According to an Agence France-Presse story carried today in the Inquirer News:
A reactor at the world’s oldest functioning nuclear plant, in Beznau, Switzerland, has been temporarily shut down because of a problem with its main pump, its operator Axpo said late Friday.
The halt at the Block 2 reactor is expected to last several days.
The Block 2 reactor at Beznau came online March 15, 1972. Block 1 at the same plant is the world’s oldest operating nuclear reactor, having started commercial operations on Christmas Eve, 1969.
Both reactors at Beznau use a percentage of mixed oxide fuel, a nuclear material that blends plutonium with either uranium, reprocessed uranium or depleted uranium.
Here’s a link to the Inquirer News article: http://newsinfo.inquirer.net/166659/faulty-swiss-nuclear-reactor-shut-down-for-repair