LOCA and pressure waves in the primary circuit of the reactor VVER-1000
28th Symposium of AER on VVER Reactor Physics and Reactor Safety (2018, Olomouc, Czechia)
Reactor dynamics and safety analysis
Consider the initial stage of the accident (first 0.5 sec.) caused by the rupture of one of the cold loops (D= 850 mm) of the primary circuit of the VVER-1000 reactor. Instantaneous rupture (0.0001 s) of the pipeline in the area between the reactor and the main circulation pump (MCP) with double-end expiration into the rupture. The produced pressure waves and their propagation in the equipment of the primary circuit of the installation are shown. The parameters of a typical reactor plant V-320 (VVER-1000) are used for the calculation, particularly, the 3rd unit of the Kalinin NPP. All initial data for the calculation were obtained from the data of the international standard problem Kalinin-3 [1-2]. The calculations were carried out using the computational best estimated code “ATHLET”, developed by the society for reactor safety (Gesellschaft für Anlagen-und Reaktorsicherheit-GRS), Germany 3 and certified in Russia for use in calculations to justify the safety of reactors with water coolant 4. The considered emergency is included in the list of different types of reports necessary for VVER safety justification 5. The obtained results can be used as boundary conditions for the analysis of equipment strength in this transition process.
1. V.A.Tereshonok, V.S. Stepanov, V.V. Ivchenkov, V.A. Pitilimov, S.P.Nikonov, Description of a Transient Caused by the Switching-off of One of the Four Operating MCP at Nominal Reactor Power at NPP Kalinin Unit 3, NEA/OECD, July 2008
2.V. A. Tereshonok, S.P. Nikonov, M. P. Lizorkin, K. Velkov, A. Pautz, K. Ivanov, International Benchmark for Coupled Codes and Uncertainty Analysis in Modelling: Switching-off of one of the four operating main circulation pumps at nominal power at NPP KALININ UNIT, 18th Symposium of AER on VVER Reactor Physics and Reactor Safety, Hungary, Eger, Oct. 6-10,2008
3. H. Austregesilo, H. Deitenbeck, A. Langenfeld, J. Scheuer, P. Schöffel, ATHLET 3.1A, Programmer Manual, March 2017
4. Аттестационный Паспорт Программного Средства №350 от 17.04.2014
5. Requirements to the content of the report on the safety justification of nuclear power Plants with a VVER type reactor (with Change № 1 from 20.12.2005.).