The basic design includes: physical calculations; thermohydraulic calculations; designbasis justification of equipment strength. System-oriented and construction-oriented approaches are used during design and engineering to ensure the reliability of systems. System-oriented approaches include: analysis of prototypes; creation of systems with the minimum necessary number of components, use of redundancy,
development of systems that do not allow the dangerous impacts of failure on their components (fail-safe design), optimization of the sequence of systems’ element operation, preliminary calculations of the system under development reliability. This takes into account: R&D results; reference data from other nuclear facilities; aging materials and mechanisms. Aging management program is created during design and operation of a nuclear facility.