Speculations On The Nenoksa Explosion

On the morning of Thursday, August 8, something exploded at the Nenoksa Naval Base in Russia, not far from the city of Severodvinsk. This article is a good summary of what we knew by Friday. Since then, the Russian government has said that a radioactive source was involved in the explosion, along with liquid rocket fuel. Reports have gone back and forth on whether radiation detectors in Severodvinsk detected anything. Five more people have been reported dead. Sarov/VNIIEF, one of the Russian nuclear weapons laboratories, has released a statement, which some folks are rushing to translate.

Update: Sarah Bidgood has translated the video. Here’s the start of her thread. No news about what was being done.

Here are some things that we know. Jeffrey Lewis and the OSINT group at MIIS are doing a good job with the small amount of information we have. I mostly agree with them, although I tend to be slightly more conservative in my confidence in the interpretations. They are publishing mainly on Jeffrey’s Twitter feed. Here’s a recent thread.

Almost exactly a year ago, when Burevestnik was announced, I wrote up what the United States had done with nuclear rocket and cruise missile engines. I saw the Rover program up close and personal and knew a number of people involved in it. One of the conference rooms I used had an unloaded Rover fuel element to be used as a pointer. Fun.

On Twitter, I’ve been a bit of a naysayer. I’m not disagreeing that Russia is testing what they believe will become their Burevestnik. I’m saying I think they’ll never have an operating system.

I think that what has happened is that someone sold a program to Putin. The visuals are cool, and the idea of a cruise missile that can just keep cruising obviously appealed to him. “Nuclear-powered” sounds good. The promoter of the program may even believe in it.

Programs have been sold this way in the United States. We are still working on the missile defense that Edward Teller bamboozled Ronald Reagan into. I recall a Labor Day weekend in which the proof test for laser isotope separation was to be completed. It wasn’t. People get overenthusiastic about their ideas or just are selling something they think would be fun to work on or to make their status higher.

But there are basic and fundamental engineering considerations that suggest that a nuclear-powered cruise missile with a very small power source, will be very difficult or impossible to build.

All flying machines trade off between power and weight. Nuclear reactors have another couple of tradeoffs, between size and critical mass and between ways to do heat transfer. With the announcement that a radioactive source was involved in Thursday’s explosion, speculation has swung to the many isotopic thermoelectric power sources. But they are not powerful enough for propulsion.

Burevestnik is supposed to be a ramjet, which means that it takes in air, heats it, and rapidly expands it out the back for propulsion. That was how the Tory reactor of Project Pluto worked. The Rover reactor, which was designed to operate outside the atmosphere, used hydrogen as a propellant gas. More details about both in my earlier post.

The reactor heats the propellant gas. That requires a fair bit of area between the heat source (reactor) and the gas. Tory and Rover accomplished this by having fuel elements with holes through them, aligned so that the gas could come in one end and go out the other. The gas went through the reactor.

The reactor could be small and transfer heat to the gas via a heat exchanger, possibly two heat exchangers. Jeffrey Lewis sent me a patent from 1979 (actually 1965, but declassified in 1979) that describes such a system. I doubt that this system was ever built, although there are some tantalizing details that suggest that some parts of building it were looked into. However, not much is said about the heat exchangers, nor the fluid that would be used in them. Since the patent is for a fast reactor, it is tempting to believe that the primary heat exchange fluid would be sodium.

When you are concerned about weight, as a cruise missile designer must be, the places to look in these designs would be the moderator and reflector for the reactor. Highly (above 90%) enriched uranium is the only possible fuel; plutonium is too hard to handle, and lesser enrichments add too much weight. The moderators in the Tory and Rover reactors also served as structural elements.

The air gaps in a Tory-type reactor require more fissile material than a solid reactor would for criticality. A reactor with external heat exchangers requires less fissile material, but the heat exchangers are additional weight.

Some of the smaller reactors now being developed for space applications have been suggested, like the KiloPower reactor. But, like the isotopic thermoelectric sources, these small reactors are for electrical power generation. They must be bigger, and therefore heavier, to provide the power necessary for propulsion.

The Tory and Rover reactors, in their containers with subsidiary equipment, were around ten feet long and 3-4 feet in diameter. The 1979 patent doesn’t give dimensions, but they would likely be similar. That’s small for a reactor, but larger than photos of the Burevestnik suggest. Here’s one for comparison.

Both liquid propellant and a radioactive source are mentioned in Russian government press releases. It is not clear how these come together for cruise missile propulsion. A nuclear reactor could not get a cruise missile off the ground, and a chemical engine would be needed for starting (more weight), but solid fuel was previously mentioned for Burevestnik. This is where we might go back to the possibility of a sodium coolant.

What if the Russians found a big breakthrough? I’ve been thinking about this for a year or more, and I can’t come up with anything that makes sense. I don’t see a way around the constraints – heat transfer requirements, critical mass – and nobody has suggested one.

Unless it’s red mercury. Or cold fusion.

 

 






43 replies
  1. 1
    Spanky says:

    Or maybe they were messing around without knowing what they were doing. The results sort of suggest that.

    Although I’m not convinced the radioactive part is necessarily part of the drive system, tbh. But again, it would be irresponsible not to speculate.

    ReplyReply
  2. 2
    Spanky says:

    Hey! Maybe the best way to find out is to take all of those yahoos that want to storm Area 51 on 9/20 and have them storm Nenoksa.

    ReplyReply
  3. 3
    susanna says:

    Thanks, Cheryl.
    Out of curiosity, when radioactive material is involved are there any procedures in place that the responsible country follows regarding effects other nations or areas might experience? Or is everyone expected to find out themselves from (for us) questionable sources, within and outside the temporary government in charge?
    And where is a reliable resource for reading followup info after such an event?

    ReplyReply
  4. 4
    MattF says:

    ‘Engineering’ problems– i.e., issues having to do with costs, tradeoffs, complexity, scaling, and the like… sometimes turn out to be unsolvable. Institutions find that hard to deal with– they think ‘we’ve hired engineers, so what else is there to do?’ But sometimes projects, no matter how promising, just won’t work.

    One can compile a list of examples of ‘won’t work’ projects, and it sure looks like ‘nuclear-fueled cruise missiles’ belongs on that list. I’d suggest various other candidates for the list, such as ‘ABM system’, ‘fusion reactor’, and maybe ‘hypersonic missile’. But we shall see…

    ReplyReply
  5. 5
    NotMax says:

    Deusexmachinium?

    ;)

    ReplyReply
  6. 6
    Another Scott says:

    BBC Russia (Google Translation):

    […]

    What happened in the Arkhangelsk region?

    On August 8, the Russian Ministry of Defense reported that an explosion occurred during a test of a liquid propulsion system at a test site near Severodvinsk in the Arkhangelsk Region.

    “As a result of the accident, six representatives of the Ministry of Defense and a developer enterprise received injuries of varying severity. Two specialists died from the wounds,” the ministry said then.

    The press service of the administration of Severodvinsk reported that a short-term increase in the radiation background was recorded. However, then this message was deleted. Pharmacists in Arkhangelsk pharmacies said that the population bought up all the iodine.

    In the White Sea, near the Severodvinsk transport tanker Serebryanka was seen, which is designed to collect and store liquid radioactive waste. This was written by nuclear weapons expert Jeffrey Lewis with reference to satellite images of the Planet project.

    What exploded?

    The newspaper Vedomosti, citing a source in the defense industry, wrote that the explosion occurred during tests of the engine of a ship’s rocket, which is in service with the Russian Navy.

    On August 10, Rosatom reported that the explosion occurred during a test of a rocket with a radioisotope element in the engine.

    “The missile tests were held on the offshore platform. After the tests were completed, the rocket fuel ignited, followed by detonation,” the ministry said.

    “After the explosion, several employees were thrown into the sea, and there was hope to find them alive. The search continued until there was hope to find survivors,” Rosatom reported.

    The representative of the state corporation also told RBC that the incident occurred as a result of a “confluence of factors.”

    “There was a confluence of factors, which often happens when testing new technologies,” the source said. “Specialists work in conditions of potential risk inherent in all tests.”

    FWIW.

    Cheers,
    Scott.

    ReplyReply
  7. 7
    RepubAnon says:

    Perhaps a multi-stage weapon with a solid or liquid-fueled booster to propel the cruise missile to ramjet speeds?

    ReplyReply
  8. 8
    NotMax says:

    Limited layman’s understanding is that, while the type and density may vary dependent on the radioactive material, shielding which normally would be a part of design for static ground-based use is pretty much not there in order to reduce weight when it comes to powered flight using radioactive materials as a propulsion system element, possibly so much so that (again, varies dependent on the actual material used) upon landing the craft itself has become a radioactive danger to health.

    Missiles, of course, aren’t intended to touch down (and take off again), but just sayin’ for purposes of general knowledge.

    ReplyReply
  9. 9
    stinger says:

    Thank you, Cheryl.

    ReplyReply
  10. 10
    artem1s says:

    Unless it’s red mercury.

    so now we know what was in Marsellus Wallace’s briefcase.

    ReplyReply
  11. 11

    I think that what has happened is that someone sold a program to Putin.

    That certainly makes sense to me. You don’t have to be an idiot to fall for this stuff, Putin has a gigantic ego, and Hell, he probably doesn’t mind throwing that money away if nothing comes of it. What’s he going to do, use it to increase Russian standards of living? Yeah, right.

    @Another Scott:

    FWIW

    In Putin’s Russia? Not much. I’m waffling over whether it’s better than silence.

    ReplyReply
  12. 12

    @susanna: I’m not sure there’s any formal requirement in place. There may be some recommendations or conventions with the International Atomic Energy Agency (IAEA). A responsible country would advise others. I’ve seen situations with lost or stolen radioactive sources where the notification is rapid and cooperative.

    The Comprehensive Nuclear Test Ban Treaty Organization (CTBTO) has networks around the globe of seismic, radionuclide, and other sensors. They are likely to report their findings on radionuclides this week.

    And where is a reliable resource for reading followup info after such an event?

    If the IAEA is called in, they will eventually issue a report. But they can be very slow, like years slow. The results from the CTBTO are reliable.

    Nations are unlikely to be fully forthcoming on weapons tests, and that’s what this is. Many non-governmental organizations now do their own analysis, called open-source intelligence. Jeffrey Lewis and his group at the Middlebury Institute of International Studies are very good at that and are working on this situation. I wouldn’t be surprised if they are the first ones out with a translation of the video. There are a number of other groups as well, with varying interests and reliability. I monitor most of them.

    ReplyReply
  13. 13
    Fair Economist says:

    I read a long time ago that the nuclear cruise missle designs would release lots of radiation while in flight, making them unsuitable for almost any purpose. Is this kind of thing a problem with these proposed Russian designs?

    Also, I agree a hyper-extended duration ramjet seems pretty dumb.

    ReplyReply
  14. 14
    Bill Arnold says:

    What if the Russians found a big breakthrough? I’ve been thinking about this for a year or more, and I can’t come up with anything that makes sense. I don’t see a way around the constraints – heat transfer requirements, critical mass – and nobody has suggested one.

    So you’re still convinced that it is not a Americium-242 reactor (of breakthrough design) as was wildly speculated about last year? If it is, then perhaps they are a little embarrassed by the name of the isotope.
    (I recognize/respect that you’re writing under classification(?) constraints, but that means we read between the lines. :-)

    ReplyReply
  15. 15
    Martin says:

    @Spanky: The Russians know what they’re doing.

    Could also have been a test of their TEM engine. Since the 60s both the US and USSR were exploring nuclear upper stage engines. These are low thrust, but high efficiency engines, so they need minimal fuel (and therefore minimal weight). Typically liquid hydrogen is used for the fuel as the design is to use a solid nuclear core to energize the hydrogen and emit it at extremely high velocity (thrust is just conservation of momentum – so mass*velocity – the higher the velocity, the less mass you need to eject and therefore carry with you). Nuclear engine development was generally stopped after treaties to limit nuclear materials in space.

    But if you want to do larger scale interplanetary travel, you need more efficient engines than chemical, so some development has been ongoing. Russia started their TEM engine work just in the last few years, based off of their RD-410 work from the 60s and 70s.

    I’m just not sure of the point of a nuclear powered cruise missile given the existence of ballistic submarines and other air launch platforms. If you thought you’d get by with the ‘it’s just a conventional warhead and not a nuclear attack’, I don’t think the pollution from the destroyed nuclear engine (effectively a dirty bomb) would cause that response. I mean, as a gee whiz government funded engineering exercise, ok, yeah, I get that. It looks great on your powerpoints, but I don’t see the strategic benefit of it over a W80 tomahawk, a sub launched cruise missile, an air launched cruise missile, or a Trident.

    But a solid core nuclear rocket does have a role that is unmet by any alternatives.

    ReplyReply
  16. 16
    Martin says:

    @RepubAnon: That wouldn’t be nuclear. Nuclear engines are low thrust. They’re great in the vacuum of space when you want to run the engine for hours on end, but pretty terrible for getting off the ground or pushing against the atmosphere. And they tend to be heavier than conventional chemical engines so they are more attractive when the savings in fuel is enough to make up for the added weight, which can happen with rockets where you carry your own oxidizer, but is really hard to get to for jets which get their oxidizer from the air they fly through.

    The window in which a nuclear powered engine makes sense in atmosphere is so narrow that I can’t think of a situation where it would make sense to do, other than to say that you did it (not that the US isn’t victim to that as well – see financial dumpster fire which is the SLS).

    ReplyReply
  17. 17
    germy says:

    In the meanwhile, the nuclear-powered cruise missile Burevestnik that Putin is do proud of exploded in Russia near Severodvinsk. The radiation levels are through the roof. The White Sea has been massively contaminated.

    https://clarissasblog.com/2019/08/10/the-russian-fukushima/

    ReplyReply
  18. 18
    Martin says:

    @Bill Arnold: From what I’ve read of Americium-242, the breakthrough is in its ability to directly produce electricity. So, as a RTG or even a power source as an intermediate between an RTG and a conventional nuclear reactor, it would indeed be revolutionary, but I don’t see any design that would allow for meaningful thrust generation.

    ReplyReply
  19. 19

    @Fair Economist: We don’t know what the Russian design is, so it’s hard to say. In both the Tory and Rover engines, the hot gas passing through them eroded the fuel elements. That’s how radioactive material would have been released.

    ReplyReply
  20. 20

    @Bill Arnold: Nothing I’m saying here has anything to do with classification. An americium reactor would be subject to the same engineering limitations as any other.

    ReplyReply
  21. 21

    @germy: No. If that were true, we would be getting reports from around Europe.

    There are a number of panicky people (or disinformation agents) pushing the idea that the explosion was a massive contamination event. Just no.

    ReplyReply
  22. 22
    germy says:

    @Cheryl Rofer: Somehow, I am not surprised that Clarissa is wrong again.

    ReplyReply
  23. 23
    Ruckus says:

    @Martin:
    I think a look at our own military would tell you the answer here.
    First priority is to always be looking for the next great thing that will make your military more powerful and rapid responding than the next guys. They also have to project where they see issues happening in the next 5, 10, 25, 50 yrs. And they like new toys. So we have planes for example that cost massively more than what they replace and don’t actually do any more or work any better, but they are shinny, new and supposedly have massively improved operational details. But look at the navy for example. Ships like DDGs used to have a realistic life of 25 yrs, now they are trying to stretch that to 50 yrs because they can’t afford all the new toys. They also stretch the operators because they can’t afford/get enough people and train them. This is not all that new a problem, it’s just that once you bounce up against reasonable technological and human limits, you have to either limit the concepts to what is reasonable or spend a lot more money, time and people to make it work. Take the nuclear cruse missile. If it worked then you eliminate a lot of the bits and pieces and people of what it takes to be an effective large player, at war, offense or defense, today.

    ReplyReply
  24. 24
    Anonymous At Work says:

    Two questions:
    1. Wouldn’t a nuclear cruise missile also have issues with payload even if they could solve the issues you mention?
    2. Wouldn’t using nuclear materials in a cruise missile negate a lot of the use for a long-range precision weapon if the area around the target gets irradiated? There are less precise options in such cases, I’d imagine.

    ReplyReply
  25. 25
    Ruckus says:

    @Martin:

    The window in which a nuclear powered engine makes sense in atmosphere is so narrow that I can’t think of a situation where it would make sense to do, other than to say that you did it (not that the US isn’t victim to that as well – see financial dumpster fire which is the SLS).

    This is what I was talking about our military system. Technology must be up to date, cutting edge even, just to stay ahead of the curve. And a lot of the technology actually narrows down what can be done with a piece of equipment, and magnifies what it takes to maintain and operate in the real world.

    ReplyReply
  26. 26
    Bill Arnold says:

    @Martin:
    No, an actual reactor. The Smallest Thermal Nuclear Reactor. (ResearchGate or sci-hub will get a pdf if one doesn’t have access.) But with something other than water as a moderator. (That’s the joke.) According to my notes, that isotope has a high thermal cross section and also more prompt neutrons per fission (3.26, vs 2.88 for Pu-239 and 2.43 for U-235). The nutsiest speculation I saw, Cheryl linked last year in her post – here (Russian popular mechanichs) (google translate does OK, though it translates the Russian word for moderator to “retarder”).

    ReplyReply
  27. 27

    @Anonymous At Work:

    1. Wouldn’t a nuclear cruise missile also have issues with payload even if they could solve the issues you mention?

    That depends totally on the tradeoff achieved between power and weight. Will be specific to the design.

    2. Wouldn’t using nuclear materials in a cruise missile negate a lot of the use for a long-range precision weapon if the area around the target gets irradiated?

    Again, it depends. And I think you mean contaminated rather than irradiated.

    It depends on what the materials are and what one wants in precision. If the nuclear-powered cruise missile carries a nuclear weapon, which Putin has suggested, whatever is in the engine is trivial.

    ReplyReply
  28. 28
    Cheap Jim says:

    Yes, I’ve often said the same to myself.

    ReplyReply
  29. 29
    Cermet says:

    @Martin: Don’t know what physics you think have changed after reading what-ever you did on that subject but currently, none have – Americium-242 can’t directly produce electricity in any fashion worth doing; so, russia has achieved no such break-through with that material since thermodynamics and nuclear physics haven’t changed.

    As for a nuclear powered cruise missile, america had done that back in the 60’s and discovered it was a radioactive disaster and that, isn’t likely any different if the russians try to follow through no matter what they try – reactor temps are just too high and materials will always melt because – thermodynamics holds – to produce enough thrust to be high hyper-sonic requires huge temps.. Also, a ram jet requires hyper-sonic speed before it can operate so a chemical rocket is necessary (booster – not a big deal since that can fall away); but once flying add on its monstrous heat signature and it would stand out like a flashlight in a dark room . So ‘seeing’ and then shooting down such a rocket would not pose any significant problems – so why build it at all?

    ReplyReply
  30. 30
    J R in WV says:

    @germy:

    “The White Sea has been massively contaminated.”

    Am thinking that USSR / Russian Federation has had several nuclear powered submarines sink in the White Sea, not to mention a shit-ton of up to huge [Tsar Bomba] nuclear explosions on islands in the White Sea, so probably already a lot of opportunities for massive contamination.

    Also thinking that this event is small beans, or perhaps small bowl of beet soup, compared to whole reactor of nuclear sub dissolving away all hot in high-pressure salt water on bottom of the White Sea.

    Am not nuclear chemist… just auto-didact from reading about these things… Worth every Krugerrand you paid for this advice!

    ReplyReply
  31. 31
    Bill Arnold says:

    @Ruckus:

    This is what I was talking about our military system. Technology must be up to date, cutting edge even, just to stay ahead of the curve.

    It’s Russia! Land of things like this: Russian ALL TERRAIN military vehicle drives on snow swamp mud water and land better than 4WD
    And one possible target audience is POTUS iDJT – nuclear powered cruise missile gap! Also might be helpful against the alien(s) [on the?] Moon, part of Mars! (I am easily amused by such things. :-)

    ReplyReply
  32. 32
    MobiusKlein says:

    @germy: Not just wrong, but reference free rumor passing.

    ReplyReply
  33. 33
    Ruckus says:

    @Cermet:

    Americium-242 can’t directly produce electricity in any fashion worth doing;

    Reread Martin’s comment. He’s not saying that it is useable, just possible, which seems to agree with you.

    ReplyReply
  34. 34
    Ruckus says:

    @Bill Arnold:
    Link no good, you fix.

    ReplyReply
  35. 35
    Marc says:

    What if the Russians found a big breakthrough? I’ve been thinking about this for a year or more, and I can’t come up with anything that makes sense. I don’t see a way around the constraints – heat transfer requirements, critical mass – and nobody has suggested one.

    Perhaps “isotopic power sources” refers to an engine technology based on radioactive decay, not fission. This breakthrough could be a relatively lightweight air-breathing ramjet using a radioisotope heat source. Assuming it’s feasible at all, I can see a host of issues, but compared to a reactor, it could be light, require a lot less shielding, and likely spew relatively small amounts of radioactive material (unless one crashes).

    ReplyReply
  36. 36

    I continue to be amazed at how many people comment without reading the top post.

    ReplyReply
  37. 37
    Bill Arnold says:

    Perhaps “isotopic power sources” refers to an engine technology based on radioactive decay, not fission.

    No, read the top post. Re Am242, here’s a researchgate link to what I linked above, that might work for people. Cheryl says HEU is the only thing that makes sense, and I trust her as the expert, but this (or some other crazy such thing) is an outlier possibility.
    The Smallest Thermal Nuclear Reactor (2005)

    This technical note investigates the question of what is the smallest possible thermal reactor. It was found that the smallest reactor is a spherically shaped solution of 242m Am(NO3)3 in water. The weight of such a reactor is 4.95 kg with 0.7 kg of Am 242m nuclear fuel. The radius of the reactor in this case is 9.6 cm.

    The Russians are trying to send the impression that that they have designed a practical version of a missile using something like that (maybe entirely different. Follow Cheryl’s links.). If so, then one joke could be that they actually got it working and weren’t faking it. I don’t understand Russian humor. :-)

    ReplyReply
  38. 38
    Ken says:

    @Cheryl Rofer: Well, you must admit that “the Russians might be trying this technology but they aren’t going to get it to work” is nowhere near as exciting as “the entire Arctic Ocean is a radioactive pit of magma!!”

    ReplyReply
  39. 39

    @Bill Arnold: That probably works out, but I can’t imagine using a water-based reactor in a missile. Also, I’d like to know how much power it generates. I’ll bet not enough.

    @Ken: This is true.

    ReplyReply
  40. 40
    Another Scott says:

    @Bill Arnold: Thanks for the link.

    They conclude:

    Thus, we have determined the mass and dimensions of the smallest possible thermal reactor. Although some realistic assumptions regarding the reactor components were made in this analysis, we have not considered any specific application-dependent features of the reactor, such as a heat removal mechanism and reactor control. Therefore, the results reported in this technical note should be considered for their scientific merit only.

    (Emphasis added)

    It’s a nice paper, but doesn’t necessarily apply to what Russia is doing. (Of course.)

    I don’t know if others have seen this, but nuclear fusion has been demonstrated on a tabletop:

    Scientists from the University of Washington built a 1.5-meter Z-pinch device that was able to sustain a nuclear fusion reaction for five microseconds.

    The Z-pinch works by trapping and pressurizing plasma in a powerful magnetic field, Physics World reports. In the experiment, the plasma field was stabilized for 16 microseconds, and fusion occurred for about a third of that time.

    Trouble is, it’s not self-sustaining and doesn’t break even.

    Back of the envelope calculations and proof of the physics is very, very far from making a practical reactor that solves the problem of interest.

    Cheers,
    Scott.

    ReplyReply
  41. 41
    Bill Arnold says:

    @Cheryl Rofer:

    Also, I’d like to know how much power it generates. I’ll bet not enough.

    The water is a problem, yes. :-) I’d assume some other moderator and a larger reactor, and a super-secret mystery design, and as said, perhaps a bit of fraud or self-delusion or other deception. If they ever do a flight test that verifiably cruises a lot further than a conventional cruise missile, then we’ll have new missile gap.

    ReplyReply
  42. 42
    Bill Arnold says:

    @Another Scott:
    The main reason I brought it up is that the Russians are claiming a “isotopic power source”, and Am 242 fits that bill (as does anything, technically, but work with me here), and also has an embarrassing name (Americium)

    “The name americium (after the Americas) and the symbol Am are suggested for the element on the basis of its position as the sixth member of the actinide rare-earth series, analogous to europium, Eu, of the lanthanide series.

    I suppose blends or aggregates of fissionables are possible too, literal nightmare fuel.

    ReplyReply
  43. 43

Trackbacks & Pingbacks

Leave a Comment

Leave a Reply

Your email address will not be published. Required fields are marked *