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 were only Technical Specifications, the Hazards Summary Report, and license amendments. This is a summary of the 50.59 rule’s evolution, from 1961 to today…Continue reading “10 CFR 50.59 – A history of the rule’s development”
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 arbitrary. Here is the reason…Continue reading “50.59 – Why 10% is the criterion for determining “more than a minimal” increase”
The Class 1E definition is found in IEEE 308. It is associated with electrical power systems found in 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 requirements. Continue reading “IEEE 323 – Qualifying electrical equipment to the harsh environments of nuclear power plants”
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 paperwork burden on both the NRC and the sites. It also gave birth to a new kind of licensing basis document. Continue reading “Technical Requirements Manual”
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 “Class 1E circuit independence – a summary of IEEE 384-1992”
“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 . . . .
“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. . . .