There has been an interesting discussion going on over at LGF about nuke weapons. The discussion was prompted by this Tech Central Station article.
I love nuke stuff. So much so that I was a Naval Nuke. A rod yanker so to speak.
About five or eight years ago we shipped 20 TONS of plutonium to Japan. In theory the Japanese were going to "dispose" of it in a specially designed reactor. Right.
BTW that is enough Pu for at minimum 1,000 weapons. (more like 8,000 actually)
So I'd add Japan to the nuclear club for the same reason Israel is in the club. Material and know how.
The #1 reason for China to put the brakes on the Norks is the knowledge that the Japanese are an unannounced nuclear power.
It seems to me that the Nork's testing of rockets by sending them in the direction of Japan is very unwise. For the Norks.
Europe has been sending nuclear material to Japan for some time. Greenpeace made their usual stink about the danger. If they only knew.
You can't ship big chunks (not over a pound likely per container). The container needs to be large enough and strong enough to keep it away from other chunks despite colision, fire, and a flooding hold. And that is just the obvious stuff.
Here is an article on the shipments from 1999. Straight from the horses mouth Greenpeace.
Weapns grade plutonium shipments to Japan.
And it was 40 tons total not twenty. i.e. Japan is now a world class nuclear power with a weapons capability second only to the USA.
The initial shipment was 450 kg said to be enough for 50 bombs. (more like 200 if well designed and fusion boosted)
The US Japanese nuclear co-operation goes back further than I thought. It could have been policy since Regan.
The U.S.-Japan agreement provides for the shipment of plutonium extracted from spent fuel rods removed from Japanese commercial reactors. The origin of the fuel rods is the United States. The agreement requires Japan to notify the United States State Department before each transfer of plutonium and to provide the United States with a transportation plan that includes a "threat assessment and a contingency plan."American Plutonium shipments to Japan
The General Accounting Office, Congress' auditor, has weighed in with its report on the first shipment of plutonium to Japan made under the 1988 Agreement for Cooperation Between the United States and Japan Concerning Peaceful Uses of Nuclear Energy. Senator John Glenn, chairman of the Governmental Affairs Committee, asked the GAO to prepare the report, which was released in June 1993.You have to scroll about half way down the page for the Japan stuff.
Interestingly enough South Korea is doing the reprocessing.
No wonder they do not see the Northern Nuke as such a threat. That would explain a lot.
Looks to me like if you are a reliable ally America will provide nuclear materials.
My guess is that all of the major Asian powers in the American orbit are nuclear armed.
That seems to be policy.
So how hard is it to design and build a weapon?
My understanding of modern plutonium based nuclear weapons is that they are all thermonuclear.
Our initial designs were developed with computers that had less power than a TRS-80. The lowest cost desktop machine of today is at minimum 1,000 times as powerful. Which says that the computations that would take a year in 1950 could be done in 8 hours or less today. And of course if you wanted to do paper tests faster of different designs just buy more computers.
FabioC adds a link to a modern nuke weapon with general design outlines, history, and lots of general guidelines for bomb design. More is easily found on the www. And there are links galore at the site.
How hard is it to design and build a nuke? You give me the Pu (say a couple of ounces accurately machined). 1,000 or 2,000 smoke detectors (to make a neutron source).
A NC machine tool capable of holding .0001" tolerance over a 5" distance (not too exotic these days). An interferometer based measuring tool.
Some test eqpt. o-scopes capable of recording around 1E9 samples a second ( again not too exotic these days).
Some test eqpt. (x-ray detectors, neutron dectectors etc)
I could work out all the required constants.
From there I buy an optics and a mechanical dynamics program and I'm off and running.
With really top notch people (don't forget this stuff was originally done with slide rules, IBM punch card machines capable of about ten calculations a second, and vacuum tubes. Feynman ran the IBM machine. It is a fascinating story.) I could get by with an eqpt budget of $20 to $40 million. Peanuts really.
The codes even done in Basic ought not be too hard. Or if you want to get really fancy Mathematica. Some one who understood x-ray grazing optics optics, stress/strain curves, partial differentials and cubic splines ought to do the trick. You go to a university and find the best politically motivated engineers and mathematicians. A team of five ought to be more than adequate. Did I mention that you need an explosive forming expert?
The reason such a big team was needed for the first one was the uncertainty and the lack of off the shelf eqpt. Everything was custom. Now a days all you pay for is the marginal cost. The R&D has already been done.
Now my training was in reactors. Weapons were mentioned in passing only from the standpoint of critical mass. But almost any engineer from open sources could figure out the requirements. Or just go to any good history of Los Alamos. (I have none to suggest).