Maximum operating power levels of the high power and equilibrium LEU cores for PARR-1 have been assessed. The criterion followed is that nucleate boiling should not commence at any point in the core, when reactor power approaches overpower limiting set point of 115% and simultaneously the coolant flow rate reduces low flow set point of 90%. Steady state operating conditions have been calculated for the assessed maximum power. These include coolant velocity distribution in the core, critical velocity, pressure drop, saturation temperature, temperature distribution in the core and margins to onset of nucleate boiling, onset of flow instability and departure from nucleate boiling. Cooling conditions for the end fuel plates have also been analyzed. (author).