# Progress, Challenges, and Sustainable Perspectives in Nuclear Energy Strategies
## 1 Introduction  
Nuclear power has experienced a remarkable resurgence in recent years. A key finding is the renewed global interest in nuclear power as an integral part of the solution to climate change [1]. Several countries have increased their commitment to increasing their nuclear power generation capacity by 2050 [2], representing a significant shift in global energy policies [3, 4]. The inclusion of nuclear power in sustainable taxonomies in several regions of the world is facilitating the financing of nuclear projects. This reflects a growing recognition of the role of nuclear power in combating climate change [5, 6] and achieving sustainable development goals [7]. As a greenhouse gas (GHG)-free power generation technology, nuclear power complements intermittent renewable sources, contributing to a balanced and sustainable energy mix [8]. A crucial technological advance in this resurgence of nuclear power has been the development of small modular reactors (SMRs) and advanced Gen IV [9] nuclear reactors. These reactors offer innovative solutions to address safety and investment issues, which have historically been major obstacles to nuclear expansion [10]. SMRs promise faster and more flexible deployment, better adapting to local and regional energy needs [8]. On the other hand, Gen IV nuclear reactors represent the cutting edge of nuclear power technology, promising significant advances in safety, efficiency, and sustainability [11, 12]. Gen IV reactors offer the potential to significantly improve fuel utilization, reduce radioactive waste,increase proliferation resistance, and provide applications beyond electricity generation, such as hydrogen [13] production and industrial process heat [14; 15]. In addition, substantial improvements in the efficiency and safety of existing nuclear power plants have been achieved [16]. These improvements have led the lifetime of operating nuclear power plants to be extended to 60-80 years in many countries [17; 18]. This not only improves the profitability of existing investments, but also contributes to the long-term stability of energy supply [19; 20]. On the other hand, innovation in the sector is not limited to the design of new nuclear reactors or the extension of the lifetime of operating nuclear power plants. Artificial intelligence, machine learning, robotics, and 3D printing are positioned as technologies to be implemented in the sector in the coming years, favoring increased operational efficiency, safety, and management of nuclear power plants [21; 22]. International cooperation in the nuclear sector has evolved significantly since its inception, adapting to geopolitical and technological changes [23; 24]. Currently, cooperation strategies are carried out more closely between countries in research, development, and deployment of advanced nuclear technologies [25]. However, despite these factors in favor of nuclear power, high initial investment costs and financing difficulties represent another crucial challenge, particularly for developing countries. High competition with cheaper energy sources, such as hydrocarbons and renewable energies [26], also poses additional economic challenges for the nuclear sector. Similarly, nuclear waste management remains a controversial and technically challenging issue [27]. Another significant challenge is the need to train and maintain specialized human talent [28] to maintain the sector's capacity to innovate and safely operate nuclear power plants in the future [29]. Renewables sources such as solar and wind have experienced a significant reduction in their levelized costs, outperforming the competitiveness of nuclear power, whose costs have increased [30]. Although nuclear power provides stability for the electricity system, renewables are growing faster in installed capacity and annual production [31].