Auxiliary equipment plant layout

Figure 18.1 Examples of plant layout with extrusion and injection molding primary and auxiliary equipment...

The water system layout should provide an adequate supply to all parts of the plant. Piping, pumps, tanks, alves, hjdrants, and auxiliary equipment should follow acceptable standards. 

Because of its small size, the reactor containment structure is located within a reactor service building. The general layout of systems and equipment within the reactor service building is as shown in Figures 1,2, and 3 with critical reactor auxiliary equipment placed near the reactor. Radwaste systems and equipment are situated at one end of the reactor service building away from the reactor. Large, heavy equipment is placed on the bottom floor elevation, while lighter equipment is located on the upper elevations. The system layouts are based on past experience with central station plants. 

Exhibit 4-27 illustrates how primary process considerations govern the elevation of the surface condenser and some of its auxiliary equipment. Because a pump is needed to remove the condensate from the hot well, the pump net positive suction head (NPSH) must be satisfied to operate satisfactorily. Vertical pumps are generally used in this application because the NPSH requirement is calculated from the bottom of the lower impeller for vertical pumps, compared with the centerline of the inlet nozzle for horizontal pumps. Setting the elevation of the inter-after condenser, usually located to the side of the suifice condenser, can be done with fewer restriaions. Ilie bottom of the inter-after condenser shell must not be more than 3 ft (900 mm) below the condensate return nozzle on the side of the hot well. The plant layout designer is then free to set the elevation as high as necessary. 

The two-vessel (catamaran) layout of the floating power unit is used providing separate vessel construction at the shipyard. The reactor plant equipment including auxiliary systems and safety systems will be installed in one vessel the turbo-generator equipment including corresponding systems will be installed in the other vessel. 

To apply the principle it is necessary that sufficient information in terms of piping (process) and instrumentation diagram (P ID), draff layout, equipment list, and sizing is available. Normal index value 0—60 light, 61—96 moderate, 97—128 intermediate, 129—159 heavy, and >159 severe. This may be read together with a toxicity index for a chemical plant. This principle is applicable for main plants but not for auxiliaries. Also there is not much correlation with known disasters. 

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