NTRS - NASA Technical Reports Server

Back to Results
Molten Salt Lattice Confinement Fusion (LCF) Fast Fission Reactor for Lunar and Planetary Surface PowerMolten salt fission reactors (MSR) have been suggested for lunar and planetary surface power systems. They have the advantage of operating at high temperature, for efficient thermal-electrical conversion, low pressure, long-lived with high nuclear fuel burnup. MSR are often designed to breed fissile 233U from natural 232Th by neutron capture and  decay via: 232Th(n,)233Th(,)233Pa(,)233U Unfortunately, this process requires 233Pa isotope separation and segregation to decay to 233U. This requirement prevents additional neutron capture that interferes with 233U breeding. Instead, Wooley’s sub-critical, fast fission, molten salt reactor would use externally generated tokamak fusion neutrons1,2 to fission all actinides.We propose a simpler fusion-fast-fission sub-critical reactor that generates fast neutrons in situ from lattice confinement fusion (LCF) to fission fertile and fissile actinides. This hybrid reactor doesn't require enriched 235U fissile pins to initiate fis-sion reactions, nor 233Pa separation and segregation during operation. Like Wooley’s, this hybrid reactor “burns” natural uranium (238U) or thorium (232Th) which avoids uranium enrichment and additional fissile material launch safety and security costs. The LCF neutron source is initiated by bremsstrahlung photoneutrons (Fig. 1)3 or isotopic neutron sources in electron-screened lattices (Fig. 2)4,5. Alternatively, the electrolytic Pd-deuterium co-deposition6protocol fast fissions7 both 232Th and 238U. However, an aqueous electrolyte-based system, without pressurization similar to conventional pressurized water fission reactors, is incapable of high temperatures due to the boiling point of the electrolyte slightly over 100 C. Molten salts can be used instead as was demonstrated at the University of Hawaii8 using a variety of Ni and Pd cathodes in lithiated, hydrided and deuterated salts. These salts have melting points often exceeding 500C making them suitable to efficiently produce electrical power9 through either Advanced Stirling Genera-tors (< 100 kWe) or closed-Brayton Cycle (> 100 kWe). This hybrid reactor could power a wide range of lunar or Martian applications from unmanned in-struments, to charging vehicles and entire facilities such as human habitats or in situ resource utilization. The power conversion cycles are Carnot Cycle limited, but generally 30% efficient at best. However, waste heat on the moon or Mars is important to surviving either two-week lunar nights or Martian nights as well as providing process heat for mineral extraction and “living off the land”
Document ID
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Lawrence Forsley
(JWK Corporation (United States) Annandale, Virginia, United States)
Theresa Benyo
(Glenn Research Center Cleveland, Ohio, United States)
Pamela Mosier-Boss
(Global Energy Corporation)
Leonard Dudzinski
(National Aeronautics and Space Administration Washington D.C., District of Columbia, United States)
Mathew Deminico
(Glenn Research Center Cleveland, Ohio, United States)
Date Acquired
February 17, 2022
Subject Category
Nuclear Physics
Spacecraft Propulsion And Power
Meeting Information
Meeting: Nuclear and Emerging Technologies for Space
Location: Cleveland, OH
Country: US
Start Date: May 8, 2022
End Date: May 12, 2022
Sponsors: American Nuclear Society
Funding Number(s)
WBS: 847801.
Distribution Limits
Public Use Permitted.
Technical Review
Single Expert
No Preview Available