Conformity assessment data model

Conformity assessment of nuclear power plant systems, including qualification of subsystems and components is conventionally done based on a set of engineering and conformity assessment documents. Model-based systems engineering provides a more structured set of artefacts, not only for the design work, but also for the conformity assessment. In this report we present a structured data model for the conformity assessment artefacts. The data model covers both the first party conformity assessment, traditionally known as verification and validation, as well as the third party conformity assessment, i.e. the attestation (qualification or certification). The data model is demonstrated in a Defence-in-Depth example of a spent fuel cooling control system. Before carrying out the demonstration, the claim hierarchy in accordance with the DiD requirements is discussed. The diversity requirement is selected for the example case. Our demonstration verifies the applicability of our conformity assessment data model to a case that reflects a real case. The data model provides good traceability of artefacts ranging from the stakeholder domain to the organisation that designs the system and finally to the attestation organisation. With a proper tool, impact analysis can be carried out. Compared to traditional document based conformity assessment process, our data model has a good chance to be accepted by engineers if a good computer tool is available that hides the complexity of the data model and guides the users to put the engineering artefacts to correct locations and to establish the traces between the artefacts.