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The Japanese government has initiated plans to release water contaminated The international community has yet to fully recognize the accelerated spread of nuclear-contaminated water through ship ballast water along the Japanese route. This increases the risk of nuclear exposure for crew members and poses ecological and environmental contamination risks to port waters, inland seas, and rivers. The lack of international attention to the marine nuclear safety crisis caused by nuclear pollution from ballast water, along with the absence of corresponding legal prevention and control mechanisms and technical safeguards, remains a critical issue. From the perspective of international law, preventing the spread of Fukushima wastewater through ship ballast water faces numerous legal challenges, including disputes over the applicability of conventions, the jurisdiction of international organizations, and mechanisms for cross-border accountability for marine nuclear pollution. As a major shipping nation adjacent to Japan, China faces significant risks of nuclear pollution from ballast water along the Japanese route. To counter such risks, it is recommended to propose measures through the International Maritime Organization to elevate international attention. Moreover, refining ballast water regulatory frameworks, establishing monitoring and warning mechanisms specific to nuclear pollution from ballast water, improving the technical capabilities of ballast water treatment systems, and promoting international cooperation in monitoring marine environments and preventing pollution are also advisable. [ABSTRACT FROM AUTHOR]

The global discourse surrounding the Japanese government's decision to release wastewater resulting from one of the most catastrophic nuclear crises in human history into the ocean has sparked intense deliberation within the international community. It is thus observed that the release of Fukushima nuclear wastewater has triggered a series of legal disputes, particularly in China, which has taken a firm stance against this action. Within China's legal circles, there has been a spirited dialogue on strategies from both international and domestic aspects to protect marine governance outcomes and safeguard the interests of Chinese citizens and enterprises in response to this matter. Accordingly, this article examines various international directives governing nuclear wastewater discharge. It asserts that, given the anticipated legal conflicts related to marine governance, exclusive reliance on the international legal framework may prove inadequate for China's response. Consequently, in response to the adverse impact of Japan's nuclear wastewater discharge into the ocean by 2023, this article posits an alternative approach rooted in China's domestic legal system and the perspective of judicial proceedings. This approach underscores the importance of precisely and adaptively applying specific legal provisions governing nuclear wastewater discharge and compensation claims, both domestically and internationally. To this end, China's endeavors should prioritize the enhancement of regulations pertaining to nuclear wastewater discharge, along with the establishment of systems such as a public welfare fund and subrogation mechanisms. Moreover, it is advisable that China augments its judicial authentication system and public interest litigation system to ensure the effective implementation of these measures. [ABSTRACT FROM AUTHOR]

Tantalum–niobium ore belongs to associated radioactive ore, which is accompanied by a certain amount of radioactive uranium and thorium. The remaining slag is enriched with a large number of radionuclides; after weathering, natural rainfall, and surface water scouring, radioactive elements such as uranium, thorium, and some heavy metal elements are exposed or washed into the soil, which poses a threat to the ecological environment and human health. In this study, for characterization analysis during, before, and after leaching, dynamic simulation experiment was carried out on a Ta-Nb slag sample in Jiangxi, China. From SEM analysis, the soluble substances adsorbed on the slag surface dissolve into the solution after leaching in simulated rainfall, and the remained slag becomes smooth with different particle sizes. The XRD diffraction analysis of the sample showed that after leaching in simulated rainfall, the existing forms of elements are different. pH of the leachate of Ta-Nb slag is 1.79; Ta-Nb slag contains many rare metal elements, nonmetal elements, radioactive elements, and some salt compounds; and the content of thorium is higher than that of uranium by EDS analysis. The release of uranium and thorium is obviously affected by the amount of leachate and pH. Under the lower pH of leaching solution, the release of uranium and thorium is more effective. The results of Fick diffusion theory and Elovich equation show that the release and migration mode of uranium and thorium in Ta-Nb slag are mainly surface elution; under acidic conditions, the release and migration of uranium and thorium are faster. This study provides basic data and scientific information for solving the key problems of pollution control of associated radioactive waste in environmental protection. [ABSTRACT FROM AUTHOR]

The Chinese government promotes nuclear energy development in the context of mitigating climate change. However, the large-scale development is still facing challenges related to the knowledge gap among the general public and the potential "not-in-my-back-yard" objection. Based on a representative national survey, we analyze Chinese people's knowledge and perceptions of nuclear energy and estimate their willingness-to-accept the potential risks of new nuclear programs in neighborhoods via the Contingent Valuation Method. Generally, more than half of people do not know anything about nuclear energy. The main factors influencing public knowledge are identified, such as the residential distance to existing nuclear power stations and the frequency of internet use. Moreover, approximately 12% of individuals with some knowledge seem to be willing to accept new nuclear power plants in their neighborhoods with no compensation needed. Specifically, the perceptions of nuclear risks and pollution from fossil fuels are significant factors influencing people's acceptance of nuclear energy. Although public knowledge does not directly influence acceptance, more knowledge seems to reduce risk perception and increase benefit perception. The residential distance to exiting nuclear stations has limited effects on people's acceptance of newly planned nuclear programs for those living in the same county with some knowledge. In general, a typical Chinese household is willing to accept USD $5.66 every month or USD $67.97 every year to bear the potential risks of the new nuclear program in neighborhoods. Significant practical implications that can be transferable to other new energy technologies and countries or regions are provided. • Chinese people's knowledge of and willingness to accept nuclear energy are analyzed. • More than half of Chinese people do not know about nuclear energy at all. • Factors influencing public knowledge include residential area, internet use, etc. • The WTA to bear risks of nuclear plant for a household is USD $5.66 every month. • Nuclear risk perception and benefit perception significantly influence people's WTA. [ABSTRACT FROM AUTHOR]

Uranium tailing ponds are a long-term potential source of radioactive pollution. Solidification treatment of uranium tailings in ponds can effectively control the diffusion and migration of radioactive materials. This study examined uranium tailings, from the beach of a uranium tailing reservoir in China, as the research object. Sodium hydroxide and water glass were used as alkali stimulants and mixed with metakaolin and fly ash to prepare five types of solids with different proportions. The freezing and thawing (FT) temperatures were set at −20 to 20℃, and 25 FT cycles were performed. The microstructure, mass loss, compressive strength, cumulative radon concentration, and radon extraction rate of the samples before and after FT were determined. The results showed that the FT cycle had a significant impact on sample surface structure. The incorporation of fly ash effectively reduced sample mass loss and inhibited radon emission. As the number of FT cycles increased, sample mass loss gradually increased, compressive strength gradually decreased, and radon emission rate gradually increased. There was an inverse correlation between the mass change of a solidified sample and the rate of radon emission. Compressive strength and radon emission rate were also negatively correlated. Considering the three indicators of mass loss, compressive strength, and radon extraction rate with metakaolin as the solidified base material, the conclusion was that 55%MK+45%F was the optimal ratio for this purpose. [ABSTRACT FROM AUTHOR]

The purpose of this study was to systematically analyze the leaching process of radionuclides from a decommissioned uranium tailings. About 40% of all forms of uranium are harmful to the environment. The particle size of soil are the main factors affecting the leaching amount. Uranium and thorium have migrated again under the influence of rainfall. The migration mechanism of uranium is mainly controlled by the internal diffusion of soil. The key to the treatment of tailings pollution is to increase the pH of the tailings and control the tailings discharge. [ABSTRACT FROM AUTHOR]

The content of radionuclide uranium in the water, soil and rice around the decommissioned uranium mine was analyzed, and the radioactive pollution, distribution characteristics, migration pattern and health risks were evaluated. Its radioactive contamination may have potentially harmful biological effects on the ecosystem and food chain. This paper pays more attention to the pollution of radionuclide 238U, 235U around the tailings dam, and makes a comprehensive comparative analysis of the pollution of water, soil and rice at 500 m, 1000 m and even 60 km around the dam. The single factor index method was mainly used to evaluate the pollution degree, and it was found that the water, soil and rice in the area around the uranium field were all polluted to different degrees. Radionuclide uranium pollution is mainly caused by uranium mining, quarry discharge and ecological cycle in the early stage. According to the characteristics of the uranium content in the study area, it is recommended to use the farmland around the tailing dam as a test site to study the radioactivity of different crops, improve wastewater treatment technology, and prevent crops with excessive levels of radioactive elements from entering the market. [ABSTRACT FROM AUTHOR]

Abstract: A custom-made, on-site radioxenon sampling, separation and monitoring system was used to monitor atmospheric radioxenon concentrations in Beijing, released from the Fukushima Daiichi nuclear power plant after the earthquake of 11 March 2011. The results show that 133Xe concentrations ranged from 393 to 26mBq/m3 from 12 to 27 April 2011, and those of 131mXe were 84 and 40mBq/m3 on 13 and 15 April 2011, respectively. The highest dose rate caused by 133Xe was 2×10−5 mSv/yr, and the average 133Xe/131mXe ratio was 3.8±0.4. [Copyright &y& Elsevier]

Only recently, the radioactive gas thoron (220Rn) and its decay products have been regarded as significant health risk in the indoor environment. This is because of new findings of increased thoron concentrations in traditional mud dwellings and considerations leading toward reduced action levels for natural airborne radionuclides. A model which describes the sources and sinks of thoron and its decay products should help to assess the indoor exposure. This work presents an extensive depiction of the influences of indoor conditions on the occurrence of these radionuclides. Measurements were performed in an experiment room and in mud dwellings in China and India. Mud even with an average 232Th concentration was identified as a significant thoron source. The spatial distribution of the decay products proved to be homogeneous, which is in contrast to thoron gas. The prominent contribution of the unattached and attached decay product 212Pb to the exposure was elaborated. The theoretically derived impact of air exchange and aerosol concentration, which determines the proportion of unattached decay products, could be confirmed. Transfer coefficients of the model were determined. The thoron model with these transfer coefficients predicts annual doses of almost 2 mSv for dwellers of traditional Chinese and Indian mud buildings, confirming the potential health impact of thoron. [ABSTRACT FROM AUTHOR]

In this study, human health risk derived from radioactive pollution in drinking water of China was assessed based on gross alpha and beta. Considering the presence of numerous data under the detection limits, the left-censored handling methods were employed to deal with the non-detected values in gross alpha and beta radioactive concentrations. Results show that concentrations of gross alpha and beta range from 4.98 × 10−4 Bq/L to 0.49 Bq/L with a mean value of 0.029 Bq/L and 5.00 × 10−3 Bq/L to 1.26 Bq/L with a mean value of 0.091 Bq/L, respectively. With the average effective dose being 1.41 × 10−2 mSv/y, the annual cancer risk due to radioactive pollution in Chinese drinking water is 7.75 × 10−7 /y. This study aimed to provide an easier method to quantify the radioactive pollution in drinking water and give a scientific basis for making policy decisions on radioactive pollution management. ga1 ● Cancer risks based on gross alpha and beta in drinking water were assessed for seven major regions in China. ● Annual committed effective doses of all age groups were lower than 0.1 mSv/y. ● Cancer risk expectation due to radioactive pollution is lower than 5.5 × 10−6 /y. ● In terms of radioactivity, the water quality in the eastern part of China is better than in the western part of China. [ABSTRACT FROM AUTHOR]

Red mud (RM), also called bauxite residue, is a strong alkaline industrial waste generated during the alumina production process. The annual production of RM in China is large, but its average utilization rate is low (only 4%). High generation and low consumption make the disposal of RM mainly by stockpiling, which has caused serious heavy metal pollution and radioactive contamination. In this paper, the various industrial utilization methods of RM in China during the past 60 years have been introduced. Moreover, some recent industrial progresses were referred. The results show that RM can be widely used in building materials, valuable metals extraction, and some novel utilization methods, such as silica-calcium fertilizer, inorganic polymer material and desulfurizer. Most of the industrial utilization methods of RM have been used until now and some successfully applied to other aluminum plants, providing some feasible routes for a large amount utilization of RM. Some industrial utilization methods (such as oil well cement and calcium silicon fertilizer) have not been used due to some problems that cannot be ignored, but it provided a lot of valuable experience and was helpful for the subsequent RM utilization. Moreover, some novel and feasible RM utilization methods were proposed and successfully industrialized, which showed that RM has a broader application prospect. Many actual practices showed that the best way to safely dispose of RM was to develop technology that could consume large amounts of RM or transform it into secondary resources, which may need more time and effort. [ABSTRACT FROM AUTHOR]

• An aerosol module based on the aerosol dynamic and hygroscopic models was added to the ATHROC code. • Three different types of benchmark experiments were selected for assessment of the improved code. • The comparative results show that the code has capabilities to accurately predict the experiments. As the main carrier of fission products, aerosols will transport in the containment and even leak into the environment during accident conditions, resulting in radioactive pollution. Thus, it is of great significance for radiation protection to study the aerosol distribution mitigation measures in containment after severe accidents. A multi-compartment lumped parameter code named ATHROC (Analysis of Thermal Hydraulic Response of Containment) was developed to analyze the thermal–hydraulic behaviors in the containment after accidents for China advance PWR. In order to satisfy the analysis of aerosol behavior in containment, an aerosol module based on the aerosol dynamic and hygroscopic models was added to the code and coupled with spray removal mechanism models. Three different types of benchmark experiments were selected for assessment of the improved code, including CVTR, LACE and CSE tests. Most of the predicted results of thermal–hydraulic responses and aerosol distribution are in realistic agreement with the experimental data. The comparative results show that the code has capabilities to accurately predict the thermal–hydraulic responses during spray activation, aerosol distribution and removal of aerosols by spray droplets. And the problems identified in the code will be further optimized in the future. Currently, the developed improved code satisfies the analysis of aerosol behavior in containment and provides a design for aerosol removal for spray system arrangement. [ABSTRACT FROM AUTHOR]

Plutonium in the environment has drawn significant attentions due to its radiotoxicity in high concentration and source term linked with nuclear accidents and contaminations. The isotopic ratio of plutonium is source dependent and can be used as a fingerprint to discriminate the sources of radioactive contaminant. 239 Pu, 240 Pu and 137 Cs in surface soil and soil cores collected from Northern Xinjiang were determined in this work. The concentrations of 239,240 Pu and 137 Cs are in the range of 0.06-1.20 Bq kg -1 , and <1.0-31.4 Bq kg -1 (decay corrected to Sep. 2017), respectively, falling in the ranges of global fallout in this latitude zone. The 240 Pu/ 239 Pu atomic ratios of 0.118-0.209 and 239,240 Pu/ 137 Cs activity ratios of 0.039-0.215 were measured. Among the investigated sites, distinctly lower 240 Pu/ 239 Pu atomic ratios of 0.118-0.133 and higher 239,240 Pu/ 137 Cs activity ratios of 0.065-0.215 compared to the global fallout values were observed in the northwest part, indicating a significant contribution from other source besides the global fallout. This extra source is mainly attributed to the releases of atmospheric nuclear weapons testing at Semipalatinsk Nuclear Test Site, which was transported by the west and northwest wind through the river valley among mountains in this region. This contribution is estimated to account for 28-43% of the global fallout in the northwest part of Northern Xinjiang. The contribution from the Chinese atmospheric nuclear weapons testing to this region is negligible due to the lack of appropriate wind direction to transport the radioactive releases to this region., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier Ltd. All rights reserved.)

Based on γ-radiation dose rate and radon concentration measurements and 238U, 232Th, 226Ra, and 40K radionuclide testing, this study identifies the radioactive anomalies of stone coal-bearing strata in East China and evaluates the natural radioactivity levels in the air, solid, water and plant media in the typical area of the regional stone coal-bearing layers. The stone coal-bearing strata in East China occur in the lower Cambrian system along the margin of the Yangtze block; additionally, the radioactive anomaly area is sporadically distributed in the stone coal-bearing layers. The background values of 238U, 232Th, 226Ra, and 40K are higher in the stone coal-bearing areas, and the spatial distribution of these natural radionuclides shows significant variability. 238U and 226Ra clearly accumulate in the coal, coal gangue and soil and are the main sources of the environmental radiation in coal mines. The γ-radiation shows a higher background value in the stone coal-bearing area, and this radioactive pollution cannot be ignored. Typically, the effective dose of γ-radiation exceeds the limit value of 5 mSv/a, and the total α and total β concentrations of the groundwater are 10-30 times the limit value at some points. The residents near the mining area are subjected to a higher radiation dose, and the groundwater, building materials, and plants have been contaminated by the radioactive pollution sporadically through time. It is necessary to strengthen the monitoring work of radioactive environments and to take appropriate control measures. [ABSTRACT FROM AUTHOR]