Category Archives: Design Basis

Class 1E Definition

Class 1E Definition

The Class 1E definition is found in IEEE 308. It is associated with electrical power systems found in nuclear power plants.

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IEEE 323 – Qualifying electrical equipment to the harsh environments of nuclear power plants

Cherenkov Radiation in the Advanced Test Reactor core, Idaho National Laboratory

IEEE 323 is the standard used to qualify electrical equipment for safety-related use in nuclear power plants. Here, we explore that standard and its requirements. Continue reading

Complying with GDC 17 and 18 – a survey of IEEE Std. 308

Class 1E power systems must be electrically isolated and physically separated

The NRC requires nuclear plants to have both onsite and offsite power systems available to supply safety-related equipment. It also requires that this equipment be periodically inspected and tested so that their condition can be assessed. These requirements are established in General Design Criteria 17 and 18. Continue reading

Class 1E circuit independence – a summary of IEEE 384-1992


Class 1E circuits must be independent from circuits of other categories. Understanding IEEE 384-1992 is vital to understanding the NRC’s circuit separation and isolation requirements. . . .  Continue reading

A note about the difference between ICEA and IPCEA

IPCEA, or ICEA? Here’s the connection . . . .

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Things to look for when doing initial background research

Background research is crucial to developing any new project or mod package. Here are some tips specifically tailored to electrical engineers . . . .

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Diversity and common-mode failures

“Diversity” means using a different kind of technology, equipment, or methodology to perform the same function. Put another way, it’s taking different approaches to solving the same problem . . . .

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Redundancy and the single-failure criterion

“Redundant” means having a second source of power or piece of equipment that acts as a backup in case the first fails to operate properly. . . .

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