Experimental Breeder Reactor II

Experimental Breeder Reactor II
Name	Experimental Breeder Reactor II
Country	United States
Location	Idaho National Laboratory
Status	Decommissioned
Reactor type	Sodium-cooled fast reactor
Thermal power	62.5 MWt
Electrical output	20 MWe
First crit	1963
Shutdown	1994

Experimental Breeder Reactor II The Experimental Breeder Reactor II was a sodium-cooled fast reactor prototype built at the Argonne National Laboratory site within the Idaho National Laboratory complex near Idaho Falls, Idaho. It served as a testbed for breeder reactor concepts developed by Atomic Energy Commission (United States), involving collaborations with Argonne National Laboratory (West), Department of Energy (United States), National Reactor Testing Station, and contractors such as General Electric and Westinghouse Electric Corporation. The facility operated from the early 1960s through the 1990s and influenced programs at Oak Ridge National Laboratory, Los Alamos National Laboratory, and international projects like Superphénix, Monju reactor, and Phénix (reactor).

Introduction

EBR-II originated from post-World War II initiatives by the Atomic Energy Commission (United States) and research agendas at Argonne National Laboratory to demonstrate fast breeder reactor principles and fuel cycle technologies. The project intersected with policies from the Atoms for Peace program and technical collaborations influenced by exchanges with United Kingdom Atomic Energy Authority, Commissariat à l'énergie atomique, and Power Reactor and Nuclear Fuel Development Corporation. Sitting within the Idaho National Laboratory complex, EBR-II became linked to programs at National Renewable Energy Laboratory through cross-agency coordination and to defense-related activities associated with Sandia National Laboratories.

Design and Technology

EBR-II was a pool-type, sodium-cooled fast reactor using metallic uranium-alloy fuel and a closed fuel cycle demonstration that included fuel reprocessing technologies developed at Argonne National Laboratory (West), with engineering support from Bechtel Corporation and materials research from Oak Ridge National Laboratory. The reactor core design drew on neutronics modeling advances from Los Alamos National Laboratory and thermal-hydraulic analysis techniques from Massachusetts Institute of Technology. Its primary coolant system employed liquid sodium and pumps supplied by industrial firms such as Allis-Chalmers and components tested in tandem with standards from American Society of Mechanical Engineers. Instrumentation and control systems incorporated digital techniques pioneered at Sandia National Laboratories and software methodologies influenced by early computing at National Bureau of Standards.

Fuel technology included uranium-zirconium and ternary alloys developed in collaboration with Union Carbide, with cladding materials testing informed by work at Argonne National Laboratory (East), Battelle Memorial Institute, and metallurgical studies at Carnegie Mellon University. The breeding ratio, neutron flux profiles, and decay heat removal strategies were evaluated using computational physics codes from Knolls Atomic Power Laboratory and validation experiments coordinated with Brookhaven National Laboratory. Safety systems featured passive heat removal concepts later referenced in design reviews by Nuclear Regulatory Commission advisors and compared with sodium-cooled concepts at Phénix (reactor) and Fast Flux Test Facility.

Operational History

EBR-II achieved first criticality in 1963 and entered experimental operations supporting programs at Argonne National Laboratory, Department of Energy (United States), and international research partners including Comisión Nacional de Energía Atómica (Argentina). Over its operational life, EBR-II hosted experiments tied to fuel cycle demonstrations, irradiation tests coordinated with European Atomic Energy Community, and materials testing aligned with initiatives at Joint Research Centre. Personnel transfers and scientific exchanges involved institutions such as Massachusetts Institute of Technology, University of California, Berkeley, Princeton University, and University of Wisconsin–Madison. Data from EBR-II contributed to reactor physics benchmarks used by International Atomic Energy Agency and informed licensing discussions with the Nuclear Regulatory Commission.

Safety Incidents and Shutdown

During its operational life EBR-II experienced sodium leaks and maintenance incidents that required intervention by teams trained under protocols developed with Los Alamos National Laboratory and Oak Ridge National Laboratory. Notable safety evaluations referenced lessons from accidents at Three Mile Island Nuclear Generating Station and later influenced analyses tied to Chernobyl disaster studies, though EBR-II did not experience a core meltdown. Economic pressures following federal budget shifts under administrations influenced by policies related to the Office of Management and Budget (United States) and changing priorities at the Department of Energy (United States) led to decisions to retire prototype reactors. EBR-II ceased power operations in 1994 amid strategic program reorientations similar to closures at Shippingport Atomic Power Station and Fermi 1.

Decommissioning and Waste Management

Decommissioning of EBR-II involved dismantlement activities coordinated by Idaho National Laboratory staff and contractors from Fluor Corporation and waste disposition handled through procedures established with the Department of Energy (United States) and facilities such as the Waste Isolation Pilot Plant. Radioactive sodium disposal, spent fuel handling, and metallurgical waste streams were managed under frameworks influenced by regulations from the Environmental Protection Agency and technical guidance from Nuclear Energy Agency. Decontamination and site remediation efforts linked with environmental assessments conducted by Idaho Department of Environmental Quality and community engagement with Bureau of Land Management and local governments in Bonneville County, Idaho were part of the closure process.

Legacy and Influence on Nuclear Technology

EBR-II's demonstrations of sodium-cooled fast reactor operation, metallic fuel behavior, and integrated fuel cycle processes informed successor designs and policy debates at Department of Energy (United States), academic programs at Massachusetts Institute of Technology and University of California, Berkeley, and international fast reactor projects like Monju reactor, Superphénix, and proposals evaluated by the International Atomic Energy Agency. Technology transfer and archival data supported advanced reactor concepts promoted by private ventures influenced by Generational nuclear reactor development initiatives and helped shape research agendas at Oak Ridge National Laboratory and Argonne National Laboratory (West). The reactor's operational record contributed to safety case studies referenced in reports by the Nuclear Regulatory Commission and informed waste management strategies adopted at sites including Hanford Site and Savannah River Site.

Category:Decommissioned nuclear reactors in the United States