We note that Iran seems to be increasing activity at a critical nuclear test site. Although the technology and basic design of nuclear weapons is widely known (sold by North Korea and the A.Q. Kahn network) actual testing of explosive configuration is necessary due to the precision necessary for the reaction to be successful. The Parchin facility (Iran) has been the scene of previous explosives testing, and according to some estimates, this has resumed. What is known for sure is that something is going on at the facility, and it is likely that the activity is directly related to the facility's primary purpose.
Knowledgeable observers are no longer shy about confirming their belief that Iran's current "negotiation" posture is primarily designed to buy time. It has been described by one observer as an "international rope-a-dope", with the west playing the "dope".
A fusion (Hydrogen) bomb would be of greatest use to Iran (a great instrument of threat - able to incinerate a whole city and generate a very large EMP), however fission bomb(s) would be less complex and also be of great value. The former are city-busters, while the latter are more tactical in nature, being capable of destroying smaller areas when delivered and exploded under optimal circumstances. Not everyone agrees about Iranian intentions, and we have included a contrary viewpoint as well. One of these views is wrong, the other right. For our part, continued Iranian "research" leaves us quite uncomfortable.
We have assembled a few references below.
From ISIS: The image also shows what appears to be a stream of water that emanates from or near the building. Based on new information that the IAEA received, the Agency asked Iran to visit this building at the Parchin site, but Iran has not allowed a visit. IAEA Director General Yukiya Amano noted recently that the IAEA has “information that some activity is ongoing” at the Parchin site 1.
Fat Man was an Implosion-Triggered Fission Bomb
The Shell: The shell consisted on two spheres surrounding one another.
The Trigger: The trigger was located in the space between both spheres. It consisted in plutonium-239 surrounded by explosive charges.
The Fuel: The fuel was uranium-235 located inside the internal sphere.
Efficiency: 17%. The design allowed via compression of the core that a good amount of fuel material reacted before the explosion.
"Modern" Fission Bombs
Modern designs are enhanced versions of Fat Man. They are also Implosion -Triggered Fission Bombs.
The Shell: Two concentric spheres constitute again the shell.
The Trigger: Plutonium pieces distributed axially all around the core are projected like bullets toward the core via explosive detonation.
The Fuel: The fuel in this case is a combination of Beryllium – Polonium.
Explosive lenses: Implosion triggered designs use explosives to start the shock wave that will compress the core. The explosives cannot though be simple charges distributed around the tamper, they are explosive bodies shaped to maximize the efficiency known as explosive lenses.
From Reuters: "We should therefore be very clear that it is entirely possible that Iran may be on the 2012 end of that spectrum and act in accordance with that warning," he said.
He did not say whether his statement was based on any intelligence assessment available to Britain, a close U.S. ally and one of six powers that made no progress in talks with Iran this month on its nuclear programme. "Iran does not yet have nuclear weapons, as assessed, however it does continue to pursue uranium enrichment and the construction of a heavy water reactor, both of which have military potential," Fox said.
From Guardian: Lady Ashton has informed reporters of her expectations for another round of talks between Iran and P5+1 on 23 May: "My ambition is that we come away with the beginning of the end of the nuclear weapons programme in Iran." Her words give a hint of how western diplomats still struggle to understand the Iranian mindset. Iranians have repeatedly staked their honour on their assurance that Iran does not want nuclear weapons. The IAEA, US intelligence experts and Israeli intelligence experts are agreed that Iran is not building nuclear weapons and has not decided to do so. Diplomatic blunders like this one can at least be put right by a further statement. The failure to honour promises, however, will deliver a mortal blow to the negotiating process launched last month.
From Reuters: In the six-page report shown to Reuters, the NCRI cited sources in the Iranian government and military as saying some 60 scientists were pursuing bomb-relevant research in 11 agencies operating clandestinely under defense ministry control. "Information ... shows that the clerical regime has expanded the organization responsible for nuclear weapons development," the report said. "This finding reveals a complete and elaborate, and highly ... secret research structure and a network for procurement of the required parts and equipment.