Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

Comparative Study of a Boron Dilution Scenario in VVER Reactors

Ivanov, K. N.; Grundmann, U.; Mittag, S.; Rohde, U.

Subsequent studies have identified many scenarios which can lead to reactivity excursions due to boron dilution. The comparative study, presented in this paper, deals with the so-called "restart of the first reactor coolant pump" scenario and its reactor-dynamic consequences for the both VVER reactor types - VVER-440 and VVER-1000. The transient simulations were performed using the three-dimensional core dynamics code DYN3D. The DYN3D modeling features, including recent developments, as well as the cross-section generation methodology, involved in these calculations, are described. The analyzed accident scenario is outlined together with the assumptions made. The results of core response in this boron dilution accident for both VVER reactors have been compared within ranges, determined by the two reactivity values of interest: the criticaly limit and the reactivity initiated accident (RIA) limit.

Keywords: VVER-reactors; boron dilution transient; three-dimensional core dynamics; reactivity initiated accidents; computer code DYN3D; group constants; cross section library; comparisons

  • Annals of Nuclear Energy 26 (1999) 1331-1339

Publ.-Id: 2044