I take a group or two of high school students once a year to tour several areas at ORNL. The supercomputing center tends to end up on most trips. If you're passing through and want a tour, call a few weeks in advance.
"With the Summit Supercomputer, U.S. Could Retake Computing’s Top Spot
Oak Ridge’s 200-petaflop Summit supercomputer will come on line in mid-2018"
Contact info at bottom. Barb Penland is who I've talked to before.
https://www.olcf.ornl.gov/about-olcf/visitor-information-tours/