For years a dozen Italian seaports have been decrying the risks they run as bases for nuclear powered or nuclear armed U.S. warships (submarines, aircraft carriers):  Augusta, Brindisi, Cagliari, Castellammare di Stabia, Gaeta, La Maddalena, La Spezia, Livorno, Napoli, Taranto, Trieste, Venezia.

Movements have grown up denouncing the use of these Italian port facilities by nuclear vessels.   The activists demand, for example, that their local administrators reveal their emergency and evacuation plans in case of an accident.   This means knowing the technical/operational aspects of the nuclear device or plant, its precise location and the exact nature of the accident – information vital for taking the proper measures but, at the same time, information that military authorities are loathe to give and, indeed, may consider top secret.

I do not intend to treat this issue any further here and invite the reader to see Massimo Zucchetti’s analysis of the problem in his article “Stop nuclear-powered naval units in Italian ports: from examining external emergency plans a simple conclusion”, in Invisible Evil, Increasingly Visible, Scientists Against War, Odradek, pp. 253-58, 2005.

But I do wish to remind the reader that military nuclear reactors present enormously greater risks than civil nuclear plants: naval reactors develop an enormous amount of power in a relatively tiny enclosure; they run on highly enriched uranium; they are cooled by pressurized water or liquid metal; they operate, not on UO2, but on a uranium-zinc or uranium-aluminum alloy; the shell containing them must be able to stand enormous pressures; lastly, they offer very limited possibilities of adjustment to changing circumstances.

It is useful, in this respect, to investigate how nuclear accidents actually occur on U.S. naval vessels.  One such study is Hans Kristensen’s analysis of declassified military documents: see “Declassified: U.S. nuclear weapons at sea”, February 3, 2016,  The study shows how much we have to learn from history – about the past but, at the same time, about our future.  Naval vessels really do collide, or catch fire, or sink; it is only a question of time before something like that happens.  This is why storing nuclear weapons on ships is so risky.

Dozens of nuclear bombs have ended up on the sea floor because they were in ships, submarines or aircraft that went down.  Here are some examples.

On May 7, 1968, the nuclear attack submarine Scorpion, after leaving the port of Naples for a mission in the Mediterranean Sea, sank at 644 kilometers off the Azores with, on board, 99 seamen, two nuclear torpedoes, and a nuclear propulsion reactor.  No more is known because the incident is classified as secret.

In January, 1968, a hydrogen bomb was lost off the coast of Palomares in Spain.

In August, 1968, the U.S. submarine Von Steuben, carrying 16 Polaris missiles and 48 nuclear warheads, struck a towing cable at 64 kilometers off the Spanish coast; when it surfaced, it hit the tanker Sealady and was variously damaged.

In 1969, a fire broke our on the aircraft carrier Enterprise off the coast of Pearl Harbor, causing explosions and almost sinking the ship.

In November, 1970, a submarine tender caught fire in the submarine port of Holy Loch, in Scotland,  with two nuclear submarines docked alongside.  All three vessels were loaded with nuclear warheads and missiles.

On November 22, 1975, during nighttime exercises, a collision took place at 112 kilometers East of Sicily between the aircraft carrier John F. Kennedy and the cruiser Belknap; the latter caught fire and burned for two and a half hours.  The blaze was finally extinguished when it had spread to just a few meters from the nuclear storage area.

In addition, there have been numerous accidents between U.S. and Soviet warships, both carrying nuclear weapons, during the Cold War.

We can exclude the incident that almost occurred during the Cuban missile crisis of 1962, when a Soviet B-59 nuclear submarine was about to fire a nuclear torpedo to sink one of the U.S. warships that were dropping depth charges on it – the incident never occurred because the Russian second in command, Archipov, opposed the action.

In May of 1974, two nuclear attack submarines, one American and the other Soviet, both carrying nuclear warheads, collided almost head-on near the naval base of Petropavlovsk on the Kamchatka peninsula.

In November of that year, after leaving the Holy Loch base in Scotland, the submarine James Madison, carrying nuclear ballistic missiles, collided with a Soviet nuclear attack submarine in the North Sea.

In 1976, a Soviet nuclear submarine, which had been hunted down in the Atlantic Ocean and then in the Mediterranean Sea for 10 straight days, surfaced near the frigate Voge, which was probably carrying nuclear anti-submarine missiles, and collided with it.

In 1988, in the Soviet territorial waters of the Black Sea, two Soviet frigates collided with the cruiser Yorktown and the destroyer Caron.

Besides the collision incidents, there have been serious diplomatic incidents involving nuclear armed and/or propelled vessels, all through the Cold War.  Several U.S. allies refused the peacetime presence of nuclear weapons within their territorial limits, due to the refusal of American authorities to confirm or deny the presence of nuclear weapons on their ships.  Another contributing factor were the (at times) violent protests by activists.  This was particularly true in New Zealand which, in 1984, denied visits to its ports by nuclear armed and/or propelled vessels, but also in Denmark and Sweden.  All this led many U.S. officials to wonder if the problems created by seaborne nuclear weapons were greater than the advantages they offered.

Even after the denuclearization of the U.S. surface and underwater fleet between 1991 and 1992,  nuclear ballistic missile submarines (SSBN) continued to have accidents, including collisions with other ships.  In 1993, for example, the SSBN Maryland remained stranded at Port Canaveral in Florida.  In March of 1998, the SSBN Kentucky, while conducting surface operations at 200 kilometers off the coast of Long Island, New York, was rammed by the attack submarine San Juan.

It is likely that most of the incidents involving nuclear ballistic missile submarines escape public attention and scrutiny.

But just imagine what would happen if, in the port of Genova, a U.S. nuclear warship ever did what the container ship Jolly Nero did on May 7, 2013.  While maneuvering to leave the port, the Jolly Nero rammed into and overturned the control tower, killing nine of the staff inside and wounding four!