Regional Basic Professional Training Course in Korea

Regional Basic Professional Training Course (BPTC) on Nuclear Safety
testability commensurate with the safety function(s) to be performed. Redundancy and
independence designed into the protection system shall be sufficient at least to ensure
that:
No single failure results in loss of protection function; and
The removal from service of any component or channel does not result in loss of
the necessary minimum redundancy, unless the acceptable reliability of operation
of the protection system can be otherwise demonstrated.
Design techniques such as testability, including a self‐checking capability where
necessary, fail‐safe behavior, functional diversity, and diversity in component design or
principles of operation shall be used to the extent practicable to prevent loss of a
protection function.
The protection system shall, unless its adequate reliability is ensured by some other
means, be designed to permit periodic testing of its functioning when the reactor is in
operation, including the possibility of testing channels independently to determine
failures and losses of redundancy that may have occurred. The design shall permit all
aspects of functionality from the sensor to the input signal to the final actuator to be
tested in operation.
The design shall be such as to minimize the likelihood that operator action could defeat
the effectiveness of the protection system in normal operations and expected operational
occurrences, but not to negate correct operator actions in design basis accidents.
Use of computer based systems in protection
Where a computer‐based system is intended to be used in a protection system, the
following requirements shall also be taken into account:
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