bjornstrom
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Depleted Uranium In Boeing 747?

Wed May 17, 2006 4:56 pm

I found this article that states that Boeing 747's are carrying around a lot of depleted uranium in its structure:

"Counterweights are used in the aerodynamic controls of planes, rockets, and helicopters to maintain the aircraft's center of gravity. Heavy density is important in keeping the counterweight small in comparison with airfoil steering surfaces. DU is very appropriate for this kind of application, and uranium counterweights are used in many civil and military aircraft. The report mentions as an example the Boeing 747, a plane which, according to its supplier, contains 1500 kg of DU as a standard amount."

http://www10.antenna.nl/wise/index.h....antenna.nl/wise/463-464/4609.html

Is this true? Is the uranium radioactive by any substantial amounts?
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zvezda
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 5:05 pm

Depleted uranium is toxic to handle, which is probably a bigger concern than low radiation levels. Density is not that much higher than lead, but the toxicity is a lot higher. I'm not asserting that this report is false, but I'm very skeptical.
 
bjornstrom
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 5:15 pm

I am aware that M1 and Leopard 2 MBT:s use APFSDSDU [Armor Piercing Fin Stabilized Discarded Sabot Depleted Uranium] or Sabot ammunition. But it requires special handling when loading and using these rounds.
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RichardPrice
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 5:24 pm

Yes its true, there are uranium weights in a lot of aircraft and there have been 'issues' where these weights have been missing after crashes.

They are slightly radioactive, but not hugely so, you could not get a fatal dose from these weights unless they were aerosoled - the worst damage would come if you swallowed some (its a poison as well), or you got bashed over the head with some.

The weights are contained in sealed units, so its hard for them to pose a risk in normal usage, only in crashes.

http://news.bbc.co.uk/1/hi/sci/tech/593649.stm

[Edited 2006-05-17 10:26:58]
 
3MilesToWRO
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 5:30 pm

Quoting Zvezda (Reply 1):
uranium is toxic

Are you sure? Plutonium certainly is, but I think I've never heard U is significantly toxic.
 
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ptrjong
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 5:36 pm

Illnesses in Amsterdam following the 1992 El Al 747 crash have been related to depleted uranium.

Quote from the NRC newspaper:
The crashed aircraft had several hunders of kilos of depleted uranium in its tail section as a counterweight, of which 192 kg has not been found.

Its use in that aircraft is considered a fact here.

Apparently the Dutch CAA was informed by the FAA in 1985 about the risks of depleted uranium (used in aircraft parts, obviously). A Dutch minister said that the FAA document did not say which specific aircraft in the world still used such parts.

So hopefully it's on the way out.

Peter
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ANother
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 6:20 pm

Quoting Ptrjong (Reply 5):
So hopefully it's on the way out.

According to the BBC news link above:

Quote:
A Boeing spokesman told BBC News Online: "The company began using DU in the early 1960s. Boeing replaced it with tungsten in the early 1980s, on grounds of cost and availability.
 
Jetmek319
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 6:25 pm

The elevator counterweights on the B727 are also depleted uranium. Depleted uranium is not toxic (unsless you ingest or breathe in the dust after machining) nor is it dangerously radioactive. There are far more toxic items on the aircraft than the depleted uranium, like the berylium used in various bushings (also on the way out) and some of the PCB's in circuit boards (also being phased out).
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Glom
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 7:46 pm

Quoting Bjornstrom (Thread starter):
Is the uranium radioactive by any substantial amounts?

No. Uranium-238 has a half life the age of the planet. It has a very low specific activity.

It doesn't get along well with the kidneys though chemically.

But at the end of the day, chemical and radiological toxicity together are not particularly intimidating. There are plenty of materials far worth worrying about, such as the paint.
 
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Zkpilot
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 7:51 pm

short answer is yes.... it has been used in commercial aircraft such as the 747.
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miamiair
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 7:55 pm

DC-10 has it as well in the rudder and elevator weights. Berrylium is just as toxic (Inhaling dust from machining operations) to you and that is used in the aviation industry as well.
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bjornstrom
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RE: Depleted Uranium In Boeing 747?

Wed May 17, 2006 8:07 pm

You learn something new every day on a.net - thanks all!  Smile
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baroque
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 12:06 am

I did not know about depleted uranium, but I guess every little bit helps. Many years ago I discovered that the sintering process was developed in WWII specifically to produce more dense counter-balance weights made out of tungsten - the problem being that the high melting point of tungsten made it difficult to melt using the methods developed for metals with a lower melting point. I always liked the phrase in a mineralogy text that went "due to its high specific gravity, tungsten is used to save weight in airplanes".
 
seanp11
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 12:42 am

Quoting Glom (Reply 8):
But at the end of the day, chemical and radiological toxicity together are not particularly intimidating. There are plenty of materials far worth worrying about, such as the paint.

Yep, you'll get exposed to much more radiation simply from being at cruise altitude. You'll get exposed to more radiation by being out in the sun. U is a primarily alpha emitter, and alpha particles can be stopped by heavy paper or your epidermis. Properly encased DU poses a very little threat.

and here's what wikipedia had to say about the use of DU as an aircraft counterweight:

Quote:
Aircraft may also contain depleted uranium trim weights (a Boeing 747 may contain 400 to 1,500 kg). This application of DU is controversial. If an aircraft crashes there is concern that the uranium would enter the environment: the metal can oxidise to a fine powder in a fire. While arguably other hazardous materials released from a burning commercial aircraft overshadow the contributions made by DU, its use has been phased out in many newer aircraft, Both Boeing and McDonnell-Douglas discontinued using DU counterweights in the 1980s.

It is also thought that the use of DU munitions during the gulf war may have something to do with the gulf war syndrome. But that's a completely different case.
 
pavlin
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 12:48 am

DU is not used anymore in commercial airplanes.Newer and expensive materials are used instead. Only early 747 (not 747-400) used it. 1.5 ton of it. That is a lot. Considering that composite 787 will be only 15 tonnes lighter than Al-LI A350
 
Dougloid
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 1:10 am

Quoting Miamiair (Reply 10):
DC-10 has it as well in the rudder and elevator weights. Berrylium is just as toxic (Inhaling dust from machining operations) to you and that is used in the aviation industry as well.

An interesting story. I never heard it mentioned at the mandatory safety training I underwent as a Douglas employee.

Here's a good article on the subject.

http://www.aeronautics.ru/archive/du-watch/us_gov_about_du.htm
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boeing767mech
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 5:49 am

The stab on the CV880 had big piece of Depleted Uranium on the tips for counter weights.

David
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tjc2
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 5:55 am

Quoting Ptrjong (Reply 5):
The crashed aircraft had several hunders of kilos of depleted uranium in its tail section as a counterweight, of which 192 kg has not been found.

Surely some could well have been destroyed in the crash?
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flyinTLow
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 6:24 am

Maybe this is a rather stupid question in here: but how uneconomical is it to put 1.5 tons of useless weight into an aircraft structure? That's already almost 1% of the aircrafts empty weight (747-100). You would think engineers could do better than use that much weight just to balance the whole thing.....

But yes, have to admitt, this is new to me as well!
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rdwelch
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 6:34 am

Quoting RichardPrice (Reply 3):
or you got bashed over the head with some.

Well, you've got that too.
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Fly2HMO
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 7:01 am

Quoting Bjornstrom (Thread starter):
Is this true? Is the uranium radioactive by any substantial amounts?

Like mentioned above, a sheet of paper would be enough to block the radiation.

Americium is slightly radioactive and it's been used harmlessly for years in residential smoke detectors.
 
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ptrjong
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 7:03 am

Quoting Boeing767mech (Reply 16):
Surely some could well have been destroyed in the crash?

Yes, the stuff burns, and that is when its gets dangerous to your health, according to the article I was quoting.

The El Al 747 crashed into an apartment block.
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AM744
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 7:13 am

Quoting Miamiair (Reply 10):
DC-10 has it as well in the rudder and elevator weights. Berrylium is just as toxic (Inhaling dust from machining operations) to you and that is used in the aviation industry as well.



Quoting Dougloid (Reply 15):
An interesting story. I never heard it mentioned at the mandatory safety training I underwent as a Douglas employee.

Aquaintace of mine who worked on AM's DC-10s confirm this.
 
RichardPrice
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 7:21 am

Quoting FlyinTLow (Reply 18):
Maybe this is a rather stupid question in here: but how uneconomical is it to put 1.5 tons of useless weight into an aircraft structure

Very, but sometimes theres absolutely nothing else you can put up there to act as the counterweight. Fuel gets depleted, so it cant be used, electronics arent heavy enough, cargo ... no. Bulking up the structure to act as its own counterweight will probably make the airframe less aerodynamically efficient in the process, so you end up shoving some very dense metal in places, fitting them in any small hole that is free.
 
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Starlionblue
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 10:05 am

Quoting Bjornstrom (Thread starter):
Is this true? Is the uranium radioactive by any substantial amounts?



Quoting RichardPrice (Reply 3):
They are slightly radioactive, but not hugely so, you could not get a fatal dose from these weights unless they were aerosoled - the worst damage would come if you swallowed some (its a poison as well), or you got bashed over the head with some.

Interestingly, coal is mildly radioactive. In large quantities it's bad for the environment. So much for "clean coal" and other bedtime stories. In fact, lots of things are radioactive, including the glowing dial hands in watches (that's how they glow).
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MrChips
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 11:51 am

Quoting FlyinTLow (Reply 18):
Maybe this is a rather stupid question in here: but how uneconomical is it to put 1.5 tons of useless weight into an aircraft structure? That's already almost 1% of the aircrafts empty weight (747-100). You would think engineers could do better than use that much weight just to balance the whole thing.....



Quoting RichardPrice (Reply 23):
Very, but sometimes theres absolutely nothing else you can put up there to act as the counterweight.

Guys, counterweights are not "useless" weight at all. In fact, they are a necessity in most aircraft designs.

In the 1950s and 1960s, most manufacturers had a hell of a time trying to sort out high-speed aerodynamics. One of the biggest problems encountered was balancing the need for a light structure with aerodynamic flutter, especially when dealing with control surfaces. Now, one of the easiest potential solutions to this problem is to change the center of gravity of the affected control surface; usually, the goal is to try and move it as far forward as possible. Since wind tunnel time is extremely expensive, and may not even re-create the conditions necessary for flutter to develop, adding weights to the control surfaces was (and in some cases still is) considered the easiest way to control this problem. Now if you need to add a lot of weight, you want something really dense, so that you can very precisely control the center of gravity - enter depleted uranium.

Really, there are bigger things out there to worry about than a little bit of DU in an airplane, so why all this fuss?
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474218
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 12:18 pm

Quoting MrChips (Reply 25):
Really, there are bigger things out there to worry about than a little bit of DU in an airplane, so why all this fuss?

Right on. Depleted Uranium (DU) has a negligible amount of residual radiation and providing the protective coatings (cad plate, primer and top coat) are in tact and it can be safely handled. However, if the protective coating is damaged and the bare surface corrodes or someone tries to drill or sand it the, dust should be avoided. As with all heavy metals it can build up in your body over time and cause problems. DU counterweights are cast to shape, machined, drilled and cad plated by a facility licensed by the Nuclear Regulatory Commission (NRC), and only a NRC approved facility can rework them. Most manufactures have switched to making their counterweights from tungsten as it does not have the bad press that DU does. One draw back of tungsten is that parts of the same size will weight approximately 10% less.
 
SFOMB67
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 2:18 pm

Quoting Jetmek319 (Reply 7):
The elevator counterweights on the B727 are also depleted uranium

The counterweights on the 742 upper rudder were depleted uranium, and marked with "warnings" about handling. The lower rudder wasn't a balanced surface, and I don't recall seeing it used as counterweights on the elevators or ailerons. At least I don't recall any warnings, as were stenciled on the rudder weights.
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VC-10
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RE: Depleted Uranium In Boeing 747?

Thu May 18, 2006 5:34 pm

Quoting Pavlin (Reply 14):
DU is not used anymore in commercial airplanes.Newer and expensive materials are used instead. Only early 747 (not 747-400) used it

From the 747-400 MM Chapt 55-20-00 Pb 201:-

Some balance weights are made from depleted uranium, which is naturally occuring uranium that has been "depleted" of most of the isotope U235. This remaining low-level radioactive uranium, similar to other heavy metals, is toxic if ingested, absorbed, or inhaled into the body.
 
Tom12
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RE: Depleted Uranium In Boeing 747?

Fri May 19, 2006 12:18 am

Quoting 3MilesToWRO (Reply 4):
Quoting Zvezda (Reply 1):
uranium is toxic

Are you sure? Plutonium certainly is, but I think I've never heard U is significantly toxic.

I think it is more the Radio active effect people are worried about, Skin is enough to block the toxin from DU. The Radio Active effect of DU is 40% less the Natural Uranium.

Quoting Bjornstrom (Thread starter):
Is the uranium radioactive by any substantial amounts?

Depleted uranium is a heavy metal that is also slightly radioactive. Heavy metals (uranium, lead, tungsten, etc.) have chemical toxicity properties that, in high doses, can cause adverse health effects. Depleted uranium that remains outside the body can not harm you.
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prebennorholm
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RE: Depleted Uranium In Boeing 747?

Fri May 19, 2006 8:45 am

Quoting FlyinTLow (Reply 18):
Maybe this is a rather stupid question in here: but how uneconomical is it to put 1.5 tons of useless weight into an aircraft structure? That's already almost 1% of the aircrafts empty weight (747-100).

Not a stupid question at all. But in fact those very heavy metals are used to in order to reduce the empty weight of the plane.

If a lighter metal such as iron was used for those balance counter weights, then they would take up more of the often very limited space. That would mean that a smaller part of the counter weights could be placed at the most efficient position, meaning that more weight would have to be used at less efficient positions to make mainly control surfaces balance correctly.

If iron had been used instead of uranium on a 747-100, and we assume that space was available for all that iron (very optimistic) then it is very likely that 2 or 2.5 tons of iron would have been needed to replace those 1.5 tons of uranium.
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SlamClick
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RE: Depleted Uranium In Boeing 747?

Fri May 19, 2006 10:05 am

I also remember reading once that (at that time) turbine engine ingnitor-exciters had a small amount of slightly radioactive material. Anyone know anything about that?

By the way there are many public buildings here in the US that are faced with stone of sufficient radioactivity that they will likely have to be treated as HAZMAT when any work is done on them.
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VC-10
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RE: Depleted Uranium In Boeing 747?

Fri May 19, 2006 6:55 pm

Quoting SlamClick (Reply 31):
I also remember reading once that (at that time) turbine engine ingnitor-exciters had a small amount of slightly radioactive material. Anyone know anything about that?

See

http://www.airliners.net/discussions/tech_ops/read.main/153272/
 
DrDeke
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RE: Depleted Uranium In Boeing 747?

Sat May 20, 2006 3:49 am

I apologize if this is a bit off-topic, but aren't at least some of the emergency exit signs used on planes powered by nuclear decay from tritium? These signs aren't marketed toward aviation use, but I am pretty sure that similar devices are used on at least some airliners:

http://www.elights.com/quesabsrsele.html

-DrDeke
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Bobster2
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RE: Depleted Uranium In Boeing 747?

Sat May 20, 2006 5:25 am

Quoting DrDeke (Reply 33):
aren't at least some of the emergency exit signs used on planes powered by nuclear decay from tritium?

Yes. Both planes that hit the World Trade Center had tritium, and tritium contamination was subsequently found in WTC sewage and basement. The levels were too low to have health effects, but high enough to be detected.

http://repositories.cdlib.org/cgi/vi...tent.cgi?article=1678&context=lbnl

http://www.llnl.gov/tid/lof/documents/pdf/241096.pdf

[Edited 2006-05-19 22:27:44]
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A/c train
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RE: Depleted Uranium In Boeing 747?

Sun May 21, 2006 3:40 am

they make good rivet blocks though !!
 
474218
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RE: Depleted Uranium In Boeing 747?

Sun May 21, 2006 4:16 am

Quoting A/c train (Reply 35):
they make good rivet blocks though !!

Please explain this statement?
 
Gary2880
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 7:03 am

scary indeed

i always did wonder how they made the tail section glow in the dark.
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MrChips
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 7:58 am

Quoting Gary2880 (Reply 37):

i always did wonder how they made the tail section glow in the dark.

What?

They use lights for that - uranium, even highly enriched U235, is not able to "glow" on it's own - contrary to what you see on TV, there are very few isotopes that can actually glow from their own radioactivity. Tritium paint only uses the tritium as a source of energy; phosphorescent compounds are actually what make it glow in the dark.

[Edited 2006-05-22 01:01:17]
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A/c train
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 4:49 pm

474218, use it too react rivets, it weighs alot and will form a good rivet. Dont ask me how too machine it though I was just given a couple, they look like sections of 757 aileron mass balance weight.
 
Gary2880
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 4:53 pm

Quoting MrChips (Reply 38):

maybe techops isn't the best place for sarcasm, ill move along  Wink
Patriotism is the last refuge of the scoundrel :- Samuel Johnson
 
ba97
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 9:00 pm

Which aircraft were the first to stop having DU put in as weights- I expect the signs are still tritium. Was there an aircraft size below which it served no benefit (e.g. Dash 8)?
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David L
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 9:00 pm

Quoting Gary2880 (Reply 40):
maybe techops isn't the best place for sarcasm, ill move along

And there was me about to say the logo lights switch simply slides a lead shield to and fro across the uranium. Lucky I didn't.  Smile
 
474218
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RE: Depleted Uranium In Boeing 747?

Mon May 22, 2006 10:39 pm

Quoting A/c train (Reply 39):
474218, use it too react rivets, it weighs alot and will form a good rivet. Dont ask me how too machine it though I was just given a couple, they look like sections of 757 aileron mass balance weight.

That's what I thought you meant (in the States we call them bucking bars, used to buck rivets). The problem, while Depleted Uranium is heavy it is also very soft. The rivet would just make an impression in the DU and the rivet would never set up.
 
seanp11
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RE: Depleted Uranium In Boeing 747?

Tue May 23, 2006 1:54 am

Quoting MrChips (Reply 38):
They use lights for that - uranium, even highly enriched U235, is not able to "glow" on it's own - contrary to what you see on TV, there are very few isotopes that can actually glow from their own radioactivity. Tritium paint only uses the tritium as a source of energy; phosphorescent compounds are actually what make it glow in the dark.

I think the myth that all radioactive substances glow in the dark comes from a real phenonemon, called cherenkov radiation. Pretty much, what you have is a bunch of charged particles (usually electrons) moving faster than the speed of light IN a substance such as water. Light moves slower than water than it does through air or a vacuum, hence why refraction exists. These electrons are moving faster than that speed, and they generate what is analogous to a sonic boom. It doesn't make much sense at first, because everybody knows that nothing can go faster than the speed of light in a vacuum, but it can go faster than the speed of light in water. This makes the water in nuclear reactors glow bright blue.

http://en.wikipedia.org/wiki/Cherenkov_radiation
 
Bobster2
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RE: Depleted Uranium In Boeing 747?

Tue May 23, 2006 2:18 am

Quoting Ba97 (Reply 41):
Which aircraft were the first to stop having DU put in as weights-

The first 550 747's had DU. That's about it. I don't think there are any other commercial aircraft using DU.

DU was used because it was essentially a waste product and the government was spending money for storage of the waste.

The alternatives are more expensive. Several metals have higher density than uranium: gold, platinum, and tungsten for example. Lead is cheaper but lower density.
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A/c train
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RE: Depleted Uranium In Boeing 747?

Tue May 23, 2006 2:42 am

474218 are you kidding ? are you sure its not just sealant marking your blocks ?!! done a fair few structures jobs with the set I have, not going to use them so much now I work on the line but ill keep them, never know if ill need them again!
 
474218
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RE: Depleted Uranium In Boeing 747?

Tue May 23, 2006 3:32 am

Quoting Bobster2 (Reply 45):
The first 550 747's had DU. That's about it. I don't think there are any other commercial aircraft using DU.

There was over 500 pounds of DU counterweights on every L-1011 built. Tungsten was offered as a spears replacements only.

Quoting A/c train (Reply 46):
474218 are you kidding ? are you sure its not just sealant marking your blocks ?!! done a fair few structures jobs with the set I have, not going to use them so much now I work on the line but ill keep them, never know if ill need them again!

I never made any blocks out of DU and if I did I would not use them. Its the dust particles that are dangerous and sanding, filing and grinding it are some of the things that are not allowed.
 
Bobster2
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RE: Depleted Uranium In Boeing 747?

Tue May 23, 2006 4:53 am

I was wrong about the early 747's being the only planes with DU. There were two others, L-1011 and DC-10.

This data was published by NRC in 1999:

Use of DU counterweights in US domestic aircraft
Aircraft, Number of aircraft, Pounds per aircraft
DC-10, 168, 2200
L-1011, 60, 1500
747, 201, 1900
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kc135topboom
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RE: Depleted Uranium In Boeing 747?

Tue May 23, 2006 12:56 pm

Quoting Dougloid (Reply 15):
Here's a good article on the subject.

http://www.aeronautics.ru/archive/du...u.htm

I wouldn't call it "good", because it is so one sided. It is true that you can be exposed to radiation from DU. But you get much higher doses of radiation from your microwave oven, and airport radars. I might add, that those of you that live on the ground floor of just about any building, gets an even higher exposure to radiation through the radon gas that leaks into all building. If you live below the ground surface, you get even more exposure.

To me, this issues is just like those who are concerned they will get wet when walking in the rain.

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