Accidents nitrogen system

On chemical plants and oil refineries, steam, nitrogen, compressed air. lubricating oil, and other utility systems are responsible for a disproportionately large number of accidents. Flammable oils are recognized as a hazard, but services are given less attention. If the modification to the lubricating system had been systematically studied before it was made, as recommended in Chapter 2, a larger vent could have been installed, or a pipe-break and funnel could have been installed at the inlet to the sump. 

Functions of the water-filled containment are to passively maintain core flooding in cases of accidents including a LOCA, to shield radiation, as well as to enclose the area for prevention of radioactive materials release to a surrounding. The main cooling system with containment water is shown in Fig. 5. There is a nitrogen gas in die upper space over the water surface of the containment. Core flooding can be maintained passively by pressure balance of the containment and... 

During LPS the pressure and temperature of reactor system is lower than during full power operation. There may be a nitrogen blanket in the pressurizer or the primary circuit may be open to atmospheric pressure. The traditional accident analysis codes (e.g. ATHLET, RELAP, CATHARE, TRAC) were not originally developed to take into account these special physical... 

The system pressure is self-controlled by the partial pressures of steam and nitrogen gas filled in the PZR in accordance with the variation in pressure and temperature of the reactor coolant system. A large volume of passive PZR can accommodate a wide range of pressure transients during system transients and accidents. 

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