Prevention of combustible gas accumulation

The design layout of the RCSASs should take into account  

Needs for room and floor drainage should be considered and provisions for these should be commensurate with the maximum level of external flooding for the site. 

The layout of the RCS should be such that, in the event of a total loss of power supplies to pumps in operational states as well as in specific design basis accident conditions, the removal of residual heat is ensured by the natural circulation of the reactor coolant. 

The design of the layout of RCSASs should allow for the inspection, maintenance, repair and replacement of SSCs, with account taken of the need for the radiological protection of site personnel. 

Design measures for radiological protection are discussed further in Ref. [10]. 

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