V. O. Posokh
SE “State Scientific Engineering Center for Control System and Emergency Response”, 64/56, Heroiv Stalinhrada ave., Kyiv, 04213, Ukraine
Approaches to taking into account the impact of power unit operating loads (normal operation, abnormal operation and emergency conditions) on the reactor support elements through interaction with the reactor vessel are described in the paper. The described approaches were first used in the calculations performed within justification of Khmelnytskyi nuclear power plant, Unit 1.
The approaches include two main steps.
At the first step the principle of calculating forces acting on the nozzles of the reactor vessel from the main coolant pipelines and the emergency core cooling system pipelines is provided. To obtain the needed forces, a 3D pipeline model is developed and then series of calculations with different input data (for the corresponding power unit operating loads) are provided.
At the second step the principle of recalculating the forces acting on the nozzles of the reactor vessel to the forces acting on reactor support elements by means of reactor beam model is shown. Reactor beam model accounts for reactor support elements, stiffness characteristics in horizontal, vertical and torsional directions which were preliminary determined.
These approaches allow to consider the impact of power unit operating loads on the reactor support elements through the interaction with the reactor vessel for further stress-strain state calculations required for the reactor support elements long term safe operation.
Keywords: reactor support elements, reactor vessel, lifetime extension, calculational substantiation of safe operation, power unit operating loads.
1. NP 306.099-2004. General requirements for the extension of the NPP unit’s operation beyond the design lifetime based on the results of periodic safety review. Kyiv: State Committee for Nuclear Regulation of Ukraine, 2004, 16 p. (in Ukr.)
2. Posokh V. O., Inyushev V. V., Kolyadyuk A. S., Dub-kovsky V. A. (2019). [Analysis of existing approaches to the calculated substantiation of the reactor support elements safe operation]. Nuclear Power and the Environment [Yaderna energetyka ta dovkillia], vol. 15, no. 3, pp. 36-41. (in Russ.)
3. PL-D.0.03.126-10. Regulation of the procedure for extending the life of equipment of systems important to safety. Kyiv, NNEGC “Energoatom”, 2010, 34 p. (in Russ.)
4. PM-D.0.03.222-14. Typical program for managing the aging of elements and structures of a nuclear power unit. Kyiv, NNEGC “Energoatom”, 2014, 60 p. (in Russ.)
5. PNAE G-7-002-86. Standards for strength calculation of equipment and pipelines of nuclear power plants [introduced with changes on 07/01/1987]. Moscow: Energoat-omizdat, 1989, 525 p. (in Russ.)
6. NP 306.2.208-2016. Requirements for seismic-resistant design and seismic safety assessment of nuclear power plant units. Kyiv: State Committee for Nuclear Regulation of Ukraine, 37 p. (in Ukr.)
7. RG-B.0.03.179-13. Typical technological regulation for safe operation of NPP units with VVER-1000 reactors. Kyiv, NNEGC “Energoatom”, 2014, 257 p. (in Russ.)
8. Posokh V. O., Vasilchenko V. M., Kolyadyuk A. S., Dub-kovsky V. O. (2019). [Determination of stiffness characteristics for VVER-1000 support components]. Yaderna ta ra-diatsiina bezpeka [Nuclear and Radiation Safety], vol. 84, no. 4, pp. 12-17. (in Ukr.)
If the article is accepted for publication in the journal «Industrial Heat Engineering» the author must sign an agreement on transfer of copyright. The agreement is sent to the postal (original) or e-mail address (scanned copy) of the journal editions.
Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License International CC-BY that allows others to share the work with an acknowledgement of the work’s authorship and initial publication in this journal.