Deformation and temperature monitoring of the concrete in the containment chamber.
Argentine Carem Reactor25
The Carem25 reactor is a 100% Argentine nuclear power plant reactor built by the Argentine government with the CNEA (National Atomic Energy Commission).
The reactor construction site is located in Atucha, a nuclear power plant in operation, about 100 km from Buenos Aires.
Location of the Power Plant
The project consists in measuring the deformations of the reactor containment with conventional sensors in an automatic way (Microvib extensometer). As well as by optical fiber (Sensolux with Sensologger T and S) during measurement series.
Temperature measurements of the poured concrete are also carried out.
The monitoring project with Cementys started in 2016 and the last on-site intervention dates from December 2018.
Microvibs are used to measure the deformations of the concrete in the containment chamber as well as the temperature of the concrete via thermistors.
There are two types of Microvibs placed on the frameworks, conventional Microvibs measuring +-1500µstrain and Microvibs RR resistant to measurement variations either +-1500µstrain or +-3000µstrain
Time and spectral measurement
All Microvibs strain gage sensors are vibrating wire sensors. The extension value of the sensor is determined by the tension of a metal cord that is excited by a voltage. The oscillations are then measured and by Fourier transform we are able to obtain a spectrum with the resonance frequency of the wire. This makes it possible to go back to the deformation value.
In addition to these so-called conventional sensors, Cementys has installed, for each level of concreting of the containment, optical fibers to be able to also measure the deformation and temperature.
The data from all these sensors are collected by a Datalogger and sent to be displayed via our THMInsight platform.
As a matter of fact, the Sensolux optical fiber allows via Sensologger S and T interrogators to make a measurement distributed along the fiber.
Microvibs’measurement installed on site
Sensolux fiber on the armature
These two interrogators use light backscattering effects in the fiber, Raman backscattering for temperature and Brillouin backscattering for deformation.
Two-day temperature curve in cement
T0 measurement of the Brillouin frequency for deformation
Microvibs cables Pulling
Containment from outside the site