Accumulator batteries installed in electrical emergency power systems of NPPs are power storages that secure quality and continuity of power supply for safety important and other sensitive systems. Key important function and characteristic of batteries is discharging time for which are batteries able to supply consumers. Better knowledge and improvement (prolonging) of this capability has been accented as one of “Stress tests” measures.
This paper deals with conceptual design considerations and limitations related to battery system, comparison of discharging capabilities of various types of batteries, identification of typical power and safety requirements of consumers supplied form batteries. Next part of paper is focused on calculation and simulation methods of complex discharging load profiles targeted to determine realistic limits of discharging times.
Finally there are described and technically commented/evaluated various possibilities to prolong power supply of vital systems from batteries in really difficult accident situation of NPP. All above mentioned is based on ENERGOPROJEKT PRAHA design experience from NPPs in Czech Republic and Slovak Republic.
