Although the SLCS performs no design basis safety-related functions, it is classified as safety-related system. The SLC system is designed to provide makeup water to the RPV to mitigate the consequences of a LOCA. The ECCS and the SLC are designed to flood the core during a LOCA to provide sufficient core cooling. By providing core cooling following a LOCA, the ECCS and SLCS, in addition to the containment, limit the release of radioactive materials to the environment. The SLCS provides the reactor with an additional liquid inventory in the event of DPV actuation. This function is accomplished by firing squib-type injection valves to initiate the SLCS. The SLCS is operational at the high pressure. The SLCS is pressurized by utilizing a nitrogen charging subsystem including a liquid nitrogen tank, vaporizer, and high pressure pump for initial accumulator charging.

The SLCS is manually initiated for its shutdown function. In addition, the SLCS is automatically initiated for events beyond the safety design basis, such as a LOCA event. The SLCS contains two identical and separate trains. Each train provides 50% injection capacity. In addition to providing water inventory to the RPV, the SLCS removes the remaining reactivity by injecting boron solution into the RPV after the reactor shutdown.