Community Coalition Against Mining Uranium (CCAMU)
Inquiry on the Impacts of the Uranium Cycle
What Uranium is Being Used For
I have been asked:|
"How much uranium is used for peaceful purposes, such as electricity generation and isotope production, and how much is used for military applications such as nuclear weapons?"
As a very rough estimate, the uranium that has been mined to date has been almost equally used for nuclear weapons and as fuel for civilian nuclear reactors. Only a minute amount has been used for isotope production. If all the uranium mines were permanently shut down as of tomorrow, isotope production would be unaffected for a very, very, very long time. The only competition would be from the bomb-makers.
Uranium is the Key
Uranium is the key element for all nuclear technology requiring energy production, whether civilian or military (including nuclear weapons as well as nuclear propulsion).
Strategic Nuclear Materials: [HEU and Plutonium]
There are only two strategic nuclear materials (materials from which one can fabricate the primary explosive for a nuclear weapon) and they are (1) HEU = highly enriched uranium, and (2) plutonium. If you REMOVE the HEU or the plutonium from any existing nuclear weapon, that weapon becomes unusable.
But every atom of plutonium is created from an atom of uranium, so without uranium to start with there would be NO strategic nuclear materials at all.
Fissile Uranium-235: [Natural U, LEU, and HEU]
Uranium found in nature is always a blend of two main isotopes, called uranium-235 and uranium-238. Only uranium-235 can undergo a spontaneous chain reaction of nuclear fission, yielding an enormous amount of energy.
So U-235 is called the "Fissile" isotope. It is the uranium isotope that provides the fuel for nuclear reactors and that has been used (in a highly concentrated form) as a nuclear explosive (e.g. in the Hiroshima bomb).
Plutonium from Uranium-238: [all plutonium is bomb-usable]
Uranium-238 is not fissile; however, when uranium-238 atoms are bombarded with neutrons, some of those neutrons may be absorbed by the U-238 nucleus and the uranium atom is then transmuted into a plutonium atom (plutonium-239, -240, -241, -242, etc.). ALL of these plutonium isotopes can be used to make bombs, (e.g. the Nagasaki bomb), and SOME of them (the odd-numbered isotopes) can be used to fuel a nuclear reactor.
Every nuclear reactor fuelled with uranium produces plutonium as an inevitable byproduct. Since plutonium-239 (the most abundant isotope) has a half-life of 24,000 years, the irradiated nuclear fuel can be chemically processed to remove the plutonium and make atomic bombs any time in the future, even thousands of years after the reactor has been shut down and forgotten.
This is the main proliferation risk of nuclear reactors. It is exacerbated by the fact that the nuclear industry plans to chemically remove the plutonium and uranium from the irradiated nuclear fuel from civilian reactors in order to re-use the fissile materials as fuel for nuclear reactors. Thus any criminal or terrorist group that gets its hands on this "recycled" nuclear fuel can much more easily access the plutonium, because the hardest part of the job has already been done by the nuclear industry in its zeal for perpetuating itself.
Uranium Fuel for Most Civilian Reactors
Most civilian reactors use either natural (unenriched) uranium or LEU = low-enriched uranium. Natural uranium consists of only 0.7 percent uranium-235 [and 99.3 percent uranium-238], whereas low-enriched uranium can range from 1 to 20 percent uranium-235.
However, anyone (like Iran) who builds a uranium enrichment facility can CHOOSE to enrich the uranium to a higher degree, and thus the capability to make nuclear weapons from HEU exists. Since all future reactors will require either enriched uranium or plutonium as a fuel, and since HEU and plutonium are the two strategic nuclear materials, the link between the peaceful atom and the military atom is quite close.... The facilities needed to produce the raw materials for civilian nuclear fuel can also be used to produce the raw materials for bombs.
Weapons-grade uranium is typically 95% uranium-235 or more, but anything more than 20 % uranium-235 is considered weapons-usable. Thus HEU takes in the range from 20 to 100 percent uranium-235. (The latter is presently unachievable.)
Until about 1970, virtually all of Canada's uranium was sold to the US military for weapons programs; in 1959, uranium was Canada's fourth most important export (after wheat, lumber and pulp) and it was all for bombs.
Since then, all of Canada's uranium has been sold for ostensibly peaceful purposes only. However, the picture has become quite blurred between the peaceful and military uses of uranium since then. See my article:
The problem is this. For a long time now, the depleted uranium (mostly U-238) left over from uranium enrichment has been used by the military for military purposes. Of course people know about the DU ammunition that has been used since the Gulf War "Desert Storm" under the first President Bush. But long before DU munitions were deployed, the nuclear weapons makers were using DU as a target material to produce the necessary plutonium for their nuclear warheads (in specially designed "plutonium production" reactors).
Moreover, DU is also used in the actual construction of the large, three-stage, "fission-fusion-fission" weapons called H-bombs. In this type of bomb, typically in the megaton range, the first stage is fission caused by plutonium (which was derived from DU), the second stage is fusion caused by 50 million degree heat acting on hydrogen isotopes (deuterium and tritium), and the third stage is direct fissioning of DU itself by the extremely energetic neutrons that are produced in abundance by the fusion reaction.
Most of the explosive power of these H-bombs comes from the fissioning of depleted uranium, which is the left-over material from the uranium enrichment process -- and almost all of the radioactive fallout (fission products) also comes from the fissioning of depleted uranium in the third stage. Thus DU plays the major role in providing the most fearsome immediate effects (blast) and the most damaging lingering effects (fallout).
Since the DU is a "free" byproduct of uranium enrichment for civilian nuclear fuel for reactors, it is very difficult to say how much uranium is used for "peaceful" as opposed to "military" applications.
Hope this helps people to understand the physical connections....