Synthesizing covalent organic frameworks for unprecedented iodine capture performance

Nuclear energy continues to be an important supplier of electricity, but it has problems with waste management and the possibility to leak radioactive material. Iodine, a potentially harmful byproduct of uranium fission, is hazardous to both the environment and human health. Therefore, developing safe, effective, and affordable storage facilities for iodine waste is crucial. Owing to their well-controlled pore structure and substantial certain surface area, covalent organic frameworks (COFs) show promise for the adsorption of radioactive iodine. The newly developed COFs (SJ-COF, YA-COF, and AA-COF) shown amazing properties, including strong thermal and chemical stability, which made them ideal for efficient iodine capture. Notably, the ultrahigh iodine capture capacities of these COFs-8.52 g g-1, 8.12 g g-1 and 7.01 g g-1-were significantly greater than most previously reported materials. And The % removal efficiency for SJ-COF, YA-COF and AA-COF from I2/cyclohexane solutions were 87.9 %, 88.6% and 82.6 % respectively. It is noteworthy that the three COFs have high selectivity, reusability, and iodine retention abilities, maintaining iodine even after five recyclings. Based on the outcomes of the experiments, the adsorption processes of the three COFs were examined, and it was discovered that iodine was bound through physical-chemical adsorption. The findings of our work provide a ground-breaking standard for the removal of nuclear waste and demonstrate the enormous potential of COFs as adaptable porous structures that may be specifically designed to address major environmental concerns.

The public perspective on renewable energy versus nuclear power for carbon neutrality in South Korea

South Korea has legislated "2050 carbon neutrality" in 2021 and is currently implementing it, and debate is brewing over which to focus on as the main means of achieving it in the power generation sector: renewable energy (RE) or nuclear power (NP). This article aims to collect and analyze data on the public preference for RE versus NP. In a national survey of 1000 people, respondents were first asked which was preferred, RE or NP, and then asked to indicate the preference intensity along a 5-point scale. Of all the respondents, 60.3% preferred RE and 27.7% preferred NP. The preference for the former was about 2.2 times more than that for the latter. However, the intensity of the preference for NP was 1.3 times more than that for RE. Both the two-limit Tobit model and ordered probit model have been applied to analyzing the factors influencing the preference. The effects of some variables on the preference for RE over NP are explained, and implications from this are discussed. The findings can be used as a reference to determine the main means of implementation of carbon neutrality or to increase the public acceptance of the specified means.

Balancing energy security and marine pollution prevention: legal challenges of utilizing nuclear power for decarbonizing maritime transportation in the Arctic region

The Arctic region is facing growing demands for energy to support various economic activities, while also grappling with the profound impacts of climate change. Black carbon particulate matter emissions reduction is a key objective to mitigate the susceptibility of the Arctic's ecosystems to the impact of climate change. Nuclear power has been suggested as a potential source of clean energy to decarbonize maritime transport in the Arctic. However, although the operation of nuclear-powered vessels and floating nuclear power platforms in the region ensures energy security and reduces black carbon emissions, it may pose significant risks of nuclear material release and radiological accidents and raise concerns about improper radioactive waste disposal. In regulating these nuclear-powered vessels and floating nuclear power platforms in the Arctic, the existing international legal regime faced a series of challenges. This research employs a method of policy analysis to analyze these legal challenges and explores how the international community could work together to cope with the challenges that arise in the Arctic during the operation of nuclear-powered vessels and platforms for maritime decarbonization purposes.

Advances in the management of radioactive wastes and radionuclide contamination in environmental compartments: a review

Several anthropogenic activities produce radioactive materials into the environment. According to reports, exposure to high concentrations of radioactive elements such as potassium (⁴⁰K), uranium (²³⁸U and ²³⁵U), and thorium (²³²Th) poses serious health concerns. The scarcity of reviews addressing the occurrence/sources, distribution, and remedial solutions of radioactive contamination in the ecosystems has fueled data collection for this bibliometric survey. In rivers and potable water, reports show that several parts of Europe and Asia have recorded radionuclide concentrations much higher than the permissible level of 1 Bq/L. According to various investigations, activity concentrations of gamma-emitting radioactive elements discovered in soils are higher than the global average crustal values, especially around mining activities. Adsorption technique is the most prevalent remedial method for decontaminating radiochemically polluted sites. However, there is a need to investigate integrated approaches/combination techniques. Although complete radionuclide decontamination utilizing the various technologies is feasible, future research should focus on cost-effectiveness, waste minimization, sustainability, and rapid radionuclide decontamination. Radioactive materials can be harnessed as fuel for nuclear power generation to meet worldwide energy demand. However, proper infrastructure must be put in place to prevent catastrophic disasters.

Value Change, Energy Systems, and Rational Choice: The Expected Center of Gravity Principle

The values that will govern choices among future energy systems are unlikely to be the same as the values we embrace today. This paper discusses principles of rational choice for agents expecting future value shifts. How do we ought to reason if we believe that some values are likely to change in the future? Are future values more, equally, or less important than present ones? To answer this question, I propose and discuss the Expected Center of Gravity Principle, which articulates what I believe to be a reasonable compromise between present and future values.

Estimating the economic cost of setting up a nuclear power plant at Rooppur in Bangladesh

Bangladesh government is in the final stage of setting up one nuclear power plant with two units at Rooppur, Ishwardi, each having 1200 MW capacity, to be launched in 2023 to meet the energy shortage urgently. The financial cost of the project is the US $12.65 billion. The primary purpose of this paper is to calculate the economic cost of setting up this plant by using the estimation method developed by Du and Parsons (2009), MIT (2003; 2009; 2018), and Singh et al.  (2018). It has been found that the economic cost is amounted to 9.36 cents/kWh for the capacity of 2400 MW. In contrast, for a similar plant in Kudankulam, Tamil Nadu, India, the corresponding cost figure is 5.36 cents/kWh for 2000 MW. Even though it seems costlier than India, the study suggests that policymakers should prefer nuclear power, as it is cost-competitive, considering the production cost of other electricity facilities. The main advantage of nuclear power is cost-competitive baseload power generation with zero carbon emission. This nuclear power plant (NPP) project is expected to boost the energy sector of Bangladesh by transforming the country from an energy deficit country into an energy surplus country.

Influence of variable oxygen concentration on the combustion derived release of radiocesium from boreal soil and peat

Radiocesium, ¹³⁷Cs, is one of the most common and dispersed human-made radionuclides. Substantial stocks of ¹³⁷Cs are stored in organic layers, like soils and peat, as a consequence of nuclear weapons fallout and accidental releases. As climate warming progresses these organic layers are subject to enhanced risks of wildfires, especially in the vast boreal biome of the northern hemisphere. Reemission of ¹³⁷Cs to the atmosphere is therefore presumed to increase. Here, we experimentally investigated the emissions and redistribution of ¹³⁷Cs in smoldering fires of boreal soil and peat by varying the oxygen concentration during combustion. For both soil and peat, significantly more ¹³⁷Cs was released through flaming combustion in 21% O₂ (50% and 31%, respectively) compared to smoldering in reduced O₂ environments (14% and 8%, respectively). The residual ashes were heavily enriched (>100%) in ¹³⁷Cs. Hence, after a wildfire induced volatilization of ¹³⁷Cs, there exists further pathways of ¹³⁷Cs enriched ash to proliferate in the environment. These results serve as a link between wildfire combustion conditions and the mobility of the ¹³⁷Cs inventory found in ground fuels of the boreal environment and can be valuable for radiological risk assessments in a warmer and a more nuclear energy reliant world.

Facilitating developments of solar thermal power and nuclear power generations for carbon neutral: A study based on evolutionary game theoretic method

Solar thermal power and nuclear power generations are two most promising clean energy power approaches, which are effective for reducing carbon emissions. In order to promote the coordinated development of solar thermal power and nuclear power in China under the background of carbon neutral, the current paper develops a partnership comprised by the energy investment company (EIC), solar thermal power plant (STPP) and nuclear power plant (NPP). By utilizing the evolutionary game theory method and current policies of China, the evolutionary process simulations of the three participants under different conditions are conducted, which demonstrate that steady states could be achieved under different partnerships. Impact investigation results of typical influential factors indicate that longer annual operation time of power plant, larger subsidy and higher electricity price sold to the power grid are favorable to promote the partnership smoothly. Suitable investment ratio of the STPP and NPP should be considered as a larger investment ratio of the STPP and NPP has incentive influence on EICs and STPPs but inhibiting impact on NPPs. The results of the current study have certain reference value for the policy and strategy formulations for facilitating the developments of solar thermal power and nuclear power generations.

Elevated levels of radiocarbon in methane dissolved in seawater reveal likely local contamination from nuclear powered vessels

Measurements of the natural radiocarbon content of methane (¹⁴C-CH₄) dissolved in seawater and freshwater have been used to investigate sources and dynamics of methane. However, during investigations along the Atlantic, Pacific, and Arctic Ocean Margins of the United States, as well as in the North American Great Lakes, some samples revealed highly elevated ¹⁴C-CH₄ values, as much as 4-5 times above contemporary atmospheric ¹⁴C-CH₄ levels. Natural production of the ¹⁴CH₄ isotopologue is too low to cause these observations nor can it explain the variations in location and depth. Numerous lab and field validation tests and blanks, as well as the relatively small number of samples that display these elevated values, all suggest that these signals are not derived from an unknown procedural issue. Here we suggest that the byproducts of nuclear power generation include localized discharges of the ¹⁴CH₄ isotopologue into marine and aquatic environments, severely altering the measured ¹⁴C-CH₄ isotopic signals. Since several of our sample sites are distant from on-land nuclear powerplants, we conduct further calculations concluding that the most elevated anomalies in ¹⁴C-CH₄ likely originate with discharge from nuclear-powered vessels.

Wind energy and sustainable electricity generation: evidence from Germany

Wind energy is one of the renewable energy sources that has been touted to address the challenges of energy security and environmental degradation. This is only attainable if countries with substantial wind energy potential use it in significant proportion to satisfy their energy needs. One promising sector where wind energy can be employed to actualize this potential is the electricity sector. However, the current reality is that fossil fuels still dominate the energy profiles of most economies of the world, including the advanced economies, with wind renewable energy source accounting for a very small proportion of the energy mix. Germany is one of the few countries that offers promising opportunities in deploying wind energy to its full potentials. This study therefore explores the feasibility of substituting wind energy for nuclear energy and other fossil fuels using Germany as a country of focus. We use the ridge regression procedure to analyse yearly time series data for the German power sector that spans the period 1986 to 2018. With respect to output elasticities of the energy inputs, the results reveal that wind and natural gas have positive output elasticity estimates while the estimates for nuclear and coal are negative. We also found that all the inputs pairs have positive substitution elasticity estimates between them. With respect to wind energy, the highest substitutability estimate occurred with nuclear power which is followed by natural gas and then coal. The study recommended that policies such as granting of tax credit for wind energy technology, reduction in property taxes for wind power facilities, and allocation of fund for research and development (R&D) in wind energy technology are recommended to promote the use of wind energy in the economy.

Scientific justifications for the political decision-making on environmental remediation carried out after the Fukushima nuclear accident

The Japanese government decided to implement environmental remediation after the Fukushima Daiichi Nuclear Power Plant (termed "1F" in Japan) accident on 11th March 2011. As the initial additional annual dose target was set to be 1 mSv or less as a long-term goal, we examined the decision-making process undertaken by the then leaders, particularly the Minister of the Ministry of the Environment (MOE) who was responsible for the final decision. We found that technically based assessment of dose targets, health effects and risk-based approaches justified by scientific experts were not communicated to the then Minister and officials of the MOE before the remediation strategy was decided. We defined how such a decision was made based on leadership theories such as the Role Theory and the Cognitive Resources Theory. Academic leaders could have examined the Windscale accident (UK, 1957), which could be considered as the closest analogue (at least in terms of radionuclide releases) to the 1F accident. Environmental remediation could have been planned and implemented more effectively whilst still maintaining the highest possible safety standards and balancing the environmental and economic burden. Appropriate scientific input should have been provided by academic leaders to political and administrative leaders and such scientific justification should have been disclosed to the general public (especially the residents of Fukushima Prefecture) so that the general public could have developed greater trust in their leaders and have more readily accepted the decisions made.

Comparison of cost efficiencies of nuclear power and renewable energy generation in mitigating CO2 emissions

The objective of this study is to compare the cost efficiencies of nuclear power and renewable energy generation in reducing CO₂ emissions. To achieve this objective, we estimate the relationship between CO₂ emissions and both nuclear power and renewable energy generation in 16 major nuclear power-generating countries, and compare the costs of both energy generation methods in reducing CO₂ emissions by the same amount. The results show that, to reduce CO₂ emissions by 1%, nuclear power and renewable energy generation should be increased by 2.907% and 4.902%, respectively. This implies that if the current amount of electricity generation is one megawatt-hour, the cost of mitigating CO₂ emissions by 1% is $3.044 for nuclear power generation and $7.097 for renewable energy generation. That is, the total generation costs are approximately $1.70 billion for the nuclear power and $3.97 billion for renewable energy to mitigate 1% of CO₂ emissions at the average amount of electricity generation of 0.56 billion MWh in 2014 in the sample countries. Hence, we can conclude that nuclear power generation is more cost-efficient than is renewable energy generation in mitigating CO₂ emissions, even with the external costs of accidents and health impact risks associated with nuclear power generation.

Rethinking the meaning of "landscape shocks" in energy transitions: German social representations of the Fukushima nuclear accident

Sociotechnical sustainability transitions are understood to involve changes in cultural meaning, alongside a wide variety of other changes. One of the most popular conceptual models of such change, the multi-level perspective, exogenously locates slow-changing cultural factors in the 'sociotechnical landscape', viewing this landscape as periodically subject to 'shocks' that may support the break-through of niche innovations. Here we emphasise that shock to a sociotechnical system has social psychological dimensions, including meaning-related correlates. Accordingly, we apply social representations theory, as a theory of meaning, to provide a social psychological account of energy landscape shock and associated policy change. For illustration we take newspaper representations of the 2011 German social and policy response to the nuclear accident at the Fukushima Daiichi power plant in Japan. The study illustrates the inter-related role of affect, identity and symbolic meaning-making in the public response to a sociotechnical landscape shock.

Knowledge and risk perception of radiation for Japanese nursing students after the Fukushima Nuclear Power Plant disaster

BACKGROUND

The Japanese have had three experiences of radiation disasters: the atomic bombs dropped on Hiroshima and Nagasaki in 1945, and the 2011 Fukushima Nuclear Power Plant disaster. The former two experiences have been covered in compulsory education programs. In light of these incidents, a strong fear of radiation has pervaded people of several generations. In such a situation, the role of nurses is important. When nurses treat residents, their attitudes change depending on how they understand and feel about radiation. The foundations of these attitudes are formed through student education. Hence, it is necessary to explore nursing students' understanding and risk perception of radiation, and the nature of radiation education received.

OBJECTIVES

To assess the levels of understanding and risk perception of nursing students regarding radiation.

DESIGN

Cross-sectional survey.

METHODS

A questionnaire survey was administered to all students (74 first-year, 79 second-year, 65 third-year, and 69 fourth-year students) in the nursing department of a Japanese national university. The response rate was 84%. Respondents were asked to rate their level of understanding of 50 phrases chosen from two supplementary texts about radiation for elementary school students and for middle and high school students, prepared by the Japanese Ministry. Further, they were asked to rate their risk perception for 30 events, and to answer six questions about radiation.

RESULTS

It was found that knowledge about radiation among Japanese nursing students was poor, because sufficient radiation education had not been provided. Hence, they displayed a greater fear of X-rays as compared to American students and members of the League of Woman Voters. However, it was also found that an increase in understanding might decrease risk perception.

CONCLUSIONS

It was concluded that nursing students require adequate education about radiation, in order to reduce their fear of X-rays and to mitigate their risk perception.

[Effect of low dose ionizing radiation on peripheral blood cells of radiation workers in nuclear power industry]

Objective: To investigate the effects of long-term ionizing radiation on peripheral blood cells of nuclear power workers. Methods: In March 2019, a total of 530 radiation exposed workers in the nuclear power industry who underwent in-service radiation occupational health examination in Guangzhou occupational disease prevention and control hospital in 2018 and with service age ≥1 year were selected as the radiation group. At the same time, 545 workers in nuclear power industry were selected as control group. According to the methods and requirements of GBZ 235-2011 ＂technical specification for occupational health monitoring of radiation workers＂ and GBZ 98-2017 ＂health requirements for radiation workers＂, the occupational health monitoring data were collected, and the change rules of peripheral blood cells in the two groups were analyzed. Results: Compared with the control group, the total number of WBC, NEUT, LYMP, Hb, MCV and MCHC in radiation group were lower than those in control group (P<0.05) , and the difference was statistically significant (P<0.05) . The MPV increased significantly (P<0.05) . Compared with the control group, the abnormal rate of WBC and Hb in the radiation group was higher than that in the control group (P<0.01) , but there was no significant difference in the abnormal rate of RBC and PLT (P>0.05) . Conclusion: Low dose ionizing radiation has a certain cumulative damage effect on peripheral blood cells of radiation workers in nuclear power industry. The change rules of different cell subtypes are different, and the changes of WBC and PLT appear earlier.

How does the water-energy-food nexus work in developing countries? An empirical study of China

As three resources that are necessary for human survival and production, water, energy and food are increasingly closely linked. In recent years, the water-energy-food nexus has attracted special attention from international organizations and academic circles. However, due to the lack of research on its internal mechanisms, there is still controversy on whether the water-energy-food nexus can be used as a new policy basis. The internal mechanisms of the water-energy-food nexus were analysed from the perspective of industrial linkages in this paper and empirically verified by constructing an SVAR (structuralvectorautoregression) model using China's data. The results showed that there were two forms of conduction in China's water-energy-food nexus: the water-energy-food nexus with nuclear power participation and that with natural gas participation. The characteristics of China's water-energy-food nexus were derived. For the interactions of the water-energy segment in China's water-energy-food nexus, the conduction from energy to water was consistent for different types of energy, while that from water to energy varied depending on the type of energy. Food production always had a negative impact on energy production, while the conduction from energy to food varied for different types of energy. The conduction between food and the water supply was not as significant as was generally considered. Especially, the impact of the water supply on food production was weak. The order of strength intensity and the duration were also available for reference. Accordingly, a new policy basis was presented under the framework of China's water-energy-food nexus. Both our research design and research findings are significant in contributing to understanding the internal mechanisms of the water-energy-food nexus, and the policy implications are also helpful for achieving better policy effects.

Specifying the Concept of Future Generations for Addressing Issues Related to High-Level Radioactive Waste

The nuclear community frequently refers to the concept of "future generations" when discussing the management of high-level radioactive waste. However, this notion is generally not defined. In this context, we have to assume a wide definition of the concept of future generations, conceived as people who will live after the contemporary people are dead. This definition embraces thus each generation following ours, without any restriction in time. The aim of this paper is to show that, in the debate about nuclear waste, this broad notion should be further specified and to clarify the related implications for nuclear waste management policies. Therefore, we provide an ethical analysis of different management strategies for high-level waste in the light of two principles, protection of future generations-based on safety and security-and respect for their choice. This analysis shows that high-level waste management options have different ethical impacts across future generations, depending on whether the memory of the waste and its location is lost, or not. We suggest taking this distinction into account by introducing the notions of "close future generations" and "remote future generations", which has important implications on nuclear waste management policies insofar as it stresses that a retrievable disposal has fewer benefits than usually assumed.

Nuclear power in the 21st century: Challenges and possibilities

The current situation and possible future developments for nuclear power--including fission and fusion processes--is presented. The fission nuclear power continues to be an essential part of the low-carbon electricity generation in the world for decades to come. There are breakthrough possibilities in the development of new generation nuclear reactors where the life-time of the nuclear waste can be reduced to some hundreds of years instead of the present time-scales of hundred thousand of years. Research on the fourth generation reactors is needed for the realisation of this development. For the fast nuclear reactors, a substantial research and development effort is required in many fields--from material sciences to safety demonstration--to attain the envisaged goals. Fusion provides a long-term vision for an efficient energy production. The fusion option for a nuclear reactor for efficient production of electricity has been set out in a focussed European programme including the international project of ITER after which a fusion electricity DEMO reactor is envisaged.

The future of Yellowcake: a global assessment of uranium resources and mining

Uranium (U) mining remains controversial in many parts of the world, especially in a post-Fukushima context, and often in areas with significant U resources. Although nuclear proponents point to the relatively low carbon intensity of nuclear power compared to fossil fuels, opponents argue that this will be eroded in the future as ore grades decline and energy and greenhouse gas emissions (GGEs) intensity increases as a result. Invariably both sides fail to make use of the increasingly available data reported by some U mines through sustainability reporting - allowing a comprehensive assessment of recent trends in the energy and GGE intensity of U production, as well as combining this with reported mineral resources to allow more comprehensive modelling of future energy and GGEs intensity. In this study, detailed data sets are compiled on reported U resources by deposit type, as well as mine production, energy and GGE intensity. Some important aspects included are the relationship between ore grade, deposit type and recovery, which are crucial in future projections of U mining. Overall, the paper demonstrates that there are extensive U resources known to meet potential short to medium term demand, although the future of U mining remains uncertain due to the doubt about the future of nuclear power as well as a range of complex social, environmental, economic and some site-specific technical issues.