BS IEC 61888 is an international standard that discusses the instrumentation important to safety of nuclear power plants.
BS IEC 61888 defines the requirements for assuring that automatic setpoints for nuclear safety system instrumentation are established and maintained within specified limits in nuclear power plants and nuclear reactor facilities.
The purpose of BS IEC 61888 is to provide descriptions and recommendations on how to determine and maintain calculations for instrument setpoints associated with IEC 61513.
BS IEC 61888 on automatic setpoints for nuclear power plants is useful for:
Inappropriate selection of a setpoint that does not leave a sufficient margin to account for instrument accuracy, the expected environment, and minor calibration variations can result in failure to trip before a safety limit is exceeded.
BS IEC 61888 provides guidance on the determination of setpoints for automatic actions, safety analysis, and maintenance of safety system setpoints for nuclear safety system instrumentation.
The recommendations may also be used to determine indicator uncertainties for testing or operator decisions.
BS IEC 61888 addresses known contributing errors in the channel from the process (including the primary element and sensor) through to and including the final setpoint device.
As a result, adopting BS IEC 61888 can ensure the various causes for drift of a setpoint out of compliance with a license requirement or technical specification are addressed and mitigated.
IEC 61888:2002