also improves defense-in-depth in the event of primary hydraulic and ARI contingencies. A fully digital Reactor Protection System (RPS) (with redundant digital backups as well as redundant manual backups) ensures a high level of reliability and simplification for safety condition detection and response. This system initiates rapid hydraulic insertion of control rods for shutdown (known as SCRAM by nuclear engineers) when needed. Two-out-of-four per parameter rapid shutdown logic ensures that nuisance rapid shutdowns are not triggered by single instrument failures. RPS can also trigger ARI, FMCRD rod run-in to shut down the nuclear chain reaction. The standby liquid control system (SLCS) actuation is provided as diverse logic in the unlikely event of an Anticipated Transient Without Scram. Fully digital reactor controls (with redundant digital backup and redundant manual (analog) backups) allow the control room to easily and rapidly control plant operations and processes. Separate redundant safety and non-safety related digital multiplexing buses allow for reliability and diversity of instrumentation and control. In particular, the reactor is automated for startup (i.e., initiate the nuclear chain reaction and ascent to power) and for standard shutdown using automatic systems only. Of course, human operators remain essential to reactor control and supervision, but much of the busy-work of bringing the reactor to power and descending from power can be automated at operator discretion. The Emergency Core Cooling System (ECCS) has been improved in many areas, providing a very high level of defense-in-depth against accidents, contingencies, and incidents. The overall system has been divided up into 3 divisions; each division is capable – by itself – of reacting to the maximally contingent Limiting Fault/Design Basis Accident (DBA) and terminating the accident prior to core uncovery, even in the event of loss of offsite power and loss of proper feedwater. Previous BWRs had 2 divisions, and uncovery (but no core damage) was predicted to occur for a short time in the event of a severe accident, prior to ECCS response. Eighteen SORVs (safety overpressure relief valves), eight of which are part of the ADS (automatic depressurization system), ensure that RPV overpressure events are quickly mitigated, and that if necessary, that the reactor can be depressurized rapidly to a level where low pressure core flooder (LPCF, the high-capacity mode of the residual heat removal system, which replaces the LPCI and LPCS in previous BWR models) can be used. Further, LPCF can inject against much higher RPV pressures,