The concept of defense in depth is a key factor for the safety of nuclear power plants.
Beginning during construction of the first nuclear power plant, the associated core principles were applied and continuously developed based on international operating experience.
The reactor pressure vessel is enclosed by the containment as the third barrier. This consists of a steel primary containment and a concrete secondary containment.
With its pipelines, shut-off valves and other components, the cooling circuit, together with the reactor pressure vessel, is the second barrier for trapping radioactive substances
The reactor pressure vessel, together with the water’s cooling circuit, is the second barrier for trapping radioactive substances.
The fuel pellets are filled into metal tubes. Together with the nuclear fuel matrix, the cladding tubes are the first barrier for trapping radioactive substances in nuclear power plants.
The nuclear fuel is pressed into pellets and compacted using the sintering process before use in nuclear power plants. This process transforms the nuclear fuel into a ceramic material, which is able to retain the fission products that arise during operation in the nuclear fuel matrix.
The barrier concept aims to trap sources of radiation in nuclear facilities across several levels. Similar to the layers of an onion, independent barriers ensure that the risk from sources of radiation are minimised for people and the environment.
