1Equipment qualification’ refers to the generation and maintenance of evidence to ensure that equipment will operate on demand, under specified service conditions, to meet system performance requirements.

2The term ‘qualified life’ is not used in all Member States. In some Member States, the term ‘qualification for the lifetime of the equipment’ serves the same purpose of demonstrating the capability of the equipment to perform its intended safety functions throughout its intended use period and in accident conditions.

3Examples of performance requirements include requirements for accuracy, resolution, range, sample rate and response time.

4In general, two levels of seismic vibratory ground motion hazard, SL-1 and SL-2, should be defined as the design basis earthquake for each nuclear installation. This is to ensure the safety of the nuclear installation in the event of a rare earthquake (i.e. SL-2) and to ensure the possibility of continued operation in the event of a less severe, but more probable, earthquake (i.e. SL-1). In some States, SL-2 corresponds to an earthquake level often denoted the ‘safe shutdown earthquake’. In some States, SL-1 corresponds to an earthquake level often denoted the ‘operating basis earthquake’.

5A ‘pre-existing item’ is an item that has been qualified in accordance with an industry standard for a similar application under similar or more severe service conditions.

6The Arrhenius ageing model is a simplified model characterizing the kinetics of chemical reactions (i.e. the degradation process), which predicts how the time taken to reach component failure varies with temperature. It assumes that short term thermal ageing at a high temperature results in the same degradation as long term ageing at a lower temperature.

7For example, see the equipment qualification programme described in Ref. [22].

8The ‘shelf life’ is the maximum time period between manufacturing and installation during which the equipment may be in storage prior to installation, so as to avoid the potential loss of important engineering properties.

9Paragraphs 4.23–4.31 of SSG-48 [13] and para. 7.8 of SSG-10 [14] provide recommendations on the integration and review of equipment qualification within the framework of the ageing management programme.