Commentaries: Art. 123

The licence holder must adopt appropriate measures to prevent failures.
The enterprise must be designed in such a way that the following requirements are met:
1. For failures with an expected frequency of more than 10^-1per year, it must be possible for the source-related dose constraints specified in the licence to be complied with.
2. For failures with an expected frequency of between 10^–1and 10^–2per year, a single such event must not lead to an additional dose which exceeds the relevant source-related dose constraints.
3. For failures with an expected frequency of between 10^-²and 10^-⁴per year, the dose resulting from a single such event for members of the public must not be greater than 1 mSv.
4. For failures with an expected frequency of between 10^-⁴and 10^-⁶per year, the dose resulting from a single such event for members of the public must not be greater than 100 mSv; the licensing authority may specify a lower dose in individual cases.
The enterprise must be designed in such a way that only a small number of failures as specified in paragraph 2 letters c or d can occur.
For failures as specified in paragraph 2 letters c and d and for failures which have an expected frequency of less than 10^-⁶per year, but which could have major impacts, the supervisory authority shall require the enterprise to adopt the necessary preparedness measures.
The supervisory authority shall specify on a case-by-case basis the methodology and boundary conditions for the analysis of failures and for their assignment to the frequency classes specified in paragraph 2 letters b–d. The effective dose or the equivalent doses arising from failure-related exposure of persons must be determined in accordance with the current state of science and technology, using the assessment quantities and dose coefficients specified in Annexes 3, 5 and 6.
For enterprises where failures as specified in paragraph 2 letter d may occur, the supervisory authority may order:
1. the measurement of installation parameters which are required to monitor the course of an accident, to produce diagnoses and forecasts, and to determine the measures necessary to protect the public;
2. the continuous transmission of the installation parameters to the supervisory authorities via a network tolerant of an failure.