Touching weps grade uranium/plutonium

[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).