Breeders have been around for quite some time now. It's just that nuclear fuel and waste handling are both really cheap, so there hasn't been any real economic incentives to abandon conventional reactors for the more frugal but also more complex breeders.

SVBR-100 and other ideas such as LFTR can be employed large-scale (replacing all other electricity generation) with moderate effort the day economic fundamentals change. Such a change would be heavy carbon taxation, for example, or peak coal. Until then, uranium reserves can easily provide the small amounts of uranium necessary for our small fleet of conventional plants.

The Carter administration, believing that essentially any processing of spent fuel from reactors was a proliferation threat, committed the US to an open (once-through) nuclear fuel cycle in the second half of the 1970s. Absent that decision, something like the LFTR might be much closer, as engineers sought higher burn-up rates and simpler reprocessing techniques.

The BN-600 reactor is a sodium-cooled fast breeder reactor located at the Beloyarsk Nuclear Power Station, in Zarechny, Sverdlovsk Oblast, Russia. That reactor has been operated successfully since 1980. The historical operations profile for that reactor can be seen in Fig. 2.1 in the IAEA tecdoc 1289 , "Comparative assessment of thermophysical and thermohydraulic characteristics of lead, lead-bismuth and sodium coolants for fast reactors". The Russian experience with that class of reactors has been much better than that of the Western Nations.