Two new passive safety systems for a demonstration nuclear heating pla
nt, the residual heat removal system (RHRS) and the boron injection sy
stem (BIS), are introduced in this paper. Their common characteristic
is that they have no driving equipment, therefore fluid circulation de
pends only on gravity (in BIS) or natural circulation (in RHRS). The i
nherent safety and realizability of both systems are illustrated in th
is paper.