Il K-278 Komsomolec, (traslitterato anche come Komsomolets russo: Комсомолец) era un sottomarino nucleare da attacco della Marina Sovietica (VMF) entrato in servizio negli anni ottanta. Fu l'unica unità della classe sperimentale Progetto 685 Plavnik, codice NATO classe Mike, pensato per testare alcune tecnologie particolarmente avanzate ed operare a profondità superiori a 1.000 metri.
Il K-278 affondò a causa di un incendio il 7 aprile 1989 nel Mare di Norvegia, alcune centinaia di chilometri a nord della città di Tromsø.
Sviluppo
I tecnici sovietici iniziarono a lavorare al Progetto 685 Plavnik (pinna in lingua russa) fin dagli anni sessanta, ma la costruzione del primo esemplare venne intrapresa presso il cantiere navale di Severodvinsk solo nel 1978. Si trattava di un esemplare unico, costruito per testare una serie di tecnologie particolarmente avanzate. Il battello venne varato il 9 maggio 1983, ed entrò in servizio il 31 dicembre dell'anno successivo.
In Occidente venne identificato con il nome in codice NATO di classe Mike. Il K-278 fu il solo della sua classe ad entrare in servizio. La costruzione di un ulteriore esemplare venne iniziata, sempre a Severodvinsk, ma i lavori non furono mai ultimati.
Tecnica
Il K-278 era un sottomarino nucleare da attacco, lungo 117,5 metri e largo 10,7. Si trattava di un battello a doppio scafo, con quello interno in titanio. L'utilizzo di questo materiale consentiva di operare a profondità estreme, di molto superiori a quelle dei contemporanei battelli occidentali: infatti, la profondità operativa era di 1.000 metri, quella massima operativa di 1.250 metri e quella di rottura di 1.500 metri.
Lo scafo interno, pressurizzato, era organizzato in sette compartimenti:
- sala siluri;
- alloggi;
- sala controllo;
- compartimento reattore;
- motori elettrici;
- turbine;
- meccanismi ausiliari.
Inoltre, sistemata nello scafo, vi era anche una sfera di salvataggio, in modo da consentire l'evacuazione dell'equipaggio in caso di incidente.
La propulsione era assicurata da un singolo reattore nucleare ad acqua pressurizzata del tipo OK-650 b-3 da 190 MW, che consentiva una velocità massima nell'ordine dei 14 nodi in superficie e dei 26-30 in immersione. Inizialmente, l'intelligence occidentale ritenne che in realtà i reattori imbarcati fossero due, del tipo a metallo liquido. Questo portò la NATO a sovrastimare la reale velocità massima del sottomarino (36-38 nodi).
L'armamento era costituito da sei tubi lanciasiluri da 533 mm, mentre il munizionamento comprendeva normali siluri e missili, sia antinave, sia da crociera (questi ultimi con la possibilità di imbarcare testate nucleari).
L’affondamento
Il 7 aprile 1989 il sottomarino, al comando del capitano Evgeny Vanin, navigava alla profondità di 335 metri a circa 180 chilometri (100 miglia nautiche) a sudovest dell'Isola degli Orsi in Norvegia. Un violento incendio si scatenò nei compartimenti di poppa e, nonostante venissero immediatamente chiusi i portelli stagni, le fiamme si propagarono attraverso le paratie seguendo il percorso dei cavi che attraversavano il sottomarino. Il reattore nucleare fu fermato con un arresto d'emergenza (SCRAM) causando la perdita della propulsione. Inoltre il controllo del battello divenne difficoltoso a causa di problemi elettrici causati ai cablaggi dall'incendio. Il comandante ordinò un'emersione di emergenza ed il sottomarino emerse, undici minuti dopo lo scoppio dell'incendio. Furono effettuate alcune chiamate d'emergenza ed evacuati i sopravvissuti.
Il fuoco continuò a bruciare alimentato dal sistema di aria compressa del sottomarino. Alcune ore dopo essere emerso il battello affondò definitivamente su di un fondale di 1680 metri. Il comandante e quattro altri membri dell'equipaggio che erano ancora a bordo entrarono nella capsula di emergenza e la sganciarono: a causa del suo parziale allagamento e della presenza di gas tossici, solo uno dei cinque raggiunse vivo la superficie.
Alcuni aeroplani inviati in soccorso giunsero rapidamente e lanciarono alcune piccole zattere di salvataggio ma molti uomini erano già morti per l'ipotermia causata dalle freddissime acque (circa 2°C) del mare di Barents. Il peschereccio Aleksey Khlobystov giunse 81 minuti dopo l'affondamento del K-278 e prese a bordo 25 sopravvissuti e 5 cadaveri. In totale perirono 42 uomini nell'incidente.
Diverse spedizioni scientifiche hanno verificato lo stato del sottomarino negli anni: nel 2019 una di queste spedizioni ha raccolto campioni di acqua attorno al relitto e all'interno di un condotto di ventilazione del Komsomolec; dai risultati preliminari risulta che, in uno dei campioni del condotto, sia presente un livello di radioattività pari a 800 becquerel per litro, cioè 800.000 volte il livello naturale, sebbene altri campioni non contengano valori così elevati.
ENGLISH
K-278 Komsomolets was the only Project 685 Plavnik (Плавник, meaning "fin", also known by its NATO reporting name of "Mike"-class) nuclear-powered attack submarine of the Soviet Navy. On 4 August 1984 K-278 reached a record depth of 1,020 metres (3,350 feet) in the Norwegian Sea. Although it was developed mostly to test technology for fourth-generation nuclear submarines, it was fully combat capable. It sank on its first operational patrol, in 1989, after a fire broke out in the aft engineering compartment.
The Komsomolets was able to surface after the fire started and remained afloat for approximately 5 hours before sinking. Of the 42 crew members who died, only 4 were killed by the fire and smoke, while 34 died of hypothermia, drowning in the frigid waters while awaiting rescue that did not arrive in time. Because of the loss of life, a public enquiry was conducted and, as a result, many formerly classified details were revealed by the Soviet news media.
The wrecked submarine is on the floor of the Barents Sea, about 1.6km (1 mile) deep, with its nuclear reactor and two nuclear warheads still on board.
Design
The Project 685 was designed by the Rubin Design Bureau in response to a challenge to develop an advanced submarine that could carry a mix of torpedoes and cruise missiles with conventional or nuclear warheads. The order to design the submarine was issued in 1966 and design was completed in 1974. The keel was laid down on 22 April 1978 at Severodvinsk. K-278 was launched on 3 June 1983 and commissioned on 28 December 1983.
K-278 had a double hull, the inner one being composed of titanium, which gave her an operating depth far greater than that of the best American submarines. The pressure hull was composed of seven compartments with the second and third protected by stronger forward and aft bulkheads creating a "safety zone" in case of an emergency. An escape capsule was fitted in the sail above these compartments to enable the crew to abandon ship in the event of an underwater emergency. Initial Western intelligence estimates of K-278’s speed were based on the assumption that it was powered by a pair of liquid-metal lead-bismuth reactors. When the Soviet Union revealed that the submarine used a single OK-650b-3 conventional pressurized-water reactor, these speed estimates were lowered.
Crew
According to Norman Polmar and Kenneth J. Moore, two Western experts on Soviet submarine design and operations, the Project 685's advanced design included many automated systems which, in turn, allowed for fewer crew members than would be expected for a submarine of its size. The manning table approved by the Soviet Ministry of Defense in 1982 called for a crew of just 57 men. This was later increased to 64: 30 officers, 22 warrant officers, and 12 petty officers and seamen.
Name
In October 1988, K-278 was honored by becoming one of the few Soviet submarines to be given an actual name: Komsomolets (Комсомолец, meaning "a member of the Komsomol"), and her commanding officer, Captain 1st rank Yuriy Zelenskiy was honored for diving to a depth of 1,020 meters (3,350 feet).
Sinking
On 7 April 1989, while under the command of Captain 1st Rank Evgeny Vanin and running submerged at a depth of 335 metres (1,099 ft) about 180 kilometres (100 nmi) southwest of Bear Island (Norway), fire broke out in the engine room due to a short-circuit, and even though watertight doors were shut, the resulting fire spread through bulkhead cable penetrations. The reactor scrammed and propulsion was lost. Electrical problems spread as cables burned through, and control of the boat was threatened. An emergency ballast tank blow was performed and the submarine surfaced eleven minutes after the fire began. Distress calls were made, and most of the crew abandoned ship.
The fire continued to burn, fed by the compressed air system. At 15:15, several hours after the boat surfaced, it sank in 1,680 metres (5,510 ft) of water, about 250 kilometres (135 nmi) SSW off Bear Island. The commanding officer and four others who were still on board entered the escape capsule and ejected it. Only one of the five to reach the surface was able to leave the capsule and survive before it sank again in the rough seas.
Rescue aircraft arrived quickly and dropped small rafts, but most of the men had already died from hypothermia in the 2°C (36°F) water of the Barents Sea. The floating fish factory B-64/10 Aleksey Khlobystov (Алексей Хлобыстов) arrived 81 minutes after K-278 sank, and took aboard 25 survivors and 5 fatalities. In total, 42 of the 69 crewmen died in the accident, including the commanding officer.
Aftermath
In addition to her eight standard torpedoes K-278 was carrying two torpedoes armed with nuclear warheads. Under pressure from Norway, the Soviet Union used deep sea submersibles operated from the oceanographic research ship Keldysh to search for K-278. In June 1989, two months after the sinking, the wreck was located. Soviet officials stated that any possible leaks were insignificant and posed no threat to the environment.
In 1993, Vice Admiral (ret.) Chernov, commander of the submarine group of which the Komsomolets was part, founded the Komsomolets Nuclear Submarine Memorial Society, a charity to support the widows and orphans of his former command. Since then, the Society's charter has expanded to provide assistance to the families of all Soviet and Russian submariners lost at sea. 7 April has become a day of commemoration for all submariners lost at sea.
An expedition in mid-1994 revealed some plutonium leakage from one of the two nuclear torpedoes. On 24 June 1995, Keldysh set out again from St. Petersburg to the Mike datum to seal the hull fractures in Compartment 1 and cover the nuclear warheads, and declared success at the end of a subsequent expedition in July 1996. The jelly sealant was projected to be safe for 20 to 30 years, that is, until 2015 or 2025.
Norwegian authorities from the Marine Environmental Agency and Radiation Agency are taking water and ground samples from the vicinity of the wreck on a yearly basis.
In July 2019, a joint Norwegian-Russian expedition took water samples out of a ventilation pipe and from several meters above, and analyzed them for caesium-137. That pipe had been identified as a leak in several Mir missions up to 1998 and 2007. The activity levels in the six samples out of the pipe ranged between less than (the on-board detection limit of) 10 Bq/l to 100 Bq/l (on July 8) and 800 Bq/l (July 9). No activity could be detected in the free-water samples. Due to dilution, there is no threat to the environment. The Norwegian limit on caesium-137 in food products is 600 Bq/kg. The background activity of caesium-137 in the water body is as low as 0.001 Bq/l. More sensitive measurements of the samples are underway.
Wreck of Soviet-Era Submarine Wreck Leaking High Radiation
It’s the plot of many a science fiction movie or dystopian novel – radiation seeps out from one source or another; thousands get sick or die, and the government pretends nothing is wrong and that the leak isn’t alarming.
That’s what happened at Chernobyl. That’s what happened at Three Mile Island in America in 1979.
Once again, Russia is the source of the problem, as one of its subs sits rotting at the bottom of the Norwegian Sea leaking radiation, after a disaster 30 years ago, during which 42 sailors lost their lives.
Those men were killed by the cold water, or by inhaling poisoned fumes while still stranded. However, 27 sailors did survive, and were rescued by two Russian ships. The sub’s commander had managed to surface briefly and call for help, so authorities were quickly notified of the disaster.
The Komsomolets sank in 1989 when a fire broke out on board. Now, scientists from Norway’s Institute of Marine Research have examined and filmed the wreck say it is leaking radiation at a level 800,000 times what is considered normal, or to some, acceptable.
The crew took samples from surrounding waters and one of the sub’s pipes to get a better idea of just how dangerous the leak might be.
The lead scientist on the project told bbc.com in mid-July that the levels are “not alarming,” but the sub was equipped with nuclear torpedoes, both with plutonium warheads. It could also fire Granit cruise missiles.
The sub, also known as K-278, lies in very deep water, more than 5,000 feet down, and any leaking radiation is immediately rendered, if not completely harmless, certainly less dangerous because the cold Arctic water dilutes it. Furthermore, because very few fish can survive at that depth or temperature, there is no threat to marine life, scientists say.
Slik ser den sovjetiske atomubåten “Komsomolets” ut i dag – 30 år etter at den sank i Norskehavet. Forskerne fikk de første bildene av vraket sent søndag kveld.
To get samples from the sub, the research team from Norway sent down a remotely-operated vehicle (ROV) to examine and film the wreck, in order to study it thoroughly in their lab. The team confirmed that the boat was very badly damaged during the fire.
However, Norway’s Radiation and Nuclear Safety Authority (DSA) explained to bbc.com that as soon as the fire began, the pressure water reactor that propelled the sub ceased operating, lessening the danger even further.
This is not the first time the K-278 wreck has been monitored; in fact, on occasion Russia and Norway have teamed up to check whether the wreck is causing more damage. This time, Russian scientists from the Typhoon Research and Production Association accompanied Norwegian radiation experts and marine scientists.
The mission’s leader, Hilde Elise Heloal, explained to bbc.com, “We took water samples from inside this particular duct because the Russians had documented leaks here both in the 1990s and more recently in 2007. So we weren’t surprised to find high levels here.”
However, she insisted, the radiation is not a threat to anyone, not even marine life. “The levels we detected were clearly above what is normal in the oceans, but they weren’t alarmingly high.”
The question now becomes: what level is too high? What can the ocean withstand before the radiation begins to damage marine life, then cause damage further up the food chain? Sooner or later these disasters do manifest themselves somehow in the human sphere; the only question is when, and how.
Can the wreck be retrieved, perhaps, before it rots completely and the radiation becomes a serious threat? And what will happen to those torpedoes?
Perhaps only scientists can answer these and other pressing questions about the dangers of nuclear materials. But of course, governments must then have the political will to enact whatever solutions science offers. That takes money, but also the willingness to admit their mistakes. And that is something no government is very good at, regardless of its philosophical leanings.
(Web, Google, Wikipedia, Covert Shores, You Tube)
Nessun commento:
Posta un commento