NRC Completes Safety Evaluation for X-energy Xe-100 High-Temperature Gas-Cooled Reactor

Regulatory Milestone Reached

The Nuclear Regulatory Commission has formally completed its safety review of X-energy's Xe-100 high-temperature gas-cooled reactor, issuing a Final Safety Evaluation Report that marks the conclusion of both primary reviews required for a Construction Permit under 10 CFR Part 50. X-energy announced the development, describing the report as a foundational step toward breaking ground on the proposed Long Mott Generating Station in Texas.

The FSER documents the NRC staff's conclusion that the proposed plant and site provide an adequate safety basis to proceed with construction. The review encompassed the Xe-100's principal design criteria, preliminary design, safety analyses, probabilistic risk assessment, and associated research and development programs.

Independent Advisory Body Endorses Findings

Separately, the Advisory Committee on Reactor Safeguards — an independent body that advises the Commission — reviewed the NRC staff's evaluation in October and supported issuing the construction permit. The committee's endorsement adds a further layer of independent technical validation to the licensing process.

Design Characteristics and Siting Implications

The Xe-100's safety case is built around the passive physics of its TRISO-X coated particle fuel and pebble-bed core design, supplemented by traditional defense-in-depth systems. A notable consequence of this safety profile is a significantly reduced emergency planning zone of 400 metres, compared with the 10-mile radius required for conventional light-water reactors.

That compact footprint opens siting options that are not available to conventional designs, including placement within the perimeter of large industrial facilities or in closer proximity to populated areas. The Long Mott Generating Station, if constructed, would be the first grid-scale advanced nuclear reactor deployed at an industrial facility in United States history.

X-energy's development of the Xe-100 has been conducted under a cost-shared arrangement with the Department of Energy's Advanced Reactor Demonstration Program.

Precedent for Future Xe-100 Projects

Although each future application will be subject to individual NRC review, the regulatory work completed for Long Mott is expected to establish replicable precedents that could improve licensing efficiency for subsequent Xe-100 deployments. Supply-chain participants and project developers tracking the advanced reactor pipeline will note that the completion of the FSER represents a concrete, documented pathway under existing Part 50 regulations rather than a new licensing framework.

D.C. Cook earns back-to-back Utilities Service Alliance Optimizer Award

D.C. Cook nuclear power plant has received the Utilities Service Alliance Optimizer Award for the second consecutive year, with the recognition presented at the 2026 USA Executive Summit. The repeat win marks a notable milestone for the plant's supply chain organisation, which has undergone a sustained transformation in how it manages supplier relationships and pursues operational improvement.

A team confronting changing conditions

The plant's supply chain function comprises 61 staff members who collectively manage relationships with hundreds of suppliers. According to reporting by ANS Nuclear Newswire, the team reached a point where it acknowledged that established methods were no longer delivering the outcomes the station required. Rather than making incremental adjustments, leadership chose to pursue a more fundamental shift in organisational culture.

The transformation centred on four stated priorities: accountability, partnership, learning, and continuous improvement. The team worked to strengthen ties with its supplier base and to extend the principles of continuous improvement beyond internal boundaries, embedding them across the broader network of organisations that support plant operations.

Significance of consecutive recognition

Plant supply chain leadership has drawn a distinction between winning the award once and winning it twice. A single award, in their framing, can reflect a discrete innovation or a strong performance in a given period. A second consecutive award, by contrast, is taken as evidence that the underlying culture has genuinely changed — that continuous improvement has become an enduring characteristic of how the team operates rather than a project-specific achievement.

The Utilities Service Alliance Optimizer Award is presented to member organisations that demonstrate measurable progress in supply chain performance. Receiving it in back-to-back years positions D.C. Cook as a reference point within the nuclear supply chain community for how cultural and structural change can be sustained over time.

Broader implications for nuclear supply chain professionals

The D.C. Cook experience offers a concrete example of a mid-sized nuclear plant supply chain team navigating the pressures facing the wider industry. With a relatively lean workforce managing a large and complex supplier network, the station's approach — prioritising supplier partnership and cross-organisational accountability — reflects themes that resonate across the sector as plants seek to maintain reliability while managing cost and schedule pressures.

The 2026 USA Executive Summit, at which the award was presented, serves as a forum for nuclear utilities to share operational and supply chain practices. D.C. Cook's recognition at that event underscores the relevance of its model to peers across the United States nuclear fleet.

Centrus Ships First New Centrifuge to Piketon as HALEU Expansion Advances

First Centrifuge Delivered from Tennessee to Ohio

Centrus has shipped the first AC-100M centrifuge produced under its expansion programme from its Oak Ridge, Tennessee manufacturing centre to the Piketon, Ohio enrichment plant. The company described the shipment as the start of a phase in which completed centrifuges will move from Tennessee to Ohio for final assembly, with manufacturing rates expected to grow over time.

The Piketon plant first became operational in 2023 under a Department of Energy (DOE) contract initiated in 2019, when Centrus constructed an initial cascade of AC-100M centrifuges to demonstrate production of high-assay, low-enriched uranium (HALEU). The facility has been producing HALEU under DOE contract since late 2023, drawing on components manufactured in 2019 and earlier years, with more than four million machine-hours of operation recorded across the centrifuge technology.

Contracts and Investment Underpinning the Expansion

In June, Centrus was selected by the DOE for a USD 900 million task order to expand the Piketon facility to include commercial-scale HALEU production. The award also carries options, at the DOE's discretion, for up to USD 170 million to produce and deliver HALEU directly to the Department, bringing the total potential task order value to USD 1.07 billion.

In January, Centrus announced a USD 560 million investment to expand and modernise its Oak Ridge Technology and Manufacturing Center, converting it into a high-rate production plant capable of supporting the manufacture of thousands of advanced centrifuges. The company has also drawn on Tennessee's USD 70 million Nuclear Energy Fund, administered through the Tennessee Department of Economic and Community Development, to support the Oak Ridge work.

Scope of Expansion and Timeline

Beyond HALEU, the Piketon expansion is intended to produce low-enriched uranium feed material for the HALEU cascades, generate additional LEU quantities for the commercial market, and address national security requirements. The first new enrichment capacity resulting from the expansion is expected to come online in 2029.

The programme is projected to create 1,000 construction jobs and 300 new operating positions in Ohio, while retaining the 150 roles already in place at Piketon when the expansion began. The Oak Ridge facility is described as the only advanced centrifuge manufacturing plant in the United States.

Supply-Chain Context for Advanced Reactors

HALEU, enriched to between 5% and 20% uranium-235, is required as fuel for many advanced reactor designs currently under development. No commercial domestic source of HALEU exists in the United States, and the DOE has been actively supporting efforts to establish a home-grown supply chain for the material. Centrus President and CEO Amir Vexler noted that completing the first centrifuge and establishing the associated supply chain represented significant milestones for the company and for domestic enrichment capability.