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Russia Says Five Died in Blast Where Radiation Spike Reported (bloomberg.com)
80 points by pseudolus 66 days ago | hide | past | web | favorite | 45 comments

The combination of

- a missile test

- involving “isotope power sources in a liquid propulsion system”

sounds seriously bad.

Am I reading too much between the lines or is this related to the crazy nuclear propulsion ICBM idea they threw out a while ago?

Not ICBM, cruise missile, and it ain’t crazy (well, from a technical standpoint - as a weapon, it’s totally crazy Dead Hand stuff) - see Project Pluto.

What’s being reported, given the context of their proclamation about nuclear powered missiles a while back, I think it’s a reasonable supposition in the absence of further information that they had something go very wrong with a static fire of a nuclear ramjet - probably not a nuclear detonation, but I wouldn’t be surprised if they a) had a supercritical moment and b) sprayed the reactor guts over a substantial area.


> I think it’s a reasonable supposition in the absence of further information that they had something go very wrong with a static fire of a nuclear ramjet - probably not a nuclear detonation

Can you explain this a bit more for those of us who know almost nothing about missiles/nuclear weapons. If I'm understanding the Project Pluto wikipedia correctly a ramjet isn't able to fire from a standstill and a nuclear ramjet would require both initial forward motion and then a nuclear detonation (not sure if that's the right word, perhaps just "reaction").

So I guess my question is, how would they safely static fire these types of missiles for testing purposes? Assuming Russia's project uses a similar setup to Project Pluto and has conventional rocket boosters to get the missile to ramjet speed is that what they'd be static firing - the boosters? And if they're testing the boosters attached to the nuclear ramjet without allowing the ramjet's reactor to go critical what would have to go wrong with the static fire that would result in radiation?

If the ramjet didn't go critical it wouldn't be of much use. The key number when you are talking about an operating reactor is called the multiplication factor--when an atom fissions on average how many other atoms will be split by the neutrons released from that fission.

When this number is less than one things just peacefully sit there. If an atom fissions the chain soon dies out. If this number is more than one things get hotter and hotter until it comes apart. If this were the whole story there would be no nuclear power, but there's one very useful detail--a small number of those neutrons are not emitted at once. This gives you a margin to control things.

When the immediate neutrons are enough to cause more than one fission you have the state known as prompt critical, you have lost control, the reactor will run wild and destroy itself. (An atom bomb is the same idea, except rather than just edging past 1 a bombmaker pushes the ratio as high as possible so it takes a city with it in destroying itself.) I am aware of two cases where reactors had issues with control rods and crossed the prompt critical line, both were immediately destroyed. SL-1 and Chernobyl.

The zone between critical and prompt critical gives you a way to control things. You have time to turn the heat up or down as needed. A nuclear ramjet is going to be designed to operate at a very high power density, it's going to be a lot closer to the line than a reactor is normally run. Stick one toe over the line and you get what SpaceX calls a RUD.

Alternately, it might have run too hot, something softened or melted and the core shape changed to cross the prompt critical line, same outcome.

Interesting, so because a nuclear ramjet runs closer to the line there’s less time to make adjustments and control things to prevent RUD. I guess that makes testing all the more difficult/dangerous.

Thanks for such a thorough explanation that I could actually follow! Much appreciated.

Just force air in with a big fan or jet engine to simulate forward motion?

Jet engine with a huge bypass factor for the compression stage, when testing on a static rig, yes.

> Project Pluto.

Sorry, should have mentioned that the Americans came up with this ugly idea.


And in defense of the Americans they canned it:

"Despite these and other successful tests, the Pentagon, sponsor of the "Pluto project", had second thoughts. The weapon was considered "too provocative",[2] and it was believed that it would compel the Soviets to construct a similar device, against which there was no known defense."

>The nuclear engine could, in principle, operate for months, so a Pluto cruise missile could be left airborne for a prolonged time before being directed to carry out its attack.

This is truly nightmare inducing stuff.

This was originally developed in the 1950's, and the successful development of SLBMs rendered it irrelevant, since as a cruise missile it would have been much easier to intercept than a ballistic warhead, as well as much slower to reach a target, and submarine launch also provided first strike immunity.

And this is what happens when your nuclear thermal propulsion system goes prompt critical on the ground. https://en.wikipedia.org/wiki/Nuclear_thermal_rocket#/media/... This was a nominal 1100MW design, the Pluto reactor was about half this output. It's insane that the Russians are testing this thing over their own territory.

> It's insane that the Russians are testing this thing over their own territory.

It would also be insane if the Russians were testing this thing over someone else's territory.

It's just insane.

Wonder if this could be about nuclear powered torpedos, rather than airborne missiles. Not sure how certain they are on the latter part. We know that there are hypersonic torpedos under development, and an intercontinental nuclear powered drone torpedo seems like it could be an effective weapon.

Sounds like it's not this actually, and it is a rocket engine; the Guardian has some other quotes on this:


You're thinking of their Status 6 torpedoes. 100kt, intercontinental range.

Sounds more like this Charlie Stross story: https://www.tor.com/2012/07/20/a-tall-tail/

Could it just be an RTG to power the rocket's systems in flight, instead of an actual nuclear propulsion system?

No reason for iodine tablets if a RTG got splattered across the landscape. If iodine tablets do any good there was fission involved. The threatening isotope is Iodine-131, half life of 8 days. It's only found associated with fission or with atom smashers.

It poses basically no direct harm, the threat is your body taking it up and putting it in the thyroid where it decays and irradiates the thyroid. Hence when it's a threat you take potassium iodide tablets--basically flooding your body with as much iodine as is safe. The fallout iodine gets diluted by all the iodine in the tablets, you absorb a much lower amount of the dangerous stuff.

RTGs have way too low power to mass ratios to be used in aviation.

That seems to be the consensus on russian twitter. Would be strange if after stealing everything that was possible Putin and his party of crooks and thieves would manage to create actual nuclear propulsion rocket, instead of animated cartoon and failed experiments.

A nuclear propulsion rocket isn't actually a very useful thing, as it spews out way too much radiation to be acceptably used in peacetime. And for war, well, several countries already have enough nuclear-tipped warheads spread around the world to end it, so additional delivery mechanisms aren't really needed.

That's the whole point, narcissist with botox cheeks gets a scary cartoon, generals and bureaucrats get mansions and hotels in europe, ordinary people get high dose of radiation. And no one cares how the cartoon relates to common sense and reality.

> mansions and hotels in europe

Also targets

Also children. Despite all the rhetoric europe and usa are the least likely places to be intentionally used as targets.

The only tested nuclear thermal rocket was open cycle (in the US at least), but even back then there were drawing board designs for closed cycle engines that would not have radioactive exhaust.

Wasn't the argument that a rocket with nuclear propulsion can keep accelerating all the way to the target, so by the time it gets there it travels at speeds that make it completely unstoppable? That would make it marginally more useful than ICMBs during war.

No, aerodynamics prevent that from being possible. But maybe you’re conflating with hypersonic cruise missiles, which are also being worked on but somewhat orthogonal?

In any case, the point of the nuclear cruise missile is that it can be essentially a drone stealth nuclear-armed bomber flying just outside of the other country’s airspace 24/7/365. Or a fleet of such drone missiles.

They can be designed to emit no radiation, except somewhat trivial activation of intake air

I find it really hard to ever know what's real when it comes to Russia.

Anything that can be reliably measured. Height of pile of dead journalists, that kind of thing.

> “short-term increase in radiation”

Guess they are lying like in 1986.

"...local authorities in Severodvinsk released a statement Thursday that said there was a radiation spike following the blast. That statement has since been deleted from the official website."


They are already trying cover it up.

Well, the big difference now is that there aren't lots of radiation from external readings, so I doubt there's a big disaster such as Chernobyl. We also have better instruments nowadays.

Of course, different winds could mean it won't be picked up by Northern Europe like last time.

For comparison, here [1] is a wiki article on a different recent radioactive release from Russia (of Ruthenium-106). International parties detected it very quickly, but it took a fair time to trace it back to it's probable source at the Mayak facility. This current event seems in some ways more serious, in other ways less, but a bit better in terms of the transparency in the Russian governmental response (they've at least acknowledged it).

[2] https://en.wikipedia.org/wiki/Airborne_radioactivity_increas...

And they said there'd be no Season 2 of Chernobyl.

NASA film on nuclear rocket development in the 60’s https://youtube.com/watch?v=eDNX65d-FBY

Slightly related: this arte documentary about nuclear weapons:



* Russia has comparatively poor capabilities in traditional weapons so they use nuclear weapons to compensate.

* USA is developing nuclear weapons for submarines that they can park at the coast of strategically important places without having to bother with criticism from the host country.

* With Trump in office, European states are wondering about whether to launch a European nuclear program for self defense.

* Baltic states are hard to defend, easy to invade. The NATO presence in the Baltics serves mainly the goal to appease the local population than to prevent any serious invasion attempt.

I thought the Baltic strategy was to have a force in place that the Russians would have to kill to get the baltics. That force couldn't stop the Russians but their defeat would cause a casus belli that gives NATO enough domestic political capital to go fully to war with Russia.

That's probably a component as well.

It's known for ages that there is no defense against nuclear submarines equipped with MIRVs that could obliterate e.g. the whole West Coast in a single shot. That's why North Korea went from cute game of a little rocket man to something super serious as they finally learned how to build both missiles and proper submarines.

Russian defense was always based on rockets anyway, they made the conscious choice long time ago as the most cost-efficient approach. So their air carriers can be weak, planes can be only half-stealth, ships can be outdated and falling apart, but rockets are always top-notch.

Putin announced in 2018 that they had nuclear-powered missiles that can fly almost indefinitely (and also hypersonic cruise missiles, supersonic nuclear torpedoes, and a couple of other terrifying doom machines). Historically, when the Russians officially disclose the existence of weapon, it's real.

That's pretty old design. Doesn't China have a supersonic submarine/torpedo now?

When the Kursk went under, there were reportedly Chinese officials onboard. They were almost certainly there to see a demonstration of super-cavitating torpedoes, and it didn't end well. So who knows what they decided afterward.

These are old, and one was probably responsible for the Kursk catastrophe many years ago. I'm speaking of high-power, nuclear, "tsunami-making" torpedoes that Putin mentioned in a presentation in March 2018. Nobody knows how these look, however, nor the hypersonic nuclear cruise missile.

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