Loss of feedwater accident simulation in VVER 1000 using APROS
Bawołek, Magdalena Małgorzata (2023)
Diplomityö
2023
School of Energy Systems, Energiatekniikka
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi-fe202401021044
https://urn.fi/URN:NBN:fi-fe202401021044
Tiivistelmä
The purpose of this thesis was to develop a model of the VVER1000 reactor in APROS, sufficient for Loss of Normal Feedwater (LONF) accident with combined Loos of Offsite Power (LOOP) analysis. The Loss of Normal Feedwater analysis is classified as an Anticipated Operational Occurrence (AOO) and as such is expected to happen at least once during a nuclear power plant's lifetime. Therefore, it has to be demonstrated that the LONF accident will not lead to further degradation of the power plant’s condition.
The conducted calculations confirm the VVER1000 reactor system's capability of sufficient energy removal from the Reactor Coolant System (RCS) throughout the transient. The acceptance criteria of not overpassing the design RCS pressure, main steam lines design pressure and maximum pressurizer level have been met during the whole simulation period.
Additionally, it has been concluded that APROS is capable of modeling the main components of the VVER1000 primary and secondary systems, as well as physical phenomena occurring in them during the simulated transient. At last, a need for further research on reverse flow in the VVER1000 primary system loops during LONF has been identified.
The conducted calculations confirm the VVER1000 reactor system's capability of sufficient energy removal from the Reactor Coolant System (RCS) throughout the transient. The acceptance criteria of not overpassing the design RCS pressure, main steam lines design pressure and maximum pressurizer level have been met during the whole simulation period.
Additionally, it has been concluded that APROS is capable of modeling the main components of the VVER1000 primary and secondary systems, as well as physical phenomena occurring in them during the simulated transient. At last, a need for further research on reverse flow in the VVER1000 primary system loops during LONF has been identified.