2000 load factors analysed by NSSS vendors

30 May 2001

The NEI tables of nuclear plant load factors to the end of December 2000 were published in the May 2001 issue. In this article, a further analysis of performance is presented for the principal nuclear unit vendors.

The annual load factor averages to the end of December 2000 are presented in the following tables in four main categories, PWRs, BWRs, PHWRs and “others”, according to the original vendors. The “others” include the UK Magnox and the Russian RBMK units, since the chance of any of these ever being ordered again has long passed. So, except for Magnox units, the figures include all units covered by the regular quarterly tables in Nuclear Engineering International for all vendors with four or more units in operation around the world for over one year as at the end December 2000. Since there are only two fast reactors, these do not appear. The table this year also regrettably had to exclude the six Bulgarian units and two units at Nine Mile Point in the USA for which data was not available.

A total of 13 three-year periods have elapsed since the first commercial nuclear power station began operation, and over that time nuclear units have come on-stream at a growing, then declining rate, reaching a peak in the 1986/88 period. The three years just ended show the first exception to the trends indicated in the small table below. Coinciding with the murmurs suggesting that controversial new energy policies may be emerging from the White House, could it be that this thirteenth triennial net total of units coming into service – that is, increasing the total number in operation around the world – marks the reversal of fortunes for nuclear power? The rapidly approaching shutdowns for the remaining Magnox units will take some offsetting! As before, in the tables where a particular category of units has been blessed with a minimum load factor of zero, the minimum quoted is the lowest achievement exceeding zero, and is marked with an asterisk. The zero does appear, however, in the table lines summing up “all” unit sizes.

Most of Framatome’s units are operating in France under the peculiar conditions of supplying nearly 80% of the nation’s electricity, and so are involved in frequent significant load-following. During the calendar year 2000, these units reached almost exactly the same figures as in the previous year, with a slight improvement in lifetime maximums, averages and minima.

The same pattern was seen in the figures covering all the 393 qualifying units, virtually the same as the previous year even though the Russian and Ukrainian units appear in these tables for the first time this year. In these countries, the RBMK series of reactors, together with the AECL units in Canada were the poorest annual performances, but both series of reactors are suffering from the extensive work being carried out on them at present. Lifetime performances held up, and AECL also had the distinction of providing the world’s record annual load factor for 2000, with Wolsong 3.

Of all the major vendors, only the Westinghouse PWR designs seem to be still working best at the smaller end of the ratings range, as used to be observed more widely. Now the maturity of the largest units is clearly showing that in most cases the maximum reliability occurs in the years when the problems of youth have been solved and before the growing maintenance requirements of the older generation grows into significance. A bit like us all really.

Abbreviations and notes

Key to non-standard abbreviations: ABBA – ABB Atom; AEE – Atomenergoexport; C-E – ABB Combustion Engineering; DAE – Indian Department of Energy; FRA – Framatome; HIT – Hitachi; MHI – Mitsubishi Heavy Industries; MTM – Mintyazhmash; NNC – National Nuclear Co (UK); SKO – Skoda; TOS – Toshiba; WES – Westinghouse. Size ranges are S(malI) <600MWe; M(edium)<=1000MWe; L(arge) >1000MWe (gross ratings). Only vendors with a total of four or more units with over one year’s operation are included. If = load factor Where the minimum annual load factor of any unit in one vendor’s size range was zero, the next lowest above zero is shown, marked with an asterisk, but the figure in the “All” row (if applicable) remains as zero. The annual load factor figures plotted are averages for successive 12-month periods to the end of the quarter shown on the horizontal axis. The figures in parentheses are numbers of units in each category.


Changing number of operating units
Nuclear reactor performance by vendor: BWRs
Nuclear reactor performance by vendor: PWRs
Nuclear reactor performance by vendor: RBMKs
Nuclear reactor performance by vendor: PHWRs
Nuclear reactor performance by vendor: PHWRs
Nuclear reactor performance by vendors: all units in above tables

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