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The production of electricity in nuclear power plants generates radioactive waste as a by-product. The waste is often placed in canisters (containers), but it remains radioactive for thousands of years, emitting invisible radiation that is harmful to humans and other living things. Scientists are currently discussing several strategies for safely storing the canisters; they need to be stored for thousands of years until the waste loses its radioactivity.

Surface Storage

One option is to store the canisters in permanent structures above ground. If properly constructed from a radiation-blocking material like concrete, such structures should remain sealed for thousands of years. Clear instructions would ensure the structures are properly maintained so that the material does not leak out and cause damage. In addition, signs with written warnings would be posted throughout storage sites to clearly indicate the purpose of the structures.

Borehole Disposal

Another option is to store the canisters in boreholes--long, vertical holes dug deep down into the earth. The waste would be lowered into the bottom of the borehole, and the remaining space filled and sealed with radiation-blocking material. Engineers already have considerable experience drilling boreholes for experimental purposes and oil exploration. In the proper area, boreholes are stable and relatively inexpensive to create.

lce Sheet Storage

Another solution is to store the canisters under the large, uninhabited surface of solid ice that has covered Antarctica for thousands of years. Radioactive waste produces a small amount of heat, so if a canister with waste were placed on the ice sheet, its heat would melt enough ice to allow it to sink farther and farther down. As it sinks, the melted ice layers above it would freeze again, sealing the waste off from the surface. Under this ice sheet, the waste should remain isolated from the surface long enough to lose its radioactivity.

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