Recommended by Ali Hainoun One of the transients that have received considerable attention in the safety evaluation of RBMK reactors is the partial break of a group distribution header (GDH). The coolant ﬂow rate blockage in one GDH might lead to excessive heat-up of the pressure tubes and can result in multiple fuel channels (FC) ruptures. In this work, the GDH ﬂow blockage transient has been studied considering the Smolensk-3 RBMK NPP (nuclear power plant). In the RBMK, each GDH distributes coolant to 40–43 FC. To investigate the behavior of each FC belonging to the damaged GDH and to have a more realistic trend, one (aﬀected) GDH has been schematized with its forty-two FC, one by one. The calculations were performed using the 0-D NK (neutron kinetic) model of the RELAP5-3.3 stand-alone code. The results show that, during the event, the mass ﬂow rate is disturbed diﬀerently according to the power distribution established for each FC in the schematization. The start time of the oscillations in mass ﬂow rate depends strongly on the attributed power to each FC. It was also observed that, during the event, the fuel channels at higher thermal power values tend to undergo ﬁrst cladding rupture leaving the reactor to scram and safeguarding all the other FCs connected to the aﬀected GDH.
|Autori:||D'AURIA F.; LOMBARDI COSTA A; CHERUBINI M; GIANNOTTI W; MOSKALEV A|
|Titolo:||Thermal-Hydraulic Analysis of Coolant Flow Decrease in Fuel Channels of Smolensk-3 RBMK during GDH Blockage Event|
|Anno del prodotto:||2007|
|Appare nelle tipologie:||1.1 Articolo in rivista|