In this age of rising electricity demand, people are trying to squeeze every last bit of power out of every power plant possible. Over the past few weeks, there has been big news about nuclear power plants trying to do just that. Constellation, the largest nuclear operator in the US, announced plans to add nearly a gigawatt of new capacity across 11 existing nuclear reactors at six plants. On October 5, the Department of Energy awarded a $4.2 billion loan to Vistra for previously announced upgrades at three plants.
The process of boosting output at existing plants is called a power uprate. Operators have been doing this since the 1970s in the US, but it has become less common in recent years as demand for electricity plateaued and cheap natural gas put financial pressure on nuclear plants. Between 2001 and 2010, the US Nuclear Regulatory Commission approved over 80 uprates. Between 2011 and 2020, the number was 33. With the rise of AI and the related boom in electricity demand, that trend is shifting. Shuttered plants like Palisades and Three Mile Island are racing to reopen, and existing plants are looking to uprate again.
Minor uprates involve changes to instrument setpoints or calculations, while major overhauls can boost reactor power by as much as 20% and require replacing equipment. The most recent major uprate in the US was at three reactors at the Browns Ferry plant in Alabama, a $475 million project that expanded capacity by 14% between 2018 and 2019. Constellation now plans to spend more than $4.3 billion on uprates to 11 reactors, enough to power roughly 700,000 US homes. Google agreed to buy electricity from these plants under a 20-year agreement, which was a major factor in making the uprates happen.
Uprates remain costly. Per kilowatt, the Constellation project is cheaper than building a new reactor but more expensive than a new utility-scale solar farm with storage or a combined-cycle natural-gas plant. Even so, demand is high. The US nuclear fleet has roughly 98 gigawatts of capacity, and depending on who you ask, between three and eight additional gigawatts could come from uprates.
Source: MIT Technology Review · Summarized by HeadlinesBriefing