Submarine K-27 - Soviet

The wrecked Soviet submarine K-27 with a reactor that was not dismantled could pose a risk of radioactive leak as much as the Chernobyl disaster.

At the height of the Cold War in 1968, 144 Soviet sailors on the K-27 submarine sailed to the North Pole to collect information about the NATO base. They did not know that they were going to face a radioactive disaster in the sea, according to the BBC.

K-27 is the only attack submarine under Project 645, developed from Project 627 (NATO designation: November). Similar to the US, the Soviet Union often tested advanced technologies ahead of its time. The K-27 is equipped with two liquid - cooled VT-1 nuclear reactors . This design has never appeared on Soviet submarines, making the K-27 more like a science project than an attack submarine.

When launched on June 15, 1958, K-27 was the first Soviet submarine to own a nuclear reactor cooled by a mixture of lead and bismuth liquid metal. This type of reactor has a smaller size and larger capacity than traditional water-cooled design. It helps submarines hide for weeks in the sea without rising or supplying. K-27 has set an impressive record in the Soviet Navy, becoming the first nuclear attack submarine to dive continuously for 50 days.

Despite impressive technology and parameters, the K-27 has a short operating life due to a nuclear reactor malfunction. On May 24, 1968, during a spying on the North Pole, one of the two VT-1 reactors was in trouble, causing the power supply to ship to drop dramatically from 87% to 7%. At the same time, gamma radiation surged in the reactor compartment. Poison gas and steam also leak from the reactor to other chambers.

K-27 during a drill exercise near NATO forces.(Photo: The Lean Submariner).

'After 5 days of journey, everything happens normally. I was talking to the other people in the # 5 compartment, next to the # 4 compartment containing two nuclear reactors, when I suddenly heard someone running. We have radiation detection equipment but don't turn on the device, nobody cares about the specs until the technician turns on the radiation meter. His face was stunned and worried , ' recalled submarine officer Vyacheslav Mazurenko.

The crew did not understand the severity of the problem until it was too late, because the radioactive gas had no taste. Two hours after the initial alarm, people in cabin 4 must be carried out by stretchers due to heavy radioactive contamination. The crew found a way for the ship to emerge, then it took five hours to bring the ship back to base on the Kola Peninsula.

'When the ship floats to the surface, the superior orders the engine to be turned off and waits for a special instruction. However, Captain Pavel Leonov decided to continue his journey. If stopped for a few more hours, no one would have survived to take the K-27 back to the base , 'Mazurenko said.

All 144 crew members were radioactive, of which 9 were killed. However, the Soviet Union continued to ship the K-27 to the sea a month later and conducted many experiments until 1973.

By February 1979, Soviet troops decided to disqualify K-27, but had a headache to find a solution to handle the nuclear reactor on board. They finally decided to sink the K-27 in a 30-meter-deep water on the Kara Sea on September 6, 1982.

The K-27 tank is filled with concrete and asphalt to enclose the two reactors and 90 kilograms of uranium-235 fuel inside, but this protection is expected to work only for 50 years. By the middle of this year, the concrete and asphalt casing on board only has a shelf life of about 15 years. That makes the K-27 like an undersea Chernobyl disaster waiting to happen.

K-27 ships in the process of being sunk.(Photo: Barents Observer).

'Sooner or later, radioactive leaks will take place if the K-27 is located there. The ship has remained in the sea for more than 30 years in a rusty state. The challenge now is to find a way to get the ship up without shaking the reactors. If that happens, uncontrollable chain reaction can be triggered, causing large amounts of radioactive material to leak into the Arctic sea environment. This type of pollution cannot be removed from the seabed, ' said Thomas Nilsen, editor of the Barents Observer.

Despite the incident on the K-27, the liquid metal cooling reactor was still completed and equipped with Project 705 submarine 'Lira' (NATO designation: Alfa). They have unprecedented fast speeds and amazing diving ability. However, all of the Lira submarines were outdated early due to expensive maintenance costs.

The United States also equipped a liquid-cooled nuclear reactor on the USS Seawolf (SSN-575) submarine in the 1950s, but it quickly removed them to return to a high-pressure water reactor.