The US Department of Energy (DOE) Loan Programs Office has invited X-energy to submit the second part of its application for a loan guarantee for the construction of a facility to fabricate TRISO-X fuel.

X-energy's pilot line at ORNL was dedicated at a ceremony in February (Image: X-energy)

The Maryland-based advanced reactor design and TRISO-based fuel fabrication company yesterday said the invitation for the Part II application continues its effort to secure funding for the construction of the first-of-a-kind facility, which will produce TRISO (TRI-structural ISOtropic) fuel based on high assay low-enriched uranium.

X-energy CEO Clay Sell said the company was continuing to build its relationship with the DOE.

"Our endeavour is for TRISO-X to be the first-to-market supplier of TRISO fuel for the emerging global advanced reactor business," he said.

Completion of the first phase of the loan guarantee application process and the invitation to proceed to the second phase fitted together with two existing cooperative agreements between X-energy and the DOE Office of Nuclear Energy, the company said. The first agreement, under the Advanced Reactor Concept Project, has seen X-Energy demonstrate TRISO-based fuel fabrication capability using commercial-scale equipment at the TRISO-X Pilot Line at Oak Ridge National Laboratory (ORNL) in Tennessee. Fuel produced on the pilot line is expected to begin qualification irradiation testing by early 2020.

The second agreement focuses on preliminary and detailed design and licence application development for the commercial-fabrication facility, and will culminate in the submission of a Part 70 licence application to the US Nuclear Regulatory Commission in 2021.

The Innovative Energy Loan Guarantee Program, which is administered by the Loan Programs Office, was created under Title XVII of the US Energy Policy Act of 2005. Launched in 2014, it provides up to USD12.5 billion to support the construction of innovative nuclear energy and front-end nuclear projects. Eligible applicants receive an invitation to submit the second part of their application after meeting basic eligibility requirements referred to in each solicitation in the first part of the application process.

The requested loan guarantee would be used for commercialisation of the TRISO-based fuel supply chain, X-energy said. The company intends to implement the fuel business as a joint venture under the name TRISO-X LLC.

X-energy is developing the Xe-100 200 MWt (75 MWe) reactor, which will use 'pebbles' of fuel containing TRISO fuel particles. Each Triso particle has a kernel of enriched uranium oxycarbide, encased in carbon and ceramic layers which prevent the release of radioactivity. The layers provide each particle with its own independent containment system, while the graphite surrounding the particles moderates the nuclear reaction. Such fuel cannot melt down.