LA Hague takes exposure seriously, nevertheless. Inside the plant, there’s a bit of the atmosphere of a James Bond movie. Protection suits and respirators hang on the walls. Scores of workers in white jumpsuits sit at computer screens in a central control room, while others control radiation-resistant robots or dexterous telemanipulators to guide, clean, or repair the equipment. The robots are in the thick of the action, and the danger lies safely isolated behind walls and leaded-glass windows 1 to 2 meters thick in workshops that have not seen a human in two decades of heavy-industrial operation.

Reprocessing at La Hague takes place in two independent but interconnected lines. At the front end of each line, robotic assemblies lift spent fuel-rod bundles weighing 500 kilograms from armored shipping casks and suspend them in 9-meter-deep pools of water. The fuel bundles are at 300 °C; after cooling for four to five years, the fuel elements are fed into the plant’s processing workshops to be chewed up, dissolved in nitric acid, and run through a series of chemical separation baths. The chemistry is fundamentally the 63-year-old Purex process developed in the Manhattan Project—Purex stands for “plutonium-uranium extraction”—but Areva says the separation equipment employed is more compact than its predecessors and generates less waste.

The major products of the separation are uranium and plutonium. The former, consisting of the isotopes U-235 and U-238, constitutes 95 percent of the spent fuel. The plutonium yield is just a little more than 1 percent. Most of the uranium is shipped to an Areva plant in southern France and, at the moment, stockpiled. Some analysts predict that uranium prices will eventually justify more reuse of La Hague’s uranium; but for now, utilities find it cheaper to use fuel freshly made from uranium ores and enriched to the precise isotopic composition they need. As for the plutonium, it is shipped across France to the Rhône Valley, where Areva’s Marcoule fuel plant blends it with uranium and fabricates it into fuel for French reactors.

The final step in the process encapsulates the high-level waste, which consists mainly of acids and solvents from the Purex process plus dangerous, extremely radioactive leftovers from the spent fuel, including isotopes of curium, cesium, and iodine. This step is called vitrification. Technicians operating remote manipulators drop the toxic blend into a bath of borosilicate glass heated to 1150 °C, then dole out the molten mix into 180-liter stainless-steel canisters. Think of a huge glass paperweight with radioactive matter inside instead of colored swirls. But this particular glass is not fragile, Blanc explains. That’s the point: the glass is supposed to immobilize the isotopes, isolating them from the environment, like bugs in amber, for thousands of years.

Once processed, two bundles totaling 528 fuel rods yield one vitrification canister 1.3 meters tall and a bit less than half a meter in diameter, plus another steel canister of similar size holding the compacted metal fuel rods. Even the largest of France’s reactors, which can produce 1300 megawatts, generate just 20 canisters of high-level waste per year. According to Areva, it’s about a factor of 10 reduction in the mass of highly radioactive waste needing to be stored under the most stringent conditions, and a four- or fivefold reduction in volume relative to leaving a plant’s spent fuel unseparated [see flowchart, “The French Nuclear System”].