From research on the web, my best guess is it looks like China's "breakthrough" new nuclear processing technology is a variant of the fast breeder reactor which uses highly radioactive highly processed plutonium isotopes or higbly processed Uranium-238 in order to generate fast neutrons which allow "spent" nuclear fuel to be re-processed into higher grade fuel.
Given that spent nuclear fuel is typically up to 5% "used" there is 95% of the extractable energy still remaining, as long as it is processed.
This, however, is a stable and well understood technology. Several nations have worked with fast breeder reactors in the past and there are a handful of functioning fast breeder reactors outside China.
In China's case, however, you could at a stretch say this is a breakthrough for them since they only have a limited supply of Uranium within their borders. The utilization of fast breeder technology allows them to use all of it rather than just the 50 years supply (at current rates of usage).
To get to the 3000 year quoted figure, however, they must be using something else other than just their Uranium reserves, since 50 x 19 comes out to 950 years instead of 3000.
I speculate that they might be using Thorium since a fast breeder reactor is quite capable of using Thorium to breed Uranium-233 which while still a very useful fissile material, is not suitable for the production of Nuclear bombs, yet another bonus.
Given that Thorium is up to 10 times as abundant as Uranium, it's conceivable that this is the answer.
Interestingly, Thorium could theoretically be used in very small modular reactors which would be perfect for shipping or air-freight applications. India has a research program underway to try to develop small scale cluster Thorium + Uranium seed reactors. Their program is called advanced "twin" fast breeder reactors.
We should support India's efforts to do this as everyone would benefit from nuclear power that did not lead to the proliferation of nuclear weapons.
EDIT: I note that China has in fact publicly declared support for a molton fluoride thorium reactor program. Interesting. The race is now on.