Equipment deemed non-replaceable
Long Term Operation of Nuclear Power Plants

The reactor vessel is the component that contains the reactor core. It forms part of the main primary circuit, the second containment barrier for radioactive materials. Maintaining its integrity is therefore an essential objective, all the more so as its replacement is difficult to envisage.

This is a cylindrical tank 10 m high and 4 m in diameter, closed by a bolted lid and fitted with 6 or 8 tubes. Its ferritic steel walls are around 200 mm thick...