Nuke Powered Bombers Aircraft and Salt Power

[CandOforprogress2]

[RME]

Science-fiction fans: Hilbert Schenck's Steam Bird.

[CandOforprogress2]

If I remeber Juluis Verns Nautilus used the same type of power mentioned here

[DSchmitt]

USA

http://www.realclearscience.com/blog/2014/07/why_not_nuclear-powered_aircraft.html

 

Soviet Union

http://www.aviation-history.com/articles/nuke-bombers.htm

 

No nuclear powered airplane has been built.

[Victrola1]

Heavy Metal – Nuclear Locomotives vs Diesel Locomotives

https://www.greenoptimistic.com/heavy-metal-nuclear-locomotives-vs-diesel-locomotives-20140428/#.WPjw49Lytdg

I am still waiting for promise of the nuclear locomotive to come true. When it comes, it should come with a real steam whistle instead of an air horn. 

[DSchmitt]

http://io9.gizmodo.com/the-days-of-atomic-locomotives-in-america-1564623650

 

http://bbs.stardestroyer.net/viewtopic.php?f=52&t=123883

 

 

[Firelock76]

CandOforprogress2

If I remeber Juluis Verns Nautilus used the same type of power mentioned here

 

Actually, in the Jules Verne novel "20,000 Leagues Under The Sea"  Captain Nemo's "Nautilus" is powered by electricity.  Nemo says the electricity is generated using sea water, but doesn't say how.  Understandable, Verne was a great writer but not a scientist himself, so he couldn't theorize how it would be done.

In the Walt Disney film of the novel (great movie!) it's strongly hinted that the "Nautilus" is nuclear powered but they don't come right out and say so, it's left to your imagination.  Although there is a great special effects mushroom cloud when Nemo's island base self-destructs.

[Paul of Covington]

Firelock76

Actually, in the Jules Verne novel "20,000 Leagues Under The Sea" Captain Nemo's "Nautilus" is powered by electricity. Nemo says the electricity is generated using sea water, but doesn't say how. Understandable, Verne was a great writer but not a scientist himself, so he couldn't theorize how it would be done. In the Walt Disney film of the novel (great movie!) it's strongly hinted that the "Nautilus" is nuclear powered but they don't come right out and say so, it's left to your imagination. Although there is a great special effects mushroom cloud when Nemo's island base self-destructs.

   Exactly as I remember it.   On the Disneyland TV show promoting the movie and in the movie itself, it was suggested that Jules Verne was foreseeing nuclear power, but when I read the book, it was pretty clear that he was talking about electricity.

[RME]

Victrola1

I am still waiting for promise of the nuclear locomotive to come true

It's here, and the French have quite a number of them, some of which achieve remarkable speed.

Of course, we're talking about the 'correct' use of nuclear power for locomotives, which is a grid of nuclear power plants feeding a constant-tension catenary infrastructure...

[CSSHEGEWISCH]

Jules Verne was pretty much on the mark with his concept of electric drive for submarines since that is what happened when the diesel engine made submarines practical, using batteries for submerged running and the diesels for surface running and battery recharging.

[erikem]

FWIW, the first generation of subs (i.e. up till just prior to the sart of WW1) used gasolene or distillate engines. Main impetus for using diesels was the much lower CO content in the exhaust than spark ignition engines along with lower volatility fuel and better economy.

As for the original top of molten salt reactors, I have run across a couple of references to some nasty corrosion problems with the materials in contact with the molten salt. IIRC, the salts have ionic and not covalent bonds, and that would imply that the molten salt would be electrically conductive - any dissimilar metals present would be setting up a battery.

[RME]

erikem

As for the original topic of molten salt reactors, I have run across a couple of references to some nasty corrosion problems with the materials in contact with the molten salt. IIRC, the salts have ionic and not covalent bonds, and that would imply that the molten salt would be electrically conductive - any dissimilar metals present would be setting up a battery.

It has been a very long time now since I came across some of the older 'original' references in the Columbia engineering library, but I think that even by the time of Rosenthal et al. (1969) the engineering issues of conductivity in a working reactor had been addressed.  The question, I thought (in the early '80s), was whether alloys that were demonstrably 'passivated' at high temperature in contact with other media (notably, for example, Inconel 600 or the Hastelloy-N that I understood had been specifically developed for fluoride-salt use in nuclear aircraft) would remain passivated with conductive salt mixtures passing at high mass flow over the developed oxide layer.

Some of the early reactors used a (nominally conductive) graphite moderator but that was not wetted by the salts used.  I have not seen any indication that galvanic corrosion due to conductive electrolyte was observed in these, nor that the metallurgy of the alloys used was point-imperfect in a way that set up for internal grain corrosion.

I believe the modern reactors are using NiMo alloys with SiC particles to reduce creep (and NiSi nanoparticles to anchor the SiC more solidly) and to my knowledge there have been no reports of damaging corrosion with these at all.

[erikem]

RME

 Some of the early reactors used a (nominally conductive) graphite moderator but that was not wetted by the salts used.  I have not seen any indication that galvanic corrosion due to conductive electrolyte was observed in these, nor that the metallurgy of the alloys used was point-imperfect in a way that set up for internal grain corrosion.

The proposals I've seen suggest that graphite is still the preferred moderator for neutron economy reasons. Be or BeO would be another possibility, but I'd wonder about how either would hold up to a long sustained neutron flux. Graphite in a molten salt reactor is probably hot enough to sustain the "Wigner energy release" mechanism that was a bugaboo for low temperature graphite moderated reactors (e.g. Windscale).

I believe the modern reactors are using NiMo alloys with SiC particles to reduce creep (and NiSi nanoparticles to anchor the SiC more solidly) and to my knowledge there have been no reports of damaging corrosion with these at all.

 

 

This is with a molten salt coolant? I'm probably pretty ignorant about recent work with molten salt coolants, with ONRL's project being the last one that I'm aware of getting a fair amount of run time.

 

My skepticism about molten salt coolant is derived from the experience with sodium cooled reactors. They worked fine on a demonstrator level, but utility scle plants have had all sorts of problems. As such, it would be useful to have a reasonable size reactor (50 MWth or higher) running more or less continuously for a few years before saying it is the future of nuclear energy.

[RME]

erikem

Graphite in a molten salt reactor is probably hot enough to sustain the "Wigner energy release" mechanism that was a bugaboo for low temperature graphite moderated reactors (e.g. Windscale).

My knowledge of the Wigner release is that long, cumulative mechanical displacement through neutron collisions at relatively low temperature builds up extensive numbers of Frenkel pairs, which can autocatalytically release generating substantial net heating comparatively suddenly.  If the graphite is soaked at around 250C or above, the damage tends to relax nondestructively. 

I still happen to believe that the graphite fire at Chernobyl was to a significant degree the result of Wigner release after the very substantial prompt-critical neutron emission.  A high-energy neutron can cause many hundreds of defects in the graphite lattice, essentially storing its energy in more locations than, say, Bragg release from a charged-particle event might.

This is with a molten salt coolant?

Explicitly, and with considerable metallurgy to back it up.  (I might add that some of this factored into the comparative metallurgy of the T1 replica lightweight rods... with the substitution of cerium for silicon carbide microspheres.)

My skepticism about molten salt coolant is derived from the experience with sodium cooled reactors. They worked fine on a demonstrator level, but utility scale plants have had all sorts of problems.

I think there are many similarities between the two (for example, handling cold shutdowns that don't critically atherosclerose the primary loops) but I think that the original Detroit Edison breeder would have run perfectly well if those last-minute beer-can vanes hadn't been added.  That thing was built like a piece of jewelry.  I also think that some of the Soviet developments in NaK eutectics that are liquid at reasonable environmental temperatures represent a reasonable way to implement liquid-metal coolant, even if they activate a bit more.  On the other hand, there isn't much doubt that sooner or later some of the primary light-metal coolant is going to encounter the fixin's of the steam generation, and the result is not going to be something even a Cornell engineer has much delight in addressing.  I don't think the alternative for any of the molten-salt coolants is quite as dramatic, but I have not run any numbers to see if any of the fluorides might hydrolyze at typical accident temperatures -- personally I don't think they would.

If I remember correctly, up to a substantial point the "ECCS" for a molten-salt reactor, even a breeder, involved dumping the coolant/reactant directly into water, similar to quenching frit in the glass industry, and from that point on, the situation with decay heat is little different, qualitatively, than what is necessary with spent-rod pools.  No issue with zirconium becoming a nasty reducing agent at elevated temperature contributing to runaway gas releases and likely meltdown as cooling integrity is lost...

On the other hand, almost as seldom mentioned as 'why the thorium cycle is relatively immune to proliferation' is what is done with the xenon, iodine, etc. created in the fuel burn.  You hear blithely that it bubbles out and is then separated, but you much less frequently hear exactly how.  There also is an awful lot of handwaving when you get to continuous reprocessing, which was clearly an assumption for most of the earlier liquid-fissile reactors.

... it would be useful to have a reasonable size reactor (50 MWt or higher) running more or less continuously for a few years before saying it is the future of nuclear energy.

I would of course find no fault with this.  And I would expect problems with scale and perhaps build quality over time to come up with the larger design.  On the other hand, we now have such good multiphysics and modeling software that many of the potential issues can be found before actual construction or even final design freeze take place.  I am tempted to say that if we are going to attempt a thorium/U233 cycle at almost any time, the molten-salt approach (either single- or double-stream) is the most attractive at either comparatively small or full scale.

[CandOforprogress2]

So.....What they seem to be saying is that Salt Cooled and Fired nuke powered plants seem to work well in that they are more heat effciatate in smaller KW plants and that certain radioactive salts that are used for the coolant can be used for the fuel as well.-----PS- The orginal idea of Nuke Powered air craft Bombers is a dead duck as far as saftey because it would be the end of the world as we know it and that ICBMS have replaced bombers anyway.----BUT-a small scale nuke power system can run a subway or a small university.

 

[M636C]

Paul of Covington

 

 

Firelock76

Actually, in the Jules Verne novel "20,000 Leagues Under The Sea" Captain Nemo's "Nautilus" is powered by electricity. Nemo says the electricity is generated using sea water, but doesn't say how. Understandable, Verne was a great writer but not a scientist himself, so he couldn't theorize how it would be done. In the Walt Disney film of the novel (great movie!) it's strongly hinted that the "Nautilus" is nuclear powered but they don't come right out and say so, it's left to your imagination. Although there is a great special effects mushroom cloud when Nemo's island base self-destructs.

 

 

   Exactly as I remember it.   On the Disneyland TV show promoting the movie and in the movie itself, it was suggested that Jules Verne was foreseeing nuclear power, but when I read the book, it was pretty clear that he was talking about electricity.

 

Of course, Rickover's SSN-571 was launched in 1954, just as the Disney movie was released in 1954. But the submarine name was announced in 1951, so it seems unlikely that the movie, rather than the book, influenced the name of the submarine.

 

However, the knowledge that the nuclear submarine was being built (it was laid down in 1952) probably influenced Disney in the movie script.

 

The Wikipedia page says that the ships "patch", the logo worn by the crew, was designed by the Walt Disney Company, which suggests more than a casual relationship.

 

One imagines Walt Disney (who personally produced "20 000 Leagues under the Sea") and Hyman Rickover had a lot in common and had probably met eachother.

 

I seem to recall that a modified NB-36H bomber actually carried an experimental nuclear reactor in flight (although it operated while airborne, what it would have been used for isn't clear, other than to test the shielding for the crew). Like other B-36s it was powered by six R-4360 radials and four J-47s.

 

Peter

[CandOforprogress2]

Well the book does say its gets its fuel from the sea and uses it to generate electrcity. So perhaps a salt generated energy system of some kind like what i am talkng about. Batterys have been around for quite some time and were used in Vernes day.