Reactor pressure vessel

The reactor pressure vessel (RPV ) (also reactor vessel ) is a vessel in a nuclear power station in which the heat-generating reactor core is located with the fuel. He is one of several barriers that prevent the escape of radioactive materials (see safety of nuclear power plants ).

The reactor pressure vessel of modern light water reactor is a cylindrical steel vessel with a hemispherical bottom and lid, which is connected to the pipes for the coolant. In a pressurized water reactor (eg Neckarwestheim 2) it has a height of about twelve meters and an inner diameter of about five meters. Its thickness is 25 cm. In BWRs, the reactor pressure vessel are due to the concept even greater. The reactor pressure vessel containing the reactor core in particular with the fuel elements and designated as core components of structures which the fuel at its intended location fix (upper and lower core grid, fuel boxes, etc.). In a boiling water reactor, the reactor pressure vessel also contains a water / steam dryer, the water droplets - which could damage the turbine - separates from the generated steam and retains in the RPV. Refueling and maintenance work for the upper lid is lifted. The lid is connected to a number of pre-tensioned bolts and nuts to the pressure vessel lower part. Two O-rings as seals made ​​of silver are typically used. The largest reactor pressure vessel is used in nuclear power plants crumbs and has a height of 22.38 m, an inner diameter of 6.78 m and a wall thickness of up to 18 cm. The reactor pressure vessel of light water reactors has a remaining risk of bursting, which was declared to be irrelevant because of their insignificance, for example by Heinrich Mandel. The reactor pressure vessel is located, together with a radially surrounding it, about two meters thick reinforced concrete cylinder which serves as a radiation shield ( biological shield ), in the interior of the containment vessel.

For larger nuclear power plants with high temperature reactors (HTR ), a prestressed container was provided as the reactor pressure vessel in which a rupture is impossible. When nuclear power plant THTR -300 by Rudolf Schulten it was a pressure vessel made of prestressed concrete, which, however, was not satisfied with the operation. For future HTR nuclear power plants is therefore also thought about pre-stressed container made ​​of cast steel or ductile iron.