USGS Last year the United States imported over 90% of its uranium for nuclear power plants.

But this could soon change, as the US Geological Survey just discovered 220 million pounds of uranium ore in the sandstone of southern Texas.

Nuclear power currently generates 19% of electricity in the US, using up about 53 million pounds of uranium per year.

The new reserves in Texas harbor at least 60 million pounds of uranium oxide, USGS researchers described in a report published December 2.

While the new report estimates that the area could contain as much as 220 million pounds — enough to fuel US reactors for nearly 5 years — it will take some looking underground to know for sure.

Two mines are already producing uranium oxide near the identified area, yielding about 80 million pounds of uranium.

The US has more nuclear power plants than any other country, but only 6% of the uranium used in 2014 came from domestic sources, according to the US Energy Information Administration.

Kazakhstan was the largest source of uranium last year, providing nearly a quarter of the stuff used in nuclear power plants.

The Limerick Generating Station, a nuclear power plant in Pottstown, Pennsylvania. Kevin Lamarque/REUTERS Nuclear is projected to make up a larger portion of US energy in the coming years, as scientists develop more efficient reactors that produce less waste.

Five new power plants are under construction in the US, and nuclear is expected to generate over 100 gigawatts of energy by 2020 — enough to power about 70 million homes.