Water pumps active protection systems

Normally where it is necessary, fireproofing is preferred over water spray for several reasons. The fireproofing is a passive inherent safety feature, while the water spray is a vulnerable active system that requires auxiliary control to be activated. Additionally the water spray relies on supplemental support systems that may be vulnerable to failures, i.e., pumps, distribution network, etc. The integrity of fireproofing systems is generally considered superior to explosion incidents compared to water spray piping systems. The typical application of water sprays in place of fireproofing is for vessel protection. 

The project plan should encompass all aspects of a fire protection system, such as the underground fire water distribution system, fire pumps, aboveground water header, valving and standpipes, structural support, and detection and alarm systems. All work on the fire protection system must be coordinated with other work activities at the site or in the operating unit. The recommended installation practices for the different types of fire protection systems are covered in consensus standards, such as NFPA. The installation process is illustrated in Figure 9-1. 

The following appendices provide generic information on the periodic operational testing parameters used in the process industries for active fire protection systems (i.e., pumps, deluge systems, monitors, hose reels, foam systems, etc.). Further information can be found in the publication, NFPA 25 Standard for the Inspection, Testing, and Maintenance of Water-Based Fire Protection Systems. 

The endothelial cells actively, as well as passively, serve to protect the brain. Because they contain a variety of drug-metabolizing enzyme systems similar to the drug-metabolizing enzymes found in the liver, the endothelial cells can metabolize neurotransmitters and toxic chemicals and, therefore, form an enzymatic barrier to entry of these potentially harmful substances into the brain. They actively pump hydrophobic molecules that diffuse into endothelial cells back into the blood (especially xenobiotics) with P-glycoproteins, which act as transmembranous, ATP-dependent efflux pumps. Although lipophilic substances, water, oxygen, and carbon dioxide can readily cross the blood-brain barrier by passive diffusion, other molecules depend on specific transport systems. Differential transporters on the luminal and abluminal endothelial membranes can transport compounds into, as well as out of, the brain. 

I - Reactor 2 - Control rod actuators 3 - Primary circuit pump 4 - Metal-and-water shielding tank 5 - Protective shell 6 - SG 7 - Recirculation channels of ECCS 8 - Active channels of ECCS 9 - Barbotage sub-system for emergency pressure suppression in the protective shell 10 - Soluble poison injection system ... 

---