Hannah Pell’s article titled “‘Peaceful’ nuclear explosives?” (Physics Today, November 2023, page 34) is informative about the US Atomic Energy Commission’s Project Plowshare, which sought to make use of nuclear explosions in applications such as gas stimulation and the creation of canals and harbors.
Pell reports that the Soviet Union was carrying out a similar program. She also makes note of the 1963 Limited Test Ban Treaty, which prohibited nations from conducting nuclear explosions in the atmosphere, underwater, and in outer space—but not underground, unless the explosion would create radioactive debris outside the territorial limits of the state conducting it.
A meeting on the Comprehensive Nuclear-Test-Ban Treaty at the United Nations Headquarters in New York City in 2016. (Courtesy of the US State Department/public domain.)
A meeting on the Comprehensive Nuclear-Test-Ban Treaty at the United Nations Headquarters in New York City in 2016. (Courtesy of the US State Department/public domain.)
Later arms-control agreements were also related to nuclear explosions for peaceful purposes. In particular, the US–Soviet Threshold Test Ban Treaty, signed in 1974 and ratified in 1990, prohibited underground nuclear weapons tests that would yield more than the equivalent of 150 kilotons of TNT. The Peaceful Nuclear Explosions Treaty, signed in 1976 and ratified in 1990, included the same stipulation for all individual nuclear explosions.
The Comprehensive Nuclear-Test-Ban Treaty, which opened for signatures in 1996 and has not yet come into force, calls for the prohibition of all nuclear explosions, regardless of yield or stated purpose. It now has 187 signatories, 177 of whom have ratified the treaty and become parties to it. The treaty provides for review conferences that “take into account any new scientific and technological developments” relevant to it. Such conferences would consider, at the request of any nation, allowing underground nuclear explosions to be conducted for peaceful purposes. If a consensus is reached to allow such explosions, the treaty says, the conference should then recommend an amendment “that shall preclude any military benefits of such nuclear explosions.”
But the preclusion of military benefits seems impossible, and the requirement for consensus among the parties seems to be a substantial obstacle for amendment. “Peaceful” nuclear explosions seem unlikely to have a future on our planet.
