Tag Archives: In- Core Instrumentation

Thermal & sensing solutions for nuclear industry

At Thermocoax, our mission is to develop state-of-the art, complete solutions for the Nuclear sector. We manage all the steps of the whole project from the design through qualification up to the final product.

Thermocoax nuclear division : our added value

Thermocoax has supported the players in the nuclear energy market over the last fourty years by supplying components and continues to be a privileged partner throughout the cycle, from fuel production to reprocessing to design and manufacturing of components for nuclear installations.

Based on operational experience, our dedicated Nuclear engineering team designs solutions using proprietary manufacturing processes while adhering to the highest Nuclear quality standards.

Thermocoax nuclear division : what we provide

Based on our unique technology we provide cabling systems, sensors and heaters for severe nuclear environments :

Some examples :


  • Accident-proof MI cable assemblies Radiation-resistant cables and connectors classified for severe accident in reactor containment.
  • Twisted MI cables TWISTCOAX® : Insensitive to high magnetic fields, the solution for fusion reactors.


Radiation sensors :

  • Self Power Neutron Detectors SPND : this sensor is the ultimate solution for in-core neutron flux monitoring. It is made with a simple manufacturing process proprietary to THERMOCOAX that makes it even more robust. THERMOCOAX NUCLEAR division has been providing SPND to research reactors and power plant since  the 1970s. Several sensors can be linked in a single thimble.

NUCLEAR - spnd

  • Self-Powered Gamma Detectors SPGD

Based on a simple working principle, this innovative sensor has been patented by CEA and provides impressive performance in reactor pool conditions

 Temperature sensors  :  

  • In-core thermocouple :

An important parameter in realtime reactor power calculation is based on core outlet temperature measurement. In case of transient, our thermocouples also prevent the nucleate from boiling at the cladding of fuel assemblies. Those two critical functions require the highest reliability and quality standards.

  •  Qualified Rtds:

In PWR, the temperature of the containment is key for reactor monitoring. Our qualified Rtds provide very short reaction time and a construction that will last for decades.

 Level sensors :

 Spent Fuel Pool Level Measurement SFPLM :

When standard technologies cannot be used, rugged design and construction of our solutions is key to fulfill stringent specifications.




The proprietary THERMOCOAX Nuclear manufacturing processes push the limits of performance and long term reliability of heaters for nuclear use.

  • Pressurizer heaters

High watt density pressurizer heaters have extended service life compared to other technologies.


  • Fuel pin simulators

They reproduce the very high flux of fuel pins by electrical heating in order to study cladding material behaviour or heat exchange with the primary coolant.

ISOPAD solutions

THERMOCOAX nuclear expertise : new challenges

THERMOCOAX has acquired a great deal of skills and expertise that are endorsed by many research reactors and nuclear power plants all over the globe.

Our solutions are working on fission reactors such as Pressurized Water reactors PWR, but also Boiling water reactors BWR, liquid metal reactors or gas-cooled reactors in Europe, China, Korea, USA, Brazil, South Africa etc.

We even provide specific solutions in the most cutting edge fusion reactors such as JET Tokamak in UK or LASER Mega Joule in France and are actively involved in the ITER program and also bespoke solutions for In-core or ex-core reactor solutions in Generation IV reactors.

Learn more about our nuclear products, below :