Photonic Doppler Velocimetry for Valve Analysis and Surveillance
- Univ. of California, San Diego, CA (United States); Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
This study is an experimental evaluation to measure and surveil the velocity of stainless steel (Carpenter 455) pistons within a forged 21-6-9 stainless steel valve body. The velocity of the piston “stroke” will be identified using Photonic Doppler Velocimetry (PDV). The piston velocity will be the measured variable of interest. The outcome of this testing series provides further understanding to whether the extracted piston velocity can provide enough information to determine valve integrity. PDV has been identified as a diagnostic of interest as it can detect surface motion at high speeds with reliable accuracy. Through preliminary studies conducted with velocity interferometer system for any reflector (VISAR), the velocity of the piston is expected to stroke with a speed of 135 m/s. The PDV technique is much more reliable and repeatable than the VISAR technique because of its high-speed precision and accuracy, so it will not only validate the preliminary data, but also provide a testing technique that is capable of being used in future valve qualification efforts. The initial testing was completed using valves that were assembled per qualified procedures in a pristine condition. These initial tests were conducted to provide baseline data. This baseline data was then compared to data collected from valves where man-made defects were introduced. These defects are discussed in later sections. Lastly, actuators used to operate the valves were loaded with varied amounts of high explosives to identify if velocity is a function of the amount of explosive in an actuator. These parameters were adjusted to conclusively determine and identify if PDV can be used as a method to assess valve integrity. It was concluded through the testing discussed in this paper that in fact, PDV is capable of measuring the differences in piston velocities based on varied parameters. As far as understanding the PDV accuracy of the measured differences, this is ongoing and will have to be assessed in continued testing series.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Univ. of California, San Diego, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- DOE Contract Number:
- 89233218CNA000001
- OSTI ID:
- 1810514
- Report Number(s):
- LA-UR-21-27165
- Country of Publication:
- United States
- Language:
- English
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