Fuel element inspection and repair

The system detecting failed rods uses an ultrasonic technique to detect the water penetrating into failed fuel rods. It is equipped with an ultrasonic probe and a mechanical system moving the probe continuously through the channels of the fuel element. The measuring system, on which experience has been accumulated over the past three years during various applications in pressurized water and boiling water reactors, has so far been used to examine fuel elements with burnups up to 35,000 MWd/te U. The fuel element repair station specially developed for this unit allows the fuel element under repair to be lifted, tilted and lowered again. The compact, functional design of the station, which minimizes space requirements in the fuel storage pool, is one way of reducing repair times. Also other core components can be inspected and repaired in the repair station. (orig.)