CARLSBAD, N.M. — More than 180 shipments of radioactive waste from sites around the United States have been sent to the federal government’s only underground nuclear waste repository since operations resumed last year following a 2014 radiation release.

U.S. Energy Department officials who oversee operations at the Waste Isolation Pilot Plant in southern New Mexico provided an update on shipments and other work at the repository during a recent conference in Phoenix.

The shipments have ramped up to about eight a week. They have come from Los Alamos National Laboratory in northern New Mexico and installations in Idaho, Tennessee, South Carolina and Texas.

Mining also is underway to create more disposal space in the ancient salt formation where the repository is located. The idea is that shifting salt will eventually entomb the waste.