In the world of nuclear isotopes, apparently there are shortages or potential shortages of more than just technetium (and the molybdenum used to make it). The Knight Journalism Tracker noted an NPR story reporting that there are shortages of plutonium-238, the isotope that powers many deep space missions. Like technetium, plutonium-238 is the byproduct of other nuclear processes. In this case the process is nuclear weapons manufacture, something both the U.S. and Russia are doing much less than they used to. Since both countries were relying on the supplies they had generated from previous weapon manufacture, the stockpiles are running low and there are no foreign sources currently manufacturing the material. Much like molybdenum and technetium, the U.S. has not produced plutonium-238 since the 1980s. Unlike those two isotopes, there are no bills in Congress (or any other plans) to address the shortfall.