U.S. Rep. Greg Walden, R-Ore., walks through a tunnel extending from the south portal during a congressional tour of Yucca Mountain near Mercury on Saturday, July 14, 2018. Chase Stevens Las Vegas …

U.S. Rep. Greg Walden, R-Ore., walks through a tunnel extending from the south portal during a congressional tour of Yucca Mountain near Mercury on Saturday, July 14, 2018. Chase Stevens Las Vegas Review-Journal @csstevensphoto