I did an “interview with RFA”:http://www.rfa.org/korean/simcheongbodo/2007/01/24/nk_reported_support_iran_nuke/ a few days ago about the alleged nuclear cooperation between Iran and North Korea (which I blogged about “here”:http://www.totalwonkerr.net/1333/wankery-department-of.)
During that interview, I said:
bq. I don’t know if Iran has nuclear weapons program or not. But if it does that program is using highly enriched uranium for the explosive material. North Korea’s program is based on plutonium. So it’s unclear how much Iran could use whatever information they got from N.Korea.
Because I was unclear on that issue, I asked a couple of physicists. It seems that data from the test of a Pu implosion device actually could be pretty helpful to a weapons program using HEU.
One physicist told me that:
bq. With the caveat that I have never seen classified bomb design info, I would think that the only big difference between the two implosion devices is that the core of the HEU device would be somewhat bigger than the core of the Pu device because about 25 kg of HEU would be needed in comparison to 8 kg of Pu. So, the weapons scientists would have to scale up the HEU device. This would require calculating how to rearrange the conventional explosives that squeeze the HEU core.
Those calculations are apparently not terribly difficult for a competent physicist.
bq. The results of the Pu test would validate (or invalidate) the computer models and techniques used to design, manufacture, and test the device. In particular, I would think that a successful Pu test would give a country substantial experience that would apply directly to key components of an HEU device, such as the HE assembly and related electronics and the initiator.
Glad I qualified what I said to that reporter.
Based on a conversation I had with a colleague, I should clarify that I am talking about the extent to which data from testing a Pu-based implosion device could help a state trying to build a similar HEU-based device. Obviously, Iran could simply choose to build a gun-type device out of HEU.
That colleague also pointed out that the design data of an implosion device would be just as important as the test data.