Sensors and Condition Monitoring for Nuclear Power Plants

Nuclear Power Plants! You must have heard about these thermal power stations that are built all over the world. Did you know that around 11% of the world’s electricity is generated by about 449 nuclear power reactors? According to World Nuclear Association, in the year 2020, nuclear plants supplied 2553 TWh of electricity.

In the 60 years of generating nuclear energy, the United States of America has produced clean and carbon-free electricity. It also said that each year, about a fifth of the country’s electricity is produced from nuclear power.

India has around 21 reactors at seven nuclear plant locations with a total capacity of 6,680 MW. Nine more reactors are under construction out of which two are at Gorakhpur and seven are being constructed under expansion plan of existing capacity at Kalpakkam, Kakrapar, Rajasthan, Kudankulam & Tarapur.

Historically, the first operational nuclear power plant became functional on June 27, 1954. In the Soviet Union, Obninsk Nuclear Power Plant became the first nuclear power plant to generate electricity for a power grid

Nuclear power plants are thermal stations that have nuclear reactors as their main heat source. But due to the highly regulated environment of nuclear power plants, paramount importance has to be given to careful planning and equally careful execution of the instrumentation and monitoring solutions.

Nuclear power plants are critical structures whose monitoring and instrumentation have to be performed during construction and over the life of the facility. Let’s dig deeper into the purpose and importance of nuclear power plant monitoring systems.

Purpose of Nuclear Power Plant Monitoring System

The structure of the nuclear power plant is fairly standard in the nature of its design. The geotechnical and structural design parameters should be monitored to confirm that standard design parameters envelope site-specific parameters. The monitoring solutions provide significant information in cases where site specific conditions exceed standard design parameters.

The geotechnical monitoring solutions is useful during the construction as well as after construction for long term monitoring when the facility is operational. A geotechnical instrumentation plan, including “alert” or “trigger” values that give instant information on actions to be taken, is part of monitoring efforts.

Monitoring of the structural integrity of containment building and individual/common raft is most important as it assists in assessing the mechanical behaviour of the building at various stages, like:

• during construction
• during the acceptance test and the periodic airtightness tests
• normal operation
• after exceptional events like earthquake

If there is any structural deterioration and damage in the plant’s structure, there is a big possibility that the radioactive fuel can spread and contaminate a vast geographical area. It would become very difficult to get rid of its deadly and dangerous effects. Hence, it is very important to implement various geotechnical instrumentation along with non-contact deformation and aerial survey.

With over 56 55 years of experience in manufacturing and supplying geotechnical instruments and online monitoring solutions, Encardio-Rite has carved its own name. Encardio-Rite is known for providing world-class digital sensors, automatic dataloggers, Data Management Systems (Drishti from Encardio-rite and Simon-e from SITES), etc.

Structural Nuclear Power Plant Monitoring Solutions

When it comes to nuclear power plant monitoring, Encardio-Rite offers a complete online web-based monitoring solution including geotechnical as well as structural instrumentation. The Instrumentation and Control systems produced by Encardio-rite have a proven track record for reliability and long-term performance under harsh conditions.

Encardio-rite also offers advanced solutions such as automatic 3D deformation monitoring using ATS, laser scanning with advanced deformation monitoring software, and aerial surveys using drones.

A typical location plan is given below showing surface and subsurface sensors that can be used for safety monitoring of nuclear power plants.

For settlement and deformation monitoring of the nuclear island raft, Encardio-rite can provide the following instruments:

1. Geodetic targets:

Encardio-rite model EPS-12–60 topographical marker/pavement settlement points and model ERT-20P2 mini prism target can be installed for monitoring settlement.

ERT-20P2 prism target

2. Settlement system:

Model ESM-40S It is a liquid level settlement system that gets embedded in the common raft foundation measuring the settlement of the portion of the raft under the reactor building. It is ideal for precision data by remote monitoring.

ESM-40S digital high precision liquid level settlement system

3. Borehole extensometer:

Model EDS-70V is an electrical multipoint borehole extensometer system with vibrating wire displacement transducers for monitoring relative vertical movement. These movements are measured with reference to deep and stable rock in which the deepest anchor is embedded …[Continue reading]