Navigation and service

Nuclear safety

Nuclear Facilities - Reportable Events - Decommissioning - Nuclear Accidents

nuclear safety

On-site accident management measures

Briefly explained:

(Design basis) accidents …

... are possible technical failures and events that were investigated and assessed according to the state of science and technology at the time the licence for a nuclear installation was granted.

They can pose a risk to people and the environment. Reliable and effective precautionary measures must be taken against such events (design-basis accidents), which are considered during the licensing process, to ensure compliance with the specified radiation exposure limits.

Beyond-design basis accidents …

... are accidents beyond the possible technical failures and events considered during the licensing process (design-basis accidents). Beyond-design-basis accidents may necessitate the use of accident management measures.

In the case of hypothetical events that were not considered as a potential incident at the time the licence was granted, and which a nuclear facility is not designed to withstand, German nuclear facilities have on-site accident management measures in place.

On-site accident management comprises all technical and organisational measures taken within a nuclear facility to prevent or minimise the release of radioactive substances.

Responsibility lies with the operator of the nuclear facility

Since the 15th amendment to the Atomic Energy Act (AtG) in 2017, on-site accident management has been stipulated by Section 7c (3) AtG, and is the responsibility of the operator of the nuclear facility. Accident management relates to the plant itself. This is in contrast to external accident management, which includes all measures taken outside a nuclear facility, and which is carried out by state authorities, e.g. the disaster control authorities of the federal states. Further information on this can be found on the website of the Federal Office for Radiation Protection (BfS) under the heading "Responsibilities of the Federal Government, the states and operators in emergency radiological protection".

Measures for on-site accident management

On-site accident management includes all measures to detect beyond-design-basis accidents as early and safely as possible, to control them and to end them with as little damage as possible.

A distinction is made between

  • damage prevention (preventive) measures and
  • damage mitigation (mitigative) measures.

Manuals for accident management measures

Every nuclear power plant in Germany has an accident management manual. It describes the necessary organisational regulations as well as the measures to prevent and minimise damage that enable staff to act appropriately.

In addition to organisational, task and activity descriptions, it contains instructions, documents and tools needed to deal with a beyond-design-basis accident. These are pre-planned measures.

In addition to the accident management manual, there is also a handbook for mitigative accident management measures. This is a plant-specific guideline that supports the on-site emergency organisation in taking measures to limit damage in the event of accidents. The plant's internal emergency response team will use the handbook for mitigative accident management measures in the event of accidents or situations for which no accident management measures have been planned, or for which the implemented accident management measures would not be effective. This handbook primarily describes strategies to limit the release of radioactive substances.

Even though, in comparison, research reactors have a lower risk potential, they are subject to the same accident management requirements as nuclear power plants. The respective regulations and measures for research reactors are described to the necessary extent in corresponding manuals.

The risk of a possible release of radioactive substances is also present in nuclear fuel supply facilities, although their risk potential is lower than that of nuclear power plants. In addition to the radiological risk, the chemotoxic risk of uranium hexafluoride and hydrogen fluoride must also be considered when drawing up the plant's on-site accident management plans. The plant operators must develop suitable measures to contain the radiological and chemotoxic risks, and submit these plans to the responsible nuclear supervisory authorities for assessment.

Accident management measures for decommissioned installations

Measures for plant-specific accident management and on-site accident management must also be taken for decommissioned plants. The existing regulations stipulated in the accident management manual are normally adopted for the remaining operation and dismantling of a plant.

However, as the dismantling measures in the respective decommissioning project progress, the prevailing conditions (e.g. activity inventory) and the resulting possible event sequences will change, meaning that the regulations will be reviewed on an ad hoc basis and at regular intervals to reflect these changed requirements. Necessary adjustments to the relevant circumstances of the decommissioning project, including the partial or even complete abolishment of the accident management manual, are subject to the change management regime.

State of 2023.12.20

© Federal Office for the Safety of Nuclear Waste Management