In any release of radioactive substances, the scale of the response depends on the distance from the plant and on prevailing weather conditions. In 2014, the German Commission on Radiological Protection (SSK) issued a Recommendation (in German). The area around operational nuclear power plants is divided into three planning areas (central zone, middle zone, outer zone). The middle and outer zones are then subdivided into 12 sectors. Beyond the outer zone, plans are also drawn up for the entire territory of the Federal Republic of Germany.
The central zone is a planning area in which preparations are to be made for specific civil protection measures outlined in the Basic Recommendations, mainly staying indoors (sheltering), distribution and intake of iodine tablets, and evacuation. The central zone extends up to approximately 5 kilometres from operational nuclear power plants.
Local conditions, such as terrain, settlement conditions and administrative structures, should be taken into account when determining the planning area. Measures in the central zone are especially urgent due to the proximity to the nuclear power plant. They are conducted regardless of the dispersion direction of radioactive substances. The measures for the central zone must be planned in such a way that, if possible, they can be implemented before any accidental release of radioactive substances. It should be possible to evacuate the entire population from the central zone within around six hours of the competent authorities being alerted. The measures to prepare thyroid blocking, i.e. the distribution of iodine tablets to all eligible persons, should be completed within the same time frame.
The middle zone surrounds the central zone, extending approximately 20 kilometres from operational nuclear power plants.
For this area, as with the central zone, measures to avert acute dangers to the lives and health of the public must be planned, taking account of local conditions. These measures primarily include sheltering, distribution and intake of iodine tablets, and evacuation. Measures in the middle zone can be implemented depending on the predicted or determined dispersion direction of the radioactive substances, if sufficient information is available to assess the radiological situation. Evacuation from the middle zone must be planned in such a way that it can be completed within 24 hours of the competent authorities being alerted. Arrangements for thyroid blocking, i.e. the distribution of iodine tablets to all eligible persons, should be set up within 12 hours.
The outer zone surrounds the middle zone. The outer limits of this planning area extend approximately 100 kilometres from operational nuclear power plants.
In this planning area – taking account of local conditions – it is necessary to plan measures to ascertain and monitor the radiological situation to determine whether there is a need for further interventions. In addition to monitoring programmes to ascertain the radiological situation, measures such as sheltering, distribution of iodine tablets to all persons eligible for thyroid blocking and warning the public not to eat freshly harvested food should be planned. Outer zone measures are generally implemented depending on the dispersion direction (predicted or ascertained through monitoring) of the radioactive substances
The competent authorities should make specific plans, for instance, for the following measures for the entire territory of the Federal Republic of Germany:
- implementation of monitoring programmes to ascertain the radiological situation,
- provision of iodine tablets to children, people under the age of 18 and to pregnant women for the purpose of thyroid blocking. Areas in the central and middle zones are subject to the regulations applicable to the planning of thyroid blocking.
In 2014, the German Commission on Radiological Protection (SSK) also issued recommendations on Planning Areas for Emergency Response near Decommissioned Nuclear Power Plants. Here, a distinction is made according to whether or not the irradiated fuel is still located within the power plant.
For nuclear power plants that have already been decommissioned, the existing planning zones – central, middle and outer – should be maintained, albeit as stipulated in the Basic Recommendations for Emergency Preparedness in the Vicinity of Nuclear Installations (2008). This means that, deviating from the distances specified in the SSK’s 2014 Recommendation, the radius for the central zone, middle zone and outer zone is approximately 2 km, 10 km and 25 km, respectively. The distant (or remote) zone, defined in the SSK’s 2008 Recommendation, located beyond the outer zone and stretching to a radius of roughly 100 km from the plant, is no longer relevant. In addition, the SSK has adopted a Recommendation on Planning Iodine Thyroid Blocking in the Vicinity of Decommissioned Nuclear Power Plants (2014). According to this Recommendation, the planning of iodine thyroid blocking no longer needs to be maintained in the vicinity of nuclear power plants that were permanently decommissioned by 2011.
For nuclear power plants which are scheduled for future decommissioning, the German Commission on Radiological Protection (SSK) recommends that as with operational facilities, the planning areas should be maintained as long as the fuel is present at the site. If fuel is still present three years after the last day of the shutdown, the Recommendations for decommissioned plants, mentioned above, should apply. With regard to the planning of thyroid blocking, the Commission recommends that this should continue for one year after the last day of the shutdown.
For nuclear power plants scheduled for decommissioning and located in another country near the border with Germany, the possibility of applying the Recommendations applicable to German installations should be discussed with that country’s competent authorities, with a particular focus on planning zones on German territory.