Radon fluxes at four uranium mill tailings disposal sites after about 20 years of service

Estimation of 238U and 232Th in soil and water of prominent fault region of Mizoram

“…As mentioned above approximately after the 1970s onwards (after intensified mining era) most radon and uranium studies were found to concentrate on reporting radiological background, risk estimation and their correlation [18][19][20][21][22][23][24][25][26]. Several relevant papers estimating radon and uranium concentrations of a particular region or site were reported till date [27][28][29][30][31][32][33][34][35][36]. Recent reporters like Bezuidenhout [27] performed mapping and estimation of radon risk in South Africa while Novikov et al [28] reports radon and uranium content in groundwater of the Zaeltsovsky-Mochishch zone of Novosibirsk in Russia.…”

“…Wang et al [29] directly measure uranium content in order to map radon hazard region in Norway. Authors like Liu et al in southern China [30], Fuhrmann et al [31] in the USA and Yong et al [32] in northwest China measured radon exhalation rate and fluxes from uranium tailing pond to determine whether it lies within world natural background. All other papers [33][34][35][36] mainly focus on reporting radon and uranium concentrations in soil, water and air.…”

“…Approximately all recent studies on radon and uranium measurement focused on assessing their background radiation, health risk and comparison with the reported global average. Although extensive work has been done; radon monitoring and especially estimating its parent nuclei still has uncertainties reflected as well in the above recent reports [27][28][29][30][31][32][33][34][35][36]. The main problem is that the radon exhalation process was influenced by several external factors such as physicochemical features of the soil (such as grain size, density, porosity, permeability etc), geophysical factors (morphology and movement of groundwater and nature of aquifers) and meteorological factors (temperature, pressure, humidity, rainfall and wind speed) [16,17,[37][38][39].…”

Evapotranspiration covers at uranium mill tailings sites

“…However, the engineered properties of the restrictive layers, created by compacting fine-textured soils, can change rapidly over time. Specifically, pedogenic processes acting on the cover soils leads to the formation of soil structure, fractures, and macropores (Albright et al, 2006;Benson et al, 2007Benson et al, , 2011Breshears et al, 2005;Fuhrmann et al, 2021;Jangorzo et al, 2013;Williams et al, 2022).…”

“…The UMTRCA covers have started to show signs of post‐closure change. The “Radon Barriers Project” evaluated four UMTRCA disposal sites 20 yr post‐closure and found that natural processes, including ecological succession and soil formation, were changing engineered covers in ways that could negatively affect percolation and radon flux requirements (Fuhrmann et al, 2021; Williams et al., 2022). Evapotranspiration covers may provide a more resilient solution to a long‐term environmental problem.…”