Around 60% of the nuclear reactors in operation had been operating for 30 years or longer, and while a nuclear reactor is typically licensed for 30-40 years, the operating lifetime can be significantly extended (IAEA, 2018). Overnight Refurbishment Cost (ORC) range between €2017400 and €2017900 per kilowatt (rounded) for additional 20 years of extended operation (D’haeseleer, W.D., 2013)