Scott F. DeMuth

SP100 space reactor design

The SP100 space nuclear reactor was designed for use as an orbital power supply, lunar or Martian surface power station, and power supply for nuclear electric propulsion, with a scaleable power range of 10s kWe to 100s kWe. The original mission was an orbital power supply for the United States (U.S.) Strategic Defense Initiative (SDI) of the 1980s. Although the original sponsors were a consortium of the U.S. Department of Defense, U.S. Department of Energy, and the U.S. National Aeronautics and Space Administration (NASA), as the SDI effort diminished with the demise of the Soviet Union the mission evolved more toward the needs of NASA. Eventually, as the grandiose missions of NASA came into question in the early 1990s and less extravagant missions became more palatable, the SP100 program was discontinued. At the time of program discontinuation a complex infrastructure of industry and national laboratories had been established, and approximately

Assessment of an SP‐100 Bi‐Modal Propulsion and Power System

1-billion invested in design and development. The SP100 was not intended as a low cost one-time-use device; but rather, a highly flexible power supply that realized a cost advantage by being capable of multiple missions, based on a common design with the flexibility to evolve. The design and development team made major progress successfully fabricating and testing technology features that were essential to meeting the stringent safety, performance, lifetime and reliability requirements of proposed missions. The following paper attempts to describe the high level of sophistication incorporated in the SP100 design, and the high degree of technology readiness at the time of program discontinuation.

SP‐100 Reactor Subsystem Development

The attractiveness of using the SP‐100 space nuclear power system for both electric power production and direct thermal propulsion is discussed. A conceptual modification to the SP‐100 generic flight system that uses its hot, primary coolant to directly heat hydrogen propellant is presented. An analytical model of the system and its orbital‐mechanical behavior is presented and used to assess the benefits of a number of orbital transfer missions. Both a 500 kW and a 2.4 MW system are assessed. Preliminary results indicate that for LEO‐to‐GEO transfers, the SP‐100 bi‐modal system offers a 100 % increase in payload over conventional chemical‐only propulsion systems with transfer times on the order of days.

SP‐100 Control Drive Assembly Development Plan

The SP‐100 reactor subsystem consists of the pressure vessel, vessel internals, and fuel elements. Type A (standard) Nb‐1Zr and rhenium materials development efforts related to fabrication of the vessel, vessel internals, and fuel cladding/liner have been completed. Type A and Type C (PWC‐11) Nb‐1Zr loop fabrication has been successfully demonstrated by prototypic testing with flowing lithium at 1350 K for 1500 hr. Development of UN fuel has been completed, and the performance validated by irradiation testing to the full life (7 yr. full power) burnup of 6 atom %. Neutronic and hydraulic core performance have been validated by engineering mockup critical experiments in the Zero Power Physics Reactor at Argonne National Laboratory, and detailed core hydraulic flow testing with water. Essentially all feasibility issues have been settled for the full life SP‐100 reactor subsystem. Remaining SP‐100 reactor subsystem development efforts are focused on further reducing mass by the use of Type C (PWC‐11) Nb‐1Zr ...

Material Protection, Accounting, and Control Technologies (MPACT) Advanced Integration Roadmap

The Control Drive Assemblies are the only active components in the entire SP‐100 system. Consequently, the design challenges dealing with self‐welding, wear, and misalignment in the high temperature and high radiation environment are significant. Because of the harsh environment, it has been necessary to test a variety of materials for such components as bearings, electromagnetic coils, clutches, brakes, and gears. The current Control Drive Assembly technology status is adequate for the 20‐KWe design with a five‐year life, but has not yet been completely demonstrated for the 100‐KWe design with a full ten‐year life. The difference in technology status for the 20‐KWe and 100‐KWe designs is due to the shorter lifetime requirement of the 20‐KWe system.

Select Generic Dry-Storage Pilot Plant Design for Safeguards and Security by Design (SSBD) per Used Fuel Campaign

The development of sustainable advanced nuclear fuel cycles is a long-term goal of the Office of Nuclear Energy’s (DOE-NE) Fuel Cycle Technologies program. The Material Protection, Accounting, and Control Technologies (MPACT) campaign is supporting research and development (R&D) of advanced instrumentation, analysis tools, and integration methodologies to meet this goal (Miller, 2015). This advanced R&D is intended to facilitate safeguards and security by design of fuel cycle facilities. The lab-scale demonstration of a virtual facility, distributed test bed, that connects the individual tools being developed at National Laboratories and university research establishments, is a key program milestone for 2020. These tools will consist of instrumentation and devices as well as computer software for modeling, simulation and integration.

INSTITUTIONALIZING SAFEGUARDS-BY-DESIGN: HIGH-LEVEL FRAMEWORK

As preparation to the year-end deliverable (Provide SSBD Best Practices for Generic Dry-Storage Pilot Scale Plant) for the Work Package (FT-15LA040501–Safeguards and Security by Design for Extended Dry Storage), the initial step was to select a generic dry-storage pilot plant design for SSBD. To be consistent with other DOE-NE Fuel Cycle Research and Development (FCR&D) activities, the Used Fuel Campaign was engaged for the selection of a design for this deliverable. For the work Package FT-15LA040501–“Safeguards and Security by Design for Extended Dry Storage”, SSBD will be initiated for the Generic Dry-Storage Pilot Scale Plant described by the layout of Reference 2. SSBD will consider aspects of the design that are impacted by domestic material control and accounting (MC&A), domestic security, and international safeguards.