Document: NUREG-0800
Document ID: b09bdecd-fb52-4a15-ab35-7b597cbbaa13
Document Type: srp
Title: Appendix 7-A
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0525/ML052500546.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
inaccuracy, calibration uncertainties and error, and time response are acceptable and reasonable. Performance of an RTD is characterized by its accuracy and response time. Accuracy is a measure of how well the RTD indicates a static temperature, and response time indicates how quickly the RTD can sense a temperature change. NUREG/CR-5560, "Aging of Nuclear Plant Resistance Temperature Detectors," asserts that the calibration and response time of RTDs are affected by aging even within design conditions, but that the aging is manageable by periodic tests performed at each refueling interval. EPRI TR-106453-3925, "Temperature Sensor Evaluation," provides additional information on RTD performance. 3. Purpose The purpose of this BTP is to provide guidance for NRC reviewers to verify that the previously cited regulatory bases and standards are met by an applicant's submittal. This BTP has two objectives: • Confirm that calibration inaccuracies, uncertainties, and errors associated with a proposed cross-calibration method are consistent with design basis and setpoint analysis assumptions, and • Confirm that a proposed cross-calibration method is adequate to confirm that RTD response times are consistent with accident analysis assumptions. B. Branch Technical Position 1. Introduction To ensure adequate performance of the RTD, its accuracy and response time should be verified at appropriate intervals. For reactor coolant system (RCS) RTD sensors, practical considerations may limit the extent and methods prudent for in-situ calibration and testing. Periodic removal and re-installation of RTDs solely to support verification of calibration or response time could potentially introduce errors due to installation and increasing personnel exposure. In addition, it may not be feasible or prudent to achieve the range of Appendix 7-A Rev. 4 — June 1997 BTP HICB-13-3 isothermal conditions in the RCS for in-situ verification of the complete calibration range of the RTDs.