Influence of operational parameters on DPA in reactor pressure vessel of VVER-440 reactor

M. Stacho, G. Farkas, V. Slugeň, S. Sojak, Slovak University of Technology, Slovakia

20th Symposium of AER on VVER Reactor Physics and Reactor Safety (2010, Hanasaari, Espoo, Finland)
Reactor physics experiment and code validation

Abstract

One of the limiting factors in terms of nuclear power plant lifetime is the reactor pressure
vessel condition. The most important ageing effect on the reactor pressure vessel is the
embrittlement. Its radiation embrittlement cause especially fast neutrons. One of the
parameters describing the radiation damage is DPA (Displacement per Atom). In this work
we are focused on describing influence of operating parameters such as boric acid
concentration, control rod position, coolant temperature and burn-up on the neutron field and
DPA in the reactor pressure vessel of VVER-440/V-213 reactor. The calculation of DPA was
realized on detailed 3D model of reactor using MCNP5 code. The goal of this work is to
improve the assessment of the reactor pressure vessel degradation and following valuation
possibility of reactor lifetime extension.

Presentation / full paper