Table 1 lists nuclear units over 150 MWe in order of their achievements as measured by the load factors for the 365 days ending 31 December 1998. No data were available for Millstone 3 in the USA for the month of December, so an estimated figure was included for that month. Nuclear units in Russia and the Ukraine are listed separately in Tables 3 and 4. Availability for the same period is included in Table 1 where data were available, which, when availability considerably exceeds load factors, helps to indicate where nuclear units are producing less than full rated capacity due to load following requirements, particularly evident in the case of reactors in France.
The remarkable list of 100% plus figures for the top 9 units in Table 1 reflects the continuing improvement in nuclear unit performance, also seen in the growth of the top quartile of performance shown in Figure 1. It must be pointed out, however, that only the top 4 actually achieved 100% or more, the others being close enough to 100% that they benefited from the rounding of the second decimal place! Ikata 2 did not quite make it – by 0.01%. Kori 4 underwent an l p turbine rotor replacement at the end of the previous year which resulted in an uprating (similar work on the other Kori units also resulted in their uprating). Its result for the year clearly show the upgrade was justified.
The increasing number of US units in the top of the table is laudable: does this reflect the changes in the market restructure over recent years, or is it due to the closure of several units that were albatrosses in these tables?
Richard Knox
[Note: An error in the production of the end September 1998 figures (March 1999 issue) resulted in the wrong two units being listed in Table 2 (reactors that have not yet operated for one year).]