The IMPAM-VVER project dealt with the following safety issue identified in recent VVER safety studies: Is it always possible to depressurise a VVER nuclear power plant (NPP) efficiently enough down to the operating pressure of the low-pressure safety injection (LPSI) system and thus ensure sufficient core cooling at all times? The main practical objective was to investigate which means and criteria for starting appropriate depressurisation measures, like the accumulators and primary/secondary feed and bleed, would be most efficient. It also assessed whether the computer codes can adequately predict the important relevant phenomena.