6.6 NRC Regulations

The NRC Regulatory Guide 1.118, NUREG-0800, and NUREG-0809 all relate directly or indirectly to sensor response-time testing. For example, Regulatory Guide 1.118 provides criteria, requirements, and recommendations for the periodic testing of plant protection systems in nuclear power plants. It states that "safety system response time measurements shall be made periodically to verify the overall response time (assumed in the safety analysis of the plant) of all portions of the system from and including the sensor to operation of the actuator."

Regulatory Guide 1.118 refers to two IEEE standards (namely, IEEE Standard 279 and IEEE Standard 338). More specifically, Regulatory Guide 1.118 states that the criteria, requirements, and recommendations in IEEE Standards 279 and 338 are generally acceptable, notwithstanding several exceptions and/or clarifications.

Regulatory Guide 1.118 was originally issued in the mid-1970s. It gave a boost to the development of new methods for in-situ testing of response time in RTDs and pressure, level, and flow transmitters in nuclear powerplants. In particular, the development of the LCSR test was in large part stimulated by Regulatory Guide 1.118. When the LCSR test was completed, a topical report was submitted to the NRC on the LCSR technique. This resulted in a SER designated as NUREG-0809. Through this SER, the NRC approved the LCSR method for measuring the in-service response times of RTDs in nuclear power plants.[11]

In addition to the LCSR method, the SER includes a review of the self-heating and noise analysis methods. In particular, the SER introduces the...