Redundant and backup components

Redundant or backup components shall be provided for those parts of the system that are necessary for safe system shutdown and for returning the system to a stable condition from all the hypothetical situations considered in the safety analysis. Examples of components that should be redundant or have backups are exhaust fans, high efficiency particulate air (HEPA) filters, and thermocouples in the combustion chamber. 

Redundant components or systems shall be tested during startup, and put into operation periodically for test purposes. However, redundant components should not be used alternately, in order to prevent both from wearing out at the same time. The quality of redundant systems shall be equivalent. 

There are other parts of the system where component redundancy is not required for safe shutdown of the system, but rather for sustaining the incineration process. In particular, these are the system components that directly affect the flow of process streams. Redundant or backup components may be considered for these parts. If redundant or backup components are not provided the Mlure of a component in these parts shall automatically switch the system to a stand-by mode. 

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