Understanding Capacity Factor Improvement at Nuclear Power Plants

Over the past two decades, nuclear power plants have achieved increasingly higher capacity factors with the same or greater levels of safety. The average capacity factor for U.S. plants in operation in 1980 was 56.3 percent; in 1990, 66 percent; and in 2007, 91.8 percent.

A 1994 analysis as the capacity factors were being improved provides some insight.

Costs went up in the 1980’s because regulations doubled staffing.
Management improved, best practices were shared and technology improvements were made to reduce outages.

-demineralized resins to increase heat exchanger life
-erosion/corrision control and monitoring
-improved steam generator chemistry to prolong steam generator life
-improved motor operated valves

Capacity Factors in 2001

Production costs are driven to a large degree by capacity factors. The following observations can be made:

* Countries already at the top of the capacity factor league table – Finland, Germany, Belgium and Spain – are holding steady at around 90% or above.

* US capacity factors are now pushing up towards the best of the European fleet.

* The US capacity factor improvement in the 1990s has added the equivalent of 23 1000 MWe plants to the grid.

* Russian and Ukrainian reactors have made noteworthy output improvements.

French capacity factors continue to be lower than technical and operational standards would indicate, due to the surplus nuclear capacity in France and the limitations on exporting the surplus to neighbouring countries.

Ukraine had capacity factor improvement program with the US. Learn international best practices and procedures.

So higher capacity factor reasons- better components and the whole industry learning and sharing the best way to run things. So unless your reactor design limits what you can do then getting to 85% is definitely doable and that is why 90% is the average.

There was learning but the whole industry learned. Plus there was the spread of quality management programs throughout business.
There was also component improvement as noted. Just as there has been improvement in the quality and life of components in cars and TVs since the 70s and 80s.

The history of car warranties

1967 2 years and 24000 miles
1970 reduced back to 1 year and 12000 miles
1981 2 years and 24000 miles, chrysler 5 years and 50,000 miles
1987 3 years/unlimited miles to 6 year/60,000 miles
2003 up to 10 year/100000 miles avg 4.7 years 55,000 miles

A modern/new nuclear plant does not have to relearn the wheel and all of its people and management are not starting with a blank slate and 1975 tech and practices.