• Journal of Soil and Groundwater Environment
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• v.23 no.4
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• pp.1-15
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• 2018

Despite of safety issues related to radiological hazards, 31 countries around the world are operating more than 450 nuclear power plants (NPPs). To operate NPPs safely, safety regulations from radiation protection organizations were developed and adopted in many countries. However, many cases of radionuclide releases at foreign NPPs have been reported. Almost all commercial NPPs routinely release radioactive materials to the surrounding environments as liquid and gas phases under control. These releases are called 'planned releases' which are planned, regularly monitored, and well documented. Meanwhile, the releases focused in this review, called 'unplanned releases', are neither planned nor monitored by regulatory and/or protection organizations. NPPs are generally composed of various structures, systems and components (SSCs) for safety. Among them, the SSCs near reactors are closely related to safety of NPPs, and typically fabricated to comply with stringent requirements. However, some non-safety related SSCs such as underground pipes may be constructed only according to commercial standards, causing the leakage of radioactive fluids usually containing tritium ($^3H$). This paper discusses SSCs of NPPs and introduces several cases of unplanned releases at foreign NPPs. The current regulation on the environmental radiological surveillance and assessment around the NPPs in South Korea are also examined.

• Nuclear Engineering and Technology
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• v.55 no.8
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• pp.2802-2811
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• 2023

In a first-of-its-kind study, terrestrial radionuclide concentrations were measured in 35 topsoil samples from the outskirts of Dhaka using HPGe gamma-ray spectrometry to assess the radiological consequences of such a vast number of brick kilns on the plant workers, general as well as dwelling environment. The range of activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K is found at 19 ± 3.04 to 38 ± 4.94, 39 ± 5.85 to 57 ± 7.41, and (430 ± 51.60 to 570 ± 68.40) Bq/kg, respectively. ²³²Th and ⁴⁰K concentrations were higher than the global averages. Bottom ash deposition in lowlands, fly ash buildup in soils, and the fallout of micro-particles are all probable causes of the elevated radioactivity levels. ¹³⁷Cs was found in the sample, which indicates the migration of ¹³⁷Cs from nuclear accidents or nuclear fallout, or the contamination of feed coal. Although the effective dose received by the general public was below the recommended dose limit but, most estimates of hazard parameters surpass their respective population weighted global averages, indicating that brick kiln workers and nearby residents are not safe due to prolonged exposures to terrestrial radiation. In addition, the soil around sampling sites is found to be unsuitable for agricultural purposes.