The Department of Energy’s Advanced Test Reactor (ATR) is in jeopardy of ceasing operations due to its aging facility and spent fuel storage nearing its capacity, the Government Accountability Office (GAO) said in a May 7 report.
The GAO recommended that DOE complete its evaluation of the Idaho Operations Office’s research and test reactor spent fuel storage facility reconfiguration plan to support the continued storage and management of ATR’s spent fuel past 2030. DOE concurred with GAO’s recommendation, according to agency comments in the report, and detailed action it has planned to address the situation.
DOE’s ATR is a one-of-a-kind high-flux thermal test reactor based at Idaho National Laboratory. The ATR facility, overseen by DOE’s Office of Nuclear Energy, provides advanced testing capabilities and isotope production for federal, industry and military partners and customers. The facility is planned to continue operations through the early 2050s.
The ATR also serves as a testing facility for the joint U.S. Navy and DOE National Nuclear Security Administration (NNSA) Naval Nuclear Propulsion Program that supports the Navy’s nuclear-powered fleet of submarines and aircraft carriers.
For the spent fuel, DOE’s research and test reactor spent fuel management facility at INL, the Idaho Nuclear Technical and Engineering Center (INTEC) Building 603, is coming up to its capacity. According to the report, as of May 2025, INTEC Building 603 spent fuel inventory included 3,432 spent ATR fuel elements, amounting to nearly three metric tons.
GAO said that DOE’s Offices of Environmental Management (EM) and Nuclear Energy currently do not have an approved plan to store ATR spent fuel outside the ATR spent fuel canal past 2029 or 2030. However, EM has the INTEC Building 603 contractor to begin a spent fuel packaging demonstration project to prepare spent fuel stored at the facility to be shipped out of Idaho.
According to the report, this action meets the 1995 Idaho Settlement Agreement and the 2020 ATR Addition commitments. The project is also being done in anticipation of an eventually approved plan for a permanent geologic repository to dispose of the nation’s waste, DOE officials said.
GAO conducted this audit from December 2024 to May 2026.