Gamma Spectrometry Results Verification under Different Conditions of High Radon Concentration in Radon Aerosol Chamber Using MCNPX Model

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F70565813%3A_____%2F14%3A%230000542" target="_blank" >RIV/70565813:_____/14:#0000542 - isvavai.cz</a>

Result on the web

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DOI - Digital Object Identifier

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Result language

angličtina

Original language name

Gamma Spectrometry Results Verification under Different Conditions of High Radon Concentration in Radon Aerosol Chamber Using MCNPX Model

Original language description

Radon concentration in caves or in other underground closed natural areas often reaches tens of thousands Bq/m3. The internal irradiation - caused by inhalation of radon daughters, and the external irradiation - caused in high radon concentration mainly by photons of 214Bi, is in such environments a serious radiation protection issue. In comparison with the 2π geometry which is typical for above ground in situ gamma spectrometry or dose rate measurements and calibration, the radionuclides presented in the rock contribute more to the dose rates, because the underground area walls are relatively close to the detector (several meters away), surrounding it. In addition, wall deposition may influence significantly the results as well. The model of natural environment may introduce uncertainties in case of inhomogeneous distribution of radionuclides, difficulties with a complicated surface shape determination etc. The precisely defined environment within the Radon Aerosol Chamber (RAC) enables the creation of different conditions with respect to the radon concentration, humidity, equilibrium factor and ratio of the attached/unattached fraction of radon daughters. An MCNPX Monte Carlo model of the RAC was developed to estimate pulse-height spectra of scintillation detectors up to 3.0 MeV focusing on the 0.609 and 1.76 MeV photo-peaks of 214Bi. The simulated detector total count rate in the photo-peaks are obtained as a sum of individual count rates caused by 214Bi in the air, and from the deposition of radon daughters on surrounding surfaces.

Czech name

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Czech description

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Type

O - Miscellaneous

CEP classification

JF - Nuclear energy

OECD FORD branch

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Project

<a href="/en/project/VF20112015013" target="_blank" >VF20112015013: Research of modern methods of detection and identification of hazardous CBRN substances and materials, methods of hazard reduction and decontamination; research of modern method for personal protection and elements of critical infrastructure</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2014

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů