I believe transmutation has been demonstrated in the laboratory on a very small scale. It takes are large system in order to do it economically, and that would take several years of development.
and alternative to transmutation by accelerator - http://www.world-nuclear.org/sym/2001/venneri.htm
The Modular Helium Reactor has yet to be developed and built.
- a reasonable overview of the situation.
Transmutation of transuranic elements also requires partitioning or separation, which is accomplished in a reprocessing facility.
The US has not reprocessed commercial fuel, nor defense fuel IIRC, in many years. Reprocessing was halted during the Carter administration (ca. 1977) out of concerns for proliferation or diversion of Pu-239 to weapons. Reprocessing appears to back on the table as an option in the fuel cycle.
Then there are those who oppose the transmutation option - http://www.ieer.org/reports/transm/pressrel.html