NLOOP

NLOOP is the KWU standard best estimate code for PWR design, licensing and operational monitoring in the fields of transient analysis and real-time simulation. It is a quick and versatile analytical tool which simulates plant response to a wide range of non-LOCA events including ATWS and to very small LOCA events. The code contains models for all major components of the primary and secondary side, for important auxiliary systems and for the essential control, limitation, protection and interlock systems. Thanks to its versatility, NLOOP can be adapted not only to different KWU plants but also to non-KWU plants. This was demonstrated by the verification of the model of a Westinghouse plant (Ringhals-2, Sweden). An accelerated interactive version of NLOOP is in use as a real-time simulation code at the KWU Nuclear Plant Analyzer for personnel training, operational support and accident management