Search - Issue 30 - THE DYNAMICS OF NEUTRON ACTIVITY AND SUBCRITICALITY OF A NUCLEAR-DANGEROUS CLUSTER IN THE CONDITIONS OF NSC-SO COMPLEX

THE DYNAMICS OF NEUTRON ACTIVITY AND SUBCRITICALITY OF A NUCLEAR-DANGEROUS CLUSTER IN THE CONDITIONS OF NSC-SO COMPLEX
DOI: https://doi.org/10.31717/1813-3584.18.30.9
Cover not present THE DYNAMICS OF NEUTRON ACTIVITY AND SUBCRITICALITY OF A NUCLEAR-DANGEROUS CLUSTER IN THE CONDITIONS OF NSC-SO COMPLEX
Category: Issue 30
Publication: 30
Summary

It is presented the results of analysis and interpretation of monitoring of the dynamics of neutron activity of a potentially nuclear-dangerous cluster of fuel-containing materials (that located in zone of penetrating of concrete slab of the reactor's vault) before and after installation of the new secure confinement (NSC) "Arka". It is shown that the constant growth (after the installation of the NSC) of neutron activity accompanies the process of water's quit from the over-moist multiplying environment and accordingly the NFD increasing is a result of positive reactivity's introducing that can lead to recurrent criticality and self-sustaining chain reaction with unpredictable consequences. Based on the results of experimental data and model calculations, the effectiveness of neutron monitoring (at the detection points) was estimated. A forecast (regarding the further neutron activity) was also made and it was obtained the criteria for expert assessment of dangerous changes of the level of sub-criticality of this cluster of FCM.

Keywords: nuclear-dangerous cluster, neutron activity, self-sustaining chain reaction, fuel-containing materials, nuclear safety monitoring system.

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