President Donald Trump has appointed Ho Nieh as the 20th Chairman of the Nuclear Regulatory Commission. This is widely viewed as the latest move by the White House to shape the agency’s leadership in line with the administration’s nuclear energy agenda.
Nieh replaced David Wright, who was selected by Trump last January to lead the nuclear safety agency. Wright will remain a commissioner until his five-year term expires in 2030.
Nieh joined the NRC as a Republican commissioner in December, when the Senate confirmed his nomination as well as that of Republican Commissioner Doug Weaver. Republicans now hold a 3-2 majority on the commission, after Trump dismissed Democratic Commissioner Chris Hanson in June without citing a cause. Hanson was NRC Chairman during the Biden administration.
“It is an honour to have been designated as the Chairman of the US Nuclear Regulatory Commission,” Nieh said. “I am grateful for the opportunity to serve again at this agency that shaped my career and commitment to nuclear safety. I also appreciate the leadership of previous Chairman David Wright in guiding the NRC through a crucial period of transition as the agency embarks on this pivotal period of change.”
He added: “I look forward to continuing to work with the dedicated NRC staff and my fellow Commissioners, and I am energised by what we will accomplish together to enable the safe and secure use of nuclear technologies. With the support of Executive Order 14300 and the ADVANCE Act, the NRC is designing the future of nuclear safety regulation.”
Prior to becoming a Commissioner, Nieh served as an officer of Southern Nuclear on loan to the Institute of Nuclear Power Operations. He joined Southern Nuclear in March 2021 to assume the role of Vice President of Regulatory Affairs after more than 20 years as an NRC staff member. During his tenure at NRC, Nieh served as Director of the Office of Nuclear Reactor Regulation, where he was responsible for reactor safety licensing and oversight programmes for operating and new reactors. His other roles included: Senior Resident Inspector; Director of the Division Reactor Projects in Region I, in King of Prussia, Pennsylvania; Director of Division Inspection and Regional Support at NRC headquarters; and Chief of Staff for Commissioner William Ostendorff.
In addition, Nieh previously worked at the Nuclear Energy Agency as Director of the Division of Nuclear Safety Technology and Regulation. He also served as Communications Advisor to the International Atomic Energy Agency and worked at Knolls Atomic Power Laboratory as a civilian instructor for the Navy’s nuclear power programme.
Nieh earned his Bachelor of Engineering in marine engineering from New York Maritime College and is a graduate of the United States Naval Nuclear Power School. He attended Rensselaer Polytechnic Institute for graduate studies in nuclear engineering and earned a Master of Business Administration from Johns Hopkins University. Nieh also completed the Executive Education in Strategic Management programme at the Harvard Kennedy School of Government.
Trump’s moves to reorganise NRC have been criticised by former commissioners including Allison Macfarlane, who are concerned that it could erode the Commission’s independence and increase the chances that dangerous design flaws may go unnoticed. The administration, on the other hand, sees nuclear power is a national security priority, asserting that the quick construction of more reactors is needed to power artificial intelligence data centres.
However, Nieh is widely respected. Environment and Public Works ranking member Sheldon Whitehouse, who criticised the White House attempts to roll back NRC independence, supported Nieh’s nomination. “He struck me as an expert and professional on the substance, and someone committed to the integrity of the NRC,” Whitehouse said at the time. “The agency badly needs both of those.”
Todd Abrajano, President and CEO of the United States Nuclear Industry Council, congratulated Nieh on his appointment. “As demand for clean, reliable power grows, the NRC’s mission to uphold the highest safety standards while enabling the next generation of nuclear technologies has never been more important,” he noted. “I have no doubt that Chairman Nieh’s experience in both domestic and international nuclear regulation positions him well to guide the agency through this new era of nuclear deployment.”
Nieh’s appointment follows a period of upheaval at NRC during which more than 260 employees left, while the general counsel and executive director of operations were replaced. An agreement was also reached which allows NRC to fast-track reactors already vetted by the Department of Energy (DOE). Some former regulators criticised this as undermining NRC’s independence reducing its role to just rubber-stamping DOE policy.
The same day Nieh’s appointment was announced, NRC’s issued new staff guidance establishing expectations for working with reactor vendors who leverage authorisations from DOE or the Department of War (DOW – formerly Department of Defense) to move their designs toward commercialisation. The guidance is a direct response to Trump’s Executive Order 14300 signed in May 2025 Ordering the Reform of the Nuclear Regulatory Commission, which seeks to reduce regulatory barriers to the development of advanced nuclear technologies. The directive referred to NRC’s lengthy and costly licensing process, structure, and culture.
According to the American Nuclear Society’s NewsWire, NRC reform is not the only way the administration has worked to build nuclear momentum. It has also “made several big bets” on DOE and DOW pilot programmes that grant approval to advanced test reactors through authorisation rather than standard NRC permitting.
“Throughout the past year, the landscape of DOE and DOD [DOW] nuclear authorisation programmes has evolved at a dizzying speed. As these authorisation programmes have seen several projects progressing toward deployment in the next one to five years, a significant question has been left largely unanswered: What will the NRC approval process look like for successful DOE and DOD pilots that then seek broader commercial deployment of their designs?”
NewsWire noted that some companies involved in authorisation programmes indicated that they have been collaborating in some voluntary capacity with the NRC as they develop their projects. Oklo, said that it planned to “continue coordination with the NRC throughout the process” of building its Aurora-INL project. Aalo Atomics hosted a number of NRC observers alongside DOE reviewers at its preliminary design review for its Aalo-X project.
The new guidance clarifies to some extent how NRC collaboration will work. Mike King, NRC’s executive director for operations, explained, “As we conduct our independent reviews, we will focus on risks associated with commercialising these designs, leveraging insights from [DOE and DOW] reviews to avoid duplicating efforts. This collaboration will make our reviews more efficient and effective and strengthen our ability to ensure safety as these innovative technologies move towards deployment.”
The NRC staff guidance emphasised NRC observation of DOE and DOW projects throughout their phases of approval and construction. NRC observation throughout the authorisation process will directly support a vendor’s future NRC licensing plans, and vendors will be responsible for requesting NRC observers at various parts of the authorisation process. NRC will coordinate with vendors to identify relevant points where NRC staff observation would yield the most benefit to both parties.
The extent of observation is defined in the guidance: “In order to ensure a clear delineation in regulatory authority, the NRC staff assigned to observe the authorisation process should limit participation to asking questions to increase understanding of key concepts of the design.” NewsWire points out that NRC makes clear these early engagement opportunities through observation and collaboration “will be entirely voluntary and at the discretion of the vendor, further highlighting that aforementioned delineation in regulatory authority”.
