# A Global Review of PWR Nuclear Power Plants
## 3 Discussion
### Simulation of the Life Extension of Operational PWR  
The extension of the operating life of nuclear power plants is a solution to energy production--without carbon emissions--for a long time [54]. Due to the aging in the most important components--which implies a continuing time-dependent degradation of materials due to service conditions, including normal operation and transient conditions--the nuclear power plants are initially designed for a technical life of 40 years [55]. It is common experience that over long periods, there is a gradual damage in the properties of materials as a consequence of neutron radiation and the corrosion these components endure [56; 57; 58]. Thus, the reactor vessel materials of the PWR design are the components most affected by neutron radiation, thereby reducing its mechanical properties [59]. On the other hand, the SG is the component of PWR design suffering the most corrosion damage [28; 60], being both stress corrosion cracking (SCC) and particle deposition the main degradation mechanisms. The degradation of steam generators tubes has involved costly modifications, inspections and even the replacement of SG in the most severe cases [61; 62]. Although the technical life of 40 years is recommended in previous studies [56], other papers [63] consider that the 40-year term was based on economic and antitrust considerations rather than on technical limitations. In recent years, countries such as France or the United States have studied the lifetime extension significantly beyond 40 years: specifically, a lifetime extension up to 60 years [64]. The PWR Generation III designs were designed for a life of 60 years [65; 66], and the United States is even planning a lifetime extension up to 80 years [67; 68; 69; 70; 71]. According to the IAEA, the half-life of operating nuclear reactors around the world is currently over 30 years [72] and in cases such as WH 2-loop, B&W, and CP0 (Generation II), the designs have already reached the initial life of 40 years [6]. In this situation, in order to provide information for making a decision about the life extension beyond the initial 40 years, this study presents a simulation of the electrical power generation capacity of operational PWR in a scenario of lifetime extension to 60 years, consequently placing a maximum time horizon in the year 2050. To do this, the progressive implementation of the PWRs that is currently under construction is also taken into account, estimating for this a construction and commissioning time of 68 months (approximately 6 years), according to previous studies [72]. Figure 18: Number of research papers indexed in SCOPUS related with the Generation III designs (data collected on April 2020). The results shown in Figure 19, in a scenario of lengthening the useful life of PWR nuclear power plants to 60 years, are clear: (i) the B&W and French series CP0 will shut down in 2040 and (ii) Westinghouse 2-loop and 3-loop, Combustion Engineering CE80 and French series CP1 and CP2 will shut down in 2050. In this way, the PWR design would go from having 259 operating in 2020 in the world to 81 nuclear reactors operative in 2050, which means 69% less operating reactors in 30 years (Figure 19). In addition, 178 PWR nuclear power plants would permanent shutdown in 30 years. Even considering new PWR nuclear power plants that could be projected in the coming years, this technology will suffer a drastic reduction in the coming years. The possible increase in the useful life to 60 years of the current operational PWRs would mean that this design maintains its global impact for other designs during the period 2020-2030, in which only 24 reactors would go into shutdown and the power generation capacity would increase as new Generation III designs--with higher generating capacity--now under construction start operating. According to Figure 19, starting in 2040, the PWR nuclear power plants will notably reduce their electrical capacity.