US lab reviews low-pressure microreactor design

06 February 2024

Idaho National Laboratory (INL) has completed a pre-conceptual design review of NANO Nuclear Energy Inc's ODIN low-pressure coolant microreactor design. The company's ZEUS microreactor design is also to be reviewed by the lab.

A rendering of the ODIN microreactor (Image: NANO Nuclear)

The microreactor company announced its Strategic Partnership Project Agreement with INL in April 2023, and requested the review to provide an external audit of the technical work completed to date on the ODIN design. "The review served to ensure that NANO Nuclear has thoroughly considered the necessary aspects of its design and the applicable regulations for advancing the technology towards a commercial product," the company said.

NANO Nuclear founder and Executive Chairman Jay Jiang Yu said the laboratory's evaluation of ODIN had provided "enormously useful and valuable insights" to assist the company's technological development. "This collaboration has equipped our world-class team with essential guidance and utilised national laboratory expertise to maintain our progress in the field of advanced nuclear reactors," he said.

According to company information, ODIN will use "conventional" uranium fuel with up to 20% enrichment, with a low-pressure coolant to minimise the stress on structural components and improve their reliability and service life. It will also use a unique reactivity control system design, aiming to have high reliability and robustness by minimising the number of moving parts. The reactor will operate at higher than conventional water-cooled reactor temperatures, and take maximum advantage of natural convection of coolant for heat transfer to the power conversion cycle at full power and for decay heat removal during reactor shutdown, operational transients, and off-normal conditions.

INL reviewed the technical information provided by NANO Nuclear on the reactor design, siting, fuel and decommissioning strategy, culminating in a panel review workshop to discuss every applicable area of the design and the future work required to successfully deliver an optimised and market-driven product. "The review panel provided recommendations and outlined a path forward for NANO Nuclear to advance and build on the work completed by its world-class scientific team to date," the company said.

INL is to carry out a similar review of NANO Nuclear's ZEUS microreactor, which features a fully solid core and is designed to fit within a standard ISO shipping container. Heat removal is through thermal conduction, eliminating the need for coolant and pumps.

"Idaho National Laboratory is a great resource to help the development and evolution of our advanced nuclear reactors," said James Walker, NANO Nuclear's CEO and head of nuclear reactor development. "Their recommendations will serve to both optimise our reactor designs, and ensure these developments simultaneously align with national standards and licensing requirements."

"The panel delivered tremendous value to us and our ODIN project," he added. "The planned review of the ZEUS reactor design is expected to provide that project with the same external input and direction which has so significantly benefitted ODIN."

Researched and written by World Nuclear News