Over the past 15 or more years of trying to talk to people in the nuclear industry about smaller power systems, I have frequently confronted with the "economy of scale" argument. When I try to explain that there are also "diseconomies of scale" that can make very large items more costly than an equivalent capability made up of a number of smaller items, the response is often some confusion. That is perhaps because the topic is not a common one in engineering economics courses or because some engineers just love designing the biggest items possible.

Yesterday, on Clean Skies TV's afternoon report, there was a segment on replacing steam generators at TMI Unit 1 that provides some pictures worth at least 1,000 of my words to explain just how diseconomies of scale work for very large items.



Note: If you watch the full edition of Clean Skies for October 12, 2009, you will see a contrast in stories that help explain why it is often frustrating for practically minded engineers interested in solutions to big energy supply problems to help people understand the scale of the challenge. Soon after showing the major movements of steam generators for a plant that provides all of the electricity needed for more than a million people, the show covered a technology that struggles to keep a single light burning. Speed bumps that generate power from cars traveling over them may be interesting, but they are irrelevant to the issue of combating energy supply challenges.