. . . .with backward countries like Russia not far behind, China in 1964 and even India in 1972(?).
Seems to me that if the United States could build one with the technology available in the 1940s, surely a country like Iran with 80 million people, many of them very talented, and today’s computer technology backed by 70 years of nuclear weapons research should be able to make a bomb in months, yet is seems like they have been trying for 10 years now and still cant seem to make weapons grade uranium.
Is it strictly international controls over the flow of radioactive materials? If not did nuclear scientists just magically get dumber? Why cant Iran do what North Korea, Pakistan, India and other third world countries have been able to do?
Because everyone is watching Iran, and if there were strong indications that they were actively working to build a nuclear weapon, odds are that Iran would be bombed by Israel and/or the United States.
So, depending on who you believe, Iran has so far made the decision to enrich uranium to a certain point that is not yet usable in a weapon, and delay activities that are solely related to building a weapon; or try to hide their illegal activities so carefully that the work is slowed.
ETA: Just to be clear, Iran has not tried and failed to make weapons grade uranium. To the best of our knowledge, they have not tried. The production so far has been for uranium enriched to a couple percent, which could then be fed through the enrichment process again to eventually come out as highly enriched uranium.
To add another layer, tinkering together what is essentially a lab experiment that will go big-badda-boom is one thing. That’s what nearly all of the first few hundred bombs built by the US and USSR were - delicate, fussy lab projects that required careful handling and final assembly just ahead of use. There’s not a lot [del]you[/del]a terrorist org or non-superpower state can do with such devices short of maybe sending them into a port on a ship - and they are not going to be James Bond “suitcase” sized, so even TSA should be able to spot them.
Developing a weaponized nuke that can take transport, handling, launch and battlefield/real world conditions is another whole level of sophistication and engineering over big-badda-boom.
And the majority of that (~80%) was spent on uranium separation and plutonium refining technologies and facilities.
Make no mistake, getting the proper concentration of U235 or Pu-241 is time consuming, expensive and difficult to do right. It takes vast amounts of power, and highly calibrated equipment. And it’s kind of conspicuous.
The US did it in 4 years during WWII by throwing the majority of the brightest physicists in the world, as well as the industrial might of the world’s most powerful nation at the problem as a first priority.
Russia is a “backward country”? The nation which put the first man in space?
Iran is one of many countries which have failed, or more accurately were unable to make a workable deterrent within a practical and realistic timeframe and cost Brazil, Argentina, Yugoslavia, Romania, Egypt also so “failed”.
(North Korea semi success relied on outside help and also the fact that they despite tye caricature have a fairly good level of industry)
Of course, they also had to develop the basic science, come up with novel fabrication and processing methods, and numerical simulations using giant classrooms of women performing arithmetic and crude mechanical integrators. The real limiting factor isn’t understanding how to construct a weapon far more complex and capable than Fat Man or Little Boy; it is producing high quality enriched uranium and being able to hold the high component tolerances necessary for reliable function.
To answer the OP. The basic theory is fairly simple. The engineering is extremely complex. You literally need to learn how to make the tools to make the tools to make the parts of a nuclear weapon and the tools and their components are something you cannot buy on the open market (black market is another issue) nor do commercial items usually substitutable.
For example gas centrifuges for enriching uranium. They spin at something like 100,000 rpm. The casing has to be made of special alloys who composition you have to figure out. Once you do that, you need to learn how to make the alloy and then machine the casing, each of it a difficult task, and each requiring special equipment and processes which you need to make and develop yourself… and the casing is just one part of the centrifuge you need to make special motors and bearings too.
(FAS on centrifuges)
Ironically, apparenty a large amount of centrifuges is indicative of a civil programme, while a lesser amount is that of a military programme, per the link.
Nobody’s brought up the obvious answer. Maybe Iran has been telling the truth all along and they aren’t trying to build a nuke? Is that position too naive to be believable?
Just to nitpick the title, the U.S. really did it in two years. Although some preliminary work was started in 1942, Los Alamos, Oak Ridge, and Hanford didn’t get going until 1943. Even that exaggerates how much got accomplished that year. The progress may have seemed glacial at the time, but in retrospect the speed is astonishing.
One thing that occurs to me: Iran’s goals for a nuke are probably a lot more sophisticated than what the US came up with in 1945. Those early bombs were much heavier and lower-yield than a modern warhead. Little Boy was such a simple design, they didn’t even bother to test it.
Furthermore, my understanding is that the US didn’t have a lot of uranium in reserve. We cobbled together what we had and shipped it out ASAP. I’m sure Iran wants to announce itself as a nuclear power with enough warheads to be a useful threat/deterrent. You don’t want to piss off half the world and only have one nuke to show for it. Ignoring North Korea (who *are *crazy enough to piss off the world for no reason) and Israel (with numbers only estimated), all of the world’s nuclear powers have more than 100 warheads. According to this site, the US didn’t get 100+ warheads until 1948 and had only 6 in 1945. Russia was also in its fifth year of possessing nukes before they broke 100.
Nobody – not even the United States – could make an atomic bomb in months, starting from scratch. The rate limiting step is how fast you can separate U-235 from normal uranium, or how fast you can breed Pu-239 in nuclear reactors. Both are agonizingly slow processes just by the nature of the physics. The US succeeded in pulling it together in 2 years in the 40s by building enormous plants that worked in massive parallel. (The K-25 plant in Oak Ridge was at that time supposedly the largest area under one roof, roughly 2,000 x 1,000 feet, and cost something like $5-10 billion in today’s dollars.)
Could the Iranians do that? Of course. But it would be very expensive and attract a lot of unwanted attention, so unless they feel like they’re in an existential crisis why would they? What they have chosen to do is enrich uranium at a leisurely pace, using small facilities, that doesn’t call for desperate levels of expense and doesn’t attract Israeli F-15s, at least right away. It will, therefore, take them years to assemble enough fissile material to make even one bomb, assuming they want to. And it seems unlikely they would want to build just one, if they build any at all.
