| Autor: |
Rudenko, O., Voyevodin, V., Gozhenko, S., Mischenko, P. |
| Předmět: |
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| Zdroj: |
Proceedings of Odessa Polytechnic University / Odes'kyi Politechnichnyi Universytet Pratsi; 2019, Vol. 57 Issue 1, p52-64, 13p |
| Abstrakt: |
Integrity of the reactor pressure vessel is a critical element in demonstrating the capability of nuclear power plant for operation to at least 80 years. Long-term exploitation of materials at elevated temperatures is manifested in a loss of ductility and a marked shift in the interval from ductile fracture to brittle transition to higher temperatures. Embrittlement of the VVER reactor vessel is associated with many factors that result from prolonged operation. Radiation embrittlement is a key factor that determines the operational long-term of any reactor pressure vessel (RPV). Given that VVERs were intended to operate for 40 years, there are issues that need to be addressed to reduce the uncertainties in regulatory application. Existing approaches in the nuclear power industry of Ukraine to assess the fracture toughness of the irradiated materials of pressure vessel are based on empirical correlations between the parameters of crack resistance and impact strength which leads to a reassessment of the long-term safe operation of RPV. VVER reactors long-term operation require accurate predictions increases in the ductile-brittle transition temperature (ΔTK) of reactor pressure vessel steels of neutron irradiation-induced that are outside the existing database. For example, the neutron dose in RPV will be at least doubled. Associated with this factor are uncertainties regarding flux effects, effects of relatively high nickel content, uncertainties regarding application of fracture mechanics and thermal annealing. In this paper, it is proposed to conduct a research of the metal on fracture toughness, directly obtained from the reactor pressure vessel, in order to study the ΔTK prediction on operating time, irradiation, temperature and number of start/stop cycles when testing sub-sized specimens. To date experimental methods of fracture mechanics allow the directly to determine the properties of materials through the testing of sub-size specimens, which allows to determine long-term of RPV. In NSC KIPT have been developed the equipment, methodology and experience, which allows obtaining additional information in the analysis of the state metal of the equipment, which has been in long-term operation. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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