# Progress, Challenges, and Sustainable Perspectives in Nuclear Energy Strategies
## 4 Discussion
This allows the creation of a time series for each topic, showing how its prevalence changes year after year. Visualizations, such as heat maps or thematic evolution graphs, are common tools to represent these temporal changes. In addition, trend analysis techniques can be applied to identify emerging, booming, stable, or declining topics. Figure 8 shows the trend graphs for the different topics. Figure 8: Temporal evolution frequency of records on nuclear energy strategies: (**a**) t1—Technological advances; (**b**) t2—Public perception; (**c**) t3—Economic factors; (**d**) t4—Waste management; (**e**) t5—Climate change mitigation; and (**f**) t6—International cooperation. Analysis of topics over time in the nuclear energy field reveals significant evolution in research and development priorities. The focus was on technological advances (t1) and the expansion of generating capacity (Figure 8a). Dominant topics included reactor design, energy production efficiency, and basic operational safety. This period was characterized by widespread optimism about the potential of nuclear energy to meet growing global energy demands. However, starting in the 1970s and especially after incidents such as Three Mile Island (1979) and Chernobyl (1986) [3; 52; 53], there has been a notable shift toward issues related to security and safety management residues (t4) (Figure 8d). Public perception and social acceptance (t2) (Figure 8b) of nuclear energy have also begun to gain importance as research topics. This period marked a turning point in which technical aspects were balanced with considerations, broader social, and environmental issues. These statements contribute to what is stated in the RQ. There has been a resurgence of interest in nuclear energy, driven largely by concerns about climate change (t5) (Figure 8e). Topics related to climate change mitigation and sustainable development have gained ground, although, as seen in the data provided, their representation in the literature still seems to be relatively low (less than 0.005). This fact highlights, based on the data analyzed in this study, an absolute annual frequency of fewer than 10 records. In parallel, there has been a renewed emphasis on technological advances, particularly in the development of Generation IV reactors and SMRs, which promises greater safety and efficiency. According to the RQ, in recent years, a growing integration of topics has been observed. Economic factors (t3) (Figure 8c) have become more closely intertwined with technological advances (t1) (Figure 8a) and environmental considerations (t5) (Figure 8e). Research into public perception and social acceptance (t2) has become more sophisticated, recognizing its crucial role in the implementation of nuclear policies. Furthermore, emerging topics, such as the integration of nuclear energy with other renewable energy sources, the application of advanced digital technologies in the operation of nuclear power plants, and the role of nuclear energy in hydrogen production and desalination [27; 54], are gaining prominence, reflecting a more holistic and multidisciplinary vision of the future of nuclear energy. Finally, regarding international collaboration (t6) (Figure 8f), the results obtained reflect the lack of interest on the part of the scientific community. In an increasingly interconnected world, international nuclear cooperation not only improves global security [55], but also promotes the peaceful use of nuclear energy to address challenges, such as climate change and energy security, ensuring that the benefits of this technology are shared equitably and responsibly among nations. Future lines of research should analyze the existence of additional areas of research that could merit more detailed exploration to fully understand the research landscape in terms of global strategies around nuclear energy. On the other hand, future studies should apply clustering or topic modeling algorithms, such as Latent Dirichlet Allocation (LDA), to increase the effectiveness of the topic analysis [56; 57].