A preliminary analysis of consistency and applicability of the available transient data to the fatigue analyses has been performed, followed by a preliminary comparison of selected design and actual transients, where selected actual transients confirmed conservativity of design transients. The most probable difficulties with interpretation of transient data in fatigue analyses have been identified with special emphasis on coolant temperatures deduced form the measured temp. at the tube outside surface. Some approaches facilitating the reconstruction of the missing data are also highlighted.
F.14 Improvements to existing production methods and tools or processes
COBISS.SI-ID: 22545191The proposed method is characterized by balanced availability of data and complexity of the computational models utilized. The method is consistent with the ASME Code, which was utilized during the design of the Krško nuclear power plant. The method is intended to be used primarily as tool supporting the component replacement schedule and preventive maintenance of nuclear power plants. Another possible use is the independent verification of design analyses supporting the plant life extension. Finally, it design also assumed the possibility of future upgrades toward a tool for design analyses.
F.01 Acquisition of new practical knowledge, information and skills
COBISS.SI-ID: 22545703The implementation of the method for monitoring the usage of nuclear power plant is demonstrated with two pilot cases: the reactor pressure vessel outlet nozzle and pressurizer surge line. Comparison of calculated partial fatigue usage factors confirms the conservativity of plant design in case of the reactor pressure vessel outlet nozzle. Possible consequences of stratified flows and thermal shocks on the fatigue usage of the pressurizer surge line were also demonstrated.
F.14 Improvements to existing production methods and tools or processes
COBISS.SI-ID: 22545447