“Radioactive Sinkers: Can We Devise High-Temperature, Rock-Melting Probes, Fuelled With the Radioactive Wastes from Reactors, Both to Dispose of Those Wastes Effectively and to Tell Us More about the Earth’s Interior? There Are Many Difficult Problems, but the Gains in Knowledge about the Deep Regions of the Terrestrial Mantle Could Be Considerable”, Christopher Talbot1978-07-13 (self-sinking waste disposal)⁠:

[A new concept for the storage of radioactive wastes in rock formations is discussed.

The storage containers would be so designed that the heat generated by the stored radioactive material would melt small volumes of rock below the container resulting in progressively deeper burial. It is also proposed that the rock-melting probes should contain laboratory facilities capable of communicating information about the deep regions of the terrestrial mantle back to the surface.

It is felt that it should be possible to construct appropriate containers capable of withstanding large pressures, high temperatures and high radiation dosage without developing substantial mechanical defects using refractory alloys or ceramics. A hypothetical model of such a probe is shown.]