Document: NUREG-0800
Document ID: e3caee65-c7fb-44ba-b41b-b7a6e49073ca
Document Type: srp
Title: Revision 5 - March 2007
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0705/ML070550077.pdf
Revision Date: 2023-06
Chapter: 7
Section ID: 7
CFR Part: 
CFR Title: 

Content:
25, "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 isothermal conditions in the RCS for in-situ verification of the complete calibration range of the RTDs. Nevertheless, the applicant/licensee should provide assurance that the calibration and response time for each RTD has not significantly changed due to aging or degradation of the sensor and its installation. One method acceptable to the Staff is to periodically provide an installed reference RTD that has been recently calibrated and response-time tested. The remaining "similar" RTDs may be cross-correlated to the reference RTD to identify any significant degradation in performance. The "similar" RTDs are those which can be shown to be subject to sufficiently similar temperature and flow conditions in the RCS. While this method does not provide for complete