Regional Basic Professional Training Course in Korea

Regional Basic Professional Training Course (BPTC) on Nuclear Safety
(2) the consequences of failure to perform its function;
(3) the probability that the item will be called upon to perform a safety function;
(4) the time following a PIE at which, or the period throughout which, it will be called
upon to operate.
Appropriately designed interfaces shall be provided between structures, systems and
components of different classes to ensure that any failure in a system classified in a lower
class will not propagate to a system classified in a higher class.
At chapter 3. IAEA SAFETY GUIDE, NS‐G‐1.2 “Safety Assessment and Verification for
Nuclear Power Plants” [6.2], Safety Classification of Structures, Systems and
Components is explained as follows:
The importance to safety of all SSCs should be established and a safety classification
system as defined in Ref. [6.1] should be set up in order to identify for each safety class:
- The appropriate codes and standards, and hence the appropriate provisions to be
applied in design, manufacturing, construction and inspection of a component;
- System related characteristics like degree of redundancy, need for emergency power
supply and for qualification to environmental conditions;
- The availability or unavailability status of systems for PIEs to be considered in
deterministic safety analysis;
- QA provisions.
In general, the following classifications should be established and should be verified for
adequacy and consistency:
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