Radon kinetics in a natural indoor radon chamber

Long Kiu Chung; Loren A Mata; Marco A Carmona; Nasser Ali M Shubayr; Qingzhi Zhou; Yongjun Ye; Kimberlee J Kearfott

doi:10.1016/j.scitotenv.2020.139167

Radon kinetics in a natural indoor radon chamber

Sci Total Environ. 2020 Sep 10:734:139167. doi: 10.1016/j.scitotenv.2020.139167. Epub 2020 May 6.

Authors

Long Kiu Chung¹, Loren A Mata¹, Marco A Carmona¹, Nasser Ali M Shubayr², Qingzhi Zhou³, Yongjun Ye⁴, Kimberlee J Kearfott⁵

Affiliations

¹ Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48104, USA.
² Faculty of Applied Medical Sciences, Jazan University, Jazan, 45142, Saudi Arabia.
³ School of Nuclear Science and Technology, University of South China, Hengyang, 421001, Hunan Province, P. R., China.
⁴ School of Resource Environment and Safety Engineering, University of South China, Hengyang, 421001, Hunan Province, P. R., China.
⁵ Department of Nuclear Engineering and Radiological Sciences, University of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48104, USA. Electronic address: kearfott@umich.edu.

PMID: 32454331
DOI: 10.1016/j.scitotenv.2020.139167

Abstract

An unusual 180 m³ storage room in the basement of a two-story laboratory building is unventilated, and separated from occupiable rooms by double steel doors. The space completely borders on soil through the concrete floor and two of its concrete walls. The room also contains a separate inner chamber with 1 m thick concrete walls designed to damp vibrations in the room above it. The space boasts a relatively high radon level, 1083 Bq m^-3, which varies with local outdoor environmental conditions. Measurements were made of radon concentrations at various locations and heights within the facility. More than a year of continuous radon concentration data corresponding to a single location are also available, along with measurements of indoor and outdoor pressure, temperature, and humidity. Data were also collected with as many as five fans placed in different locations and cycled on for variable time periods. First order linear kinetic models were created to explain the observed approaches to steady state due to changing conditions and wash-out resulting from intentional ventilation. Results demonstrate a good fit between changes in the radon concentration level and the developed compartmental models. However, no significant differences were observed between radon concentration at different locations or heights in the chamber.

Keywords: Indoor radioactivity; Instrumentation; Radon; Ventilation.