Feifei Wu

According to the Soil Pollution Prevention and Control Law, the decommissioning sites of nuclear facilities can be divided into three open scenarios - agricultural land, class I construction land and class II construction land. Relevant parameters (including soil density, contamination depth, effective porosity of contaminated soil, personal water intake, personal breathing volume, etc.) were selected for calculation. Based on the dose screening value of 0.01 mSv per year, the residual level in the soil was calculated and the main nuclide pathways were analyzed. The study provides the principle of determining soil residual radioactivity level according to different land use types and irradiation routes, so that the treatment target of contaminated sites is more scientific and detailed, and at the same time, the environmental management of the management department can be adjusted. Compared with the recommended values in foreign guidelines, the rationality and variety of residual radioactivity levels can provide technical support for the revision of "Regulations on Acceptable Levels of Residual Radio-activity in Soil of Proposed Open Sites (Provisional)" (HJ53-2000).

The meteorological parameters, e.g., wind direction, wind speed and atmospheric stability, affect greatly the diffusion of pollution and radiological environmental impact assessment. Based on the hourly meteorological data obtained from an automatic monitoring station, the radiological impact indicated by the air concentration, individual dose and maximal individual effective dose were analyzed and compared between 2020 and 2021. The paper concluded that children are the main group to be the most easily infected, and the critical exposure path is internal exposure from inhalation. This paper offers a new window for timely decision-making for radiological safety under different climate conditions.

The suitability evaluation of human settlements over time and space is essential to track potential challenges towards suitable human settlements and provide references for policy-makers. This study established a theoretical framework of human settlements based on the nature, human, economy, society, and residence subsystems. Evaluation indicators were determined with the consideration of the coupling effect among subsystems. Based on the extended Fourier amplitude sensitivity test algorithm, the global sensitivity analysis was used to determine the weights of indicators. The human settlement suitability was evaluated in 30 provinces of China between 2000 and 2016. The findings were as follows: (1) human settlement suitability index (HSSI) values increased significantly in all 30 provinces from 2000 to 2016. The suitability index of the residence subsystem in China exhibited the fastest growth, followed by the society and economy subsystems. (2) HSSI in eastern provinces with a developed economy was higher than that in western provinces with an underdeveloped economy. In contrast, the growth rate of HSSI in eastern provinces was significantly higher than that in western provinces. (3) The inter-provincial difference in HSSI narrowed down from 2000 to 2016. For subsystems, the difference narrowed down for the residence system, whereas it widened for the economy system. (4) The suitability of the nature subsystem has become a limiting factor for the improvement of human settlement suitability, especially in economically developed provinces, such as Beijing, Shanghai, and Guangdong. The results can be helpful to support decision-making and policy for improving the quality of human settlements in a broad nature, human, economy, society, and residence context.