SIMULATION OF CONTAINMENT HYDROGEN CONTROL SYSTEM ATIGNALINA NPP

摘要

Accident Localisation System (ALS) of Ignalina NPP is arn"pressure suppression" type confinement, which protects thernpopulation, employees and environment from the radiationrnhazards.rnAccording to the Safety Analysis Report for Ignalina NPPrn～110 m3 of hydrogen is released to ALS compartments duringrnthe Maximum Design Basis Accident. If the volumernconcentration of hydrogen in the compartment reaches 4 %,rnthere is a possibility for a combustible mixture to appear.rnTo prevent the possible hydrogen accumulation in the ALSrnof the Ignalina NPP during an accident the H2 control system isrninstalled.rnThe results of the performed analysis derived the places ofrnthe possible H2 accumulation in the ALS compartments duringrnthe transient processes and assessed the mixture combustibilityrnin these places for a maximum design basis accident scenario.rnSuch detailed analysis of H2 distribution in the ALS of IgnalinarnNPP was not performed before.