Search - Number 12 - NEUTRON-PHYSICAL CHARACTERISTICS OF NUCLEAR DANGEROUS ACCUMULATIONS OF FUEL CONTAINED MATERIALS

NEUTRON-PHYSICAL CHARACTERISTICS OF NUCLEAR DANGEROUS ACCUMULATIONS OF FUEL CONTAINED MATERIALS
Cover not present NEUTRON-PHYSICAL CHARACTERISTICS OF NUCLEAR DANGEROUS ACCUMULATIONS OF FUEL CONTAINED MATERIALS
Category: Number 12
Publication: 12
Summary

Results of calculation of neutron-physical characteristics of a critical assembling (a fuel - a moderator - a reflector), geometry of which is inscribed into the real scopes of fusion penetration area of fundamental flag of the reactor shaft in south-east part of subreactor apartment 305/2 are given. The dynamics of development and self-quenching of neutron anomaly, which was registered in June, 1990 is analysed. It is shown that the anomaly was caused by a critical incident, acceleration and self-quenching of which were a result of water feeding to accumulation of fuel contained materials, hidden in a fusion penetration area. The version of "blast-furnace" process of formation of such accumulation is examined, at which as a result of interaction of fuel flux with the concrete of bed plate and " furnace charge" from the fragments of an active zone, an easy oxide layer (U < 5 % mas.) forms the horizontal stream of black lavalike fuel contained materials, and a heavy lower stratum (U > 50 % mas.) remains in the fusion penetration area and in case of water presence presents is nuclear dangerous.
Keywords: fuel contained materials, critical assembling, neutron anomaly, reactivity, criticality.