Analysis of existing thermal-hydraulic analysis methodologies in the framework of resource extension of reactor pressure vessels
DOI:
https://doi.org/10.15276/opu.3.56.2018.04Keywords:
lifetime extension, reactor vessel, thermal hydraulic analysis, thermal shock, methodAbstract
At the moment, Ukraine and a number of other countries are implementing a program to extend the
operation of nuclear power plants beyond the design period. This is economically advantageous, since the level of capital expenditures
required for this is much lower than with the construction of new power units. Special attention is paid to assessing the technical condition
and extending the operation of the reactor vessel, since the vessel is the most expensive and complex element in terms of manufacturing and
replacement. For this assessment, in particular for thermal analysis, in the world special techniques are applied. In this paper, we analyze the
main existing methods of thermal-hydraulic analysis used in Ukraine and the world, in order to determine their relevance in relation to the
specifics and current state of Ukrainian NPP units. Ways of optimizing thermal-hydraulic analysis are outlined, in particular, due to a
reasonable reduction in the number of considered scenarios. The scientific and practical value of this work lies in the fact that the identified
deficiencies in existing methods, taking into account practical experience, will allow developing a current methodology that will allow you to
focus on a deeper study of representative accident scenarios and will be applicable for the thermal-hydraulic analysis of Ukrainian NPPs,
taking into account the current domestic experience. The research methodology consists in the analysis of existing methods with an
appropriate assessment of their applicability and relevance for NPPs of Ukraine, as well as taking into account the practice of performing
thermal hydraulic analysis when extending the life of domestic NPPs. The study led to the conclusion that the practice of performing
thermal–hydraulic analysis in Ukraine is ahead of theoretical knowledge, international and domestic early experience. Thus, domestic
methods require updating and improvement and can be applied as part of work to extend the operation of Ukrainian NPPs for which the
relevant work has not yet begun, as well as when renewing.
Downloads
References
Guidelines on pressurized thermal shock analysis for WWER Nuclear Power Plants. IAEA-EBPWWER-08 (Rev. 1). 200). IAEA. Vienna. 73 p.
Unified procedure for lifetime assessment of components and piping in VVER NPPS “VERLIFE”. 2008. ÚJV Řež, a. s. Řež. 279 p.
Pressurized Thermal Shock in Nuclear Power Plants: Good Practices for Assessment. Deterministic Evaluation for the Integrity of Reactor Pressure Vessel. IAEA-TECDOC-1627. 2010. IAEA. Vienna. 229 p.
Методика розрахунку на опір крихкому руйнуванню корпусів реакторів АЕС з ВВЕР під час експлуатації (МРКР-СХР-2004). РД ЭО 0606-2005. 2004. Концерн «РОСЕНЕРГОАТОМ». Москва. 65 с.
Методика оцінки міцності і ресурсу корпусів реакторів ВВЕР в процесі експлуатації. МТД.0.03.391-09. 2012. ДП “НАЕК “Енергоатом”. Київ. 66 с.
Thermal-Hydraulic Evaluation of Pressurized Thermal Shock. NUREG-1809. 2005. US NRC. Washington. 333 p.
Technical Basis for Revision of the Pressurized Thermal Shock (PTS) Screening Limit in the PTS Rule (10 CFR 50.61). NUREG-1806. 2007. US NRC. Washington. 339 p.
Kral P., Vyskocil L. Thermal Hydraulic Analyses for PTS Evaluation: Comparison of Temperature Fields at RPV Predicted by System TH Code and CFD Code. ICONE26-81007 . 26th International Conference on Nuclear Engineering. Volume 6A: Thermal-Hydraulics and Safety Analyses. London, England, 2018. 11 p.
Höhne T., Kliem S., Bieder U. IAEA CRP benchmark of ROCOM PTS test case for the use of CFD in reactor design using the CFD-Codes ANSYS CFX and TrioCFD. Nuclear Engineering and Design. 2018. Vol. 333. P. 161–180.
Willemsen S., Koem E. Assessment of rans CFD modelling for pressurised thermal shock. The 11th International Topical Meeting on Nuclear Thermal-Hydraulics (NURETH-11). Paper 121. 2005. 15 p.
Lucas D., Bestion D. On the simulation of two-phase flow pressurized thermal shock (PTS). The 12th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-12). Paper 35. 2007. 22 p.
PRA Procedures and Uncertainty for PTS Analysis. NUREG/CR-6859. 2010. US NRC. Washington. 39 p.
Pištora P., Pošta M., Lauerova D. Probabilistic assessment of pressurised thermal shocks. Nuclear Engineering and Design. 2014. Vol. 269. P. 165–170.
Ориняк І., Батура А., Дубик Я. Визначення залишкового ресурсу корпусів реакторів відповідно до критеріїв опору крихкому руйнуванню на основі методів лінійної та нелінійної механіки руйнування. Збірник доповідей 5-ї Міжнародної «науково-Практичної Конференції «Безпека та Еффективність Атомної Енергетики». ДП “НАЕК “Енергоатом”. Одеса. 2016. С. 76–85.
Oryniak A., Radchenko S., Orynyak I. The Brittle Strength Assessment of WWER-1000 Reactor Pressure Vessel Nozzle With Cladding. Procceding of the ASME 2013 Pressure Vessels and Piping Conference PVP2013. Paper PVP2013-97561. 2013. 11 p.
