Atomics International

Atomics International was an American nuclear research and development organization created within North American Aviation in 1948. It began as the company’s Atomic Energy Research Department and was established to pursue the rapidly expanding postwar interest in nuclear science, reactor technology, and government-sponsored atomic-energy applications. The organization worked from facilities in Downey and the western San Fernando Valley of California, eventually concentrating much of its reactor testing and support work at Area IV of the Santa Susana Field Laboratory. The organization’s early work included small aqueous homogeneous reactors used for research, training, neutron production, and isotope-related applications. In 1952, one of its low-power reactors became the first nuclear reactor to operate in California. In the mid-1950s, the department was renamed Atomics International and pursued two complementary technology paths. The first was commercial and experimental power generation using sodium-cooled and organic-moderated reactors. The second was the development of compact nuclear power sources for remote and space applications under the U.S. government’s Systems for Nuclear Auxiliary Power program. Atomics International’s most prominent terrestrial project was the Sodium Reactor Experiment. In 1957, the reactor supplied electricity to the commercial grid serving Moorpark, California, making it the first U.S. nuclear reactor to generate electricity for a commercial power system. A 1959 fuel-channel obstruction caused partial melting in 13 of the reactor’s 43 fuel elements. The reactor was repaired and restarted in 1960, continuing operation until 1964. The organization also contributed to demonstration reactors at Hallam, Nebraska, and Piqua, Ohio, although both projects encountered technical difficulties and operated for only limited periods. Its SNAP work produced compact reactors and associated nuclear-power technology intended for satellites and other demanding environments. SNAP-10A was launched by the United States in 1965 and became the first nuclear reactor operated in space by the country. The program was subsequently cancelled, ending a major line of Atomics International’s government-funded development work. The company also operated hot-laboratory and fuel-handling facilities, performed radiochemistry and reactor-fuel development, and conducted non-nuclear energy research, including coal gasification using molten-salt technology. As enthusiasm for nuclear power and government reactor development declined, Atomics International gradually moved away from designing and testing nuclear reactors. In 1978 it was combined with other Rockwell International activities in the Energy Systems Group, ending its existence as an autonomous division. The remaining operations were folded into Rockwell’s Rocketdyne division in 1984. Nuclear programs ended in 1989 and the remaining non-nuclear research activities ended in 1998. Rockwell later sold Rocketdyne, but the historical environmental obligations associated with the Santa Susana site remained a continuing government and property-management issue. Atomics International is therefore best understood as a former technical division rather than a continuing standalone brand.

Atomics International originated in 1948 when North American Aviation created its Atomic Energy Research Department to manage nuclear research for government and commercial purposes. Its first major facility was at North American’s Downey plant in California, where the department designed and operated a small aqueous homogeneous reactor. On April 21, 1952, that reactor became the first nuclear reactor to operate in California. In 1955, the department adopted the Atomics International name and expanded its work across the San Fernando Valley and the Santa Susana Field Laboratory. The organization initially pursued reactor technology as a potential commercial energy business. It selected liquid sodium as a promising coolant because of its heat-transfer characteristics and relatively low operating pressure at high temperatures. This work led to the Sodium Reactor Experiment, constructed at Santa Susana. On July 12, 1957, the SRE supplied electricity to the commercial grid serving nearby Moorpark, a milestone in U.S. nuclear-energy history. In July 1959, an organic contaminant blocked narrow cooling passages in fuel assemblies and caused partial melting in 13 of 43 fuel elements. Atomics International repaired the reactor, restarted it in September 1960, and operated it until 1964. Atomics International also supported experimental commercial-reactor projects. It designed the sodium-cooled Hallam Nuclear Generating Station reactor in Nebraska and the organic-moderated and cooled Piqua reactor in Ohio. Both were demonstration projects for the Atomic Energy Commission and both experienced technical problems that limited their operating lives. Alongside these large systems, the organization built low-power water-boiler-type reactors ranging from a few watts to higher research power levels. The L-54 design was supplied to universities and research institutions, including Japan, where one installation became known as Japan Research Reactor-1. A second major line of work was the U.S. government’s Systems for Nuclear Auxiliary Power program. Atomics International became a principal contractor for compact, lightweight nuclear-electric systems intended for space, land, and marine uses. Reactor development, fuel work, radiochemistry, and testing required specialized facilities at Santa Susana. The 1965 launch of SNAP-10A made it the first nuclear reactor launched into space by the United States. The government subsequently cancelled the broader SNAP program, leaving several government-owned facilities at the site. The company’s other activities included operation of the Atomics International Hot Lab, fuel-rod disassembly and decladding, reactor-fuel fabrication, irradiation work, radiochemistry, and development of molten-salt coal-gasification technology. In 1966, a government liquid-metal research center was established at Santa Susana using facilities associated with the earlier SNAP work; it later became the Energy Technology Engineering Center. Declining government and commercial interest in nuclear development led to organizational consolidation. In 1978, Atomics International became part of Rockwell International’s Energy Systems Group and ceased to operate as an independent division. In 1984, the remaining activities moved into Rocketdyne. Nuclear programs ended in 1989, while non-nuclear research continued until 1998. Later ownership changes involving Rocketdyne did not restore Atomics International as a standalone business. The former operating sites, particularly Santa Susana Area IV, became associated with long-term cleanup and environmental review concerning historical chemical and radiological impacts.

1. 1998Final non-nuclear research ends

   Remaining non-nuclear research activities conclude.

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2. 1989Nuclear programs end

   Nuclear research and operating programs associated with the organization cease.

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3. 1984Merged into Rocketdyne

   Remaining activities are transferred to Rockwell’s Rocketdyne division.

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4. 1978Combined into Energy Systems Group

   Rockwell International consolidates Atomics International with other energy operations.

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5. 1965SNAP-10A launched

   The compact reactor becomes the first U.S. nuclear reactor launched into space.

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6. 1964SRE operation ends

   The Sodium Reactor Experiment is permanently shut down after restart and subsequent operation.

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7. 1959SRE fuel-damage incident

   Cooling-channel blockage causes partial melting in 13 fuel elements.

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8. 1957Sodium Reactor Experiment supplies grid power

   The SRE begins supplying nuclear-generated electricity to the Moorpark commercial grid.

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9. 1955Department renamed Atomics International

   North American Aviation gives its nuclear organization the Atomics International name.

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10. 1952First California nuclear reactor operates

    A small aqueous homogeneous reactor at Downey becomes the first nuclear reactor to operate in California.

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11. 1948Atomic Energy Research Department created

    North American Aviation establishes the internal department that would become Atomics International.

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A pioneering government and commercial nuclear-technology developer focused on experimental reactors, compact nuclear power, and aerospace-related energy systems.

• Sodium Reactor ExperimentExperimental nuclear reactor1957

  An experimental sodium-cooled reactor developed at Santa Susana to demonstrate nuclear electricity generation. It supplied power to the Moorpark commercial grid in 1957, suffered partial fuel-element melting in 1959, was repaired and restarted in 1960, and operated until 1964.

• SNAP-10ASpace nuclear-power system1965

  A compact nuclear reactor developed under the Systems for Nuclear Auxiliary Power program. Its 1965 launch demonstrated the use of a U.S. nuclear reactor for space power and represented Atomics International’s most visible aerospace achievement.

• Aqueous homogeneous reactorsResearch reactor1952

  Small reactors using an enriched uranyl-sulfate solution as both fuel medium and moderator. Atomics International developed models for research, training, neutron production, and isotope work, including the L-54, which was installed at institutions in the United States and abroad.

• Hallam Nuclear Generating Station reactorDemonstration power reactor1962

  A demonstration reactor developed for Nebraska using liquid sodium as coolant and graphite as moderator. It formed part of the organization’s effort to establish alternative commercial reactor concepts but encountered technical and operational limitations.

• Piqua Nuclear Power Facility reactorDemonstration power reactor1963

  An experimental Ohio reactor using an organic coolant and moderator. Developed as an Atomic Energy Commission demonstration project, it operated for only a limited period because of technical difficulties.

• Atomics International Hot LabNuclear laboratory service

  A specialized facility used for fuel-rod disassembly, decladding, and support of SNAP and other reactor research. It was later operated under Rockwell International and formed part of the technical infrastructure inherited by successor organizations.

• 1984Transfer remaining operations to RocketdyneM&A

  Rockwell ended the Energy Systems Group while retaining selected technical capabilities and programs.

  What changed. The remaining Atomics International activities were merged into Rockwell International’s Rocketdyne division.

  Aftermath. The Atomics International name no longer represented an autonomous operating division, and later nuclear work eventually ceased.

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• 1978Consolidate into Rockwell’s Energy Systems GroupStrategy

  Interest in nuclear power and government reactor development had declined, reducing the rationale for maintaining an autonomous division.

  What changed. Rockwell International combined Atomics International with other energy activities in the Energy Systems Group.

  Aftermath. Atomics International ceased to function as an independent division, although its technical work continued under successor structures.

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• 1955Adopt the Atomics International identityStrategy

  North American Aviation’s nuclear research department had expanded beyond basic research into reactor development and government programs.

  What changed. The parent company renamed the department Atomics International and developed it as a dedicated nuclear-technology division.

  Aftermath. The new division became a major participant in U.S. experimental reactor and space-nuclear programs.

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• 2009Santa Susana Field Laboratory contamination investigationControversy

  Federal environmental authorities investigated possible radiological and chemical contamination associated with historical reactor and energy research in Area IV of the Santa Susana Field Laboratory. Cleanup responsibilities and the condition of the former site remained subjects of regulatory action after Atomics International ceased operations.

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• 1959Sodium Reactor Experiment fuel-melting incidentControversy

  An organic contaminant blocked cooling passages in SRE fuel assemblies, causing partial melting in 13 of 43 fuel elements. The reactor was repaired and restarted, but the incident became a significant safety event in the organization’s operating history.

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• 1998Non-nuclear research activities cease

  The last remaining non-nuclear research activities linked to Atomics International ended.

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• 1989Nuclear research programs cease

  The remaining nuclear research and operating programs associated with Atomics International ended.

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• 1984Remaining operations transferred to Rocketdyne

  After the Energy Systems Group was ended, the remaining Atomics International activities were merged into Rockwell International’s Rocketdyne division.

  M&A
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• 1978Energy Systems Group absorbs Atomics International activities

  Rockwell International combined Atomics International with other operations in its Energy Systems Group as nuclear research activity declined.

  Leadership change
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• 1965SNAP-10A becomes the first U.S. nuclear reactor launched into space

  The successful launch of SNAP-10A demonstrated a compact nuclear reactor intended to provide electrical power for space applications.

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• 1957Sodium Reactor Experiment begins supplying electricity to a commercial grid

  Atomics International’s Sodium Reactor Experiment generated electricity for the Moorpark area, marking an early U.S. demonstration of nuclear power supplied to a commercial electrical system.

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1. Atomics International