The U.S. Nuclear Regulatory Commission (NRC) has granted an extension for the construction completion dates of the Bellefonte Nuclear Plant Units 1 and 2, owned by the Tennessee Valley Authority (TVA), until October 1, 2021. The initial construction permits were issued in 1974, but the projects have been delayed. The NRC found that there is a valid reason for the extension and that it does not pose significant safety risks. This extension allows more time to resolve an ongoing legal dispute concerning the plant's sale.
Simple Explanation
The bosses in charge of keeping nuclear power plants safe have given more time to finish building a power plant that they started a looong time ago, because there are some things that need to be figured out in court first. They believe it won't make the plant unsafe, so they're okay with waiting a bit longer.