Lieutenant General Ronald L. Burgess, Jr., director of the Defense Intelligence Agency for the United States Department of Defense, stated recently that Iran has the “technical, scientific and industrial capability to eventually produce nuclear weapons.”
Prophesying is a very easy job; sooner or later everything happens. In mathematics, this common-sense wisdom is supported by the Poincaré Recurrence Theorem that, roughly speaking, states that a dynamic system in an endless evolution in time will ultimately pass through any possible state.
For instance, a Jewish state might emerge in the Holy Land, the Soviet Union might collapse, and the Messiah could even come some day.
At one time or another, the aforementioned events were considered almost identical in terms of low probability of occurrence. Today, if a timeline is not required, plenty of laymen might prophesy on the eventual acquisition of nuclear capability by different powers. After all, to merely prognosticate, there’s no need for expensive and dangerous information-gathering by multiple intelligence bodies.
Another kind of prophecy, beloved by these communities, are Worst Possible Scenarios, just for tomorrow. Nobody can be dismissed or castigated if the scenario happens to prove false. After all, it’s important to “be on a safe side.” Besides, the Israeli public likes doomsday prophecies. They fit a certain Jewish paranoid consciousness.
In the recent past, however, paranoid fears have too often been justified.
Israelis rightfully doubt the strange American thesis that there will be no signs of true Iranian intent for nuclear weaponization until the moment that weapons are actually being made. This is simply not the way R&D is performed.
For the time being, all the prophecies concerning the Iranian nuclear program are fixed on the schedule of uranium enrichment. According to common wisdom the new subsonic centrifuges are already in place. They work incessantly and could produce 20 kilograms of 93%-enriched Uranium — U-235 — in a few months. Then, as the American intelligence community states with impeccable authority, Supreme Leader Khamenei may decide to make some nukes. American intelligence purports to be capable of overhearing this Khamenei order practically on the spot, as if it were among the participants in the Iranian decision-making process, with plenty of time to provide President Obama with an option to intervene as he sees fit.
The Israelis rightfully doubt this American axiom. Mainly, they object to the strange thesis that there will be no signs of true Iranian intent for nuclear weaponization until the moment that weapons are actually in production. This is simply not the way that R&D, both civilian and military, is performed. The target of an R&D program is set from the very beginning. Otherwise, the program would never arrive at any final goal. One cannot find oneself with an A-Bomb just by pursuing general knowledge in theoretical physics. Seventy years ago, an A-Bomb was built by theoretical physicists, of course, but they weren’t just pursuing pure knowledge; they wanted a nuke to stop Hitler.
As Seymour Hirsh wrote in June last year, the so-called National Intelligence Estimate (NIE) “makes it clear that US intelligence has been unable to find decisive evidence that Iran has been moving enriched uranium to an underground weapon-making center.”
Seymour Hirsh is a serious and well-informed writer. To paraphrase, he means that there is no assembly hall for the bomb where all activities are to be focused through the final stage. Hence, the Iranians must be far from completion — as Uzi Eilam, former chairman of the Israel Atomic Energy Commission, has pointed out in his rare publications and appearances.
In fact, the NIE report was published only once, in 2007, and it stirred up quite a fuss. It forced the Russians, who had abandoned the Bushehr Nuclear Power Station in 2005, to return with rods of fission materials for the reactor. Indeed, on what grounds could they refuse to supply the rods if the NIE stated the absence of any Iranian nuclear weaponization program?
Let us dare to question common wisdom. Let us suppose that the timing depends on the bomb’s design: gun assembly or implosion.
Since then, the NIE reports have all been kept secret, but the main content has been divulged through the press. Actually, there was nothing new to report. The American intelligence community did not see any signs of the implementation of a weaponization program. “The important thing is that nothing substantially new has been learned in the last four years and none of our efforts — informants, penetrations, planting of sensors — leads to a bomb,” Seymour Hirsh writes, quoting his high-level source. In recent days, the Los Angeles Times published the same joint conclusion of 16 American intelligence agencies.
So, what is the real state of affairs, besides the openly-debated issue of the centrifuges?
The critical difference between ‘gun assembly’ and ‘implosion’ nukes
Here we come upon a shared Israeli-American axiom: The minute there are enough fission materials, the bomb will be put together in a few months. But let us dare to question this common wisdom. Let us suppose that the timing depends on the bomb’s design.
Basically, there are two types of nuke designs: gun assembly and implosion.
Gun assembly involves a system of two hemispheres of Uranium-235, running in the opposite direction at a high speed. When they meet, the total mass of the two hemispheres exceeds the so-called critical mass for Uranium-235, and the chain reaction-fission develops into a total explosion. The idea is that many of the neutrons will hit some atoms, since the volume of the non-compressed Uranium-235 is big enough.
As Professor David Bodansky, a nuclear research expert with 65 years of experience, states in his book Nuclear Energy (Springer, 2009): ”A gun assembly uranium bomb is practical.” The design, however, is considered inefficient in terms of the ratio of explosion power to the mass of Uranium-235 involved. One needs a lot of enriched uranium to get a relatively small yield.
The implosion scheme, in its simplest form, involves a sphere of Uranium-235 or Plutonium-94 (or both), surrounded by ultra-efficient explosives. When the explosives are detonated, the sphere of the fission material (uranium or plutonium) is highly compressed, i.e. the density grows rapidly and almost all neutrons hit densely packed atoms, so that fission develops swiftly and consumes all fissionable material.
The explosion itself is also ultra-efficient: less fissionable material is needed and the energy yield is much greater.
The difference between the two designs is staggering. For a gun assembly bomb of 10 kilotons, about 19.5 kilograms of 93%-enriched Uranium-235 are needed. The uranium implosion design requires only 6.5 kilograms.
As the late Edward Teller recounted, the idea of the implosion design belongs to John von Neumann, the prodigious mathematician who, like Teller himself, was of Jewish-Hungarian descent. One night, von Neumann visited Teller to discuss ideas over a cup of tea. The next morning, the two men entered Robert Oppenheimer’s office. The Los Alamos director immediately grasped the power of von Neuman’s concept and changed the direction of the Manhattan Project on the spot.
Teller was a die-hard anti-communist, and he couldn’t forget Oppenheimer’s communist past. But he recognized Oppenheimer’s grandeur as a scientific leader, and he knew implosion was the way to go.
The implosion design, however, is incomparably more complicated than gun assembly. First and foremost, the detonation of explosives should be absolutely simultaneous and uniform in all directions. The fission material is a very complex composition of Uranium-235, Uranium-233, Uranium-234, and other instances. As Bodansky politely puts it, ”with great technical effort, it is possible to make a uranium explosion weapon, and less uranium is needed.”
Both Americans and Brits started with plutonium implosion design, and only at later stages did they begin experimentation with uranium implosion. More than a decade later, as the ’50s came to a close, they began to develop more compact uranium implosion gadgets, about 22-inches in diameter.
The International Atomic Energy Agency’s 2011 report delivered a John Le Carré-style twist. The report hints (without proof) that a 77-year-old Russian physicist named Vyacheslav Vasilievich Danilenko may have taught the Iranians simultaneous detonation and shock wave implosion
during the six years he spent in Iran.
The Chinese, however, actually started with an uranium implosion bomb. In fact, they began building in the mid-’50s under Soviet guidance. Hundreds of Chinese students studied physics and mathematics in Soviet Universities. In 1958, Khrushchev signed an agreement with Mao, promising help, full documentation, and a real A-Bomb with spare components. However, by late 1959, the Soviets had second thoughts and at the very last moment, cooperation came to a dead stop. Thus began the great Sino-Soviet rift, which lasted 30 years. Four years later, however, on October 16, 1964, the Chinese detonated their first bomb. It was a uranium implosion bomb. In just four years they were able to implement with nothing more than the scheme they were taught by the Russians. The Russians, who were reluctant to go on with this incredible technology transfer, taught the Chinese the most complicated design there was, in the hopes that they would not be able to move ahead alone.
The Chinese proved them wrong.
To the best of my knowledge, everybody in the intelligence community, including all peripheral freelancers and experts prolific on the issue of Iranian nukes, is united in the belief that the Iranians have chosen the uranium implosion scheme.
The role of a mysterious Russian
The International Atomic Energy Agency’s (IAEA) 2011 report gave this story a sort of John Le Carré-style twist. The report hints (without proof) that a 77-year-old Russian physicist named Vyacheslav Vasilievich Danilenko may have taught the Iranians simultaneous detonation and shock wave implosion during the six years he spent in Iran between 1996 and 2002. He purportedly left them a cylinder marked as R265 (265 referring to the diameter in millimeters) and set their sights on implosion wave generation. Danilenko denied these accusations, of course, but the belief that he taught Iranians the design of a compact uranium implosion bomb is widely spread in the intelligence bodies and among freelance experts.
It is not clear whether Danilenko is an expert in nuclear weapons design. But we do know that he spent some 30 years in a secret Russian “Atomic City” coded as Chelyabinsk-70 (today, a “normal” town known as Snezhinsk). Chelyabinsk-70 was established as a counterpart to the first secret Soviet Atomic Center, coded as Arsamas-16 (today, Sarov). Arsamas-16 was widely considered to be dominated by Jews, and in fact, almost all leaders of the initial Soviet Atomic program were Jewish. Not everyone who worked there, however, was involved in the design of nuclear weapons. The same holds true for the Kurchatov Institute in Moscow. The first Soviet nuclear reactor is still there. But the researchers represent every field in physics; some of them choose to live in Israel as physics professors. In fact, none of the Kurchatov researchers who live abroad today were involved in bomb design.
Danilenko has a field of expertise: nanodiamonds. These are produced by an explosion that disperses graphite into a cloud of carbon nano-particles. In 1962, Danilenko made a classified Soviet patent for this process. Everything concerning nanodiamonds was classified in the Soviet Union. In 1992, after the collapse of the Soviet Union, Danilenko left the secret Atomic City and started patenting his inventions for himself.
Is it possible that he taught the Iranians how to design a compact uranium explosion device?
They’ll do it eventually
Meanwhile, the Iranians are besieged with sanctions. The importance of these prolonged sanctions lies in the technological isolation. Everybody, including the Chinese, knows that everything is under scrutiny; nothing is secret for long in the age of the internet. Those who dare to supply Iran with some vitally important technology may become the enemies of the United States, perhaps forever. Thus, the Iranian developers and researchers are in a state of almost total isolation; they have to invent everything from scratch, just as the Russians did 65 years ago. Danilenko, who left Iran 10 years ago, could hardly have taught them in advance. A real design requires real parameters and real fission components composition.
But he may have seeded the illusion, intentionally or not, that a compact uranium implosion design is feasible.
In principle, the Iranians can do it all, maybe even in five years, as former Mossad chief Meir Dagan thinks. Or maybe it’ll take 10 years. But they’ll do it eventually, as Ronald Burgess suggests. Nobody starts with compact uranium implosion; it’s the most difficult design to execute. Everybody starts with something simple. True, Iraq had big plans to make a uranium implosion bomb in 1991, but they were unlucky all the way. Copying Iraq is a bad example.
It took India 20 years to develop a device, not even an operational bomb. It took the Russians, the Dutch, and the French many years to achieve some level of excellence in the field of uranium enrichment and centrifuges. And even uranium enrichment may not go as fast as expected. It took five years to install the new Iranian centrifuges, and Iran is not a country with lots of experience in chemical machinery production. These centrifuges should be reliable, but it may take the Iranians some time to make centrifuges of really good quality in order to produce hundreds of pieces per month. Uranium enrichment is very difficult chemistry. And chemistry requires time and patience.
With all this in mind, it is worthwhile to think about whether the Iranian nuclear project is ripe for being bombed. It may be premature to do it today. The intelligence community has to be responsible for fine tuning, not solely for cries of alarm.
Alexander Libin was born in North Siberia in the city of Norilsk in 1944. After graduating from the Math Department of Moscow University (MGU) he immigrated to Israel in 1972 and got a PhD in Applied Math from Tel Aviv University. He has since taught math in several Israeli Universities. In the first half of the 1990s, Mr. Libin was stationed in Moscow as Immigration Officer for the Israeli Embassy.