From the Sun [caution tabloid]:
Russia and the US have both said Poseidon torpedoes are a new breed of retaliatory weapon which can cause radioactive tsunamis and make whole coastlines uninhabitable.
Putin told a group of soldiers wounded in the war against Ukraine that the test launch happened on Tuesday. He said: “Yesterday, another test was conducted for another prospective system – the unmanned underwater device ‘Poseidon,’ also equipped with a nuclear power unit. “For the first time, we managed not only to launch it with a launch engine from a carrier submarine, but also to launch the nuclear power unit on which this device passed a certain amount of time.”