Generally, the operational schedule of an NPP is known significantly in advance by the TSO, thus easing the planning and scheduling for the whole electrical production system. Also, nuclear power plants are extremely reliable, with a very small unexpected outage rate (typically less than 0.5 trips per reactor-year in France) which reduces significantly the needs for balancing and the associated costs. In most cases, the nuclear system is able to continue producing power at a reduced level and feed the onsite electric support system.