Organically moderated and cooled reactor

An organic moderated and cooled reactor (English organically moderated and cooled reactor, OCR, also organic moderated reactor experiment, Omre ) is a type of nuclear reactor in which an organic substance as a coolant and moderator is used. In all previously built reactors of this type, a mixture of biphenyl and terphenyl was used. Basically, however, any hydrocarbon can be used, because they are composed of the elements carbon and hydrogen, which are both very good moderate neutrons. For example, Otto Hahn, used in the discovery of nuclear fission a block of paraffin as a moderator.

The structure of organic moderated and cooled reactor essentially corresponds to a pressurized water reactor: in a large reactor fuel elements are numerous, bathed by the organic coolant. In the fuel rods, the nuclear chain reaction takes place. The liberated heat is removed by the coolant. In a heat exchanger, the organic coolant transfers its energy to the water, which evaporates. The steam drives turbine, in turn, a generator which generates the electricity.

Disadvantages

In addition to the known dangers of all nuclear power plants have organic moderated and cooled reactors mainly one major drawback: the high temperatures in the vicinity of the fuel rods, the coolant is cracked over time. This process is favored by the strong radioactivity ( radiolysis ). This differs to the fuel elements, elemental carbon (soot ) from, why they need to be cleaned very complicated from time to time.

Assembled units

To date, only a few reactors of this type have been built, and in the foreseeable future, no new buildings will be made. The following list four examples:

• Type of reactor