Heat removal system: This system consists of two pumps that are used to remove decay heat during reactor shutdown. They pump water into the circulation circuit while bypassing the circulation pumps, so the latter are not required. This system should only be used during reactor shutdown and should be disabled during the run-up. It cannot sustain higher reactor powers. On the panel, there is also an emergency Low Pressure Power Injection pump as a part of the system. It should be utilized when the reactor water level drops below the minimum. This pump operates effectively below 3000 kPa as it cannot inject water against higher pressure. These systems are powered by the Safety Bus, and in case of offsite power loss, they require diesel generators to provide power.
Reactor Core Isolation Cooling: This system is an alternate way to cool the reactor under pressure should there be any problem with primary cooling. Either it's offsite power loss, severe pumps malfunction or leakage, the reactor should be scrammed and cooling isolated. In that case feedwater is provided by steam driven pump from a storage tank, and it requires no electric power while the rest of the steam is vented directly into the suppression pool. Pump inlet will dictate the pump RPM and an amount of feedwater available, while a relief valve should be used to control reactor pressure. The system will work as long as there is steam pressure available and requires no electrical power, therefore it can keep the reactor cool during even long blackouts. When there is little steam available, offline cooling pumps and LPCI should be used instead.