Lightbridge Ltd has completed work to design an experiment for the irradiation of samples of its metallic fuel material in the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). The work was carried out in collaboration with INL under the US Department of Energy's Gateway for Accelerated Innovation in Nuclear (GAIN) voucher programme and marks a milestone towards testing of the material in the reactor.

The blue glow of Cerenkov radiation inside INL's ATR (Image: INL)

The scope of the work saw teams from Lightbridge and INL establish a test plan for the measurement of key thermophysical properties of Lightbridge Fuel material before and after irradiation in the ATR. INL has performed a detailed design and established the safety case needed for insertion of the experiment in the reactor, including the control of parameters such as sample enrichment, thermal-hydraulic capacity, maximum sample temperature, neutron fluence, and the physical location of test capsules within the ATR.

Lightbridge President and CEO Seth Grae said this "makes the design and safety case" for Lightbridge Fuel samples to be tested in the ATR. "I want to thank the teams at Lightbridge and Idaho National Lab for their collaborative efforts under the truly unprecedented conditions of a global pandemic to complete this important work. I also want to thank the Department of Energy and the GAIN program for their continued support of advanced nuclear technology research at Lightbridge," he said.

The next step will be to contract for the high-assay low-enriched uranium material and fabrication of the sample coupons for insertion into the ATR, the company said yesterday. "Lightbridge's goal is to have the experiment available for insertion into the ATR when its core internal change out maintenance outage is completed. The actual experiment insertion is subject to the final duration of the outage, the availability of testing positions in the ATR and INL's prior commitments for testing," it added.

The Reston, Virginia-based advanced nuclear fuel technology development company says its proprietary next-generation metallic nuclear fuel technology concept is significantly more economical and safer than traditional fuel. Earlier this year, it said it would prioritise developing the technology for fuel for future small modular reactors.

The GAIN initiative was launched in November 2015 by the US Department of Energy (DOE) to provide a way to fast-track nuclear innovation, providing stakeholders with a means of accessing DOE research and development infrastructure to help them meet the challenges of bringing new technologies towards engineering-scale demonstration.

The GAIN voucher awarded to Lightbridge in December 2019 valued the project at about USD846,000, with three-quarters of this amount funded by DOE for the scope performed by INL. The company has to date received two vouchers under the GAIN programme to support the development of its proprietary next-generation metallic fuel technology: a second voucher, awarded in March this year, is for a collaboration with Pacific Northwest National Laboratory to demonstrate Lightbridge's nuclear fuel casting process using depleted uranium, which is a key step in the manufacture of the fuel. That project is valued at about USD664,000, with three-quarters of this amount funded by DOE for the scope performed by the laboratory.

Test reactors such as the ATR and the DOE's planned Versatile Test Reactor are crucial for the development of advanced nuclear fuel technologies and materials. ATR is a thermal neutron test reactor which first began operations in 1967. It operates at very low pressures and temperatures compared to a large commercial nuclear power plant, and its testing capabilities are used by the US military, federal, university and industry partners and customers.

Researched and written by World Nuclear News