Techniques are provided for seal flush systems. A system may include a reactor circulation pump configured to circulate a slurry through a polymerization reactor. The slurry may include an olefin monomer, a catalyst, and a diluent. The system may also include a catalyst-inhibiting additive system configured to supply a catalyst-inhibiting additive to a seal of the reactor circulation pump and a seal flush system configured to generate a seal flush mixture and supply the seal flush mixture to the seal of the reactor circulation pump.