinate), and how the measurement results can be shared with other partner organisations. Another important consideration was the preparation of the team conducting the measurement. The total cost of the survey was significantly reduced by the fact that the measurement was manageable by one technician and one expert. A quality assurance system had to be established to meet all relevant standards and strict documentation requirements. In addition to operating at high background radiation, these measurements presented additional challenges due to the low activity of hidden and mixed radioactive sources.
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