Oh. Oh. The critical mass of Curium-245 with SS-304 reflector is just 4.73 kg, r = 4.7 cm.

[NNadir]

The following is from the journal article Journal of NUCLEAR SCIENCE and TECHNOLOGY, Vol. 39, No. 10, p. 1072–1085 (October 2002)

The American National Standard for Nuclear Criticality Control of Special Actinide Elements, ANSI/ANS-8.15- 1981,1) has been reviewed for revision by a working group chaired by Norman L. Pruvost since 1996.2) The standard was intended to provide criticality safety guidance for fissionable actinides other than the so called “big three” actinides, ²³³U, ²³⁵U and ²³⁹Pu, that have been traditionally discussed by the ANSI/ANS-8.1Working Group. The ANSI/ANS-8.15Working Group was arranged to consist of five US members and four non-US members, who are from France, Japan, Russia, and UK. One of the authors of this paper (HO) has been the Japanese member of the group since 1997, to whom at first three curium isotopes were assigned: ²⁴⁶Cm for inclusion, and ²⁴⁵Cm and ²⁴⁷Cm for revision...

...Present authors, therefore, calculated critical and subcritical masses of ²⁴⁵Cm, ²⁴⁶Cm and ²⁴⁷Cm to accomplish the task.12) In addition to the requested three curium isotopes, they recently made calculation for ²⁴³Cm and ²⁴⁴Cm as a part of ten fissionable nuclides that had comparable critical masses to that of ²³⁵U.13) The critical and subcritical masses of the curium isotopes were calculated as precisely as possible by using modern computational tools and the most recently published evaluated nuclear data files for standardizing these quantities in reference to the previous data. Based on the present and previously obtained critical mass values subcritcal mass limits were recommended to the ANS-8.15Working Group and the values were discussed by its members...

An example of the relation between the radius of a fuel sphere and the calculated neutron multiplication factor k_eff is shown in Fig. 1 for ²⁴⁵Cm metal without reflectors. This figure illustrates how to obtain the radii of fuel sphere, 6.00, 5.35 and 4.72 cm, corresponding to k_eff =1, 0.9 and 0.8, respectively, from the fitted curve. The critical mass was derived
as 12.3 kg Cm, and the subcritical masses corresponding to k_eff =0.9 and 0.8 were determined to be 8.71 and 5.99 kg Cm, respectively, by multiplying the fuel density 13.57 gCm/cm3 to the corresponding volumes (see Eq. (2)). (1) Critical and Subcritical Masses of ²⁴³Cm to ²⁴⁷Cm in Metal The critical and subcritical masses of a sphere of the five curium isotopes, ²⁴³Cm to ²⁴⁷Cm, in metal were calculated with the three reflector conditions: bare...

Suitcase bomb!!!!! We're doomed!!!!!!!!!!!!

Hide under the bed!!!!! Duck and Cover!

:scared: :nuke: :tinfoilhat:

I wonder how come we haven't had thousands of suitcase bombs hauled into American cities by now by suitcase bomb terrorists?

Any ideas?

:eyes:

[mike_c]

1. where does one find nearly 5 kg of curium-245, exactly...?

Gotta go look it up, but I'm assuming the primary source of Cm²⁴⁵ is fission reactors. Lots of bad stuff in there, but curium is only the tip of that particular iceberg.

[NNadir]

3. It's um, easy.

That's why, in spite of many hundreds of dangerous fossil fuel wars going on one after another, almost continuously since the mid 20th century, the thing we really care about is suitcase bombs.

Almost anyone can get 5 kg of Cm-245.

[ThoughtCriminal]

8. Really?

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

"The isotope curium-248 has been synthesized only in milligram quantities, but curium-242 and curium-244 are made in gram amounts, which allows for the determination of some of the element's properties. Curium-244 can be made in quantity by subjecting plutonium to neutron bombardment. Curium does not occur in nature."

I did not see any figures for Cm-245 production.

[NNadir]

10. I may be somewhat too subtle in the use of irony.

[ThoughtCriminal]

12. I miss the old days!

http://www.scientificamerican.com/slideshow.cfm?id=radioactive-products

If mom had let me, I'd have transmuted enough by now.

[NNadir]

13. I would buy that kit for my kids in a New York second. I had to show my kid a video of a Berkeley

lecture where the professor brought out a cloud chamber.

It's just not the same.

I personally had several radium sources when I was a kid. One was designed to hold up to your eye. If you locked yourself in a dark closet, one could see alpha decay flashes.

They were probably relatively dangerous those sets, but not nearly as dangerous as ignorance.

For the record, when he was head of the AEC, Glenn Seaborg oversaw the irradiation of a large amount plutonium in a high flux reactor, after which 3 kg of curium was isolated after many years of irradiation. It was a mixture of isotopes.

[lumberjack_jeff]

2. Why? Samsonite. It's kick-ass luggage. n/t

[NNadir]

4. You mean there's been lots of suitcase bombs, but all the explosions have been contained by great...

luggage?

I knew there had to be an answer.

[lumberjack_jeff]

9. I suppose the NSA is going to knock on my door now that I've spilled the beans.

"Samsonite: Homeland Security's first line of defense"

[NNadir]

11. You'll probably find your posts classified. However, you have a great future...

...as part of the entrenched nuclear weapons establishment.

You just won't be able to tell your wife and kids what it is, exactly, that you do for a living.

[Birthmark]

5. They used models?

Then it's nonsense. Ask any global warming denialist, they'll you: Models are evidence of nothing. So give any AGW-denialists all the Cm you can. THEY know it's safe. :sarcasm:

[NNadir]

6. Well, it seems that THEY couldn't get their hands of 5 kg of Cm-245.

I wonder why that is?

[Birthmark]

7. They could try, couldn't they? :) nt

[Name removed]

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