On the basis of present research, it is concluded that loop type
heat pipe can be successfully utilized for dissipating decay heat
from nuclear reactor core. The proposed heat pipe emergency core
cooling system with cylindrical evaporator composed of 62 vertical
tubes, each 150 mm diameter and 6 m length, mounted around the
periphery of nuclear fuel assembly and 21 m 10 m 5 m finned
condenser installed outside the primary containmentwas designed
to dissipate decay heat from reactor vessel with 1380 MW full load
thermal capacity to ambient air at 40 C. Overall thermal resistance
of the heat pipe unit was 1.44 105 C/W. Within 6e7 h, the
proposed heat pipe system can reduce the reactor temperature
below 250 C from initial working temperature of 282 C. It is
recommended to use initial water charge of 32 kg/s for 10 min to
accelerate the cooling time of the core and provide safer ECCS
cooling system. With heat pipe ECCS and 10 min water charge, the
core cooling time can be reduced. The proposed heat pipe system
can be operated completely passive which will provide safer
operational environment to nuclear power plants.