AlN Single Crystal Accelerometer for Nuclear Power Plants

Reliable vibration sensing is essential to the immediate detection of unusual vibrations, ensuring the safety of nuclear power plant structures. For nuclear power plant applications, the sensor element must endure the harsh environment while retaining reliable performance. Aluminum nitride (AlN) single crystal is considered a promising candidate for the sensing unit due to its robustness to high temperature (HT) and irradiation conditions. However, there are few efforts in developing industrial accelerometers using AlN bulk-machined materials. This article aims to develop a shear-type accelerometer with AlN single crystal plates. The accelerometer's design is based on the numerical simulation results, followed by the fabrication of the sensor and the extensive validation under HT (similar to 1000 degrees C). The sensitivity of the accelerometer was about 9.2 pC/g. The prototype sensor showed stable performance at varying temperatures from room temperature to 1000 degrees C. Furthermore, the sensitivity of the accelerometer was successfully sustained for 10 h under HT exposure of 1000 degrees C, and no obvious mechanical damage was detected after the test. After gamma irradiation for 1 month, the sensor performed stably, without any significant change in sensitivity. The developed AlN accelerometer can be a promising option to monitor the structural integrity of nuclear power plant structures.

Automated summary

This article introduces the development of a shear-type accelerometer using AlN single crystal plates, which shows stable performance under varying temperatures from room temperature to 1000 degrees C. The sensitivity of the accelerometer was sustained for 10 hours under exposure to 1000 degrees C, indicating its potential as a promising option for monitoring the structural integrity of nuclear power plant structures.