Correcto. If this deal does not invoive Viet Nam receiving enrichment technologies then I see absolutely ZERO point of Viet Nam doing business with the U.S. The protocol of Viet Nam's nuclear policy is self-sufficient in enrichment capabilities.
If Viet Nam receives the enrichment technologies then later enrich uranium that is not supplied by the U.S; then Viet Nam does not break the 123 agreement. If this deal does not involve any senstive technology transfers then I'm really puzzled on why two sides have spent a couple of years of negotiation considering Viet Nam can easily contract the Russian or Japanese to build the nuke plant on any time.
First...You do not need to know how to enrich uranium in order to know how to operate or even to build a nuclear reactor.
Second...Enrichment technologies are expensive enough that it is far less expensive with buying uranium on the open market.
So if you think that Russia or Japan, both signatories of the NPT, is going to sell Viet Nam both a nuclear power plant and enrichment technologies, you are seriously mistaken.
Uranium-235 - Wikipedia, the free encyclopedia
Uranium-235 is an isotope of uranium making up about 0.72% of natural uranium. Unlike the predominant isotope uranium-238, it is fissile, i.e., it can sustain fission chain reaction. It is the only fissile isotope that is a primordial nuclide or found in significant quantity in nature.
That .72% concentration is what make U-235 so rare that it requires literally tons of Earth processing to get enough concentration for a nuclear power plant chain reaction, let alone concentrate enough for a nuclear weapon.
Uranium in the environment - Wikipedia, the free encyclopedia
Uranium is a naturally occurring element found in low levels within all rock, soil, and water. This is the highest-numbered element to be found naturally in significant quantities on earth.
But what make U-238 and U-235 different is that 3 electron mass. That is how little it is. Currently, the most popular method to separate the two isotopes is the centrifuge method. This is where uranium is mixed into a gas and spun inside a cylinder at over 60,000 rpm.
Maraging steel - Wikipedia, the free encyclopedia
Maraging steels (a portmanteau of "martensitic" and "aging") are steels (iron alloys) which are known for possessing superior strength and toughness without losing malleability,...
The cylinders are made of maraging steel, among the most expensive alloys on the market. So crucial is it for enrichment technologies that any large quantity (tons) of purchase of maraging steel will automatically be flagged for investigation by Interpol and all the major powers' clandestine intelligence services. Supposedly some of these agencies do not have acronyms and their operatives are sanctioned by their countries to operate outside the laws to do whatever necessary to gain information as to who is buying tons of maraging steel, the purchase methods, and why are there steps taken to hide the identities of the buyers and sellers.
NRC: Uranium Enrichment
This rotation creates a strong centrifugal force so that the heavier gas molecules (containing U238) move toward the outside of the cylinder and the lighter gas molecules (containing U235) collect closer to the center. The stream that is slightly enriched in U235 is withdrawn and fed into the next higher stage, while the slightly depleted stream is recycled back into the next lower stage.
Literally thousands of centrifuges are necessary in a multi-stage enrichment operation. Each cylinder must have its own seismic isolation module/station or even the entire plant is on its own seismic isolation.
Uranium Enrichment - Current Issues (USEC Paducah and Portsmouth plants, USA)
(USEC) confirming the company's commitment to install seismic modifications in two buildings at its Paducah, Kentucky, Gaseous Diffusion Plant by September 30.
Clean electricity is a necessity because the slightest fluctuation will affect cylinder rotation speed stability and will not separate the isotopes due to that tiny 3 electrons mass difference. If no -235 isotope is detected in later stages, then the first stage must be taken apart and troubleshoot to find out why.
Finally...As little as 3-5% concentration is enough for a civil use nuclear powerplant and can be purchases cheaply and quickly.
Uranium Markets: World Nuclear Association
Higher than 10% and it will trigger suspicions regarding nuclear weapons grade enrichment and proliferation.
It looks like you have not done even basic research into the issue.
Viet Nam have nothing to gain in trying to acquire enrichment technologies, either clandestinely or through hard labor. Either path will take vital money from rebuilding the country because of communist ineptitude. A functional nuclear powerplant will alleviate much of that rebuilding pain by providing inexpensive electricity to the people.