Volcana was onced called Claire Selton. As a teenager. Claire showed an aptitude for pyrokinesis (the ability to start fires with one's mind.) Her parents sent her to Metropolis's Center for Paranormal Studies so that she could learn to control and develop her power, but she soon spirited away by government agents who had big plans for her. According to the director of the Center, the agents "stripped away her past, code named her Volcana, and tried hardest to turn her into a living weapon."
But Volcana wouldn't go along with the plan. She escaped from the agents, became a hunted fugitive and survived the only way she could: by stealing. Superman stopped her and she was put on a deserted island where Superman delivered her food in exchange that she stayed on the island and didn't harm anyone.She later made a cameo appearance in the episode "Unity". Here she had a brief fight with Supergirl, obviously having left her island.
Justice League and Justice League Unlimited
Volcana made appearances in the episodes "Only a Dream" and "Hereafter" of Justice League,In the episode Only a Dream Volcana is incarcerated at a Metropolis jail and takes advantage of a prison riot to escape with fellow villain Firefly. Exactly why she left the island is unknown, but knowing her personality, it was likely due to boredom and wanting to live a life of excitement once again. She shows a willingness to kill using her powers in this episode, which brings the character to a more sinister level than before.
It was established in the "Fearful Symmetry" episode of Justice League Unlimited that the government project that created her was a government program that was a precursor or early version of Project Cadmus. It would not be strictly the Cadmus we see in Unlimited, as Amanda Waller claims that it was formed in the wake of the Justice Lords (and it has been established that Project Cadmus began following Darkseid's brainwashing of Superman at the end of Superman: The Animated Series).
She has also appeared as a member of Gorilla Grodd's Secret Society and was seen battling the invading forces of Darkseid in the series finale. In this episode she is shown to fly under her own power, which is probly how she left the island to rejoin society. Unlike Livewire, Volcana witnesses Darkseid's return and was saved by Sinestro and Star Sapphire. She is one of the few survivors alive at the end of the battle and was last seen taking advantage of the "five minute head start" the Justice League gives her after fighting with Darkseid ceased.