In the attack mode, the facility is closed to protect filters, personnel, and pertinent equipment from blast pressure. The HVAC system is totally isolated from the outside. Ventilation and exhaust air is recirculated through carbon filters for odor removal. The prime mover combustion air is ducted through the primary dust separator and a scrubber for dust removal and temperature control. Contaminated dust slurry from the scrubber is piped to the outside.
Facility operation is independent of commercial power.
The seal-up period begins with attack warning and continues until the outside environment is tolerable. Fuel is supplied from hardened tanks, and cooling water is supplied from hardened heat sinks and cooling towers. Disaster conditions . Under disaster conditions, the installation is inoperative due to damage or exhaustion of cooling water, fuel, or oxygen. To sustain life it may be necessary to utilize oxygen generation and carbon dioxide absorption equipment.