[Vineyard]

Of course, a little research by the authors of the article, and they could have included a little tidbit:

One large-scale, 330-megawatt-electrical, HTGR has been built in the United States - the Fort St. Vrain reactor in Colorado. It was a commercial failure and was closed in 1989. It routinely faced operating problems and had a forced outage rate of over 60 percent. Its lifetime capacity factor was only 14.5 percent. Baseload power plants, like nuclear power plants, are normally designed to have capacity factors of 75 percent or more.

http://www.pharmaciaretirees.com/pebble_bed_reactors.htm

describes in great detail the High Temperature Modular Graphite Reactor (HTGR) - also known as the Pebble Bed Reactor.

Mike

[kidd]

Fort St. Vrain was not a pebble bed reactor, nor was it modular. It was a helium cooled reactor, though.

I believe that it was initially built as a demonstration unit. Commercially, it was a disaster.