Vessel supports selection

Chapters 11-13 cover the selection and sizing of downstream disposal systems, reaction forces which require piping and vessel supports, maintenance, documentation and change management. Additional material is given in Annexes 1-8 and is referenced from the,text as required. This includes consideration of any safety factor to be applied to the calculated relief size. 

Because the skirt is an attachment to the pressure vessel, the selection of material is not governed by the ASME Code. Any material selected, however, should be compatible with the vessel material in terms of weldability. Strength for design is also not specified for support material by the ASME Code. Usually, in the absence of any other standard, the rules of the AISC Steel Construction Manual will be utilized. For elevated temperature design, the top three feet of skirt at the attachment point should be of the same material as the shell. 

The fifth component is the stmcture, a material selected for weak absorption for neutrons, and having adequate strength and resistance to corrosion. In thermal reactors, uranium oxide pellets are held and supported by metal tubes, called the cladding. The cladding is composed of zirconium, in the form of an alloy called Zircaloy. Some early reactors used aluminum fast reactors use stainless steel. Additional hardware is required to hold the bundles of fuel rods within a fuel assembly and to support the assembhes that are inserted and removed from the reactor core. Stainless steel is commonly used for such hardware. If the reactor is operated at high temperature and pressure, a thick-walled steel reactor vessel is needed. 

A process may be viewed as the equipment used to produce or process a specific product or group of products, its directly related support utilities, and its physical location. In this context, process equipment includes vessels, tanks, piping, instruments, and controls, as well as specific items of equipment that handle solids, liquids, or gases. This section provides guidance on suggested fire protection for selected items of process equipment, support utilities, and the facility itself. 

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