Thread: is beryllium not toxic after all?

Latest issue of AM has article about large Mitsui machines used to mill beryllium mirrors for the James Webb telescope. Includes pictures in which it appears the machines are not enclosed, and staff are watching whilst not wearing masks.

Are these shots posed? Is beryllium not actually toxic?

http://en.wikipedia.org/wiki/Beryllium

Not nice stuff...

Very bad stuff here. Especially if inhaled as dust.Old Bill

Although perhaps not as toxic as that polonium "poison" which was used against a former Soviet operative, recently in the news, beryllium, like polonium and plutonium, is an alpha emitter.

Normally, alphas can't hurt you as almost anything will stop them, even a sheet of cigarette paper.

However, if ingested, alpha emitters can, and have, killed.

Berylliosis is a chronic lung disease caused by prolonged exposure to beryllium, a chemical irritant to the lungs. With prolonged exposure, the lungs become hypersensitive to it causing the development of small inflammatory nodules, called granulomas. Granulomas are seen in other chronic diseases, such as tuberculosis and sarcoidosis. Ultimately, this process leads to restrictive lung disease, a decreased diffusion capacity. Clinically patients experience cough and shortness of breath. Other symptoms include chest pain, joint aches, weight loss and fever.
Occupations with the highest potential for exposure to beryllium are those involved with primary production, metal machining, and reclaiming scrap alloys. Other high-exposure occupations are in the nuclear power, aerospace, and electronics industries. Some of the current uses of beryllium include the following:

Nuclear reactors and weapons
Inertial guidance systems
X-ray tube windows
Turbine rotor blades
Spark plugs
Laser tubes
Electrical components
Rocket engine liners
Ceramic applications
Springs, gears, aircraft brakes, aircraft engines, landing gear, and bearings
Oil and gas industries
Injection and blow mold tooling
Welding electrodes
Electrical contacts
Computer electronics
Automotive electronics

Berylliium is not very volatile, the oxide is the main problem it has to be inhaled, machining wet and making chips is not likely to cause that, dry grinding is another matter entirely.

It is a bit like seeing a scuba diver playing with loose asbestos and concluding that is is not hazardous to human health, you need to know under what circumstances it is hazardous and if the operation is likely to produce those circumstances

beryllium, like polonium and plutonium, is an alpha emitter.

Where did you hear that Be is radioactive?

It has a lot of applications in nuclear work, but it isn't a radioactive material.

You can check out www.brushwellman.com for everything you want to know about beryllium but were afraid to ask [img]smile.gif[/img]

bryan_machine

I think the photo you are referring to is posed, but having the machine's door opened indicates to me that it's very likely that the machine is stopped, so the danger posed by machining beryllium is reduced.

As everyone else here indicated (and as Old Bill says), beryllium is "bad stuff," and shouldn't be trifled with.

"Where did you hear that Be is radioactive?

"It has a lot of applications in nuclear work, but it isn't a radioactive material."

Be emits neutrons ... very dangerous ... when hit by alphas ... which are everywhere ... which is why a Be-Po "initiator" was used in "Trinity", "Little Boy", "Fat Man", and numerous other first-generation fission bombs.

When shielded by a thin film of, say, gold, the Be, which has an instable nucleus, won't let go of its extra neutron, because the gold film prevents the Po alphas, or any other alphas for that matter, from reaching it.

But, when compressed very, very fast, to a very, very high pressure, say, at the very center of a U or Pu or "composite" U/Pu "pit" which is imploded, the Be and Po instantaneously mix, and about nine neutrons are released from the "initiator", thereby ensuring the reliable detonation of the weapon.

"Initiators" are still classified, but second- and subsequent-generation weapons use a substitute device, a neutron pulse generator, which, incredibly, was well known in the peer-reviewed literature, prior to WW-II.

It is the spontaneous emission of neutrons by the (unshielded) Be nucleus, which makes it dangerous, especially when inhaled.

The neutron emission does not rely solely on alpha absorption. True enough, it is used for applications requiring very high neutron populations per generation, such as initiators.

Commercial use as startup sources for power reactors utilize the high energy gamma from Antimony 124 to liberate neutrons from Be9. It is the "battery" used to provide initial reactor start-up, and provides initial indication on Source Range instrumentation.

[ 06-06-2007, 01:26 PM: Message edited by: Dirtdobber ]

"The neutron emission does not rely solely on alpha absorption."

True, a neutron could be emitted spontaneously, as the Be nucleus is unstable.

However, the emission of neutrons by the Be is ensured by the presence of a strong source of alphas, from the Po, which is what occurs during initiation of the weapon.

Removing the initiator from the center of the pit, substituting about a gram of tritium for the initiator, and then initiating the weapon externally, using a neutron pulse generator, significantly increases the yield of the fission weapon, and facilitates a "dial a yield" device.

Ok I misspoke there. I probably should not have refered to photoneutron source for commercial use whilst you obviously referred to a greater capacity for energy release in a shorter period of time, 2-3 shakes.
I should have said it need not rely solely on alpha for neutron release. For the extremely short period you are referring to though, you need lots of neutrons per generation and reflectors and "other stuff." Considering the materials involved in your energy release, you're not looking for thermalization as I might look for it in commercial power reactor.

A major difference being that one machine is only intended to survive the energy release for a very short while, while the other one must survive considerably longer.

How's that for beating all around it

"Considering the materials involved in your energy release, you're not looking for thermalization as I might look for it in commercial power reactor."

True, as the lifetime of the fission bomb process is about 80 shakes, and that is a very, very short time.


"How's that for beating all around it"

Well done!

I once visited a machine shop in Burbank California. It was the cleanest machine shop I ever saw in my life.

They did parts for aerospace components and were noted for machining beryllium. At that time (1980), they were still using manual machines.

The lathes and milling machines used for beryllium were dedicated and completely enclosed with dust collector hoses dropping down from the ceiling and connected to a clear sliding hood over each machine. They were in a separate room and the operators were wearing respirators. It looked to me to be excellent the way they handled the material.

question, cobalt, not radioactive, isotope Co60 very radioactive, are there long living isotopes of Be ? ar any for that matter
mark

Wow, been a while since I looked at nuclide chart. Hadda think how to read the thing.

Be 10,11,12 artificial isotopes, all Beta- decay. Be 11 & 12 half life measured in seconds. Be 10 1/2 life 1.6 million years.

Be9, stable. Be 8 very short lived,alpha decay. Be 7 53 days half life, gamma decay. Be 6 very short.

Note this is not spontaneous and are bombardment reactions. There's a little more to it than this but I hope this is close to what you asked.

I remember that beryllium is "posionous". I used to have a reoccuring job that involved little clevis like parts. They were made out of copper hardened with Beryllium. I never remember having any ill effects but thanks for the info

Beryllium metal dust can cause major lung damage and beryllium salts are very toxic. Compounds containing beryllium are very poisonous and only to be handled by a professional under controlled conditions. One route for beryllium into the biosphere is by way of industrial smoke. It seems that some types of camping gas mantle may cause problems as a consequence of their beryllium content

http://www.webelements.com/webelemen...t/Be/biol.html

Newman109
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Rate Member - posted 06-07-2007 03:20 PM Profile for Newman109 Email Newman109 Send New Private Message Edit/Delete Post I once visited a machine shop in Burbank California. It was the cleanest machine shop I ever saw in my life.

They did parts for aerospace components and were noted for machining beryllium. At that time (1980), they were still using manual machines.

The lathes and milling machines used for beryllium were dedicated and completely enclosed with dust collector hoses dropping down from the ceiling and connected to a clear sliding hood over each machine. They were in a separate room and the operators were wearing respirators. It looked to me to be excellent the way they handled the material.

That's the way we did it at Boeing.