CARLSBAD, N.M. (AP) — The U.S. Department of Energy has commissioned a national group of scientists to study the viability of diluting surplus weapons-grade plutonium and storing it permanently at the federal government’s underground repository in New Mexico. The panel of about 15 scientists from universities, corporations and laboratories around the nation will evaluate the storage potential at the Waste Isolation Pilot Plant, the nation’s only facility for permanently disposing of tons of Cold War-era waste contaminated with small amounts of plutonium and other man-made radioactive elements. The scientists held their first meeting in November in Washington, D.C., then gathered again Tuesday in Carlsbad, where officials gave presentations and fielded questions on the feasibility of bringing plutonium to the repository, the Carlsbad Current-Argus reports. Critics are unconvinced the Waste Isolation Pilot Plant can safely hold the plutonium, or that the facility’s mission can be expanded via federal law in an appropriate amount of time. Experts estimated about 34 metric tons of surplus plutonium exist around the world, mostly in the U.S.