[DennisP]

Breeders aren't necessarily proliferative. The IFR for example ends up with a mix of plutonium isotopes which is more difficult to weaponize than natural uranium ore. The main problem is the need for a high fissile load at startup, but the same mix works for that.

Thorium breeders are another possibility, as long as you're not isolating protactinium.

Another route is Transatomic's design. It's not actually a breeder, and runs on uranium enriched as low as 1.6%, but burns up almost all the transuranics because it leaves them in the fuel mix for a long time, removes fission products, and has really good neutron economy.

Even if you use breeders with potential proliferation issues, one way to go would be to keep those reactors in weapons states, and use them to dispose of the waste from non-weapons states.