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Keywords: Nuclear power plant; Indoor gamma dose; Radon and thoron 384 Case StudySeasonal Variation of Indoor Gamma Dose and Radon, Thoron Measurement in the Dwellings around Kudankulam Nuclear Power Plant [...]

Natural radioactivity content in different types of building materials obtained from Chennai city has been determined. In this study, the most commonly used building materials such as clay bricks, cement, sediment, tiles, marbles, and granite have been considered for quantifying natural radioactivity content using gamma-ray spectroscopy. The annual effective dose (AED) values obtained in this study, varying from 0.04 mSv to 0.57 mSv, are deduced from the natural radioactivity content; these are lower than the European Commission Report 112 recommended level of 1 mSv. Therefore, the use of all the building materials in question, collected from in and around Chennai, in the construction of dwellings is considered to be radiologically safe for the inhabitants. [ABSTRACT FROM AUTHOR]

In the aftermath of devastating tsunami, studies were undertaken to assess its impact on the environmental radioactivity profile in the beach sands along the entire east coastal region of Tamil Nadu state (~1000 km) and compared with previously established pretsunami distribution profile. The results of the present study clearly indicate that the radioactivity content of 232Th and 238U in the beach sands registered a steep fall (52% and 41%, respectively), whereas the 40K activity has increased by 26%. This is attributed to the hydrodynamics of tsunami waves, which removed huge quantities of beach minerals that have been built-up over a few decades. The individual activity content of the three primordial radionuclides, total activity content, comparison between pre- and post-tsunami data for all the 32 sites, and their statistical analyses are covered in the paper. [ABSTRACT FROM AUTHOR]

Radon concentration and gamma dose rates have been measured in different types of dwellings (94 dwellings) of the east coast of Tamil Nadu, India, on a quarterly basis using solid state nuclear track detectors and thermoluminescent dosimeters, respectively. Higher level of radon concentration is observed for winter season followed by spring, rainy, and summer seasons. On the contrary, the gamma dose rate for winter season is slightly lower than other three seasons. In this study, the average annual radon concentration (19.02 Bq/m3) is much lower than the recommended safe limit of 300 Bq/m3 while gamma dose rate (1.5 mGy/y) is much higher than the world average value of 0.520 mGy/y. [ABSTRACT FROM AUTHOR]

A phoswich detector, housed inside a low background steel room, coupled with a state-of-art pulse shape discrimination (PSD) electronics is recently established at Radiological Safety Division of IGCAR for in vivo monitoring of actinides. The various parameters of PSD electronics were optimised to achieve efficient background reduction in low-energy regions. The PSD with optimised parameters has reduced steel room background from 9.5 to 0.28 cps in the 17 keV region and 5.8 to 0.3 cps in the 60 keV region. The Figure of Merit for the timing spectrum of the system is 3.0. The true signal loss due to PSD was found to be less than 2 %. The phoswich system was calibrated with Lawrence Livermore National Laboratory realistic chest phantom loaded with 241Am activity tagged lung set. Calibration factors for varying chest wall composition and chest wall thickness in terms of muscle equivalent chest wall thickness were established. 241Am activity in the JAERI phantom which was received as a part of IAEA inter-comparison exercise was estimated. This paper presents the optimisation of PSD electronics and the salient results of the calibration. [ABSTRACT FROM PUBLISHER]

The article presents an investigation on the gamma dose rate in 159 dwellings around the proposed Kudankulam nuclear power plant in Radhapuram and Nanguneri taluks. To measure the environmental gamma radiation, the researchers employed CaSO4:Dy. The geometric mean value of indoor gamma dose rate in Radhapuram was 305 ± 48nGy h―1 and 273 ± 50 nGy h―1 for Nanguneri taluk. The study revealed that the annual effective dose of indoor gamma radiation to the population was 1.5 mSv and 1.36 mSv in Radhapuram and Nanguneri taluks, respectively. From the data gathered, it was concluded that the sand used for the construction and the soil beneath the dwellings are the main influencing factors in indoor gamma dose rate.