I have blogged about the dangers of flooding at nuclear power plants before. Nuclear power plants require huge quantities of water to cool the reactors. Therefore, nuclear power plants must be located near rivers, lakes or oceans. With the increased dangers of major storms caused by global climate change, this means that nuclear power plants will become more vulnerable to flooding. It was the flooding at Fukushima that cause the melt-down of three nuclear reactors. Of the one hundred operating nuclear power reactors in the U.S., there are at least twenty five power plants that are in danger of serious flooding.
Boone Dam is on the South Fork Holston River in Tennessee. The hydroelectric and flood control dam is owned and operate by the Tennessee Valley Authority. The dam is a concrete gravity-type dam. It is one hundred sixty feet high and one thousand five hundred and thirty two feet long. It has a maximum discharge rate of one hundred thirty seven thousand cubic feet per second. The V-shaped reservoir behind the dam is called Boone Lake and it covers about forty five hundred acres.
In October of 2014, a sink hole was found at the bottom of the dam and six days later, water was found seeping under the dam near the site of the sink hole. Upon finding this seepage, the operators of the dam began lowering the water level earlier in the year than usual. The operators of the dam are working to discover exactly why and how the water is seeping under the dam.
What makes the leak under Boone Dam especially troubling is that it is upstream from three TVA nuclear power plants. If that dam were to break, the ensuing flood could threaten seven nuclear reactors. Aside from any existing structural weaknesses, a major upstream flood caused by storms could possibly weaken the dam.
A magnitude five point nine earthquake occurred in Virginia, right across the border from the dam, in 2011. Recent research into earthquake impact has revealed that the shaking of the earth caused by a quake can travel much further than was originally thought. This means that if there is another quake in Virginia, it could possibly weaken or rupture the Boone Dam.
The situation with the Boone Dam highlights a major issue with nuclear power plants compared to other low-carbon energy sources such as wind and solar. If a wind farm or a solar power station were flooded, it would cut off the power generated by these sources but that would be the extent of the damage. On the other hand, if a nuclear power plant is flooded, the result may be a catastrophe such as the 2011 Fukushima nuclear disaster. Japan is still dealing with the aftermath of the accident four years later. People had to be permanently evacuated from nearby towns. Huge amounts of radiation were released into the atmosphere and are still being released into the Pacific Ocean.
With extreme weather and flooding increasing worldwide and one fifth of the U.S. nuclear power reactors in danger of flooding, the NRC must increase pressure on nuclear power plant owners to harden their power plants against possible floods.