Nuclear Energy
Table of Contents
--- Coal-to-Nuclear Transitions ---
I recently was browsing around the Department of Energy's Office of Nuclear Energy website and came across something I'd not yet heard about, but which I find very exciting... coal-to-nuclear transitions. This is where a coal power plant (either operating or decommissioned) is retrofitted to operate with nuclear power generation. This would provide the benefit of already having a large amount of infrastructure on site (turbines, distribution wiring, generators, piping, etc.) which could be fed steam (and thereby electricity) from something like a small modular reactor (SMR) or advanced reactor (AR). As a greater emphasis is placed on moving away from dirty fossil fuels like coal and oil to "cleaner" fossil fuels like natural gas or green/renewable energy generation, many utilities are looking to retire their coal power plants (CPPs). According to the US Energy Information Administration (EIA), 28% of operating CPPs will be retired by 2035. As of September 2021, there were no new coal power plants scheduled to be built in the US [source]. In fact, at Iowa State University (where I graduated from), I took a tour of their university power plant which had been converted from coal to natural gas-fired generation. This makes me wonder what percentage of CPPs are retired versus how many are converted to something like natural gas. Converting to natural gas certainly can reduce emissions and, in the case of the ISU power plant, using cogeneration can substantially increase the efficiency of a power plant as well. This is an improvement, but we can do better. We can fully eliminate generating station emissions (and provide other economic benefits) by transitioning over to nuclear power generation at these sites. The US Department of Energy estimates that to meet the 2050 net-zero carbon emissions goal, the US will need to construct 200 gigawatts (GW) of additional nuclear power capacity. Some of this can be installed at already operating or recently retired nuclear sites (around 60-95 GW of capacity), but the rest could find a home at the sites of CPPs that are being phased out across the country [source].
The Department of Energy released a great report in 2022 titled "Investigating Benefits and Challenges of Converting Retiring Coal Plants into Nuclear Plants" [PDF]. In it, the authors look at the percentage of both retired and operational CPPs that would be candidates for nuclear power plants (NPPs). They find that a wide majority of retired CPPs considered, 80%, are suited to being fitted with ARs and some of them, around 20%, are even suitable candidates for larger light water reactors (LWRs). When considering operating CPPs, the number of amenable sites for an AR refit is the same (80%), but the number of suitable sites for an LWR jumps up to 40%. This presents a considerable amount of opportunity to expand nuclear power generation while also avoiding much of the complicated aspects of constructing a nuclear site from scratch (also called "greenfield" construction). The potential cost savings for overnight constuction (where factors like interest, capacity factor, and financing costs are neglected) are in the range of 15% to 35% as compared to overnight greenfield construction. Additionally, due to nuclear power plants having the highest capacity factor (i.e., time spent on and generating power) of any form of power generation as well as the introduction of other support activities, it is projected that a nuclear refit could provide around 650 more permanent jobs to the community. This does not include the additional jobs that could be created outside of the region as a result of more demand for nuclear fuel and parts. Nuclear jobs pay more, so the local community would see an increase in wages and could see in increase of economic activity up to $275 million. The environment would be substantially improved by a coal-to-nuclear transition, seeing as much as an 86% decrease in steady-state greenhouse gas (GHG) emissions. As for waste concerns, the ash waste from coal-fired generation would still need remediation, but the waste developed by the nuclear power plant (NPP) would be comparatively negligible and could be stored at existing dry cask storage sites away from the community. The waste itself would present no danger to the surrounding community if stored on-site, but by storing it at existing facilities (say, those already being managed and supervised by the utility provider) the possibility of local debate impeding construction or long-term operation could be avoided. Ultimately, people will need to understand how miniscule the risk is from nuclear waste and not allow it to impede the installation of NPPs in their area, but that is a topic for another time.
The company TerraPower has been undertaking the construction of a new NPP based on its Natrium reactor in Kemmerer, Wyoming near the site of a retired CPP. They will utilize the existing utilities infrastructure and skill base from those who have been working at the plant. The Natrium reactor concept can be seen below in a rendering from TerraPower.
This reactor is not only one of the first advanced reactor designs (Generation IV) to see construction in America, but the NPP will also be a great demonstration for the refitting of CPPs with nuclear technology. The DOE is clearly excited about the opportunity as they've invested $2 billion in getting the plant going. It is a sodium-cooled fast reactor (SFR), meaning it is capable of burning spent fuel from the current fleet of operating reactors and produces much less transuranic waste (plutonium and other actinides). This could be a major selling point for convincing communities to welcome SFRs to their local utilities.
While it may be more costly than natural gas, I am certainly hoping that more utilities will consider the idea of installing NPPs at retired coal generating sites. Especially given that the DOE is so keen on getting more reactors online in the coming decades. Programs do exist to push these options over the typical fossil fuel plants, such as the DOE's Gateway for Accelerated Innovation in Nuclear (GAIN) program through the Idaho National Laboratory. They offer hundreds of thousands to millions of dollars in funding to kickstart nuclear projects. An aggressive transition to nuclear energy can allow us to break our dependence on fossil fuels, especially if the US embraces more electric transportation options (not just cars, but more electric trains!).