Touching weps grade uranium/plutonium

[Pengwuino]

What would the timetable be for health for a person who touches with their bare hands, weapons grade nuclear material. Theres this stupid movie on and this guy was holding material for his "home made nuclear bomb" and I am thinken.. come ooooon.

 

[Astronuc]

The pits are warm to the touch.

I know some folks who dismantle nuclear warheads. Obviously, one tries to minimize exposure.

It would be quite simple to take a representative mass, e.g. 10 kgs of both Pu and U, and use the decay constants to figure out the activity, and from that the dose. The activity then gives one a distributed energy source with which one can determine the heat flux. With the appropriate surface heat transfer coefficient, one can determine a reasonable approximation of the pit surface temperature.

 

[Morbius]

What would the timetable be for health for a person who touches with their bare hands, weapons grade nuclear material. Theres this stupid movie on and this guy was holding material for his "home made nuclear bomb" and I am thinken.. come ooooon.

Pengwuino,

If you are talking about handling pure Plutonium-239; there would be
ZERO effect. Pu-239 decays by emitting a 5.245 MeV alpha particle.

Because alpha particles have a charge of +2 [ they are doubly ionized
helium nuclei ]; they interact very strongly with matter and lose their
energy very quickly - hence they have a very short range. The range is
so short, that the alpha particle will not even penetrate the dead layer
of skin that surrounds your body. Therefore, the radiation from the
Plutonium doesn't interact with live tissue - therefore, the health effect
is zero.

In fact, when Russian scientists had assembled the Plutonium core for
"Joe I"; the first Russian nuclear test which was their copy of Trinity;
the Russian scientists presented the core of the device to Joseph Stalin,
and he held it in his hands and commented about it being warm to the
touch.

It's not good practice to handle radioactive material in that manner -
at least one should wear latex gloves. In one of her, "Behind Closed Doors"
programs, Joan Lunden went to Los Alamos where she handled a ball of
Plutonium while wearing latex gloves. The ball was also coated in a
thin layer of stainless steel to protect the surface.

If you are talking about weapons grade uranium, again the risk is zero.
Weapons grade uranium is mostly Uranium-235, which has a half-life of
703.8 million years! Since the radioactivity is inversely proportional
to the half-life, and Plutonium-239 has a half-life of 24,110 years ;
Uranium-235 is 29,191 times LESS radioactive, atom per atom; as is
Pu-239.

When you see movies where Plutonium and Uranium [ even weapons
grade ] are protrayed as this stuff that glows green and will give you
deadly radiation sickness if you get anywhere near it - then you know
you are watching a movie by someone that is absolutely CLUELESS
about nuclear technology and radioactive materials.

Dr. Gregory Greenman
Physicist

 

[russ_watters]

Morbius, I was under the impression that Pu is one of the most radiologically toxic substances on earth. Is it only if you inhale it?

 

[Morbius]

Morbius, I was under the impression that Pu is one of the most radiologically toxic substances on earth. Is it only if you inhale it?

Russ,

The fact that the alpha particles have a high LET - Linear Energy Transfer -
which means they lose a lot of energy per unit distance is a double-edged
sword.

If the alpha emitter is external - it means that the alpha particles can't
get in - they can't get through the dead layer of skin.

However, if you ingest or inhale the alpha emitter - then you've "solved"
the problem of getting into the body for the alpha emitter.

The alpha particle in that case is now IN the body right next to living
tissue. Now the fact that the alphas have a high LET means that they
deposit their energy in a very short track - hence they do a lot of
damage - which accounts for the high radiological toxicity.

The dose is a measure of energy deposited per unit mass of material.
The original unit - the rad - is 100 ergs per gram. The SI unit is the
Gray which equals 1 Joule per kilogram = 100 rads.

The "dose equivalent" takes into account that different forms of
radiation have larger or lesser effects. So the dose is multiplied by
a "Quality Factor" to give the "dose equivalent. The "Quality Factor"
for photons [ gamma and X-rays ] is one. The Quality Factor for alphas
is 20.

When you multiply "rads" by a quality factor, you get a dose equivalent
in "rems" [ rads equivalent man ]. For the SI units, when you multiply
a dose in Grays by a Quality Factor - you get a dose equivalent in a unit
called the Sievert.

So, an alpha emitter like Plutonium OUTSIDE the body - is not to worry.

An alpha emitter INSIDE the body is going to do a lot of damage.

Courtesy of the University of Michigan:

http://www.umich.edu/%7Eradinfo/introduction/lesson/properties.htm

http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/R/Radiation.html

Dr. Gregory Greenman
Physicist

 

[Pengwuino]

So what's the danger in a 'dirty bomb' if touching this stuff is not so dangerous?

 

[russ_watters]

So what's the danger in a 'dirty bomb' if touching this stuff is not so dangerous?

Theoretically a "dirty bomb" does oxidize or aeresolize it, so you can breathe it. However, the reality of the dirty-bomb threat is somewhat overblown. Most media reporting on the subject seems to operate under the all-radioactivity-is-equally-bad misconception. But composition and method of dispersion matters.

Next question for Morbius: I know uranium is somewhat volatile - I thought Pu would just about spontaneously combust in air at room temp...?

 

[Astronuc]

Both uranium and plutonium are pyrophoric when finely divided, as in powder, or shavings, e.g. from a machining operation. The solid material should not be a problem unless there is a good source of oxygen.

Regarding spontaneous combustion, IIRC Pu still needs a flame source.

 

[Morbius]

So what's the danger in a 'dirty bomb' if touching this stuff is not so dangerous?

Penguino,

You are confusing two very different concepts - and types of weapons.

A so-called "dirty bomb"; or RDD - Radiological Dispersion Device - doesn't
use "weapons grade" material!

An RDD uses highly radioactive material bundled with explosives. When
the explosive explodes, it disperses highly radioactive material - material
that emits gamma radiation, around.

Gamma radiation, which is electromagnetic radiation - photons - like
X-rays, except even more powerful and energetic; will NOT stop at the skin.
Gamma radiation is highly penetrating.

So a "dirty bomb" disperses this highly radioactive material around - so
that it maximizes the number of people that are exposed to it.

Weapons grade material, on the other hand, like Uranium and Plutonium
is not very radioactive at all - only very slightly - and as I've stated, the
type of radioactivity from Uranium and Plutonium is very easily shielded;
a piece of paper, or the dead layer of skin on your body will do.

Although Uranium and Plutonium are not very radioactive, they are
"fissile" - that is they readily undergo the nuclear fission reaction. If one
arranges a device such that one can, on command, assemble this weapons
grade material into a "prompt supercritical" configuration - and add a
neutron source - the result will be a rapidly growing uncontrolled chain
reaction of nuclear fission - thus releasing tremendous amounts of
energy. Such a device is a nuclear weapon.

So you have two VERY DIFFERENT animals here. Weapons grade material
can be made into a nuclear weapon - but it is pretty useless for the
"dirty bomb" that you are talking about.

Dr. Gregory Greenman
Physicist

 

[Morbius]

Theoretically a "dirty bomb" does oxidize or aeresolize it, so you can breathe it. However, the reality of the dirty-bomb threat is somewhat overblown. Most media reporting on the subject seems to operate under the all-radioactivity-is-equally-bad misconception. But composition and method of dispersion matters.

Next question for Morbius: I know uranium is somewhat volatile - I thought Pu would just about spontaneously combust in air at room temp...?

Russ,

Yes - Plutonium is "pyrophoric" - that is it can spontaneously combust in
air at room temp. It does that if you have a fine powder - with lots of
surface area per unit volume. Therefore, when the surface oxidizes - and
releases heat - you can start combustion. It's not really "spontaneous" -
you need a triggering event - but something like the heat of friction,
should the powder become "sandwhiched" between two moving surfaces -
will trigger the combustion.

However, if you have a big ball of Plutonium - the surface will oxidize -
but the whole ball isn't going to catch fire.

Think of ordinary baking flour. You aren't concerned that the baking
flour sitting in the canister in your kitchen is suddenly going to explode.

However, a fine "mist" of airborne flour is very explosive - and you used
to hear a lot about grain elevators in the Midwest where flour was
stored in large quantities exploding. Here it was the flour "mist" that
was spontaneously combusting.

Dr. Gregory Greenman
Physicist

 

[Pengwuino]

@Morbius

I understand the different types of weapons but what I wasnt understanding is how i assumed you just had unrefined uranium in a dirty bomb... and its deadly as hell... but when its refined (which to my mind brings up 'concentrated' deadliness or what not), how is it all of a sudden not so deadly. Well actually no i don't understand now. What materials are used in hypothetical dirty bombs if not the same unprocessed uranium that eventually winds up as refined nuclear weapons material?

 

[Morbius]

@Morbius

I understand the different types of weapons but what I wasnt understanding is how i assumed you just had unrefined uranium in a dirty bomb... and its deadly as hell... but when its refined (which to my mind brings up 'concentrated' deadliness or what not), how is it all of a sudden not so deadly. Well actually no i don't understand now. What materials are used in hypothetical dirty bombs if not the same unprocessed uranium that eventually winds up as refined nuclear weapons material?

Pengwuino,

First - uranium isn't "deadly as hell" - either in refined nor unrefined form.

I assume you understand that the radioactivity of an isotope is
INVERSELY proportional to the half-life - that is the shorter the half-life,
the more radioactive the isotope is, and consequentially, the longer
the half-life, the less radioactive an isotope is.

Natural uranium, fresh from the ground, is 99.3% U-238 and 0.7% U-235.

The U-238 [ which is what "depleted uranium" is made of ] has a half-life
of 4.5 BILLION years - so it is only very slightly radioactive. With such
a long half-life, it's almost stable.

The U-235 has a half-life of 704 MILLION years. While U-235 is a little
over 6 times more radioactive than U-238; it is still only slightly
radioactive.

Weapons grade uranium is mostly U-235. So while about 6X more active
than natural or depleted uranium; it is still very low.

So in terms of radioactivity; depleted uranium has the least, natural
uranium somewhat more than depleted; and weapons grade 6X the other
two - but still very low.

Additionally, as before, uranium is an alpha emitter. Alpha radiation
will not penetrate a sheet of paper, nor the dead layer of skin.

You don't use uranium in an RDD or "dirty bomb". The types of materials
that one would use in an RDD should be relatively short lived gamma
emitters. Cobalt-60 and Cesium-137 would be good candidates.

There is so much really BAD information in the media. The media
reporters don't understand this stuff - and haven't made an effort to
understand it - because it's really very simple.

In the media, a "nuke" is a "nuke" is a "nuke". They don't draw a distinction
between RDDs and a real nuclear weapon. That's why there are a lot of
people that think that "weapons grade" uranium goes into a "dirty bomb".

After all, a "dirty bomb" is a weapon - so you use "weapons grade". WRONG!

An RDD or "dirty bomb" has virtually nothing in common with a real
nuclear weapon. A dirty bomb doesn't use "weapons grade" uranium.
It also doesn't make a big explosion that can level a city - only a real
nuclear weapon does that.

A "dirty bomb" is a very, very, simple device relative to a real nuclear
weapon.

Dr. Gregory Greenman
Physicist

 

[stoned]

in that movie about first US nucluar bomb, one of the scientist died from touching two sphers of weapon grade uranium. you know what I'm talking about ?

 

[Morbius]

in that movie about first US nucluar bomb, one of the scientist died from touching two sphers of weapon grade uranium. you know what I'm talking about ?

Stoned,

Not quite.

What you are most likely referring to is the case of Louis Slotin.

The part of the movie "Fat Man and Little Boy", in which the character
played by John Cussack receives a fatal radiation dose is a piece of
fiction that did not occur during the Manhattan Project - but is modeled
after an accident at Los Alamos that occurred 2 years later.

Louis Slotin was a scientist at Los Alamos, and in 1947 he was doing an
experiment at Los Alamos checking the critical mass for a bomb core in
what they called "tickling the dragon's tail".

He had 2 hemispheres of uranium - that if assembled would give you a
critical mass. He was supposed to get them almost, but not quite
assembled by holding them apart with a screwdriver.

Unfortunately, the screwdriver slipped - and the 2 hemispheres
assembled in a critical mass - there was a nuclear chain reaction -
and Slotin died several days later from massive radiation.

But this is NOT radioactive decay of the uranium. He accidently
assembled a bomb core. It was a fission chain reaction - like what
happens in a nuclear bomb when it's detonated that produced the
massive radiation. Louis Slotin, in essence, set off a small nuclear
"explosion" - and he died from the radiation.

Dr. Gregory Greenman
Physicist

 

[stoned]

thanks for claryfing, one question : would there be a regular nuclur explosion with mushroom and stuff ( like hiroshima ) from that accident ?

 

[Pengwuino]

An RDD or "dirty bomb" has virtually nothing in common with a real
nuclear weapon. A dirty bomb doesn't use "weapons grade" uranium.
It also doesn't make a big explosion that can level a city - only a real
nuclear weapon does that.

A "dirty bomb" is a very, very, simple device relative to a real nuclear
weapon.

So what's all the fuss with people saying "terrorists will steal nuclear material and set off dirty bombs!"? I mean if this is such basic information, why is it never disputed out in the media?

 

[hitssquad]

Pengwuino,

Uranium-235 and plutononium-239 are fissile radioisotopes — and therefore they can be used to make fission weapons — but they do not happen to be very radioactive. If you were making a dirty bomb, you might want to use radioisotopes that are much more radioactive — such as cesium-137, strontium-90, etc. You can find those radioisotopes in nuclear waste.

So, we are worried about terrorists stealing:

1. weapons grade plutonium or uranium, in order to make fission weapons (atomic bombs that produce a large blast like the ones dropped Hiroshima or Nagasaki)
   
   
2. nuclear waste, in order to make dirty bombs (rudimentary devices composed of ordinary chemical explosives surrounded by highly-radioactive isotopes intended to be dispersed by the chemical explosives in populated areas in order to poison people and create terror)

 

[Pengwuino]

So, what, you steal nuclear waste and extract the highly radioactive components?

What kind of material is used at nuclear power plants then and how do they produce nuclear waste (and what is the nuclear waste cmposed of in general). Also, what's the dangers associated with the Yucca mountain thing. I am getting from you guys that nuclear waste is highly radioactive... and then say its inversely proportional which means its half life would be relatively short.. but people complain that we're dealing with materials that'll be radioactive for tens of thosuands of years. Or is 10,000 years considered very short time when it comes to radioactivity...

 

[hitssquad]

Fission products and how they are produced

So, what, you steal nuclear waste and extract the highly radioactive components?

I think isotope separation would be comparatively difficult for what is supposed to be a relatively simple-to-make device. I suppose one might grind the pellets up into a powder before emplacement into the dirty bomb. That might be difficult as well, though, since working with the waste directly instead of remotely is radiologically hazardous.

Garwin writes about this subject, so perhaps you can find what you are looking for on his Federation of American Scientists (FAS) site:
http://www.fas.org/rlg/20.htm

What kind of material is used at nuclear power plants then

In light water reactors — the type used in the United States for electrical power production — the fuel is low-enriched uranium. This is uranium that has been enriched in the fissile isotope U-235 from its natural representation level of 0.7204% to a representation level of 2.5-3.5%. Most of rest of the uranium is U-238 (a non-fissile isotope).

MOX can also be used. This is a mixture of uranium and recycled or reused plutonium.

and how do they produce nuclear waste

The U-235 is fissioned and in doing so produces fission products. The fission products are considered waste, since they themselves cannot be fissioned (some of them would be useful in medicine and industrial activities, however). Here is a graph of the different fission products produced and their relative proportions:
http://www.euronuclear.org/info/encyclopedia/f/fissionyield.htm

(I also attached this graph at the end of this post.)[/color]
Notice how the graph is bimodal — i.e., it has two peaks. One peak is around atomic mass number 95 and the other peak is around atomic mass number 140.

Another type of waste produced is comprised of so-called transuranics. These are produced starting when Uranium-238 captures a neutron which subsequently decays to a proton. Since elements are defined by the number of protons their atoms have, as you can see this produces an element that is higher than — or trans — Uranium. The process continues for a ways beyond uranium, and we get an assortment of elements — that were not in the fresh, unburned fuel — including Plutonium, Neptunium, Curium, and Americium.

(and what is the nuclear waste cmposed of in general).

Mostly, the spent fuel is still U-238 (which by itself has very low radioactivity and presents very little radiological danger), just as it was before it was burned in the reactor. There is less U-235 than the fuel started out with, since much of it was burned (fissioned), and the rest (~1% by weight?) is composed of the radiohazardous products I just mentioned.

Also, what's the dangers associated with the Yucca mountain thing.

Some party might steal the waste and make dirty bombs out of it. Some party might steal the waste and extract the Plutonium therein to use to make fission bombs. The waste might leak into the environment through groundwater. The waste might be purged from the repository by a volcanic eruption. The waste might be purged from the repository by a meteor impact. The waste might be purged from the repository by terrorists blowing the repository up.

Im getting from you guys that nuclear waste is highly radioactive. and then say its inversely proportional which means its half life would be relatively short.

Some of its halflife would be short. The waste is composed of multiple isotopes, which in turn procuce other isotopes as they decay, and so on. This procuces a complex decay graph over time of total radioactive flux produced by the waste. It does not produce a simple logarithmic curve. See Garwin and Charpak:

people complain that we're dealing with materials that'll be radioactive for tens of thosuands of years.

I cannot speak for them. Bernard Cohen points out...
[URL]http://www.phyast.pitt.edu/~blc/book/BOOK.html[/URL]

...that some stable isotopes (such as those of lead, selenium, etc.) are poisonous, too — and they last forever, instead of decaying from more-poisonous to less-poisonous as nuclear waste does.

is 10,000 years considered very short time when it comes to radioactivity...

Every practical-sized clump of radioisotopes is radioactive — for what I would conceive to be practical purposes — forever. The radioactivity does not end until the last radioisotope decays to a stable isotope. Analogy: would the Earth's gravity turn off when you eventually travel far enough away, or would it just keep getting dimmer and dimmer as the space between you and the Earth grew?

 

[Morbius]

So, what, you steal nuclear waste and extract the highly radioactive components?

What kind of material is used at nuclear power plants then and how do they produce nuclear waste (and what is the nuclear waste cmposed of in general). Also, what's the dangers associated with the Yucca mountain thing. I am getting from you guys that nuclear waste is highly radioactive... and then say its inversely proportional which means its half life would be relatively short.. but people complain that we're dealing with materials that'll be radioactive for tens of thosuands of years. Or is 10,000 years considered very short time when it comes to radioactivity...

Penguwino,

What you are dealing with are a bunch of people that are very adept at
lying - and a media that is uncritical.

If you reprocess nuclear waste and recycle actinides like Plutonium
back to the reactor as fuel - then the longest lived nuclear waste
component is Cesium-137 which has a half-life of 30 years - not the
10s of thousands of years. The parts of the nuclear waste that have
the long half-lives, like Plutonium are NOT very radioactive - and can
be used as fuel - so we don't have to keep them around.

There's nothing contradictory here if you think about it. It's just as I
stated above, the radioactivity is INVERSELY proportional to the
half-life. The long lived radioisotopes have very low levels of radiation,
and are easily shielded. The intensely radioactive isotopes don't live
very long - they have short half-lives.

The problem is that unthinking people lump the two together - so they
think they have long-lived intensely radioactive waste - and that is just
plain NOT TRUE! Be mindful of that next time you hear your local
anti-nuclear fanatic speak.

The input fuel for nuclear power plants is slightly enriched uranium -
only slightly radioactive - because it came out of the ground that way.
In the reactor, some of the uranium is fissioned. The result of fission
are the "fission fragments" which are the true waste - radioisotopes
such as Cesium-137, Strontium-90, Iodine-131..

These are the intensely radioactive materials - Cesium-137 has a half-
life of 30 years, Strontium-90 has a half-life of 29 years, and Iodine-131
has a half-life of 8 days. But they disappear at a fast rate.

Sometimes the uranium doesn't fission, but absorbs a neutron - and
the atom is transmuted into something else. This is where you get the
Plutonium and other actinides. Plutonium-239 has a half-life of
24,000 years. The other actinides have similarly long half-lives.

However, what you want to do with the Plutonium and other actinides
is to remove them from the waste - and put them back into the reactor
as fuel. On this second go-round, they will fission and become fission
products like Cs-137, Sr-90, and I-131.

So there's no reason to have long-lived radioisotopes in the waste.

One often hears that we have 77,000 metric tonnes of nuclear waste.
That's true - that's how much nuclear waste has accumulated in the
nearly one-half century of the use of nuclear power. That's the TOTAL
accumulation. But people imagine that 77,000 tonnes is a mountain.
Actually, the volume of nuclear waste is about the volume of a high
school gymnasium. As hittsquad points out - the vast majority of
this volume is Uranium-238; about 94% of it. This U-238, with a half
life of 4.5 BILLION years is only slightly radioactive - no more so than
when it came out of the ground. If we reprocessed the nuclear waste
to remove the relatively benign U-238; then the amount of nuclear
waste drops by about a factor of 20.

This is what other countries do when they reprocess their nuclear waste.
Great Britain's Nuclear Fuels Ltd has a plant at Sellafield to reprocess.
France has their facilities at La Hague. Unfortunately, the USA does
not reprocess - because the anti-nukes got Congress to pass a law in
1978 to forbid it.

You have to hand it to the anti-nukes; they get Congress to pass a law
to outlaw the solution to the problem - thus guaranteeing that they have
something to complain about. Good tactic - although disengenuous.

As far as Yucca Mountain - it has been VERY, VERY thoroughly studied
by scientists at LLNL, for example:

http://www.llnl.gov/str/Glassley.html

LLNL scientists recommended proceeding with Yucca Mountain years
ago. The concept of geological disposal has been endorsed by our best
scientists - the National Academy of Science and Engineering. In fact,
it was the National Academy of Sciences that first suggested geological
disposal back in the late '50s.

Unfortunately, Yucca Mountain has turned into a political football -
with lots of people telling lies to scare you - and the media doesn't
check it out. For example, they tell you that there will be accidents
in the transportation of the waste. However, the waste is shipped in
casks that are indestructible with respect to transportation accidents.

Sandia National Labs has tested the casks extensively - parking the
cask-laden truck on a railroad track, putting rockets on a locomotive
and slamming it into the casks at speeds exceeding anything a real
train could do:

http://www.sandia.gov/recordsmgmt/ctb1.html

See the video at:

http://www.nei.org/doc.asp?catnum=2&catid=83

They also set the casks in vats of burning jet fuel:

http://www.sandia.gov/media/firetest.htm

Sandia is one of the Labs that manage our nuclear weapons. The reason
Sandia was chosen to conduct the tests on the fuel casks is that they
do the tests on the casks that are used to ship nuclear weapons around.
If the casks is safe enough to ship something like a nuclear weapon
around - it surely is safe enough to ship a small quantity of nucear waste.

Dr. Gregory Greenman
Physicist

 

[Morbius]

Some party might steal the waste and make dirty bombs out of it. Some party might steal the waste and extract the Plutonium therein to use to make fission bombs.

If one is a terrorist and wants to get one's hands on a dangerous weapon -
why try and steal nuclear waste to make a dirty bomb. If you are going
to hijack a convoy - why not hijack one that is carrying a real nuclear
weapon?

The reason they don't - is that the convoy with the nuclear weapon is
VERY heavily guarded. Also, the convoys are disguised - they look like
ordinary commercial shipping.

The same will also hold when nuclear waste is shipped.

There's never been a successful attack or hijacking of a nuclear weapons
convoy - and that will also hold true with nuclear waste convoys.
There is a limited amount of that now. Some waste is shipped to a
commercial lab near Livermore [ not associated with LLNL ] for
examination in their laboratories.

I'm in Livermore - and have absolutely no qualms what so ever sharing
the highways and byways with trucks containing this cargo.

Dr. Gregory Greenman
Physicist

 

[imabug]

Anybody trying to fabricate a dirty bomb would be foolish to go after a nuclear weapon or nuclear waste convoy. It would be much easier to go after the well logging and non-destructive testing companies that use high activity Co-57 and Cs-137 sources used for their daily activities. These would be much more effective in an RDD than uranium or plutonium. These sources are typically very high activity (thousands of GBq) and security is not always that high. Most times they are simply locked in a shielded box and put away in a truck. There have been more than a few instances of these sources being misplaced, or the truck being stolen (by people after the truck, not the radioactive source). There was one incident reported recently where a truck containing a source was stolen when the driver went into a donut shop for a snack and left the truck running!

 

[Grogs]

I'm in Livermore - and have absolutely no qualms what so ever sharing
the highways and byways with trucks containing this cargo.

Dr. Gregory Greenman
Physicist

Morbius:

It's funny you should mention this. When I lived in Virginia, I volunteered as an EMT for the local rescue squad. We got called out one afternoon (along with the professional fire fighters) to a truck pulled over on the side of the interstate. He was carrying (IIRC) a Benzene derivative packed in 55 gallon drums in the back of his truck. When the driver felt his load shift, he did the right thing: pulled over and called the fire department.

Based on the MSDS (Material Safety Data Sheet) the only thing the fire fighters would do (even in full respirators) was to open the back of the truck, say 'yep, one of the barrels is leaking,' and close it back. We closed down that particular section of I-664, including the Monitor-Merrimack Bridge Tunnel for about 6 hours. We also had to call in a HAZMAT team in full white suits to clean up the mess.

The point of all this is that we went to an enormous amount of trouble here over just a few gallons that were still pretty well contained (in the back of the truck.) If he had instead wrecked the truck and spilled all of its contents, we probably would have had to evacuate thousands of people and spend days, if not weeks, cleaning up the mess. And there was nothing special about this truck. There are thousands just like it carrying hazardous chemicals around the country every day.

While people protest if we move a few kilos of plutonium around inside of a 12 inch thick steel box and completely ignore the millions of gallons of hazardous chemicals that are protected by a few millimeters of aluminum. As you say, you've got to hand it to the anti-nuke folks. They've managed to stop something that's almost a non-problem while completely missing the much bigger problems out there.

 

[Morbius]

While people protest if we move a few kilos of plutonium around inside of a 12 inch thick steel box and completely ignore the millions of gallons of hazardous chemicals that are protected by a few millimeters of aluminum. As you say, you've got to hand it to the anti-nuke folks. They've managed to stop something that's almost a non-problem while completely missing the much bigger problems out there.

Grogs,

Well said... well said.

Dr. Gregory Greenman
Physicist

 

[Rogue Physicist]

Hi Morbius: Since this seems to be an area in which you have considerable knowledge, I would like to ask what you think of the hazards of Thorium, as it has been used extensively in the manufacture of radio tubes, for instance in 'thoriated tungsten' emitters. Obviously there are a lot of used/JAN surplus tubes out there that people are building radio sets out of, and also 'dumps' where factories used to be during and just after the 2nd World War.
What do you think the hazards of the tubes and also the various byproducts from that (formerly popular) industry are? Would they be equivalent to the hazards around Watch-dial companies?

There's never been a successful attack or hijacking of a nuclear weapons

Isn't this a little inaccurate? For instance I seem to recall that weapons grade material has gone missing on several occasions, including shipments that seemed to have ended up in Israel, which belonged to the U.S. These 'hijacks' seemed to have been 'allowed' or planned, since nothing was done about it...

 

[jdsneeder]

This is what other countries do when they reprocess their nuclear waste.
Great Britain's Nuclear Fuels Ltd has a plant at Sellafield to reprocess.
France has their facilities at La Hague. Unfortunately, the USA does
not reprocess - because the anti-nukes got Congress to pass a law in
1978 to forbid it.

You have to hand it to the anti-nukes; they get Congress to pass a law
to outlaw the solution to the problem - thus guaranteeing that they have
something to complain about. Good tactic - although disengenuous.

Dr. Gregory Greenman
Physicist

President Reagan rescinded Carter's ban on reprocessing.

http://www.nei.org/index.asp?catnum=3&catid=583

Early reprocessing attempts were less than successful, i.e. West Valley, Morris, Savannah River, and with the price of uranium staying well below the costs estimated at the time, reprocessing doesn't have an economic justification.

That said, I think "permanent disposal" of spent nuclear fuel is a bad idea and monitored retrievable storage (MRS) is the way to go because I'm pretty sure we will need that U at some point in the future.

 

[Pengwuino]

What kind of known reserves of uranium are known to exist? Like.. how much is recoverable and how much is used each year?

 

[jdsneeder]

What kind of known reserves of uranium are known to exist? Like.. how much is recoverable and how much is used each year?

It took me about 10 seconds to go to www.google.com and enter "uranium resources"

The first link gave a pretty good overview in just a few paragraphs.

http://www.world-nuclear.org/factsheets/uranium.htm

This thread was also on the front page:

https://www.physicsforums.com/showthread.php?t=78004

I'm not trying to flame you, but doing a little research on your own and then asking specific questions of the members here would be the courteous thing to do.

Dr. Greenman has always (going back as far as I remember - the sci.energy days in mid/late 90s when I first saw him posting) been a *very* patient and helpful poster and people shouldn't take advantage of his nature.

 

[Pengwuino]

Sorry but for some odd reason... (possibly because its 6am and i still haven't gone to sleep)... i thought those numbers would be really unknown for some reason and that googling would bring up conspiracy theories.

 

[Morbius]

President Reagan rescinded Carter's ban on reprocessing.

http://www.nei.org/index.asp?catnum=3&catid=583

Early reprocessing attempts were less than successful, i.e. West Valley, Morris, Savannah River, and with the price of uranium staying well below the costs estimated at the time, reprocessing doesn't have an economic justification.

jdsneeder,

I'm afraid NEI is wrong.

President Reagan couldn't lift the ban on reprocessing - it was written into
a law. When Congress forbids something, the President just can't lift it.

That law is known as the Nuclear Non-Proliferation Act (NNPA) of 1978.

The Congress has to recind its previous ban on reprocessing; and to my
knowledge, Congress has not done that. The ban remains in effect.

Now the U.S. Government can reprocess for defense purposes - perhaps
that is what NEI is referring to. The Government can reprocess
irradiated nuclear fuel if it wishes to obtain more plutonium for
weapons. However, it has not had to do so - as weapons are retired, and
no new weapons are being built - there is no need for additional plutonium.

However, the ban on commercial reprocessing still remains.

Dr. Gregory Greenman
Physicist

 

[jdsneeder]

jdsneeder,

I'm afraid NEI is wrong.

President Reagan couldn't lift the ban on reprocessing - it was written into
a law. When Congress forbids something, the President just can't lift it.

That law is known as the Nuclear Non-Proliferation Act (NNPA) of 1978.

The Congress has to recind its previous ban on reprocessing; and to my
knowledge, Congress has not done that. The ban remains in effect.

Now the U.S. Government can reprocess for defense purposes - perhaps
that is what NEI is referring to. The Government can reprocess
irradiated nuclear fuel if it wishes to obtain more plutonium for
weapons. However, it has not had to do so - as weapons are retired, and
no new weapons are being built - there is no need for additional plutonium.

However, the ban on commercial reprocessing still remains.

Dr. Gregory Greenman
Physicist

Hmm, it seems that everyone (including the .gov) has this wrong...

http://www.nrc.gov/reading-rm/doc-collections/insp-gen/2005/05-a-10.pdf
http://books.nap.edu/books/0309050421/html/243.html

Having skimmed the NNPA, I didn't find anything prohibiting commercial reprocessing. Perhaps you could provide a reference.

 

[Astronuc]

The United States, neither a producer nor a consumer of commercial plutonium fuel-cycle services, still retains a unique position of global influence on the issue. One-quarter of the world’s nuclear power plants are located in the United States, as are the hundreds of thousands of tons of spent fuel generated by these reactors. The United States is also the largest supplier of uranium enrichment and fuel-fabrication services. It exercises "consent rights" under the terms of the NNPA to permit or prohibit the separation of plutonium from vast amounts of foreign spent fuel containing "U.S.-origin" uranium. The Department of Energy’s Office of Arms Control and Nonproliferation characterized this influence in a recent nonproliferation assessment.

Because of its pivotal role in preventing the proliferation of nuclear weapons and its own extensive nuclear programs and activities, the manner in which the United States manages its nuclear materials has an influence on other states, both by example and in the way it supports U.S. diplomatic efforts and initiatives. U.S. technical and policy choices frequently influence other countries. Thus, management decisions taken in the United States can positively or negatively affect initiatives to further enhance the global nonproliferation regime and bolster the international norm against the acquisition of nuclear weapons. [27]

There are now no elements of a commercial plutonium fuel cycle (reprocessing, MOX fuel fabrication or irradiation) operating in the United States. U.S. nuclear electric utilities abandoned efforts to develop such a fuel cycle more than a decade ago. However, the European plutonium industry is now avidly attempting to penetrate this largest potential market for its services. As other members of today’s panel can attest, BNFL and Cogema have each established a major corporate presence in the United States.

from nci.org

There are no active facilities in the US for reprocessing 'commercial' spent nuclear fuel. The weapons grade (WG) to MOX program involves 'military' material, not commercial.

The second link (http://books.nap.edu/books/0309050421/html/243.html) provided above address WG MOX, not commercial.

The US by policy does not reprocess, mainly because the US cannot credibly discourage reprocessing by other countries if the US reprocesses.

I am not familiar with Reagan rescinding Carter's ban. IIRC, Clinton reaffirmed Carter's ban, but I am not up to speed with the details. This issue came up elsewhere, and the ban by Carter was clear.

Until recently, there was no interest by commercial companies to start manufacturing MOX. The costs and liabilities are huge.

 

[Watts]

Contamination Hazard

Penguino,

So you have two VERY DIFFERENT animals here. Weapons grade material
can be made into a nuclear weapon - but it is pretty useless for the
"dirty bomb" that you are talking about.

Dr. Gregory Greenman
Physicist

I have spent the last six years at a category 1 nuclear fuel manufacturing facility. I spent two years manufacturing high enriched reactor fuel and spent the last four as a Health Physicist and Nuclear Measurements Specialist. I served as project Health Physicist during the decommissioning of a Pu MOX facility, high enriched uranium scrap recovery facility, and high enriched uranium fuel manufacturing facility. I have worked with my share of Pu and it is a huge contamination problem. I do know from experience once it is out of containment it spreads rapidly and is a serious air born problem. A gram or 2 of Pu-239 would make a rather nasty dirty bomb.

 

[Morbius]

I. A gram or 2 of Pu-239 would make a rather nasty dirty bomb.

Watts,

I'm afraid you drastically overestimate the problem with a 2 gm Pu-239 "dirty bomb".

Do the calculation - 2 grams is only about 1/8 of a Curie.

Additionally, 2 grams dispersed by an explosive is going to be a bit of a clean up problem,
but unless the people in the area just sit there and don't evacuate - this 2 gm dispersal
will not be a big public health problem. This has been studied very well by scientists
from our national laboratories.

Lawrence Livermore National Laboratory released a report in 1995 on a plutonium "dirty bomb":

http://www.llnl.gov/csts/publications/sutcliffe/

which concluded:

"In summary, the claims of dire health consequences from the introduction of plutonium
into the air or into a municipal water supply are greatly exaggerated. The combination of
rapid and almost complete sedimentation, dilution in large volumes of water, and minimal
uptake of plutonium from the GI tract would all act to preclude serious health
consequences to the public from the latter scenario. And although the dispersal of
plutonium in air (as the result of a fire or explosion, for example) would cause immense
concern and cleanup problems, it would not result in widespread deaths or dire health
consequences, as terrorists might hope."

Dr. Gregory Greenman
Physicist

 

[Watts]

Care should be taken when speaking out loud

Let me apologies for my loose use of terminology. I don’t agree with the toxicity claims by the general mainstream. Based on my experience working with Pu it does have a tendency to spread rapidly. The Pu I have worked with represents a isotopic mixture of different isotopes of Pu including Pu-238,239,240,241.242, and Am-241. My intent was Pu in general not strictly Pu-239. You are correct based on the specific activity of Pu-239 .12 uCi of activity would be present. At the same time 2 grams of Am-241 produces 19.92 uCi of activity, Pu-238 produces 35.6 uCi of activity, and Pu-241 produces 206 uCi of activity. These isotopes I recall being found in the in the composition I am calling Pu. I cannot remember the exact ratios. However I do recall using the Am-241(based on the 59.54 gamma ray line in the spectrum) isotope to determine the amount of Pu-239 present. I do remember that the Pu-239 was 2.02 times the Am-241 activity for that particular mixture. You could determine the amount of Pu-241 present in 2 grams of Pu from the amount of Am-241 in growth. The facility was shut down in the late 60’s so I suspect equilibrium based on the half-life of Pu-241 (15.16 years). The isotopic mixture would be facility dependent and the location in the part of the process it was removed from. My point being that a mixture of these isotopes in measurable quantities does produced an alpha contamination hazard in a confined area.

 

[Paulanddiw]

It takes quite a bit of effort to get a mushroom-type explosion. You have to hold the fissile bodies near each other for an period of time for the neuton flux to build up. If you don't, the bodies will just get hot and melt. Pu and/or U melt at red heat, so it'd probably burn up you bench that you'd be experimenting on. Of course, there will be an enormous gamma radiation emission during all of this. Easily kill a person.

 

[sean_omahoney]

@Moribus

What would happen if you were to touch nuclear waste out of a plant?


(It's my homework assignment.)

 

[QuantumPion]

Morbius, I was under the impression that Pu is one of the most radiologically toxic substances on earth.

No on both sides. There are non-radioactive molecules which are fatal in far more miniscule amounts, such as Dimethylmercury. And on the radioactivity side, plutonium is not very dangerous compared to, say Cobalt-60 (strong gamma emitter) or Iodine-131 (short half life, concentrates in body).

 

[QuantumPion]

@Moribus

What would happen if you were to touch nuclear waste out of a plant?


(It's my homework assignment.)

You wouldn't be able to. A rad engineering co-worker of mine once did a calculation: if you placed an unshielded spent fuel assembly at one end of a football field, and starting from the other end, ran right towards it, you would drop dead of radiation poisoning at about the 15 yard line.

 

[nikkkom]

You wouldn't be able to. A rad engineering co-worker of mine once did a calculation: if you placed an unshielded spent fuel assembly at one end of a football field, and starting from the other end, ran right towards it, you would drop dead of radiation poisoning at about the 15 yard line.

I wanted to point something similar about how deadly spent fuel is, but then I realized that question has too many unknowns to make sense.

How big the chunk of waste I'm trying to touch - kg? gram? nanogram? How old the waste is - 1 day since reactor was scrammed? 10 years? 10000 years?
"Nuclear waste out of a plant" is what exactly? Spent fuel? All non-fissile materials in spent fuel? (If yes, from which reactor exactly?) The output of La Hague? (If yes, (1) in what form - raffinate? Glass?... (2) from what day and batch of fuel?).
Etc. etc. etc.

Depending on these additional data, the answer ranges from "we touch this waste every day (when, for example, we inhale air with a few atoms of reactor-produced Kr-85 in it)" to "you would die".

 

[Rive]

You wouldn't be able to. A rad engineering co-worker of mine once did a calculation: if you placed an unshielded spent fuel assembly at one end of a football field, and starting from the other end, ran right towards it, you would drop dead of radiation poisoning at about the 15 yard line.

It would be interesting to see (and redo) that calculation, because it sounds really ridiculous.

Chernobyl had some (really fresh) spent fuel around during the cleanup, and part of it was cleaned up manually. With only a few direct fatalities - and none of those fatal radiation poisonings were the 'dropping dead' kind.

Ps.: by the previous conversations here in the forum I have the impression that 'average' spent fuel has a surface radiation of 100-1000 Sv/h. If so, then you can touch it. At least once...

 

[nikkkom]

It would be interesting to see (and redo) that calculation, because it sounds really ridiculous.

Chernobyl had some (really fresh) spent fuel around during the cleanup, and part of it was cleaned up manually. With only a few direct fatalities - and none of those fatal radiation poisonings were the 'dropping dead' kind.

Soviet authorities did not bother tracking the fates of the conscripts who performed that work. I have a reason to believe that the fatalities were much more numerous that "a few": these young boys were just discharged from the service and sent back home to "rest", where they soon died from "unrelated causes".

 

[nikkkom]

Ps.: by the previous conversations here in the forum I have the impression that 'average' spent fuel has a surface radiation of 100-1000 Sv/h. If so, then you can touch it. At least once...

He said "if you placed an unshielded spent fuel assembly...". Typical fuel *assembly* is several meters long and has more than 50 fuel rods. So, you need to multiply your levels by about 100...

 

[Rive]

Soviet authorities did not bother tracking the fates of the conscripts who performed that work. I have a reason to believe that the fatalities were much more numerous that "a few": these young boys were just discharged from the service and sent back home to "rest", where they soon died from "unrelated causes".

A tracking record exists. However... Even you are talking about young men who were sent home. The secondary meaning of this is that they left the site alive. So they did not 'dropped dead on the 15 yard line'...

He said "if you placed an unshielded spent fuel assembly...". Typical fuel *assembly* is several meters long and has more than 50 fuel rods. So, you need to multiply your levels by about 100...

For surface radiation? I don't think so. IMO a cylindrical source with different diameter, but with a similar surface radiation will do for a simplified calculation.

 

[Dmytry]

re: plutonium dust inhalation: alpha particle emitting strongly radioactive dust in lungs should not be expected to have identical biological effects to more uniform sources. Such dust particle would burn away the tissue around itself, leading to a tiny necrosis while the nearby cells would regenerate (divide).

The one rather interesting thing about nuclear power is that the nuclear power plant really does have rather staggeringly huge toxic repository (measured in LD50s) compared to a toxic chemical plant, even if you consider just the internal exposure to Cs-137 and/or I-131
I did comparison between Bhopal and Chernobyl release based on WHO figures for internal exposure from consumed caesium and iodine.
http://dmytry.com/blog/?p=15

That shouldn't be very surprising though; for the amount of deposited energy, the radiation is very lethal; the energy that heats you uniformly by 0.001 K would kill you if delivered in form of ionizing radiation, but not in form of almost anything else (unless concentrated on vital organs, e.g. stabbing or gunshot).