Making My Nuke Look Like Your Nuke

[marcusl]

Calls like this one to make international databases of nuclear "signatures" available publicly make sense to me as a way to help deter theft and transfer of nuclear materiel:
http://www.nature.com/nature/journal/v443/n7114/full/443907a.html"
The rationale is that a state that manufactured material used in a detonation or dirty event could be identified and held accountable after the fact.

I wonder how foolproof this might be, however. Wouldn't a state that is determined to transfer nuclear material to, e.g., a terrorist group, try to spoof their material? With the aid of the international database, in fact, they'd attempt to dope their material with just the right trace additives to make it look like it came from someone they consider to be an enemy.

My question is, how difficult is it to do this, given that a nuclear country will have advanced capabilities in separation, metallurgy, etc.?

 

[Morbius]

Calls like this one to make international databases of nuclear "signatures" available publicly make sense to me as a way to help deter theft and transfer of nuclear materiel:
http://www.nature.com/nature/journal/v443/n7114/full/443907a.html"
The rationale is that a state that manufactured material used in a detonation or dirty event could be identified and held accountable after the fact.

I wonder how foolproof this might be, however. Wouldn't a state that is determined to transfer nuclear material to, e.g., a terrorist group, try to spoof their material? With the aid of the international database, in fact, they'd attempt to dope their material with just the right trace additives to make it look like it came from someone they consider to be an enemy.

My question is, how difficult is it to do this, given that a nuclear country will have advanced capabilities in separation, metallurgy, etc.?

marcus,

The 3 authors of the article you cite are VERY knowledable in the field.

Michael May is a former Director of Lawrence Livermore National Laboratory [LLNL].
Jay Davis is a former Associate Director of LLNL, and is the founding Director of
the Pentagon's Defense Threat Reduction Agency.
Raymond Jeanloz is a current staff member of LLNL.

It's not as easy as you think it is to spoof the system. Remember we are talking
about the isotopic composition. It's VERY DIFFICULT to isolate particular isotopes
to seed into the composition to spoof the detectives.

Additionally, the "mix" of isotopes is important. If we consider plutonium that was
"cooked up" in a reactor; the operating history of the reactor, how long it operated,
how long it was shutdown, how long it operated following restrart... the day to day
variations of the operation of the reactor during the time the plutonium was "cooking"
actually impose a "signature" on the plutonium. It's not just how much of one isotope,
but the relative abundances of many isotopes.

It would take a laboratory that has very, very sophisticated mass spectrographs.
There aren't many places that have the needed capability - and even for them the
task would be daunting.

Dr. Gregory Greenman
Physicist

 

[marcusl]

marcus,

The 3 authors of the article you cite are VERY knowledable in the field.

Michael May is a former Director of Lawrence Livermore National Laboratory [LLNL].
Jay Davis is a former Associate Director of LLNL, and is the founding Director of
the Pentagon's Defense Threat Reduction Agency.
Raymond Jeanloz is a current staff member of LLNL.

Thank you for your reply, Dr. Greenman. I'm aware of the authors' credentials, and once had the privilege to join a small group that discussed nuclear threats and arms control with Dr. May and other experts. Let me be clear that I'm trying to address my own lack of knowledge in this area, and do not intend any criticism of this proposal.

It's not as easy as you think it is to spoof the system. Remember we are talking
about the isotopic composition. It's VERY DIFFICULT to isolate particular isotopes
to seed into the composition to spoof the detectives.

Additionally, the "mix" of isotopes is important. If we consider plutonium that was
"cooked up" in a reactor; the operating history of the reactor, how long it operated,
how long it was shutdown, how long it operated following restrart... the day to day
variations of the operation of the reactor during the time the plutonium was "cooking"
actually impose a "signature" on the plutonium. It's not just how much of one isotope,
but the relative abundances of many isotopes.

It would take a laboratory that has very, very sophisticated mass spectrographs.
There aren't many places that have the needed capability - and even for them the
task would be daunting.

Dr. Gregory Greenman
Physicist

Good, this is the information I was looking for. So I get that, in addition to elements present in the raw mined ore, the enrichment or breeder reactor will create transmuted elements and isotopes, there will be decay products, and various ratios will give some indication of what, you indicate, could be complex time history. I had wondered whether technology used for chemically separating elements and alloying metals, e.g., might be applied to the spoofing task. From your comments, I'm guessing the signature will be composed of hundreds of isotopes measured to ppm levels. In any case metallurgical capability is insufficient to spoof IAEA and other detectives.

Thanks again for your detailed reply.

 

[Morbius]

Good, this is the information I was looking for. So I get that, in addition to elements present in the raw mined ore, the enrichment or breeder reactor will create transmuted elements and isotopes, there will be decay products, and various ratios will give some indication of what, you indicate, could be complex time history..

marcus,

I think you got it. The reactor is creating various isotopes consistent with the
concentration of their parent nuclides in the reactor. If you shutdown the reactor
for maintenance, routine or otherwise; then the radioactive nuclides will decay at
their own rates for whatever time the reactor is down. This gives you a new mix
of nuclides.

When you restart the reactor, you are manufacturing nuclides at a rate consistent
with this new mix until you shutdown the reactor again. Additionally, the mix is
constantly evolving as the reactor operates.

This is they type of thing that fuel management computer codes have to calculate
when doing re-load calculations for the reactors. It gets to be very complex just
to calculate.

Dr. Gregory Greenman
Physicist

 

[marcusl]

So you think an international database of nuclear signatures would be feasible and reliable, assuming that the IAEA is allowed adequate access to facilities and samples.

 

[Morbius]

So you think an international database of nuclear signatures would be feasible and reliable, assuming that the IAEA is allowed adequate access to facilities and samples.

marcus,

Years ago in the early '80s; I worked at Argonne National Laboratory. One of the
more senior scientists there was doing something like that back then. As I recall,
he was working with the IAEA at the time.

Dr. Gregory Greenman
Physicist

 

[marcusl]

Cool. Anything we do to discourage proliferation is a good step.

 

[Astronuc]

Adding to what Morbius mentioned, it would be difficult to precisely match a particular isotopic vector, and there are two principle vectors invovled, one being the Pu-vectors, and the other being the additives and impurities. Then in addition to composition, there are microstructural perculiarities which are process dependent, and that in addition to composition, makes it virtually impossible to match different material.

I just read a piece about the Safeguards Analytical Laboratory at the IAEA's Seibersdorf Lab in Vienna - http://www.iaea.org/programmes/naal/sal/index.htm

I think they are quite capable of determining the origin of a material.

As Morbius mentioned it would be extremely difficult to take one material and try to pass it off as another.