Funky, the english Wikipedia page. It says that the German pebble bed reactor was abandoned due to 'political and economic' reasons.
The truth can be read in the German version of the article, it simply did not work problem free. It is also mentioned further down in the English article. The German article about this specific reactor, the THTR-300, goes into detail.
The pebbles were breaking. The concrete got too hot. The reactor got too hot in its center. Taking out pebbles could only be done when he reactor was running with reduced power. It also had an accident where the reactor was leaking radioactivity.
All in all the handling of the pebbles had many ugly surprises for pebble bed reactor designers. They were breaking at a rate of 1000 higher than expected.
The German pebble-bed was built in 1983 and shut down in 1989. Pebble bed reactor designers have had 21 years to improve on that design, and they've not been idle. All real nuclear reactors have problems before you've had time to work out the bugs in the design. They're big, complicated machines, and they have to meet some pretty stringent engineering specs.
The German THTR-300 was the first attempt to build a full-scale pebble bed reactor, after they'd run just one smaller research reactor. Problems with the design are to be expected. That's not an indictment of pebble bed reactor designs; that's just how nuclear engineering works. I'm glad that the pebble bed guys are finally picking themselves off the floor and continuing on with the Chinese HTR-PM reactors, which were designed to avoid the problems which plagued the THTR-300.
The truth can be read in the German version of the article, it simply did not work problem free. It is also mentioned further down in the English article. The German article about this specific reactor, the THTR-300, goes into detail.
The pebbles were breaking. The concrete got too hot. The reactor got too hot in its center. Taking out pebbles could only be done when he reactor was running with reduced power. It also had an accident where the reactor was leaking radioactivity.
All in all the handling of the pebbles had many ugly surprises for pebble bed reactor designers. They were breaking at a rate of 1000 higher than expected.