Wyniki wyszukiwania - Biblioteka Nauki

Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl

Ograniczanie wyników

3 Acta Geophysica

Znaleziono wyników: 3

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

A comprehensive study of radon levels and associated radiation doses in Himalayan groundwater

100%

Prasad M. , Kumar G. A. , Sahoo B. K. , Ramola R. C.

tom Vol. 66, no. 5

1223--1231

The concentration of radon in groundwater is mainly governed by the radium content in the rocks of the aquifer. The internal exposure to high levels of radon in water is directly associated with the radiological risk to members of public. In this work, radon concentrations were measured in groundwater of Garhwal Himalaya, India, using scintillation detector-based RnDuo and silicon detector-based RAD7 monitors. An inter-comparison exercise was carried out between RnDuo and RAD7 techniques for a few samples to validate the results. The radiation doses associated with the exposure to radon in water were estimated from measured values of activity concentrations. An attempt has been made to see the effect of geology, geohydrology and different types of sources on radon levels in Himalayan groundwater. The experimental techniques and results obtained are discussed in detail.

Study of radon flux and natural radionuclides (226Ra, 232Th and 40K) in the Main Boundary Thrust region of Garhwal Himalaya

75%

Kandari T. , Prasad M. , Pant P. , Semwal P. , Bourai A. A. , Ramola R. C.

tom Vol. 66, no. 5

1243--1248

The Himalayan region is subdivided lithologically into four regions in which the junction between the lower Himalaya and Shivalik is known as the Main Boundary Thrust (MBT). It is well known that the environmental radon concentration depends upon various geological factors including faults, thrust, cracks and the composition of the soil. Radon gas eventually comes out from the fault/thrust zones having radium as its prominent source. Hence, it is important to study the behaviour of emission of radon present inside the earth crust as well as the levels of natural radionuclides in soil. In this study, the levels of natural radionuclides and exhalation rates of radon in the soil of MBT region of Garhwal Himalaya, India, were determined by using gamma ray spectrometer and scintillation detector-based Smart Radon Monitor, respectively. The average activities of 226Ra, 232Th and 40K were found 71.9, 88.2 and 893.6 Bq Kg-1, respectively. The measured radon surface flux was found to vary from 13.08 to 1626.4 Bq m-2 h-1 with a mean value of 256.5 Bq m-2 h-1. The measured activity levels were used to assess the doses associated with the contaminated soil.

Measurements of radon flux and soil-gas radon concentration along the main central thrust, Garhwal Himalaya, using SRM and RAD7 detectors

75%

Bourai A. , Aswal S. , Rawat M. , Prasad M. , Naithani N. , Joshi V. , Ramola R. C.

tom Vol. 61, no. 4

950--957

Radon in the Earth’s crust or soil matrix is free to move only if its atoms find their way into pores or capillaries of the matrix. 222Rn atoms from solid mineral grains get into air, filling pores through emanation process. Then 222Rn enters into the atmosphere from air-filled pores by exhalation process. The estimation of radon flux from soil surface is an important parameter for determining the source term for radon concentration modeling. In the present investigation, radon fluxes and soil-gas radon concentration have been measured along and around the Main Central Thrust (MCT) in Uttarkashi district of Garhwal Himalaya, India, by using Scintillation Radon Monitor (SRM) and RAD7 devices, respectively. The soil radon gas concentration measured by RAD7 with soil probe at the constant depth was found to vary from 12 ± 3 to 2330 ± 48 Bq m–3 with geometrical mean value of 302 ± 84 Bq m–3. The significance of this work is its usefulness from radiation protection point of view.