Optimized Capacity: Global Trends and Issues 

2014 edition

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This report draws upon data collected in the International Atomic Energy Agency’s (IAEA) Power Reactor Information Service database to present a snapshot of the performance of the world’s operating nuclear power reactors as well as a breakdown of the principal causes of capacity loss for the period 2010-2012.

While the idling of the Japanese fleet resulted in a decrease of the global average capacity factor to 72% in 2012 (down from 77% in 2010) the global median capacity factor remains at about 84%. There is however a range of performance levels around that median with a long tail of reactors showing
clear potential for improvement. Best performing units still regularly achieve greater than 90% – an industry benchmark. The potential for >90% capacity factors does not appear to be limited by reactor age and can be achieved by any of the major reactor types. This serves as testimony to the general
robustness of existing nuclear technology and the commitment of the organizations involved.

The main findings of the report include:

• The vast majority of energy loss is within plant management control.
• Combined maintenance and refuelling outages are the single biggest cause of planned energy loss. Improving outage performance is key to achieving a high capacity factor.
• Best performing nuclear units manage to minimize scrams and achieve both productivity and safety.
• A strong safety record is a pre-requisite to a high capacity factor.
• An increasing number of plants have been put into long-term shutdown for regulatory reasons or because of component issues related to upgrades.
Preventing similar occurrences is an industry-wide priority.
• Regardless of plant performance, policy and market forces have led to premature retirements in certain countries, and are putting other units under pressure. Action is needed to prevent the further loss of clean, reliable and low-cost nuclear energy in these places.