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After final shut down of a nuclear facility preparatory works for decommissioning are carried out during the post operational phase. The following decommissioning requires a comprehensive licensing process which
includes an environmental impact assessment as well as aspects of
radiological protection. Not only nuclear power plants have to be decommissioned at the end of
their operating time, but also other kinds of nuclear facilities being
licensed under § 7 of the Atomic Energy Act, such as prototype or
research reactors and nuclear fuel cycle facilities. Depending on type
and purpose of the facility there can be a broad variance in type and
amount of the respective contamination. BfS provides tables, where
German nuclear reactors and facilities in operation and in
decommissioning are listed. Contamination and activation
Each facility or plant, which came into contact with
radioactive material, is contaminated with this material afterwards to a
greater or lesser extent, i.e. residues of this material are found on
surfaces, in tanks, tubing, etc. These contaminations can be removed by
adequate decontamination measures. That means, the contaminated surface is mechanically or chemically
removed. If this process is successful, the bulk material can be
released from regulatory control. It is handled as non-radioactive material henceforth and only the
removed surface layer has to be disposed of as radioactive waste.
Decommissioning strategies
There are several decommissioning strategies. Facilities can be
dismantled directly or kept under almost maintenance-free conditions for
several years (safe enclosure). The latter is done to reduce radiation levels by radioactive decay. In Germany a large number of power and prototype reactors, research reactors, and nuclear fuel cycle facilities have already been decommissioned. Several facilities have already been dismantled completely, i. e. the plants were demolished and the sites were released and recultivated. Practical experience with decommissioning is available. In the Atomic Energy Act (AtG) individually allocated electricity volumes have been laid down for each operating power reactor in Germany. After production of this electricity volume the operating licence for the respective power reactor will expire. Since August 2011 the Atomic Energy Act specifies individual latest shut-down dates for all power reactors. This results in the step-wise shut-down of all German power reactors and their subsequent decommissioning. Decommissioning guideline
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