Well, no. At least not any more. Probably. They did have a huge property out in Western Australia. Seismometers around the world recorded a large seismic event in this tectonically stable area back in May 1993. Some say the signature was like a nuclear blast. But nobody thought to go check it out. For years. When someone finally went out there, long after Aum Shinrikyo had abandoned the sheep station, they found a technical lab, and many sheep who had died from exposure to several things. Including radiation and sarin. Bill Bryson kinda created the modern mythology of the Aum-Nuke in his book, "In a Sunburned Country", but ... the facts are all there. They are all weird. And you can extrapolate that Aum possibly had a successful nuclear test on that site, long before their sarin gas attack on the Tokyo subway. So... yeah. Do with that what you will...