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
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CFR Title: 

Content:
erformance requirements and failure criteria assumed in the plant accident/event analyses are satisfied by the cross-calibration process and testing results. • The technical basis for the acceptance criteria and values of cross-calibration points monitored in-situ throughout the RTD range, to ensure that the data are adequate for detecting degradation or systematic drift. Traceability of the Installed Reference RTD to Laboratory Calibration Data Laboratory calibration involves measuring the RTD's resistance at several known temperatures. The data are then used to provide a calibration curve for the device. In addition, the RTD response time can be determined under laboratory conditions using controlled temperature baths and a methodology to calculate the RTD response time over the measuring temperature range. The installation of a calibrated RTD should include a test procedure to demonstrate the response time applicability of the laboratory test results. Loop current step response (LCSR) BTP 7-13-5 Revision 5 - March 2007 testing is an acceptable way to verify that the conditions of the installed RTD are adequately correlated to the laboratory test data. Response time testing of the installed RTDs using LCSR should use an analytical technique such as the LCSR transformation identified in NUREG-0809, "Review of Resistance Temperature Detector Time Response Characteristics," to correlate the in-situ results with the results of a laboratory-type temperature test. Acceptable Methods for In-Situ Testing Verification of RTD calibrations should be accomplished by installing a newly calibrated reference RTD sensor and then cross-correlating with the measurements of the other RTDs subject to the same temperature and flow environment. A critical element in this approach is providing assurance that all sensor elements are subject to sufficiently similar temperature and flow environments. Other methods, such as using a diverse parameter to provide a cross- correlation