The Nuclear Research and Consultancy Group (NRG) in the Netherlands has demonstrated the capability to measure material expansion during irradiation with micrometer accuracy at temperatures above 750°C. The technology, never adopted before in a reactor, allows high accuracy measurement of material deformation under load over time, thermal expansion, irradiation induced swelling and shrinkage, at high temperatures and during irradiation. The technology was developed at the High Flux Reactor (HFR) at Petten and will help in the development of improved reactor materials and nuclear fuels, NRG said in a 2 November statement.

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. “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.