What is meant by ‘plant uptime’?

Plant uptime refers to the percentage of time a nuclear power plant is operational and capable of generating electricity compared to the total time it is available. This metric is crucial for assessing the reliability and efficiency of the plant, as it indicates how often the plant is successfully producing power versus being offline for maintenance, repairs, or any other reasons.

High plant uptime is a desirable attribute as it indicates a well-maintained facility that can consistently deliver power to the grid, thereby maximizing the return on investment, minimizing fuel costs, and providing stable electricity supply. In the context of nuclear energy, which has significant capital and operational costs, maintaining a high uptime is essential for economic viability.

The other provided options do not accurately capture the essence of 'plant uptime.' The total number of personnel on-site reflects workforce capacity and not operational status, while routine inspection and maintenance times relate more to downtime planning rather than uptime directly. Lastly, annual power generation output, while related to operational efficiency, does not denote the time aspect of plant availability and is a measure of productivity rather than uptime.