A Bulava nuclear-capable missile was tested by the Russian Navy in May 2018 TASS/Tass/PA Images

Russia's facing another potential nuclear crisis. Following last week's explosion at the military base in Nyonoksa, in north-west Russia, residents are preparing for a minor evacuation.

At the center of the problem appears to be the nuclear rocket engine 9M730 Burevestnik – known as SSC-X-9 Skyfall to Nato. The accident on Thursday caused a 30-minute spike in radiation levels in the nearby Severodvinsk; seven people have reportedly died.


So what do we know about the rocket behind this destruction? Given the secretive nature surrounding military technology, it's impossible to know exact details of what the engine is capable of but analysts can pick up some clues from what has been disclosed.

What we concretely know about the Burevestnik are only the facts Vladamir Putin gave on March 1, 2018, during an address to the Federal Assembly – that the Burevestnik is a nuclear-armed, nuclear-propelled cruise missile.

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This nuclear propulsion is what makes the engine stand out – it's a literal flying nuclear power source. In theory nuclear propulsion allows the rocket to have a supposedly “unlimited range” – yet is also the source of its issues.

“The Burevestnik is technically an intercontinental cruise missile,” says Mathieu Boulègue, a research fellow on the Russia and Eurasia programme at Chatham House. The idea that the missile’s range is unlimited is a slight misnomer, Boulègue explains. “The Soviet Union used to develop these cruise missiles with a theoretical range of about 3,000 kilometers,” he says. “So when they say unlimited, it technically means over 3,000 kilometers.” In essence, the Burevestnik would offer persistence and range far greater than anything on the market – it would fly at a very low altitude and relatively great speed for an amount of time over the existing ranges of that category of cruise missile.


The use-value of a weapon like this, explains Douglas Barrie, senior fellow for Military Aerospace at the International Institute for Strategic Studies, is in the second or third strikes. “This is a retaliatory weapon – it’s intended to ensure that even after a full-blown nuclear exchange, I'm going to be capable of ‘bouncing your rubble’,” he says. “You could launch this and park it somewhere, having it in holding orbit out of the way of other incoming missiles and still be confident, inverted commas, that it would that it would survive and hit a target.”

The Burevestnik’s theoretically phenomenal range relies on its nuclear propulsion. Though again, there isn’t a lot of reliable information on the detail behind this process. “It appears to be a nuclear-powered missile, i.e., produces thrust by possibly leveraging the heat generated during nuclear reactions to heat up ingested air to produce thrust,” says George Nacouzi, a senior engineer at the RAND Corporation. “If designed properly this “engine” would run for a very long time: as long as the nuclear reactions are producing the required heat to power the engine.” (Nacouzi emphasises that the technical detail behind the process may very well be different).

Standard cruise missiles are usually propelled by ‘Ergol’ or hypergolic propellant. “[The Burevestnik’s] Ergol is modified to include nuclear-powered propellant, which is basically using the power of splitting the atom to fuel its flight,” says Boulègue. “Mixing Ergol with nuclear propulsion is dangerous, as the accident has shown, because it’s super unstable – the technical challenge behind it is to make sure it is stable.”

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The explosion comes as tensions have heightened around Russia's nuclear programme. In the 2018 Federal Address, Putin stressed that the Burevestnik, along with an arsenal of other new nuclear weaponry, would render Nato defenses "completely useless”, stating that "Russia still has the greatest nuclear potential in the world, but nobody listened to us.”


He stated that their construction was a direct response to the US’s 2002 withdrawal from the 1972 Anti-Ballistic Missile Treaty, under George W. Bush. (The Trump administration responded that "Russia has been developing destabilizing weapons systems for over a decade, in direct violation of its treaty obligations").

One of Russia's other missiles in development – the SSC-8 – promoted the US to pull out of the Intermediate-Range Nuclear Force treaty which was signed in 1987. The US dropped the treaty on August 2 after Russia failed to meet deadlines it had set for the country to stop working on new weapons. Putin reacted by also dropping out of the treaty.

The Burevestnik may yet play a part in these political negotiations, says Barrie. “Given where we are in terms of arms control at the moment, is [the Burevestnik] something that the Russians might throw on the table as an arms control card with the US in some future negotiation?”

Nuclear propulsion, and its inherent instability, has historical antecedents. Ars Techinca says a similarly propelled weapon was originally envisioned for the US military's SLAM program of the early 1960s, but was dropped by the Kennedy administration for being “too proactive”.

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Couple this with the fact that you expect problems during test programs – this is their point – the accident is not unexpected, even if it is dangerous. “Even a conventional missile, on the propulsion side, is dealing with combustible or volatile materials,” says Barrie. “You then put on top of that a nuclear reactor, if that is what this is, it gets all the more complicated and all the more challenging all the more difficult.”

Finally, explains Barrie, it's important to remember that, as far as we know, the technique has never worked. “Looking at the history of test launches for this program all indications we see in the public domain are that they haven’t got any to work yet,” he says. “So this is, unsurprisingly proving to be a very, very difficult program to develop, but they still seem to be continuing to push through it.”

So why does Russia persist with it? Boulègue explains that we need to bear in mind that just because the missile is in development today, it doesn’t mean it will actually be deployed at any time. “There are a lot of reasons to believe that this project might be abandoned along the way in the 2020s if it proves too costly, too dangerous, and basically, useless,” he says. “This is not the first time the Russians have announced systems they've never deployed, and it will not be the last.”

The project itself is the weapon. “The system is among six or seven others that were unveiled by Putin in March 2018,” says Boulègue. “With these doomsday weapons the message itself is the weapon – it is part of Russia's chest-thumping, great power politics, rhetoric aimed at showing military technology superiority to us, and trying to justify military expenditure and demonstrate Russia's military security for the Russian population.”

Updated August 17 and August 23, 2019 The explosion was not nuclear, but included the release of nuclear materials and an inaccurate quote surrounding intercontinental ballistic missiles has been removed

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