Plutonium ryanite was a fissionable explosive used for terraforming applications and large scale excavations on Class R planets. This explosive was used as well for the demolition of small asteroids. The development of this explosive was credited to the Adams Research Group, an institution located on Wynsdey III. In 2367, this compound was stored on aboard the Federation starship USS Enterprise-D.
In that year, plutonium ryanite was on a list of explosives that Lieutenant Commander Data and Counselor Deanna Troi searched through in an attempt to find one that could produce enough energy to release the USS Enterprise-D and an alien ship from the Tyken's Rift. (TNG: "Night Terrors")