The long-term reduction in potential hazard of geologically stored nuclear wastes achievable by partitioning and transmutation (PT) of the actinides discharged from a mixed-oxide (MOX)-fueled light water reactor coupled to a MOX-fueled liquid-metal fast breeder reactor (LMFBR) is considered for three PT cases:1. 32 cycles of PT with plutonium sent to the repository at every cycle2 .same as item 1 with plutonium sent to the LMFBR as fuel3. PT cycles continued indefinitely.Cross-section and isotope inventory data are taken from the literature for similar facilities and processes and converted to an effective cycle-by-cycle burnup pattern. The effect of PT on potential population hazard into the indefinite future is evaluated on the basis of activity leached from the repository, transported by groundwater, and ingested. The calculation is carried out with two different sets of losses of actinides from facilities, one of which includes very small uranium and plutonium losses. The short-term fatalities expected due to accidents and operational releases are increased up to 67%. The decrease in long-term potential hazard with PT is minimal with the standard loss fractions. In the small loss set, the loss of uranium (which dominates the long-term hazard) is assumed to be very small. The factor of 25 reduction observed in this case is reduced to a factor of 3 when uranium is deleted from the tally. With uranium deleted, both loss fraction sets give the same long-term hazard reduction with PT.