A report on Wednesday showed that nuclear power in global gross electricity generation fell below 10 per cent last year to the lowest level in the last four decades.
Nuclear energy generated 2,653 terawatt hours of electricity last year, accounting for 9.8 per cent of global generation - the lowest since the 1980s, according to the annual World Nuclear Industry Status Report WNISR.
As a low-carbon power source, it could be vital in helping countries meet climate targets, but several plants around the world are coming to the end of their life expectancies and many new ones have been delayed.
The United States generates the most nuclear power in the world, followed by China.
As of mid- 2022, 411 reactors were operating in 33 countries, four less than a year earlier and 27 below a 2002 peak of 438.
The average age of reactors is around 31 years old because of the slow pace of new projects coming on stream.
At least half of the 53 reactors under construction are delayed. In the first half of the year, five new units were operational, while eight were closed last year.
In the last year, the investment in new nuclear construction projects was around $24 billion, accounting for 6.5 per cent of the total investment of $366 billion in non-hydro renewables projects.
Nuclear power is losing ground in terms of cost as reactors are seen as less economical and slower to build.
The cost of energy, which compares the total lifetime cost of building and running a plant to lifetime output, fell to $36 per megawatt hour MWh last year for solar photovoltaic from $359 MWh, while the cost for wind fell to $38 MWh from $135 MWh, according to the report.
Nuclear power costs went up by 36 per cent last year to $167 MWh from $123 MWh in 2009.