Gas centrifuges are more efficient but involve advanced mechanical engineering which is not easy to master. Iran, for example, still struggles to master the technology of an older generation of centrifuges. Aerodynamic technologies work on a principle similar to the centrifuge but without moving parts, only the gas moves. There are three such technologies: Becker jet nozzle (Brazil), Helikon vortex tube (South Africa) and its derivative, the Aerodynamic Separation Process (ASP) of Klydon Pty (South Africa). Aerodynamic methods are mechanically simpler but much less efficient on both energy and separative capacity aspects.

There are two possible routes for improvement:

* Increasing the efficiency of existing methods – Proliferators may care less about efficiency by itself but it affects the detectability of enrichment facilities (e.g. size and energy consumption).

A possible key to increasing the efficiency of diffusion or aerodynamic methods is the new pressure exchange (PX) technology which made sea water reverse osmosis desalination, another energy hungry process wasting a lot of compressional energy, so much more efficient that product prices dropped by a factor of ten. Desalination uses liquid/liquid pressure exchangers but similar devices could work with gases, the phase used in Uranium enrichment, maybe via a liquid intermediate stage. Pressure exchangers applied to
gaseous diffusion or aerodynamic process could possibly make them much cheaper. By the way, centrifuge technology could also benefit from PX technology and become even more efficient.

* A new enrichment method – Some possible ideas are: acceleration collimation of
molecular beams in vacuum, a novel low relaxation environment similar to a superfluid, maybe electrophoresis/dielectrophoresis in the liquid phase combined with other separation processes?

It’s difficult for a developing, even a developed, country to enrich Uranium and
this difficulty is a significant barrier for proliferation via the Uranium route. If most countries could enrich Uranium and thus be always on the brink of acquiring simple nuclear weapons the rules of the nuclear game would change. Non-proliferation will be practical only if enrichment is renounced, except in cooperative centers closely supervised by the IAEA.

International or regional cooperative centers can be useful in two ways: getting a dangerous technology out of a country that may misuse it (e.g. Iran) or create a political counter-weight to such a country, for example building an enrichment center in the Sinai peninsula to be shared by Egypt, Israel, Jordan and Saudi Arabia would negate part of the political benefits of having an independent nuclear program, the main concern about Iran.