- As nuclear plants age, they need to either be updated to comply with safety standards so that they can continue to be granted operating licenses, or they will have to be decommissioned.
- There are two decommissioning processes: safe storage, in which the plant is shut down and left alone for a period of up to fifty years before the actual decommissioning process starts; and immediate decommissioning.
- In both cases, once decommissioning starts, it must be complete within ten years.
- Many plant decommissioning plans use a hybrid approach, in which some plant elements are decommissioned immediately and others are placed in safe storage for a period of time to allow radioactivity to decay to safer levels.
- Decommissioning is a very expensive process which must be considered as part of the total cost of a nuclear reactor, costing up to one billion dollars in some cases.
New nuclear plant designs have the potential to coexist with renewables and help ease the transition to a completely renewable energy system by producing carbon-free baseload power. However, there are still nearly a hundred outdated nuclear reactors operating in the United States. As the use of renewable energy grows, many of these old nuclear plants will need to be decommissioned. Solar and wind become more economical each year, while old nuclear plants only become more costly to operate. In addition, cheap natural gas can cause nuclear generating capacity to be displaced (Venkatesh, 2012), which could lead to plant closures in the long term. The process of decommissioning nuclear plants is costly. There is also potential for contamination of surrounding areas if nuclear waste from the plant is mishandled during the deconstruction process.
There are two primary options for decommissioning: immediate decommissioning, in which the site is deconstructed and decontaminated immediately; and safe storage, in which the reactor is contained for up to 50 years and then decontaminated later. In both cases, the actual decommissioning process must be completed within 10 years. The safe storage process allows some contamination to decay to safe levels, reducing the expense of decontamination. It also allows for more time to secure funding for decontamination. However, it takes much longer for the site to be usable with this process. Most plants use a hybrid approach in which some elements of the plant are decontaminated immediately while others have funds set aside and are cleaned later (Nuclear Energy Institute [NEI], 2016).
No matter which method is chosen, the process of decommissioning is considered complete when the site is no longer radioactive. The NEI’s fact sheet on decommissioning nuclear plants states: “Once public concerns are addressed, the NRC will terminate the license if all work has followed the approved license termination plan and the final radiation survey shows that the site is suitable for release,” (2016). Total costs for decommissioning a single plant can exceed one billion dollars, and over the next three decades, many of the US’s 99 nuclear reactors will need to be decommissioned, as they were built in the 1970s and will be reaching the end of their useful lives (Song, 2011). To put this in perspective, this is between 10% and 25% of the cost of building the plant to begin with. In addition, some utilities are retiring nuclear plants early, due to stable power demand and the cost of nuclear energy relative to other power sources such as natural gas (Hylko, 2017).
Waste disposal accounts for about 30% of the cost of decommissioning (Song, 2011). When a nuclear plant is decommissioned, all low-level nuclear waste (contaminated with small amounts of radiation) is transferred to facilities built for low-level waste. All non-nuclear waste from the plant can be placed in conventional landfills or recycled (Song, 2011). High-level waste will be moved to storage facilities. At this point there is no central long-term repository for high-level nuclear waste where it can safely be stored indefinitely.
Venkatesh, A., Jaramillo, P., Griffin, W. M., & Matthews, H. S. (2012). Implications of changing natural gas prices in the United States electricity sector for SO2, NOX and life cycle GHG emissions. Environmental Research Letters, 7(3), 034018. doi:10.1088/1748-9326/7/3/034018
US Energy Information Administration. (2017). Decommissioning nuclear reactors is a long-term and costly process. eia.gov.
Song, L. (2011). Decommissioning a Nuclear Plant Can Cost $1 Billion and Take Decades. Reuters.
Hylko, J. (2017). No Longer an Afterthought, Nuclear Plant Decommissioning Industry Matures. POWER Magazine.
Nuclear Energy Institute. (2016). Decommissioning Nuclear Power Plants. nei.org.
US Department of Energy. (2016). US Energy and Employment Report. US Department of Energy.
World Nuclear Association. (2018). Nuclear Power in the USA. world-nuclear.org.