What Are Putin's Nuclear 'Doomsday' Poseidon Torpedoes?

This week Russian naval vessels, including the cruise missile submarine Belgorod, were detected leaving a testing area in the Arctic Sea and heading back to port.

Senior U.S. officials told CNN they believe the plan may have been to test a new nuclear-powered torpedo, the Poseidon, which Italian newspaper La Repubblica dubbed "the weapon of the apocalypse."

American government insiders told the network they suspect the Russians may have experienced technical difficulties, leading to the mission being aborted.

The test of a Poseidon nuclear-powered torpedo would likely have further inflamed tensions between Moscow and Washington, which are already sky-high following Russia's invasion of Ukraine in February.

On Friday Ukrainian troops raised their flag in the key southern city of Kherson, which was captured by Russian forces during the first weeks of the war.

The Institute for the Study of War, a U.S.-based think tank, has said Russian troops could suffer more than their Ukrainian counterparts over the next few months due to a lack of winter clothing.

What Is the Poseidon Nuclear-Powered Torpedo?

The Poseidon nuclear-powered torpedo is an unmanned underwater vehicle, capable of carrying either a nuclear or conventional warhead.

According to a Congressional Research Service (CRS) report, published earlier this year, Poseidons are intended as retaliatory weapons in the event of a nuclear strike on Russia.

Their existence was first announced by President Vladimir Putin in 2018, during his state of the nation address.

The Russian leader said: "The nuclear power unit is unique for its small size while offering an amazing power-weight ratio. It is a hundred times smaller than the units that power modern submarines but is still more powerful and can switch into combat mode, that is to say, reach maximum capacity, 200 times faster."

According to Russian news agency TASS, the Poseidon is designed to be launched hundreds of miles from its target, and can hug the ocean floor to avoid coastal defenses.

The Belgorod, which according to the CRS can carry eight Poseidons, was delivered to the Russian navy in June.

What Damage Could it Do?

In November 2020, Christopher Ford, at the time U.S. assistant secretary of state for international security, said Poseidons were designed to "inundate U.S. coastal cities with radioactive tsunamis."

Speaking to Newsweek earlier this year, Shaun Burnie, a senior nuclear specialist at Greenpeace, compared Poseidon to the notorious "doomsday" nuclear weapons built by the Soviet Union during the Cold War.

"It's reported that the yield is up to 100 megatons—hence the apocalypse reference," Burnie said, speaking of the impact the torpedo could have if used with a nuclear warhead.

"One suggestion is that the weapon contains large amounts of cobalt 59 which on detonation becomes radioactive cobalt 60—the aim being to maximize the amount of radioactivity released and that it is long-lasting. Such a weapon was built by the Soviet Union during the Cold War intended as a doomsday device to put as much radioactive cobalt into the upper atmosphere to be capable of making large parts of the planet uninhabitable."

Mark Foreman, a nuclear expert at Chalmers University of Technology in Gothenburg, Sweden, told Newsweek Poseiden is particularly dangerous because it can detonate underwater.

He explained: "Subsurface nuclear detonations tend to be very dirty, the radioactivity from the fuel in the bomb along with the radioactivity generated by bombarding sea water with neutrons will be very horrible.

"The U.S have experience of letting off atom bombs under water. When this is done it tends to generate a spray of water which is very radioactive. If this spray lands on a surface of a ship or other thing and then dries out then it tends to be very hard to remove from the ship."

The Russian Foreign Ministry has been contacted for comment.