nuclear airliners?!?!?

[robunos]

just came across this on 'Times Online'....

http://www.timesonline.co.uk/tol/news/environment/article5024190.ece

cheers,
Robin.

 

[Orionblamblam]

Nuclear-powered aircraft ... will be transporting millions of passengers around the world later this century,

Ah... no. Unless compact fusion powerplants come about, or some breakthrough occurs with so-far-discredited notions like cold fusion or hafnium isomers, there's basically no chance in hell that a nuclear airliner will fly.

 

[KJ_Lesnick]

Plus if that thing crashes...

 

[chornedsnorkack]

Plus if that thing crashes...

Kosmos satellites routinely do, by design.

 

[avatar]

helium 3 is the way to go.provided we find it on the moon and make a fusion reactor that can use it.

 

[KJ_Lesnick]

chornedsnorkack,

Kosmos satellites routinely do, by design.

Are they nuclear powered?


avatar,

helium 3 is the way to go.provided we find it on the moon and make a fusion reactor that can use it.

I thought helium 3 was a product during the solar fusion process?


KJ Lesnick

 

[chornedsnorkack]

chornedsnorkack,

Kosmos satellites routinely do, by design.

Are they nuclear powered?

Yes.

The reactor fuel assembly is 53 kg, 60 cm long, 20 cm diametre, consisting of 37 cylindrical fuel elements with 31,1 kg (beginning of life) of 90 % U235 enrichments.


I thought helium 3 was a product during the solar fusion process?

[/quote]

It is. And it stays in the core of the Sun, eventually fusing in its turn.

 

[Michel Van]

latest on Fusionreactor for Aircraft engine

was the Polywell reactor from by Robert Bussard
http://en.wikipedia.org/wiki/Polywell

test prototype build for US navy

research contract as future replace for fission reactors in Sub and Aircraftcarrier.
Bussard explane that the reactor build small enough to fit in cargoaircraft

 

[Just call me Ray]

Plus if that thing crashes...

Kosmos satellites routinely do, by design.

RORSAT (Radar Ocean Recon SAT) had routinely done it, by design ("COSMOS" was a U.S.-applied designation to anything put into Low Earth Orbit by the Soviets that wasn't otherwise identifiable - though these included the entire RORSAT range they also included a number of anonymous but civilian satellites as well as a number of interplanetary probes and other equipment that failed to escape LEO as well as test equipment, including a test of the intended Soviet LEM).

The RORSAT program was an earlier Cold War program now defunct, with most of the mini-reactors being ejected into a stable high orbit; however, at least two RORSAT sats have returned to Earth with their reactors, including one that crashed into the Sea of Japan after a failed launch and another that failed to achieve LEO and burned up over northern Canada, leaving an extensive radioactive debris field. A third RORSAT nearly failed to eject its reactor when spent, but a backup system managed to launch the reactor into a lower than intended, but evidently still stable high orbit.

If anything, this only highlights the concern, though RTGs (Radioisotope Thermoelectric Generators) are fairly common for interplanetary probes and possibly some satellites. Rather than a full-blown nuclear reactor, these devices merely convert the natural radioactive emissions of radioisotopes such as Pu-238 or Sr-90 into electrical power. Though these devices do not generate significant electrical output, they have the advantage of having a long "battery life," especially if a radioisotope with a very long half-life is used (hence why Pu-238 and Sr-90 are the most popular RTG fuel sources).

Besides, even a modern "compact" nuclear reactor is going to be huge. The only payload the NB-36 was able to carry was the reactor itself. Never mind the 6 tons of lead shielding it carried just behind the crew compartment, protecting only the crew (the amount of shielding needed for a passenger plane would make said plane more suitable as a submarine)

 

[KJ_Lesnick]

Chornedsnorkack,

From what I remember, in the sun the reaction occurs basically involving two hydrogen nuclei which collide, one becomes a neutron and shoots off a positron and neutrino, in which the positron is often annihilated by an electron. Another proton hits the deuteron (proton neutron pair -- a deuterium nucleus) and produces helium 3 and produces a gamma burst which actually produces the energy for the fusion reaction. Another He3 often collides with the mix which produces regular old Helium4, and two protons.

You are correct though that once the sun exhausts all it's hydrogen it will fall inward until the pressure reaches such a point that the helium fuses into heavier elements which results in the star expanding considerably and becoming a red-giant...


Michael Van,

latest on Fusionreactor for Aircraft engine

was the Polywell reactor from by Robert Bussard
http://en.wikipedia.org/wiki/Polywell

test prototype build for US navy

research contract as future replace for fission reactors in Sub and Aircraftcarrier.
Bussard explane that the reactor build small enough to fit in cargoaircraft

Is this fusion reactor stable?

Is it configured in such a way that it cannot produce a nuclear explosion (ie is it possible for it's normal power levels to spike high enough to cause something like that to happen)?


Just call me Ray,

That sounds about right...


KJ Lesnick

 

[chornedsnorkack]

Plus if that thing crashes...

Kosmos satellites routinely do, by design.

If anything, this only highlights the concern, though RTGs (Radioisotope Thermoelectric Generators) are fairly common for interplanetary probes and possibly some satellites. Rather than a full-blown nuclear reactor, these devices merely convert the natural radioactive emissions of radioisotopes such as Pu-238 or Sr-90 into electrical power. Though these devices do not generate significant electrical output, they have the advantage of having a long "battery life," especially if a radioisotope with a very long half-life is used (hence why Pu-238 and Sr-90 are the most popular RTG fuel sources).

RTG is useless unless the radioisotope has a short half-life. And Pu-238 is nasty stuff. Half-life under 90 years makes it a powerful alpha-ray source - far more dangerous than Pu-239 (half-life 24 000 years) let alone highly enriched U-235 (over 700 millions of years). You cannot scram a RTG! It keeps radiating at the same intensity when the heat is no longer needed, when the isotopes have been scattered to four winds and incorporated in human tissues. Whereas a neutron chain reaction nuclear reactor stops chain reacting when the critical conditions are disrupted and when the contents are scattered, their total activity is very low because of the huge lifetime of U-235...

Besides, even a modern "compact" nuclear reactor is going to be huge. The only payload the NB-36 was able to carry was the reactor itself.

A RORSAT reactor without shielding weights 130 kg. Not too much to carry on a small general aviation piston plane (when not running, of course!)

Never mind the 6 tons of lead shielding it carried just behind the crew compartment, protecting only the crew (the amount of shielding needed for a passenger plane would make said plane more suitable as a submarine)

Note that the MTOW of a NB-36 was just 162 t. Airbus 380 or An-225 could carry much bigger payloads.

 

[avatar]

I thought helium 3 was a product during the solar fusion process?

and it is precisely solar winds over eons that have led to the deposition of helium 3 in moon regolith.

it is one the primary reasons for renewed interest in lunar exploration.

here's a pdf on lunar deposits

http://www.lpi.usra.edu/meetings/lpsc2007/pdf/2175.pdf

 

[Michel Van]

KJ Lesnick: Is this fusion reactor stable?

after Bussard claime yes
see the Wiki link for more info
http://en.wikipedia.org/wiki/Polywell
bussard him self on Polywell
http://video.google.com/videoplay?docid=1996321846673788606

 

[avatar]

since we are talking about Bussard might as well give our friends at american antigravity a look in


http://www.americanantigravity.com/articles/682/1/Dr-Robert-Bussards-Fusion-Breakthrough/Page1.html

 

[avatar]

RTGs have a very poor output is to weight ratio if you like and a MW class RTG will be massive.

On the other hand small nuclear fission reactors are a pain as well on account of greater neutron loss and the high fuel enrichment levels that are required.

Fusion if and when possible is the way to go.

 

[Simon666]

On the other hand small nuclear fission reactors are a pain as well on account of greater neutron loss and the high fuel enrichment levels that are required. Fusion if and when possible is the way to go.

Fusion pretty much always produces neutrons, even with the trumped up He3. The "easiest" form of fusion, deuterium-tritium, produces some nice neutrons at 14 MeV.

 

[Grey Havoc]

A couple of recent developments:

http://up-ship.com/blog/?p=19227

http://www.dvice.com/2013-2-22/lockheeds-skunk-works-promises-fusion-power-four-years

(Note: there are some typos in the Dvice article.)