Thermal hydraulic analysis for upgradation of Pakistan Research Reactor-1 from 9 to 10 MW

Thermal hydraulic aspects of Pakistan Research Reactor-1 have been studied to upgrade its power level from 9 to 10 MW. Standard computer codes and correlations were used to compute: pressure drop and flow through different channels of the core, coolant critical velocity beyond which fuel plates may collapse, temperature distribution in the core, heat fluxes at onset of nucleate boiling, onset of flow instability and departure from nucleate boiling. Natural convection cooling at low power was also analyzed. Results indicate that the cores have reasonably high safety margins and reactor power can be upgraded to 10 MW without compromising on reactor safety. (author)