Long term performance and aging characteristics of nuclear plant pressure transmitters

This report presents the results of a comprehensive research and development project conducted for the NRC to study the effects of normal aging on calibration and response time of nuclear plant pressure, level, and flow transmitters and to develop and validate new methods for testing the performance of the transmitters as installed in nuclear power plants. The project involved research in seven areas as follows: (1) Aging tests of complete transmitter assemblies, (2) Aging tests of critical components of transmitters, (3) Testing the effects of sensing line length, blockages, and voids on the response time of pressure sensing systems, (4) Oil loss phenomenon in Rosemount and other transmitters, (5) Validation of new methods for on-line testing of response times of pressure transmitters, (6) On-line detection of oil loss, in Rosemount transmitters, and (7) Analysis of Licensee Event Report (LER) and Nuclear Plant Reliability Data System (NPRDS) databases for failures of pressure sensing systems in nuclear power plants.