NRG develops in-core expansion measurement technology

The Nuclear Research and Consultancy Group (NRG) announced yesterday it has successfully demonstrated the capability to measure material expansion during irradiation with micrometer accuracy at temperatures above 750°C. The technology – developed at the High Flux Reactor (HFR) at Petten in the Netherlands - will help in the development of improved reactor materials and nuclear fuels.

"Measuring the dimensions of multiple material samples of a few millimeters thickness with 1 micrometer accuracy at 9 meters distance, during operation in a high flux nuclear reactor system, at temperatures beyond 750°C, is quite a challenge," NRG said in a statement.

However, after a number of laboratory tests in which different concepts were developed, constructed, tested, dismissed and improved, a final concept was developed a year ago. The design was completed by a team of material and fuel experts, nuclear engineers and technicians, and constructed and assembled in the Petten workshop, NRG said. It noted this is the first time the technology has been adopted to be used in a nuclear reactor.

"The data we can now generate provides input and validation information for the new generation of material and fuel performance models," NRG said. "The nuclear community has been waiting for this, as these new models will provide better knowledge and insight, and will allow efficient development of better and safer materials and fuels for current and new nuclear power plants.

The facility will be irradiated in an even higher flux position in December, it said, where temperatures beyond 1200°C can be achieved. NRG said several projects are planned for 2017 in which the focus will be on new nuclear fuel behaviour characterization, as a basis for safer fuels.

In addition to being used for materials testing, HFR is one of the world's main radioisotope production facilities, supplying about 70% of the medical isotopes in Europe and about 30% of global production.

Researched and written
by World Nuclear News