EDN: KRGNYS
Authors & Affiliations
Akhmedov I.S., Kiselev A.E.
Nuclear Safety Institute, Russian Academy of Sciences, Moscow, Russia
Akhmedov I.S. – Research Engineer. Contacts: 52, Bolshaya Tulskaya st., Moscow, Russia, 115191. Tel.: +7 (495) 955-22-73; e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it..
Kiselev A.E. – Head of Department, Dr. Sci. (Tech.).
Abstract
Reflooding of the dried core of pressurized water reactors can have negative consequences for the explosion safety of NPP, which are expressed in the intensive generation of hydrogen. Therefore, it is necessary to justify the effectiveness application of reflooding in a severe accident with loss of coolant, which means to exclude the possibility of hydrogen explosion under the NPP containment. This paper presents the results of numerical research of a severe accident with guillotine rupture of the pressurizer surge line (two-side break Du346) in a VVER-1000 power unit using the SOCRAT code certified by Rostechnadzor. The analysis of the calculation results demonstrated that the current level of knowledge about the reflooding phenomenology and uncertainty of the hydrogen combustion criteria do not allow to exclude completely the increase of the severity class of the accident consequences according to the INES-2008 scale in case of water supply to the superheated core compared to a scenario without a reflood. Thus, the accident management measures considered in the paper are not always effective, and the decision on their implementation during a severe accident should take into account the current state of power unit.
Keywords
VVER, spray system, containment, reflooding, core, hydrogen, large break, severe accident, SOCRAT
Article Text (PDF, in Russian)
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UDC 621.039.586
Problems of Atomic Science and Technology. Series: Nuclear and Reactor Constants, 2024, no. 4, 4:15
