10 CFR 50.59 – A history of the rule’s development
Prior to 1962, the 50.59 process for modifying a nuclear plant without requiring prior Commission approval did not exist. There was no UFSAR. There…
Licensing Basis
Archive
Category: Licensing Basis
50.59 – Why 10% is the criterion for determining “more than a minimal” increase
It’s given as guidance in NEI 96-07 without a basis, and 10% is not mentioned in the regulations at all. But the basis isn’t…
Licensing Basis
Class 1E Definition
The Class 1E definition is found in IEEE 308. It is associated with electrical power systems found in nuclear power plants.
Design Basis
IEEE 323 – Qualifying electrical equipment to the harsh environments of nuclear power plants
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…
Design Basis
Technical Requirements Manual
The NRC made some rule changes in the mid-1990’s that simplified a critical component of a nuclear power plant’s licensing basis. This reduced the…
Licensing Basis
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…
Design Basis
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…
Design Basis
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…
Design Basis