Statistical Assessment of Operating Experiences of Power Reactors in France, Japan, and the United States

Statistical correlations for unavailability of power reactors across countries are sought. France, Japan and the United States, are selected because of their different political climates surrounding nuclear power through the 1990s. Outage data reveal that the dominating type of outage is different in each of the countries in spite of the similar plant types. In France, unplanned, externally caused, partial outages overwhelm other types of outages in number. In Japan, planned outages dominate in terms of number and duration. Unplanned outages are the major type in the U.S. These differences are not only due to technical differences but also to differences in economic and regulatory environments. Results of linear regression analyses suggest that unavailability factors are so random that country of operation, age of reactor and type of reactor cannot predict them well. This finding seems contrasting to an earlier study in the literature.