Rosatom rocket engine failure

[Nothalogh]

2 minutes ago, Cheif Operations Director said:

elaborate, sorry I do not know a ton about nuclear tech.

Prompt Criticality can cause a thermal power output spike

[Cheif Operations Director]

Just now, KeranoKerman said:

I would guess that they are using a fission reactor engine. Fusion is very hard to make work, and an rtg rocket breaking apart would have radiation seep out. A nuclear reactor going critical would create a flash of high energy  photon radiation, possibly making some atoms undergo alpha and beta decay.

Right, but how exactly are they going to harness such heat in an engine. I mean they COULD use the reactor to heat up a single gas and then expel that gas out of a nozzle, cutting combustion out of the process entirely. 

[Nothalogh]

Just now, Cheif Operations Director said:

I mean they COULD use the reactor to heat up a single gas and then expel that gas out of a nozzle, cutting combustion out of the process entirely. 

That's exactly how Open Cycle NTRs work

[Ultimate Steve]

Just now, Cheif Operations Director said:

Right, but how exactly are they going to harness such heat in an engine. I mean they COULD use the reactor to heat up a single gas and then expel that gas out of a nozzle, cutting combustion out of the process entirely. 

Yes, that is usually how nuclear engines work. Open cycle, you basically flow the fuel straight through the reactor, closed cycle, you have heat transfer devices that heat the fuel indirectly. Closed cycle is safer, but open cycle is more efficient. This way you can get specific impulses of around 1000, plus or minus some, depending on how far you push it.

[KeranoKerman]

Just now, Cheif Operations Director said:

Right, but how exactly are they going to harness such heat in an engine. I mean they COULD use the reactor to heat up a single gas and then expel that gas out of a nozzle, cutting combustion out of the process entirely. 

That’s how they work, with liquid hydrogen 

[Ultimate Steve]

1 minute ago, KeranoKerman said:

That’s how they work, with liquid hydrogen 

Technically you can use anything, but hydrogen is the most efficient. I like the idea of a water powered engine, you can refuel at a lot of places that way.

[Nothalogh]

5 minutes ago, Ultimate Steve said:

You can also go Orion style and blow up nukes behind you to push you forwards. That's also not a good idea in most cases.

 

6 minutes ago, Ultimate Steve said:

That's also not a good idea in most cases.

 

I reject this line of thinking

[kerbiloid]

(Oops, probably ninja'd)
_{https://translate.google.com/translate?hl=ru&sl=ru&tl=en&u=https://www.interfax.ru/russia/672241}

Edited August 10, 2019 by kerbiloid

[kerbiloid]

3 hours ago, Nothalogh said:

They said it was a " liquid-propellant engine" that had an ”isotope power source".

Isotopes? Check.
Liquids? Check.
Wut's wrong?

P.S.
By the 5 page of discussion they've invented a Daedalus-propelled cruise missile.

[magnemoe]

2 hours ago, Ultimate Steve said:

Yes, that is usually how nuclear engines work. Open cycle, you basically flow the fuel straight through the reactor, closed cycle, you have heat transfer devices that heat the fuel indirectly. Closed cycle is safer, but open cycle is more efficient. This way you can get specific impulses of around 1000, plus or minus some, depending on how far you push it.

Closed cycle was on the table for nuclear planes, the idea is pretty pointless for rocket engines unless you use the reactor as an power source to run high isp electrical powered engine like vasmir or ion. 

And this sounds like an fail with an NTR, could be so simple as over-pressure in chamber 

[kerbiloid]

Before overcomplicating things, gentlemen should keep in mind that it's just a single-use apocalyptic device.

[Nothalogh]

1 minute ago, kerbiloid said:

Before overcomplicating things, gentlemen should keep in mind that it's just a single-use apocalyptic device.

I prefer my apocalyptic devices to be built according to the standard engineering model, and with a barber's chair for the captain's seat

[YNM]

3 hours ago, Cheif Operations Director said:

elaborate, sorry I do not know a ton about nuclear tech.

https://en.wikipedia.org/wiki/Criticality_accident#Recorded_incidents

Basically, the rate of chain reaction depends on the amount of neutrons that can trigger the reaction further; if there's less that can be produced off what was required to do the fission in the first place, then the condition is subcritical; but if the rate is precisely the same, then the reaction is critical, and there's a tendency that it would go towards supercriticality (basically an uncontrolled chain reaction, as seen in nuclear bombs). The rate depends, among many things, in how many neutrons are bounced back to the material, and if the radioactive material are handled or arranged wrongly, you can create a critical condition which leads to bad things.

While the design of NTRs would most likely avoid criticality at all cost, it is possible that the way it was assembled or handled makes it more dangerous than the final product.

Though the problem with that explanation in this case would be the "explosion" and the burns. If it was a criticality accident and it made for an actual explosion, then yes the radioactive materials (which are likely to be long-lived) would've been scattered all over the place - yet reports doesn't say of any ensuing radioactivity after the explosion; but if it just blows off one part of the containment vessel (say, the top enclosure) and it returns back to subcriticality, then the radioactive materials might remain within the vessel and not spread all over the place, consistent with a brief spike in radioactivity, but this wouldn't be an "explosion".

Edited August 10, 2019 by YNM

[kerbiloid]

Fully offtopic, just to illustrate that everything is already made by Scott Manley.

Spoiler

 

upd.
Btw what is the main conclusion we can make from this video?

Spoiler

True experts use MechJeb.

 

Edited August 10, 2019 by kerbiloid

[Maggie]

I found a article on the Triton Hopper drive which maybe the type of motor that is referred in the article. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20170006624.pdf. 

[RCgothic]

So just to point out that the US withdrew from the IRNF treaty this week in protest about "new kinds of Russian cruise missile".

And I remember another news bulletin earlier in the year about potential Russian hypersonic nuclear power cruise missiles with unlimited range.

Could be one of them that let go in testing?

[kerbiloid]

The new cruise missiles are not nuke-propelled, while the nuke-propelled one is (if is) global.
So, unlikely this can have any relation to the treaty.

Edited August 10, 2019 by kerbiloid

[steve_v]

2 hours ago, YNM said:

While the design of NTRs would most likely avoid criticality at all cost, it is possible that the way it was assembled or handled makes it more dangerous than the final product.

Though the problem with that explanation in this case would be the "explosion" and the burns. If it was a criticality accident and it made for an actual explosion, then yes the radioactive materials (which are likely to be long-lived) would've been scattered all over the place - yet reports doesn't say of any ensuing radioactivity after the explosion; but if it just blows off one part of the containment vessel (say, the top enclosure) and it returns back to subcriticality, then the radioactive materials might remain within the vessel and not spread all over the place, consistent with a brief spike in radioactivity, but this wouldn't be an "explosion".

My guess is that it wasn't a problem with reactor per-se, but rather with the propellant - flow problems or hydrogen leaks causing a fuel-air explosion and possibly minor reactor damage, or it's a LANTR type design and it was a fuel-oxidiser explosion.
Nuclear reactors cores don't really "explode" as such, AFAIK the only explosion-like incidents on record were actually steam or hydrogen explosions in the reactor vessel. Even Chernobyl was technically a steam explosion IIRC.
If the core did somehow go prompt-critical, you have a nuclear bomb - or at the least total core destruction, and that's likely going to kill more than 5 people as well as producing considerable fallout.

[kerbiloid]

(Unrelated to the thread topic).

What is "hydrogen" in a storable missile???

[YNM]

4 hours ago, steve_v said:

Nuclear reactors cores don't really "explode" as such, AFAIK the only explosion-like incidents on record were actually steam or hydrogen explosions in the reactor vessel.

True, but it'd still cause a spread of the radioactive material (and such event would be what I'm willing to call as an "explosion", because otherwise it's just a flash of light and radiation, but no radioactive source material).

Edited August 10, 2019 by YNM

[DDE]

13 hours ago, Cheif Operations Director said:

I doubt RT got that part wrong

Oh, please. They’re Buzzfeed-level hacks struggling to translate Russian reports that use deliberately obfuscating jargon.

9 hours ago, RCgothic said:

So just to point out that the US withdrew from the IRNF treaty this week in protest about "new kinds of Russian cruise missile".

And I remember another news bulletin earlier in the year about potential Russian hypersonic nuclear power cruise missiles with unlimited range.

Could be one of them that let go in testing?

Burevestnik exceeds the maximum range threshold for an intermediate missile as stipulated by the INF. The INF bans any land-based missiles (and, technically, UCAVs) with a maximum range between 500 and 5000 km. The bone of contention was that the Russians took the Kalibr ship-to-shore missile (range >2500 km) and put it on a truck.

14 hours ago, Nothalogh said:

So, with what we know of the various types of Nuclear Thermal Rockets

Hold your horses.

Until Rosatom confirmed its involvement, and since the ‘radiation spike’ was originally reported at a negligible 0.06 microsieverts, all of this matched the description of a Sineva SLBM.

[Cheif Operations Director]

11 minutes ago, DDE said:

Oh, please. They’re Buzzfeed-level hacks struggling to translate Russian reports that use deliberately obfuscating jargon.

Yea, lol all I’m saying that, that one part of the report is hard to mess up.

[DDE]

7 minutes ago, Cheif Operations Director said:

Yea, lol all I’m saying that, that one part of the report is hard to mess up.

You seriously expect a bunch of harried interns that must excrements out a report in ten minutes or less to give any mind to nuclear physics?

[Cheif Operations Director]

1 minute ago, DDE said:

You seriously expect a bunch of harried interns that must excrements out a report in ten minutes or less to give any mind to nuclear physics?

No, but they were quoting rosatom

[DDE]

21 minutes ago, Cheif Operations Director said:

No, but they were quoting rosatom

...and that didn’t prevent most of information getting lost in translation. For starters, the word питание refers exclusively to electric current. To which you then baselessly speculated:

14 hours ago, Cheif Operations Director said:

I find this interesting though, why would an isotope based power source suddenly dissipate its energy?

Perhaps you, and not the Russian government, are the one who should be kept away from nuclear energy.

Edited August 10, 2019 by DDE