Assessment of Soil Radioactivity Associated with Risk and Correlation with Soil Properties near Maanshan Nuclear Power Plant, Taiwan  
[PERSON]  
1 Disaster Prevention and Mitigation Technology Research Center, General Research Service Center, National Pingtingting University of Science and Technology, Pingtingting 91201, Taiwan;[EMAIL_ADDRESS] (T-C.C.; [EMAIL_ADDRESS] (Y-L.X)1)1  
[PERSON]  
2 Department of Environmental Science and Engineering National Pingting University of Science and Technology, Pingting 91201, Taiwan 2  
[PERSON]  
1 Disaster Prevention and Mitigation Technology Research Center, General Research Service Center, National Pingtingting University of Science and Technology, Pingting 91201, Taiwan 2  
[PERSON]  
1 Disaster Prevention and Mitigation Technology Research Center, General Research Service Center, National Pingtingting University of Science and Technology, Pingting 91201, Taiwan 2  
[PERSON]  
1 Disaster Prevention and Mitigation Technology Research Center, General Research Service Center, National Pingtingting University of Science and Technology, Pingting 91201, Taiwan 2  
Correspondence: [EMAIL_ADDRESS]; Tel.: +886-8-7703202 (ext. 6690); Fax: +886-8-7740122  
typically have more radium, such as monazite, whereas sedimentary rocks contain less radium such as limestone [8].  
Furthermore, analyzing variations in activity ratios, such as radioactivity ratio of \({}^{232}\)Th/\({}^{226}\)Ra, of natural radionuclides can provide valuable information about geochemical processes in the environment and serve as a gauge for the occurrence of these radionuclides [9].  
The Maanshan nuclear power plant (NPP) is situated in the Hengchun Peninsula, within the Kenting National Park (KNP), Taiwan. The Peninsula is surrounded by the Taiwan Strait, Bashi Channel, and the Pacific Ocean. This park is a popular tourist destination, attracting over a million visitors annually [10]. To ensure the safety of residents and visitors, it is crucial to assess the potential radiological hazards that may arise from naturally occurring and man-made radioactive substances within the soil [1]. Studies conducted by [PERSON] et al. [11] and [PERSON] et al. [7] show that there are varying levels of natural radioactivity in the soil of the Hengchun Peninsula. Some areas have high activity concentrations of 268-390 Bq/kg, 24.0-25.8 Bq/kg, and 20.0-21.0 Bq/kg for \({}^{40}\)K, \({}^{232}\)Th, and \({}^{238}\)U, respectively, while others have low activity concentrations of 17-74 Bq/kg, 2.1-4.0 Bq/kg, and 2.8-3.6 Bq/kg for \({}^{40}\)K, \({}^{232}\)Th, and \({}^{238}\)U, respectively. This variation is due to the different soil compositions found in the region [7]. Additionally, the Maanshan NPP is set to be decommissioned in 2025, and, after decommissioning, there will be ongoing monitoring of environmental media such as soils to ensure that radioactivity levels remain safe [12].  
The purpose of this research is to analyze the levels of gamma-ray-emitted natural nuclides, including \({}^{40}\)K, \({}^{226}\)Ra, and \({}^{232}\)Th, as well as the artificial nuclide \({}^{137}\)Cs, in soil samples surrounding the Maanshan NPP. To understand the dominate factors of radioactivity, the relationship between radioactivity and soil properties is examined. Through the use of radioactivity ratios, the mineral composition of the soils is investigated. To ensure the safety of both residents and visitors, the radiological hazard indices, such as radium activity equivalent (Ra\({}_{\text{eq}}\)), external hazard index (H\({}_{\text{ex}}\)), external absorbed dose rate (D\({}_{\text{Rex}}\)), and external annual effective dose equivalent (AED\({}_{\text{ex}}\)) are calculated [13; 14]. The results of this study on soil radioactivity can serve as a baseline for future monitoring of soil radioactivity after the decommissioning of the Maanshan NPP.