Calculation of Novovoronezh re-criticality experiment with CASMO/HEXBU code system
20th Symposium of AER on VVER Reactor Physics and Reactor Safety (2010, Hanasaari, Espoo, Finland)
Reactor physics experiment and code validation
Abstract
Reactor shut down margin is an important safety parameter. According to the Finnish regulations
recriticality is not allowed to occur in transient and accident cases after reactor scram. With the
Loviisa VVER-440 reactors the most limiting case is cooling in steam line brake accident in the
end of cycle with strong coolant temperature coefficient of reactivity. The reactor recriticality
temperature was measured in 1988 with Novovoronezh-4 end of cycle 15. The experiment was
used to validate our CASMO-4E and HEXBU-3D/mod6 calculation system. The results are
presented and discussed in this paper.