K-27

K-27. A unique nuclear submarine of the Soviet Navy, it was the sole vessel of its Project 645 design, an advanced modification of the November-class submarine. Commissioned in the early 1960s, it was notable for its experimental liquid metal-cooled nuclear reactor and was involved in a catastrophic radiation accident that led to its eventual scuttling. The vessel's history remains a significant case study in Cold War naval engineering and nuclear safety failures.

Design and development

The design originated as a deep modification of the first-generation November-class submarine, intended to evaluate the performance of a revolutionary VT-1 reactor that used a lead-bismuth eutectic as its primary coolant. This technology, championed by Soviet scientists, promised higher power density and efficiency compared to traditional pressurized water reactors used in contemporary United States Navy submarines like the USS Nautilus (SSN-571). The development was led by design bureau SKB-143 under chief designer A. K. Nazarov, with critical reactor work overseen by the Institute of Physics and Power Engineering in Obninsk. The submarine's construction took place at Severodvinsk Shipyard No. 402, facing significant technical challenges related to maintaining the liquid metal coolant in a molten state. Its unique propulsion plant was considered a major technological leap for the Soviet submarine fleet, aiming to provide superior submerged speed and endurance.

Operational history

Following its commissioning into the Northern Fleet, K-27 began extensive sea trials and operational testing in the Barents Sea. In 1964, it undertook a long-endurance cruise, successfully operating for over 50 days while submerged, a demonstration of its advanced design capabilities. The submarine was primarily engaged in proving the viability of its novel reactor system under various operational conditions, rather than in frontline anti-submarine warfare duties. Its service was relatively brief, focused on experimental missions that pushed the boundaries of Soviet naval nuclear propulsion. The crew, trained at specialized facilities in Obninsk, worked under the command of Captain 1st Rank Pavel Leonov to master the complex and untested systems.

Nuclear accident and aftermath

On 24 May 1968, during a routine patrol in the Barents Sea, the starboard reactor suffered a catastrophic failure. A sudden loss of coolant flow led to severe overheating, causing massive fuel element failure and the release of intense gamma radiation and radioactive gases such as krypton-85 into the reactor compartment and adjoining spaces. Nine crew members received lethal doses of radiation and died, while 83 others suffered from acute radiation syndrome. The commanding officer, Pavel Leonov, ordered an emergency surfacing. The crippled submarine was towed back to its base at Gremikha, where the damaged reactor compartment was isolated. After years of study and failed repair attempts by specialists from the Kurchatov Institute, the vessel was declared irreparable. In 1981, following a decision by the Council of Ministers of the USSR, it was loaded with bitumen and furfurol, and scuttled in the Kara Sea at a depth of approximately 33 meters, creating a long-term environmental concern.

Legacy and significance

The disaster of K-27 served as a grim lesson for the Soviet Navy, directly influencing the safety protocols and design philosophy for subsequent submarine reactors, including those on the Alfa-class submarine. The accident remained shrouded in secrecy for decades, emblematic of the opaque handling of nuclear incidents during the Cold War. The scuttling site has been a subject of ongoing environmental monitoring by organizations like Bellona Foundation and the Norwegian Radiation and Nuclear Safety Authority, highlighting issues of radioactive waste disposal in the Arctic Ocean. The vessel's unique VT-1 reactor technology was later developed further for the Lira-class submarine program. The story of K-27 is often cited alongside other Soviet naval catastrophes like the K-19 and K-278 Komsomolets as a critical chapter in the history of naval nuclear power.

Specifications

* **Displacement:** 3,420 tons surfaced; 4,380 tons submerged * **Length:** 109.8 meters * **Beam:** 8.3 meters * **Propulsion:** Two VT-1 reactors with lead-bismuth eutectic coolant, powering steam turbines and two shafts * **Speed:** 14.7 knots surfaced; 30.2 knots submerged * **Test depth:** 300 meters * **Complement:** 105 officers and enlisted personnel * **Armament:** Eight 533-mm torpedo tubes for standard Soviet torpedoes

Category:Soviet submarines Category:Nuclear submarines Category:Maritime incidents in 1968