Nordic boiling water reactors (BWR) employ ex-vessel debris coolability as a severe accident management (SAM) strategy. Effectiveness of this strategy depends on melt release conditions from the vessel, that recognized as the major source of uncertainty in quantification of the risk of containment failure in Nordic BWRs in ROAAM+ Framework. In this work we perform the analysis of the effect of water recovery in station blackout accident in Nordic BWR on the timing and mode of vessel failure and melt release conditions using MELCOR code. The analysis is performed using Morris method in order to evaluate the sensitivity of the vessel failure mode and melt release conditions and associated uncertainty due to user-defined modelling parameters and modelling options in MELCOR code.