In contrast, the air-cooled PRHRS, ensuring the main reactor operation parameters to decrease to a more safety value, is more effective than water-cooled PRHRS for long term cooling.
The result shows the performance possibility of the long term cooling increases slightly in the short period of the time step.
In particular, this paper shows an application of MELCOR code to model beryllium steam reaction in a particular accidental sequence for the long term cooling.
The passive containment cooling system (PCCS) of the simplified boiling water reactor (SBWR) is a passive condenser system designed to remove energy from the containment for long term cooling period after a postulated reactor accident.
Results obtained for various transients show that high pressure vent and sump recirculation lines provide natural circulation flow path for long term cooling of core to avoid core heat up.
The scoping analysis had proved that AHT (>10% containment volume) decreased the required number of PCCS HXs to be installed less than a half, failure of valves caused marginal increase in HXs to be installed, and external HXs had merits over in-tube HXs for long term cooling.
Furthermore, this study focuses on the comparison of important parameters in the main components such as Reactor Pressure Vessel (RPV), Containment, and Suppression Pool (SP) of the integral facility for those types of the LOCAs tests in three different phases of LOCAs, namely, the blowdown phase, Gravity Driven Coolant System (GDCS) period and long term cooling PCCS period.
The long term cooling during the Marine Isotope Stage (MIS) 3 and the modest temperature drop of ~ 5 °C from 79to6565 ka are best explained by interactions among multiple climate forcings including insolation, atmospheric CO2 concentration, global ice volume, and regional glacier activities.
The Earth has been in a long term cooling trend since the Miocene Climactic Optimum, 15 17 Ma ago.
The experimental results show that the PCCS has successfully provided a continuous removal of core heat and a long term core cooling can be reached for all cases of SBLOCA.
So, by way of the ocean currents, the impact would initiate a long-term cooling.
