Passive storage

Vitrified HLW Interim passive storage Disposal optimization... 

Active storage (cleaning) Storage in an environment that is continually being cleaned to remove potential contaminants. See also Passive storage. 

Anodic passivation and its appHcation to sulfuric acid equipment such as stainless steel acid coolers and carbon steel storage tanks has been weU studied (102—104). More recently, sheU and tube coolers made from Sandvik SX or Saramet have been installed in several acid plants. These materials do not requHe anodic protection. 

This ranking implies that human errors are more likely to occur than active equipment failures (functioning equipment, such as a mnning pump) and that active equipment failures are more likely to occur than passive equipment failures (static, nonfunctioning equipment, such as a storage tank). 

Anodic Protection This electrochemical method relies on an external potential control system (potentiostat) to maintain the metal or alloy in a noncorroding (passive) condition. Practical applications include acid coolers in sulfuric acid plants and storage tanks for sulfuric acid. 

LESF (Figure 3.4.5-5), exemplified for the large LOCA, is compared with SELF. Event tree headings are the refueling water storage tank (RWST) a passive component, an engineered safety system (SA-1) and four elements of the containment system. Other examples of the LESF method show human error in the event tree while the criteria for system success is usually in the tan It tree analysis. 

Passive Equipment not physically actuated in order to perform its function (e.g., piping, storage tanks). 

The fifth type of passive system is the natural convective loop, in which the collector is placed below the living space and the hot air that is created rises to provide heat where it is needed. This same principle is nsed in passive solar hot water heating systems known as thermosiphons. The storage tank is placed above the collector. Water is heated in the collector, becomes less dense, and rises (converts) into the storage tank. Colder water in the storage tank is displaced and moves down to the collector where it is heated to continue the cycle. 

Nitric acid readily attacks lead if dilute and the metal should not be used for handling nitrate or nitrite radicals except at extreme dilutions and preferably with a passivating reagent such as a sulphate, which will confer some protection. An example of this is the wash water from cellulose nitrate units. Corrosion decreases to a minimum at 65-70 Vo HNO3 and lead has been used for storage of nitric acid in the cold at this concentration . Resistance to a mixture of 98-85 Vo HjSO and nitric acid of 1 -50-1 -52 S.G. can be excellent °. ... 

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