Russian rocket accident releases radiation

[Baluncore]

TL;DR Summary

Radiation has been released following a Russian rocket explosion at the Nyonoksa naval ballistic missile test site.

https://www.abc.net.au/news/2019-08...-kills-two-sparks-radiation-concerns/11398604
Radiation has been released following a Russian rocket explosion at the Nyonoksa naval ballistic missile test site.
Part of the White Sea has been closed. 5 people now reported killed.

Ballistic missile test site, Nyonoksa; 64.646° 39.22°

Submarine base nearby, where subs are decommissioned;
Severodvinsk 64.586° 39.816°

I doubt they would test fire an engine with a multiple warhead in place, so I suspect it was a decommissioning accident of a fuelled rocket.

Could a short burst of radiation be released if there was no critical nuclear reaction?

 

[Rive]

Could a short burst of radiation be released if there was no critical nuclear reaction?

I think the key point is this:

the radiation level rose to 2 microsieverts per hour for about 30 minutes before returning to the natural level of 0.1 microsieverts per hour.

20X rise for half an hour - this is out of the range of increase what rain would induce, for example: but not excessively. I wonder if the explosion could trigger some radon release from the ground?
I think there is no reason to suspect any critical reaction behind this.

 

[Baluncore]

Could a propellant have become slightly radioactive after many years close to nuclear warheads in the submarine silos. Then after being burned, the hot smoke plume might have been detected as it drifted over the nearby town?

 

[mfb]

Speculation seems to turn towards a nuclear powered cruise missile, specifically 9M730 Burevestnik aka SSC-X-9 Skyfall. A ramjet, powered by a nuclear reactor instead of burning propellant. Something like SLAM or Project Pluto, but presumably with better containment as it is not the 1960s any more.

 

[Baluncore]

Interesting. The involvement of an offshore platform reminded me of an unusual visit by a jack-up platform to the Sverodvinsk submarine facilities. Google Earth showed it was there from 9/14/2009 until 8/21/2011, (NASA pictures). Dvinskiy bay is typically 30 to 100 m deep.

Why might such a platform visit and obstruct the inner circle of the nuclear submarine industry for two years if it was not being prepared for a military test program?

 

[artis]

If I'm not mistaken both fissile Plutonium (239) and U 235 decay by alpha emission so the idea of rocket fuel becoming radioactive sitting next to a fissile material seems impossible.

Also I have to agree with @Baluncore assertion that one would unlikely test a missile within ones own territory with active nuclear warhead on top.
Seems like @mfb provided information seems most probable. Althoygh if such indeed is the case then the recorded radiation levels and their quick decrease seems impossible does it not?

If indeed this is a nuclear powered ramjet or something like that I do wonder what is the benefit besides much much extended fuel reserve because as far as I understand this, the specific heat/thrust that a rocket can provide is more limited by the materials that make up the rocket than the fuel , chemical fuels can reach steel melting point as well as a nuclear one but obviously melting a rocket in flight is useless.
Besides don't they have to use weapons grade Pu or U235 for such a rocket engine in order to save weight ?

 

[mfb]

A quick decrease at some measurement station can have a lot of causes - a cloud of radioactive material can pass and cause a short spike without leaving much behind, for example.

The benefit of a nuclear ramjet is the large range and longevity. Supersonic flight across the whole planet, to an arbitrary list of targets at arbitrary times. Chemical fuels can't do that, supersonic aircraft need refueling very often.

Besides don't they have to use weapons grade Pu or U235 for such a rocket engine in order to save weight ?

Huh? The warheads are separate from the engine.

Also I have to agree with @Baluncore assertion that one would unlikely test a missile within ones own territory with active nuclear warhead on top.

Well, we know the US flew (or is still flying?) over its own territory with nuclear weapons many times. A few bombs have been dropped by accident, and at least one came close to a nuclear explosion. And that's just the public information.

 

[artis]

@mfb Yes surely I wasn't implying about the warhead nuclear material but about that of the ramjet engine, obviously we are talking about heat here, so heat from a nuclear reaction instead of a chemical one, my question I guess then is what percentage of enrichment are we talking about for such a ramjet engine (surely the internet must hold some info but I'm sure it's not on the first pages of google)
Because unlike a sitting commercial plant this thing is a rocket and has to fly so obviously one would want to achieve criticality of the ramjet engine with less fuel mass.

 

[DEvens]

Could a propellant have become slightly radioactive after many years close to nuclear warheads in the submarine silos. Then after being burned, the hot smoke plume might have been detected as it drifted over the nearby town?

Not the way you seem to be suggesting. Activation from being exposed to neutron radiation is possible. But warheads have extremely little neutron radiation.

Some of the decay products of Uranium are themselves radioactive and also gaseous. Ordinarily they get trapped inside the material of the Uranium. If the Uranium were abruptly turned to powder or vapor, such as might happen in a big enough explosion, then this gas could be released. That would produce a puff of radiation that would then disperse quickly.

 

[Astronuc]

Time magazine reports, "
The failed missile test that ended in an explosion killing five scientists last week on Russia’s White Sea involved a small nuclear reactor, according to a top official at the institute where they worked.

The institute is working on small-scale power sources that use “radioactive materials, including fissile and radioisotope materials” for the Defense Ministry and civilian uses, Vyacheslav Soloviev, scientific director of the institute, said in a video shown by local TV."

https://time.com/5649826/russia-nuclear-accident/

 

[Rive]

Just a question: am I right that involvement of working nuclear reactor in any jet-type engine would mean O => N₁₆and gamma decay, more or less like in a BWR reactor?

Still can't get around the short lived radiation burst, so far from the site.

 

[hutchphd]

Wonderful a fission grade open loop nuclear jet engine reactor randomly flying around. What a good idea!

 

[geoelectronics]

Time magazine reports, "
The failed missile test that ended in an explosion killing five scientists last week on Russia’s White Sea involved a small nuclear reactor, according to a top official at the institute where they worked.

The institute is working on small-scale power sources that use “radioactive materials, including fissile and radioisotope materials” for the Defense Ministry and civilian uses, Vyacheslav Soloviev, scientific director of the institute, said in a video shown by local TV."

https://time.com/5649826/russia-nuclear-accident/

It could have been a NTR (Nuclear Thermal Rocket), but "nuclear powered" could also mean SNAP or RTG (Radioisotope Themal Generator) electric generators. The latter abound in Russian technology and have been involved in numerous accidents. What bothers me is that no one can (or will) say what the isotopes were that increased the radiation level. Does no one do Nuclear Metrology anymore?

George Dowell

 

[hagopbul]

Dose the accident duo to a turbine problem or reactor problem ?

 

[Baluncore]

Dose the accident duo to a turbine problem or reactor problem ?

The explosion threw people from the platform into the sea. That might suggest an uncontrolled thermal energy release rather than the mechanical failure of a turbine. At this stage there is no evidence of, or reason for chemical propellants to be involved. That leaves loss-of-control of an isotope based thermal generator as the probable cause. That may also explain the :half an hour" of above average radiation reported from a nearby city.

We still don't know where in the White Sea the accident happened. That area has restricted access, and no platforms are shown on the navigation charts in the region. At the moment my best guess is based on marine navigation charts that show three special purpose buoys located at 65.225135°, 38.814129°. That is out in the middle of Dvinskiy Gulf, away from marked shipping routes, and over 23 nm (nautical miles) from the nearest land. It is about 35 nm north of the Nyonoksa naval test site, and 47 nm NW of Severodvinsk. Does anyone have any better location information for the accident?

Will the experimental program continue after such an accident? The platform will have been damaged by an accident of that magnitude. Before tests can continue it may need to be returned to the the Severodvinsk shipyards for repairs. If the platform is contaminated it may be abandoned where it is, or sunk elsewhere. Searching the nearby seafloor of Dvinskiy Gulf for fragments of the radiation source may be the priority.

 

[hagopbul]

You are saying that the reactor is not providing heating to the air flow but it provides electrical power and the cruise missile is like a Tesla for missiles

 

[Baluncore]

You are saying that the reactor is not providing heating to the air flow but it provides electrical power and the cruise missile is like a Tesla for missiles

Who is? I am not.

 

[hagopbul]

Look in previous replys " Radioisotope Themal Generator) electric generators"

 

[artis]

@hagopbul I don't think "Tesla missiles" are possible because a car drives on a road so all the energy for movement can be applied to the wheels by motors, a rocket has to fly through air and as all jet engines also a rocket engine works by hot exhaust gas which provides thrust against the colder surrounding air.
So one needs hot air/gas at the exhaust and if the rocket has no chemical fuel burn then it needs another source and this is why we are talking about a nuclear reactor going critical heating itself up and then air passes through it.
I think its something like a heat exchanger only radioactive, look up windscale , it was a British air cooled reactor for weapons material (Pu, U?) production. then imagine a rocket with a smaller but similar such reactor.

But reading the info here I think it is hard to say for certain what exactly this was due to scarcity of information

 

[artis]

@hagopbul By the way I think we need to make the clear distinction between a nuclear reactor and radioisotope thermal generator, because the isotope generator is just a piece of radioactive material that left alone produces decay heat and this heat can be converted to electricity but can only supply a rather small power and is normally used for space probes and satellites I think, the whole generator can also be made compact.
A nuclear reactor on the other hand can produce lots of power and if we are talking about a flying rocket I think only a reactor could power the heat necessary not a radioisotope generator.

 

[hagopbul]

When I said Tesla missile I was using metaphor , reactor is a strong possibility

 

[Rive]

Wonderful a fission grade open loop nuclear jet engine reactor randomly flying around. What a good idea!

I really can't get around the fact (is it really a fact?) that the measured increase in the gamma background vanished in half hour. That suggest highly volatile, but no solid or any 'sticky' release.
Due the distance direct radiation is also unlikely.
Weird.

That might suggest an uncontrolled thermal energy release rather than the mechanical failure of a turbine. At this stage there is no evidence of, or reason for chemical propellants to be involved.

Maybe the explosion was the launch booster and the cruise engine remained intact?
So far there is no announcement of observed release from any country around. The accident was almost a week ago already.
Weird.

 

[hagopbul]

Maybe it is not a reactor , let say it is two material reactor , is that possible , 1st stage and second stage that will explain the spike

 

[hagopbul]

That means the heat exchanger is not like the slam but little different

 

[geoelectronics]

I really can't get around the fact (is it really a fact?) that the measured increase in the gamma background vanished in half hour.

Did they say Gamma Radiation Background? If so did they mention the instrument that measured it and where? I can tell you in Nevada, surrounding the NNSS (formerly NTS, the Nevada Test Site) is ringed by detectors that DO measure Gamma Radiation and all report to a public network that anyone can monitor. Those I believe.

A couple of things- most public reports of "radioactivity" are not scientific, and the reporters seem to believe "radioactivity" is a noun, to the extent it can "leak out". e.g. "Radiation has been released following a Russian rocket explosion at the Nyonoksa "
Quite often units of measurement are used quite incorrectly, maybe even universally so. Fact is, radioactivity is a property of certain atoms, so it's atoms of some material or the other that leaks out. Analyze the radioactivity, don't just measure it.
And comparing it to normal background is silly. Normal background comes from natural Uranium, Thorium, their progeny, and Potassium-40 in the Earth as well as a contribution from Cosmogenically generated particles, among other lesser contributors. Therefore local background differs widely from one geographical locale to another, mostly depending on the "ground".(earth). Take a radiation detector up in a balloon, airplane or out to sea on a rowboat to see what I mean.

The US developed a nuclear thermal rocket in the 1950's (Project Rover) and beyond. None have flown but have been test fired on ground stands since the 1960's. Refer to KIWI, Phoebus, Pewee and the Nuclear Furnace. One was tested on Jackass Flats, I've been there and have stood on the rim of the Sedan Crater. Twice.

From misc. previous posts here:

"I doubt they would test fire an engine with a multiple warhead in place, "
I agree, but they would load it with depleted uranium dummies, to simulate the density and center of gravity of a real one.

"20X rise for half an hour - this is out of the range of increase what rain would induce, for example: but not excessively. "
In a real release like Fukushima Hydrogen Gas Vent Explosion volatile material was gassified selectively by its boiling point, which is why I can detect Cs-134 and Cs-137 in the soil there but not Sr-90. Chernobyl on the otherhand spewed pulverized particle far and wide, but even today it's the mostly Cs-137 we see at a distance. There are many many more fission products that have much shorter half-lives, from minutes on up, the iodines for example become airborne easily and are of great contribution for their respective (T/2 )X6 lives.

"Could a propellant have become slightly radioactive after many years close to nuclear warheads "
Yes anything could, even depleted uranium has a small SF decay. Not likely tho.
Fact is an initiator in a nuclear weapon and new reactors is there to provide starting neutrons, there are so few naturally.

"If I'm not mistaken both fissile Plutonium (239) and U 235 decay by alpha emission so the idea of rocket fuel becoming radioactive sitting next to a fissile material seems impossible. "
Correct, Pu-239 alpha decays to U-235 100% probability. The newly formed nuclide is in excited state and immediately releases energy, which results in an X-Ray emission from the electron shell.

Well, we know the US flew (or is still flying?) over its own territory with nuclear weapons many times
Not any more. Used to, but not never armed with the pit. All the pits are stored underground in Amarillo Texas. I remember a single case several decades ago where one was accidentally flown across the US continent north to south. Some high ranking heads rolled. Think about it- how do they transport them now? Hint: Ghost Fleet.

". A few bombs have been dropped by accident, "
Yes, several, one off the coast of Georgia USA, several in Spain. I took a picture of my assistant sitting on the one from Spain, also on Atomic Annie the Nuclear Cannon.Annie the Nuclear Cannon. "Althoygh if such indeed is the case then the recorded radiation levels and their quick decrease seems impossible does it not? "

Nothing nuclear related is impossible. Radioisotopes range in half lives from fractions of a second to the age of the universe.

Thanks
George Dowell

 

[Astronuc]

CNN reported that the village Nyonoksa was to be evacuated, then the Russian government canceled the evacuation.
Aug 12 - https://www.cnn.com/2019/08/12/europe/russia-military-blast-radiation-intl/index.html
Aug 14 - https://www.cnn.com/2019/08/13/europe/russian-village-evacuation-missile-explosion-intl/

It's about 430 km to the Finnish border, so it might be difficult to collect isotopic data, especially in the wind blew south over Nyonoksa, or towards the east or SE.

I doubt an RTG (too low power) or a SNAP system. RTG are always on, so that is a disadvantage. One could adapt a BES-5 or TOPAZ system.

ArsTechnica's article
https://arstechnica.com/information...ise-missile-blows-up-creating-mini-Chernobyl/

 

[mfb]

what they described as "an isotopic power source for a liquid engine installation."
[...]
Unlike SLAM's Tory nuclear engine, which relied on air passing directly through the nuclear core of the engine, the Burevestnik’s engine uses a liquid metal to both cool the reactor and transfer the heat to air passing through the scramjet.

That fits together.

 

[geoelectronics]

From misc. previous posts here:
Not the way you seem to be suggesting. Activation from being exposed to neutron radiation is possible. But warheads have extremely little neutron radiation.

Some of the decay products of Uranium are themselves radioactive and also gaseous. Ordinarily they get trapped inside the material of the Uranium. If the Uranium were abruptly turned to powder or vapor, such as might happen in a big enough explosion, then this gas could be released. That would produce a puff of radiation that would then disperse quickly.
[/QUOTE]

"But warheads have extremely little neutron radiation."
True- Very little external radiation of any kind actually. To the extent that a missile on a ship can't be verified as chemical or nuclear in only a few minutes. Reports available, but not for publication online.

"Some of the decay products of Uranium are themselves radioactive and also gaseous."
The statement is true, but it should be mentioned in the weapon context that this is highly refined uranium elements (and isotopes), not uranium ore. Time needed to reestablish secular equilibrium for U is in geological age terms. This both U-238 and U-235, although U-235 does it much quicker.
Refined thorium reaches secular equilibrium very quickly in human terms and is also the parent of a Radon gas.

George Dowell

 

[Rive]

https://www.reuters.com/article/us-...russian-border-days-after-blast-idUSKCN1V510N
https://www.dsa.no/en/news/94883/tiny-amounts-of-radioactive-iodine-in-air-measured-in-finnmark

 

[geoelectronics]

https://www.dsa.no/en/news/94883/tiny-amounts-of-radioactive-iodine-in-air-measured-in-finnmark

Now we are in my realm.
Not theory, Nuclear Metrology (measuring of) Now I'll search to see if they have identified the specific radioiodine isotope.

Update: Here is the report from Reuters:
"OSLO (Reuters) - Norway’s nuclear safety authority is analyzing tiny amounts of radioactive iodine detected in the air in northern Norway in the days after a deadly explosion during a rocket engine test over the border in Russia.

Russia’s state nuclear agency, Rosatom, said on Saturday that five people killed in the blast were its staff members, and the accident involved “isotope power sources”, giving no further details."

Scanning the charts I see 15 common radioactive iodine isotopes. Their half lives range from less than 25 minutes to the one I use for instrument calibrations, I-129 @15.7 Million years.
Even a small lab can analyze which ones are present, I have a shirt pocket unit that will do that in less than 1 minute.

IF they ever release the isotope# we will know where it came from. Finland/Norway are very much alert to this sort of monitoring, after Chernobyl dumped Cs-137 (a fission product) on them. Still today in ordinary household fireplace ash can be found Cs-137.

George Dowell

 

[geoelectronics]

Not the way you seem to be suggesting. Activation from being exposed to neutron radiation is possible. But warheads have extremely little neutron radiation.

Some of the decay products of Uranium are themselves radioactive and also gaseous. Ordinarily they get trapped inside the material of the Uranium. If the Uranium were abruptly turned to powder or vapor, such as might happen in a big enough explosion, then this gas could be released. That would produce a puff of radiation that would then disperse quickly.

Please name the gaseous elements present in a refined uranium or a plutonium weapon. Can't seem to find any except helium. Is that what you mean?

Thank you.
George Dowell

 

[Astronuc]

Please name the gaseous elements present in a refined uranium or a plutonium weapon. Can't seem to find any except helium. Is that what you mean?

Eventually some radon, but in refined/purified U or Pu, there is essentially no decay products, since the half-lives are long. Natural decay products are removed when the ore is processed, concentrated and converted.

Regarding fission products, one needs to look at the Xe, Kr decay chains, and actually, they start with Te and Se, respectively. In the case of Xe, one looks at Te -> I -> Xe -> Cs -> Ba -> La, for each of A=128 - 145. Most radionuclides are both fission products and decay products, but with varying half-lives.

Spontaneous fissions produce neutrons, but spontaneous fission rates are low in U-235 and Pu-239.
https://en.wikipedia.org/wiki/Spontaneous_fission#Spontaneous_fission_rates
There is very little activation of systems due to neutrons from spontaneous fission.

Initially, the Russian government mentioned a radioisotope system, apparently not wanting to admit a nuclear reactor. We're still learning about the event.

 

[geoelectronics]

" Regarding fission products, one needs to look at the Xe, Kr decay chains, and actually, they start with Te and Se, respectively. In the case of Xe, one looks at Te -> I -> Xe -> Cs -> Ba -> La, for each of A=128 - 145. Most radionuclides are both fission products and decay products, but with varying half-lives."

I was talking about before the bomb went of. Hopefully, not too much fission going on normally.George Dowell

 

[mfb]

An alternative option: A nuclear powered torpedo. Same idea, basically, just in the water instead of the air.

 

[davenn]

it was a pretty big bang ...
pic via the LA Times

 

[Rive]

pic via the LA Times

I think that pic is from this accident:


Not related

I can't express fully how deeply do I hate news sites for using anything convenient as 'illustration'

 

[Baluncore]

it was a pretty big bang ...
pic via the LA Times

I believe your picture may be of explosions at a military ammunition depot near the city of Achinsk in eastern Siberia’s Krasnoyarsk region in Achinsk, Russia, on Aug. 5. Can you link to the source?
The nuclear power unit for the 9M730 Burevestnik cruise missile was being tested on a platform in the While Sea. It exploded in the morning (about 9AM) on August 8th. That is 2800 km WNW of Achinsk.

 

[mfb]

I think that pic is from this accident

Nice find. As this video is from 2013 the LA times picture is clearly not from the recent accident.

 

[artis]

Well judging from this thread and the scrap of news elsewhere I think I can say that even in the 21st century with many cell phones etc around countries like Russia can still hide a secret in plain sight pretty well due to their political regime and societal structure. If this happened in the west it would have made national news for the past two weeks every single day, the greenpeace would be protesting 24/7 and a bunch of other incompetent people would blame everything on civil nuclear energy.

 

[Baluncore]

The power reactor being tested was designed to fly on a cruise missile, so it would lack heavy protective screening. The staff operating the reactor, were presumably in a protective radiation shelter on the platform. In order for people to be thrown from the platform, that shelter would need to have been destroyed by the explosion.

Radiation levels in Severodvinsk were variously reported for either half an hour, or for two and a half hours, as being 4 to 16 times the background. That radiation was reported as gamma radiation.

My question now is; If an unshielded nuclear reactor was operating on the horizon, what gamma radiation might be immediately detected at that distance? The period of elevated gamma radiation may represent the duration of the test, prior to and then the explosion, and not due to wind drift of the products after the explosion.

I think the Dvinskiy Gulf of the White Sea has sufficiently restricted access to keep things well hidden. An offshore platform, out of sight of land, serviced from the the Severodvinsk nuclear submarine base, is most unlikely to have any local civilian viewers, even in late summer.

Potential enemies knows more of your countries secrets than the public. Military secrecy is there because without it, the public would see proof of the gross incompetence of the military and lobby for removal of the leaders, or withdrawal of funding.

 

[geoelectronics]

My question now is; If an unshielded nuclear reactor was operating on the horizon, what gamma radiation might be immediately detected at that distance? The period of elevated gamma radiation may represent the duration of the test, prior to and then the explosion, and not due to wind drift of the products after the explosion.

No radiation would be detected at a distance really. Radioactive MATERIALS (especially gas ones) could leak out and be carried by the wind to other locations, where they subsequently go though nuclear decay and then the radioactivity from that decay would be detected.

But we don't know if this is a reactor. Nuclear power doesn't require a reactor always, if the electrical demands are modest. For example, plutonium 238 was used to power internal heart pacemakers. Pu-238 isotope isn't fissile, Russians use it in smoke detectors as an alpha ionization source.
If anyone wants to know how Radioisotope Thermal Generators work, how and why they are used in interplanetary spacecraft etc. I can explain, but perhaps in another thread by itself.

Hint- Thermal=heat.

George Dowell

 

[etudiant]

It is possible to reconstruct the nature of the emission from the spectrum of decay products detected.
So the authorities must have a pretty good idea of what happened. However, apart from noting the increased iodine isotope detection, they have disclosed nothing, perhaps in order to avoid violating the terms of the various monitoring network agreements.

 

[geoelectronics]

It is possible to reconstruct the nature of the emission from the spectrum of decay products detected.
So the authorities must have a pretty good idea of what happened. However, apart from noting the increased iodine isotope detection, they have disclosed nothing, perhaps in order to avoid violating the terms of the various monitoring network agreements.

I agree. Radioactive Iodine is commonly used in many industries, medical, and geophysical surveys, even water well and waste water injection wells. The sources are many and involve different isotopes of iodine but the decay photons will give the answer right away. That is common nuclear metrology, used everywhere in the world every day by ordinary trained technicians.

George Dowell

 

[davenn]

I think that pic is from this accident:


Not related

I can't express fully how deeply do I hate news sites for using anything convenient as 'illustration'

Yes, looks probable

 

[Baluncore]

But we don't know if this is a reactor. Nuclear power doesn't require a reactor always, if the electrical demands are modest.

We know that, unlike a nuclear reactor, heat generation by RTGs cannot be dynamically adjusted in flight, or turned off while in temporary storage prior to a launch. I think we are over the distractive and dismissive information releases. I am sufficiently convinced that it was not an RTG accident. I think we know now that a power unit for, or a 9M730 Burevestnik nuclear powered cruise missile was being trialled. It has been admitted that the explosion happened on a platform in the Dvinskiy Gulf of the White Sea.

It may be tangentially hypothetical, but my revised question is; What gamma radiation might be expected from the operation of an unshielded 100kW reactor?

 

[geoelectronics]

We know that, unlike a nuclear reactor, heat generation by RTGs cannot be dynamically adjusted in flight, or turned off while in temporary storage prior to a launch. I think we are over the distractive and dismissive information releases. I am sufficiently convinced that it was not an RTG accident. I think we know now that a power unit for, or a 9M730 Burevestnik nuclear powered cruise missile was being trialled. It has been admitted that the explosion happened on a platform in the Dvinskiy Gulf of the White Sea.

It may be tangentially hypothetical, but my revised question is; What gamma radiation might be expected from the operation of an unshielded 100kW reactor?

No comment, sorry.

George Dowell

 

[anorlunda]

An alternative option: A nuclear powered torpedo. Same idea, basically, just in the water instead of the air.

Oh, that sounds like a great engineering project. The freedom from the severe power to weight ratios needed for a flying object make it all much simpler. It could flash seawater to steam, to drive a turbine and a propeller for very effective propulsion. Seawater could also provide shielding to protect electronics from radiation.

The article says that these torpedoes are twice the size of submarine launched ballistic missiles. That provides lots of volume and mass for propulsion, payload, and navigation. Think double the size of the missile below.

Military strategists can spend entire careers working on the implications of delivering payloads 20 minutes, or 20 hours, or 20 days after launch, thinking of ICBM/cruise/torpedo variants.

 

[etudiant]

The Wall Street Journal reports that 4 Russian nuclear monitoring stations have gone silent since the accident.
https://www.wsj.com/articles/more-r...n-officials-says-11566232680?mod=hp_lead_pos6I have no idea whether this is a common practice or not, but it is surely suggestive.
However, the complete absence of detailed disclosure on part of the monitoring institutions is peculiar. A reactor accident that spews radioactive material is something they should be reporting on, unless they interpret their remit as purely confined to nuclear explosions.

Separately, the Russians have had extensive experience with liquid metal cooled reactors, which can operate at much higher temperatures than any water cooled design. Such a reactor would be a plausible heat source for a nuclear powered missile. Afaik, one of their main problem is that the metal coolant, usually lead or some lead/bismuth alloy, is prone to dissolve the pipes in which it runs. Perhaps this was such an incident. I've no idea however whether anyone has modeled a LOCA for these designs.

 

[anorlunda]

Afaik, one of their main problem is that the metal coolant, usually lead or some lead/bismuth alloy, is prone to dissolve the pipes in which it runs.

That might be acceptable in a missile with a design life of just a few hours.

The main fuel pumps in the Saturn V rocket had a design life of 200 seconds. 120 seconds of that was used in two pre-flight tests, and 60 seconds during the actual launch, leaving 20 seconds spare lifetime. My point is that components considered permanent in ordinary applications, can be considered consumable in short life applications like a missile.(Sorry, no link to that Saturn V data, but I could probably find it if someone wants me to.)

 

[etudiant]

Excellent point, design life is set to actual use.
That might actually help explain the accident, if they were testing the system several times and inadvertently exceeded the actual use life of some critical component.