An investigation of transient boiling heat transfer and burnout caused by exponential heat generation rate to a ribbon heater in a pool of water at atmospheric pressure was carried out. It was confirmed that transient nucleate boiling can exist beyond stationary burnout heat flux. The transient DNB and critical heat fluxes were expressed as functions of the exponential period. The life of quasi-stationary nucleate boiling was defined and measured. An attempt was made to show the dynamic expression of transient burnout caused by any waveform of heat generation rate.