Small Modular Reactor - sources of proliferation resistance advantages

If the new ENHS proves practical to implement, it might significantly improve the economics, safety, proliferation-resistance and public acceptability of nuclear reactors:

Proliferation Resistance: This energy system is expected to be highly proliferation-resistant, even when installed in developing countries. The fuel is brought to the country inside the sealed reactor module, and is taken out of the country in the same sealed module. It is never necessary to ship, store or handle fuel in the developing country except inside the reactor vessel, and the reactor vessel need not be opened at any time in the developing country. In addition, the long-life core can be designed with non-proliferating uranium (~ 15% enrichment) and the spent fuel need not be taken out of the vessel/storage cask for dozens of years.

[Source: DOE Nuclear Energy Research Initiative (NERI) Project Abstract, "STAR: The Secure Transportable Autonomous Reactor System, Encapsulated Fission Heat-Source", November 22, 1999]