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Chitra N, Sundar SB, Valan II, Subramanian V, Jose MT, Venkatraman B. MODELING AND EXPERIMENTS TO ESTIMATE RADON EMANATION FACTOR IN SOIL-GRAIN SIZE AND MOISTURE EFFECT. Radiat Prot Dosimetry 2021; 194:104-112. [PMID: 34132341 DOI: 10.1093/rpd/ncab087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 04/05/2021] [Accepted: 05/19/2021] [Indexed: 06/12/2023]
Abstract
The influence of soil grain size on its radon emanation mechanism was investigated by developing a Monte-Carlo model. The proposed model supplements the previous formulations by accounting for the effect elicited by specific surface area of the sample. The specific surface area of a sample is governed by its grain size and it strongly influences the emanation rate which is a surface phenomenon. The emanation study was further extended to include the moisture effect. Experiments were carried out with two soil samples; Soil-2 and Soil-4 collected from different terrains, to analyze the role played by moisture in the emanation mechanism. The above model was augmented with provisions to include the moisture input. The model could reproduce the experimental results. There is an abrupt increase in the emanation factor when the moisture content changes from 0 to 2%. Thereafter, the increase is gradual and finally becomes steady when the moisture level reaches 10%. Soil-2 and Soil-4 showed sizeable difference in their radon emanation factor values. This could be explained based on the parent226Ra distribution pattern which stems from the mineralogical composition of the samples. Quartz was predominantly found in Soil-2, whereas Soil-4 shows peaks corresponding to minerals namely ilmenite, Rutile and Zircon confirming relatively higher concentration of heavy minerals than Soil-2. The emanation factor values of the individual minerals reported in the literature were used to decide upon the 226Ra distribution depth and with this input the model to ascertain the experimental observations.
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Affiliation(s)
- N Chitra
- Radiological and Environmental Safety Division, Kalpakkam 603102, Tamilnadu, India
- Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu, India
| | - S Bala Sundar
- Radiological and Environmental Safety Division, Kalpakkam 603102, Tamilnadu, India
| | - I Inigo Valan
- Radiological and Environmental Safety Division, Kalpakkam 603102, Tamilnadu, India
| | - V Subramanian
- Radiological and Environmental Safety Division, Kalpakkam 603102, Tamilnadu, India
- Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu, India
| | - M T Jose
- Radiological and Environmental Safety Division, Kalpakkam 603102, Tamilnadu, India
- Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu, India
| | - B Venkatraman
- Radiological and Environmental Safety Division, Kalpakkam 603102, Tamilnadu, India
- Homi Bhabha National Institute, Indira Gandhi Center for Atomic Research, Kalpakkam 603102, Tamilnadu, India
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Valan II, Maniyarasan S, Mathiyarasu R, Sridhar SGD, Narayanan V, Stephen A. Seasonal observation on radionuclide concentration in Krusadai Island Mangroves, Gulf of Mannar, India. J Radioanal Nucl Chem 2016. [DOI: 10.1007/s10967-016-4956-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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