An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Radiation Protection

What are the characteristics of Yucca Mountain?

The Yucca Mountain Repository is a proposed Department of Energy (DOE) site that would be the United States’ first geologic repository for the permanent disposal of spent nuclear fuel and high-level radioactive waste. The EPA has set environmental standards to protect public health and the environment from radioactive material in the repository; in order to become licensed by the Nuclear Regulatory Commission (NRC), the Yucca Mountain repository must meet these standards.

Yucca Mountain is a volcanic ridge located in Nye County, Nevada, approximately 90 miles south-southwest of the county seat, Tonopah, and 100 miles northwest of Las Vegas. The area has a desert climate.  Yucca Mountain is made of layers of ashfalls from volcanic eruptions that happened more than 10 million years ago. Over that period of time, the ash from those volcanic eruptions turned into a rock type called “tuff,” an igneous rock which has varied characteristics depending on the situation in which it was formed.  Due to regional geologic forces, the crest of Yucca Mountain was formed by the tuff layers’ movement. Below the tuff is carbonate rock formed from sediments laid down at the bottom of ancient seas that existed in the area.

For more information about the site and license application, visit the DOE webpage and the NRC webpage.

For more information about EPA’s role at Yucca Mountain, please visit 40 CFR Part 197 Resources.

Return to Frequent Questions about Radioactive Waste: Yucca Mountain.