On Mar 27, the world's first reactor demonstration project for Hualong One (HPR 1000) -- the installation of sensors for the reactor internals of unit 5 of Fuqing nuclear power station in coastal Fujian province -- was completed, according to officials.

They said this laid a solid foundation for the follow-up flow induced vibration test.

Hualong One conducted the test official operations in order to verify the safety technology inside the nuclear reactor with the closest actual data.

The flow induced vibration sensor is a "stethoscope" for the safety monitoring of flow induced vibrations of the reactor internals during the hot functional test, officials said.

The measured data can be compared with the theoretical predicted vibration values. This helps determine the vibration intensity of the reactor internals under normal working conditions and provides a basis for the comprehensive evaluation of flow induced vibrations of the reactor internals.

There are 47 flow induced vibration sensors in Fuqing unit 5, which are distributed around the core. The placing of the sensors took a long time, fulfilling high quality requirements and were they were installed with great difficulty, officials said.

On May 31, 2016, China Nuclear Power Engineering Co Ltd -- together with the Nuclear Power Institute of China, Fuqing Nuclear Power, China Nuclear Industry 23rd Construction Corporation, CNPE consulting and other units -- established a special flow induced vibrations test team for the reactor’s internal systems.

Officials said that sensor welding quality was a critical factor in determining the success or failure of flow-induced vibration tests. They said that as a result, the special group attached great importance to the welding work.

Before installation, special spot-welding operators were organized to practice.

During the installation process, technicians and quality inspectors arranged to check the welded ties and sensors one by one.