Classification of systems and components into safety classes and quality standard classes

On the basis of a meaningful classification of the systems for the entire plant, every system or component is allocated a safety class. Every allocation is based on the performance of a safety analysis in which the radiological effects of a component failure for plant personnel and the environment are evaluated. The subdivision into five safety classes is therefore also based on the related limit values of the Radiation Protection Ordinance. The HTR-500 metallic pressure vessel closure with simple cover head was selected as an example for the procedure for such a classification. (DG)