The Technical Specifications, or Tech Specs for short, are the documented technical parameters that govern the plant’s safe operation. Whereas the UFSAR reads more like a textbook, the Tech Specs usually consist of many different tables that list requirements, actions, and their frequencies. . . .
The Tech Specs establish the technical parameters that the plant must operate within to keep it operating safely. They are governed by 10 CFR 50.36. From out of it emerge terms like “Limiting Condition for Operation” (LCO) and “Operable.” If the plant falls below any limiting condition for operation because certain critical equipment has become inoperable, then it must perform a “Required Action” as directed by the TS. Depending on how critical the LCO is, the consequences of failing to be able to perform the Required Actions ramp up in severity.