The main goal of this advanced BWR is to replace the active safety systems used in current designs with passive safety systems enabling:

• Reliable control of the various design basis accidents;

• Low probability of beyond-design-basis accidents (core damage frequency);

• Limitation of the consequences of a core melt accident to the plant itself;

• High plant availability;

• Economic competitiveness.

Various features have been changed compared to existing BWR designs, including:

• Larger water inventory in the reactor pressure vessel (RPV) above the core permits passive core cooling;

• Larger water storage capacities inside and outside the reactor containment providing long grace periods and avoiding the need for prompt operator intervention, especially during and after accidents;

• For transients as well as for accident control, emergency condensers and containment cooling condensers to passively remove decay heat from the core and containment, respectively;

• Activation of key safety functions such as reactor scram, containment isolation and automatic depressurization is backed up by passive systems (passive pressure pulse transmitters);

• Passive cooling of the reactor pressure vessel exterior in the event of a core melt accident ensures in-vessel melt retention;

• Despite the introduction of passive safety systems for accident control the operating experience gained from current BWR plants constitutes the basis for the new concept;

• Simplification of reactor auxiliary systems and systems used for normal power operation.