Irradiation Embrittlement of WWER RPV Steels Irradiated at High Fluences
DOI:
https://doi.org/10.21608/jntas.2020.34215.1023Keywords:
reactor pressure vessel, neutron fluence, irradiation embrittlementAbstract
A statistical analysis of data obtained during impact testing of surveillance specimen of 15 WWER-440 RPVs operating in Russia, Ukraine, Armenia, Hungary, the Czech Republic and Slovakia was performed. The raw data used were selected from the IAEA International Database. As a result of the analysis, the influence of P and Cu to Tk increase was observed at a fluence up to 5 x 10^20 cm^-2 (E > 0.5 MeV), more than double design end of life WWER-440 fluence value. A proposal to increase the application range of normative dependences ΔTk(F) on reactor pressure vessel from 3 x 10^20 cm^-2 to 5 x 10^20 cm^-2 has been prepared to amend the regulatory and technical documents regarding the adjustment of the residual life of WWER-440 RPVs. It will allow the WWER-440 RPV to be operated for 60-80 years without annealing the base metal and in some cases without annealing the irradiated welds.
References
PNAE G-7-002-86. (1989). Rules of strength calculation for equipment and pipelines of nuclear power plants. Energoatomizdat.
MT 1.2.1.15.0232-2014. (2014). Fracture toughness calculation for 65 years lifetime extension of WWER-440 RPV. Concern Rosenergoatom.
Amaev, A., Kryukov, A., Levit, V., & Sokolov, M. (1993). Radiation stability of VVER-440 vessel materials. ASTM Special Technical Publication, 1170(4), 9.
Alekseenko, N., Amaev, A., Gorynin, I., & Nikolaev, V. (1997). Radiation damage of nuclear power plant pressure vessel steel. American Nuclear Society.
Kryukov, A., Debarberis, L., Haehner, P., Gillemot, F., & Oszvald, F. (2012). Thermal annealing as a method to predict results of high irradiation temperature embrittlement. Journal of Nuclear Materials, 432, 501.
Fedotova, S., Kuleshova, E., Gurovich, B., Frolov, A., Maltsev, D., Zhuchkov, G., & Fedotov, I. (2018). APT studies of phase formation features in VVER-440 RPV weld and base metal in irradiation-annealing cycles. Journal of Nuclear Materials, 511, 30.
Kryukov, A., Sevikyan, G., Petrosyan, V., & Vardanyan, A. (2014). Irradiation embrittlement assessment and prediction of Armenian NPP reactor pressure vessel steels. Nuclear Engineering and Design, 272, 28.
Margolin, B., Yurchenko, E., Morozov, A., Pirogova, N., & Brumovsky, M. (2013). Analysis of a link of embrittlement mechanisms and neutron flux effect as applied to reactor pressure vessel materials of WWER. Journal of Nuclear Materials, 434, 347.
Gillemot, F. (1995). The IAEA database ageing of reactor pressure vessel steels and welds. IAEA Specialist Meeting on Irradiation Embrittlement and Mitigation, Espoo, Finland.
Downloads
Published
Issue
Section
License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
