Duke Energy’s decision to shut down the Crystal River 3 reactor in Florida rather than pay for expensive repairs to its containment dome has focused attention once more on the lengthy process for decommissioning nuclear power plants. Since Dominion Nuclear’s announcement last year that it will shutter its Kewaunee plant in Wisconsin, the country now has two reactors entering this process.
Duke took the first step on Feb. 20, when it gave the NRC its official certification that it had permanently ceased operations at Crystal River 3 and permanently removed the fuel from the reactor. Those certifications effectively changed the plant’s operating license to a “possession only” license – in other words, the company is no longer permitted to load fuel into the reactor vessel and operate the plant.
After these initial certifications, the process can be quite slow. Duke will have up to two years to develop and submit its decommissioning plan – officially called the post-shutdown decommissioning activities report, or PSDAR in NRC-speak. The report will include a description and schedule for decommissioning activities, their estimated cost, and a discussion of why any anticipated environmental impacts have already been reviewed in previous environmental reports on the plant.
Once the NRC receives the PSDAR, we will publish it for public comment and conduct a public meeting near Crystal River to explain the decommissioning process. Duke will not be able to conduct any major decommissioning activities until 90 days after NRC receives the PSDAR.
Under NRC regulations, Duke can take up to 60 years to complete the process, from cessation of operations to final decommissioning and termination of license. Why so long? There are actually two advantages: Radioactivity decays over time, making the final cleanup easier; and the company’s decommissioning trust fund continues to grow. This stage of decommissioning is called SAFSTOR, as the company maintains the shuttered plant in safe storage until final cleanup begins.
Throughout this process, Duke will be able to use some of its decommissioning funds. It can spend up to 3 percent of the fund on decommissioning planning as it develops the PSDAR, and up to 20 percent to maintain and monitor plant safety during the SAFSTOR period. NRC limits use of the funds to ensure that enough money remains to complete cleanup and follow the process through to license termination.
The NRC requires Duke to clean up the site so that residual radiation is quite low – specifically, that no person on the site would receive a dose above 25 millirem per year. (In comparison, the average American receives 310 millirem per year from natural radiation, and the dose from a single chest X-ray is about 10 millirem.) At least two years before Duke reaches that point, it must submit a license termination plan, detailing the final steps. NRC inspectors will verify that the site has been decontaminated to the NRC’s requirements. Duke will then ask the NRC to terminate the license, or modify it to apply only to a spent fuel storage facility, if needed.
One popular question is the cost of decommissioning a nuclear power plant. Estimates vary, and of course it has been several years since a plant has been decommissioned, but the NRC estimates that the costs generally range from $300-400 million. This estimate applies only to NRC-mandated activities – in other words, reaching the radiological criteria. Dismantling other parts of the plant (such as support buildings) would cost extra, so the company’s estimate might be higher.
Throughout the entire decommissioning process, the NRC’s objective is to protect public health and safety while ensuring that the site is cleaned up to our requirements.
Additional Note: There are two other possible methods for decommissioning. DECON involves active decontamination of the site, either immediately after operations cease or after a period of SAFSTOR. The third, ENTOMB, is just what it sounds like – radioactive contaminants are permanently encased on site in structurally sound material such as concrete and appropriately maintained and monitored until the radioactivity decays to a level permitting restricted release of the property. To date, no NRC-licensed facilities have requested the ENTOMB option.