US nuclear fuel developer Lightbridge Corporation has announced that it has entered into landmark agreements with Idaho National Laboratory (INL), in collaboration with the US Department of Energy (DOE), to support the development of Lightbridge Fuel. The framework agreements comprise an “umbrella” Strategic Partnership Project Agreement (SPP) and an “umbrella” Cooperative Research and Development Agreement (CRADA), each with Battelle Energy Alliance, (BEA), DOE’s operating contractor for INL, with an initial duration of seven years.

The initial phase of work under the two agreements is expected to culminate in irradiation testing in INL’s Advanced Test Reactor (ATR) of fuel samples using enriched uranium supplied by DOE. The initial phase of work aims to generate irradiation performance data for Lightbridge’s delta-phase uranium-zirconium alloy relating to various thermophysical properties. The data will support fuel performance modelling and regulatory licensing efforts for the commercial deployment of Lightbridge Fuel.

It is anticipated that subsequent phases of work under the two agreements will include post-irradiation examination of the irradiated fuel samples, loop radiation testing in the ATR, and post-irradiation examination of one or more uranium-zirconium fuel rodlets, as well as transient experiments in the Transient Reactor Test Facility (TREAT) at INL.

Lightbridge President and CEO Seth Grae said this “marks a major milestone for Lightbridge and our fuel development programme”. He added: We look forward to working closely with INL, which Congress has designated as the nation’s lead nuclear energy research and development laboratory and is DOE’s lead nuclear fuel testing laboratory. Securing a long-term strategic relationship with INL, in collaboration with DOE, gives Lightbridge access to state-of-the-art ATR and TREAT reactor test facilities.”

However, Lightbridge has long enjoyed support from DOE and INL. In January 2018, Lightbridge Corporation and France’s Framatome launched Enfission, a 50-50 joint venture (JV) company to develop, license and sell nuclear fuel assemblies. The previous year Lightbridge and Framatome (then Areva) had signed an agreement to set up a JV to develop, manufacture and commercialise Lightbridge’s advanced metallic fuel. In May 2019, Lightbridge Corporation announced that Framatome had received a voucher from the DOE’s Gateway for Accelerated Innovation in Nuclear (GAIN) programme to support the development of Lightbridge Fuel in collaboration with the INL.

This was Framatome’s third GAIN voucher and its first supporting the Lightbridge Fuel design conducted by the Enfission JV. Framatome said the voucher would enable it to apply focused attention on key licensing steps to commercialise Lightbridge Fuel. The voucher was valued at $477,000 for work to be carried out over 12 months.

In April 2020, Lightbridge entered into a cooperative research and development agreement with Battelle Energy Alliance (BEA), the operator of INL, to design an experiment for irradiation of metallic fuel material in the ATR. That agreement was valued at $845,000, with DOE funding three-quarters of this the GAIN programme. Lightbridge and INL were to establish the test plan for measuring key thermo-physical properties of Lightbridge Fuel material both before and after irradiation in the ATR.

The following year, in March 2021, Lightbridge and France’s Framatome terminated their Enfission joint venture. In July 2021 announced a Cooperative Research and Development Agreement (CRADA) with the Battelle Memorial Institute, Pacific Northwest Division, the operating contractor of the Pacific Northwest National Laboratory (PNNL), in collaboration with the DOE. The goal of this agreement was to advance a critical stage in the manufacturing process of Lightbridge Fuel by demonstrating a casting process using depleted uranium-zirconium material. The total project value of the CRADA was approximately $663,000, with three-quarters of this funded by DOE for the scope performed by PNNL.

In June 2022, Lightbridge announced that the Massachusetts Institute of Technology (MIT) had been awarded approximately $800,000 by DOE’s Nuclear Energy University Program R&D Awards to study the deployment of Accident Tolerant Fuels (ATF) in Small Modular Reactors (SMRs). The project, funded entirely by DOE, would include simulation of the fuel and safety performance of Lightbridge Fuel inside a SMR designed by NuScale Power.

Lightbridge is developing a new fuel design that incorporates an extruded metallic bar composed of a zirconium-uranium matrix within a zirconium alloy cladding. Lightbridge says this will: significantly increase fuel thermal conductivity (compared with ceramics) promoting lower operating temperatures; offer complete retention of fission products avoiding release of those products upon cladding failure; and support higher power and longer fuel cycles.

The fuel is designed to work in both new and existing ($20+ billion market) reactors. Lightbridge also claims that its fuel increases power output and extends the length of the fuel cycle and offers nuclear plants a better solution for load-follow operations on a grid with renewables.

INL’s nuclear research capabilities rely heavily on the ATR, located at the ATR Complex on the INL Site near Idaho Falls. Numerous upgrades and improvements have been done since ATR entered service in 1967. ATR is a one-of-a-kind pressurised water test reactor that operates at very low pressures and temperatures compared with a large commercial nuclear power plant. The main product of a test reactor is neutrons rather than heat. ATR uses a beryllium reflector to help concentrate neutrons in the core, where they are needed for fuels and materials testing. ATR employs a unique design in which key internal components can be completely replaced during a core overhaul (Core Internals Changeout) every 10 years on average to enable long-term operations. The sixth core overhaul took place during 2021-2022.

Image: Fuel test assembly (courtesy of Lightbridge)

Date: Saturday, 17 December 2022
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