DOE PAGES title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Tritium Control and Capture in Salt-Cooled Fission and Fusion Reactors: Status, Challenges, and Path Forward

Journal Article · · Nuclear Technology
DOI: https://doi.org/10.13182/NT16-101 · OSTI ID:1394392
 [1];  [1];  [1];  [1];  [2];  [3];  [4];  [5];  [6]
  1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
  2. Univ. of Wisconsin, Madison, WI (United States)
  3. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
  4. Shanghai Inst. of Applied Physics (China)
  5. Idaho National Lab. (INL), Idaho Falls, ID (United States)
  6. Univ. of New Mexico, Albuquerque, NM (United States)

Three advanced nuclear power systems use liquid salt coolants that generate tritium and thus face the common challenges of containing and capturing tritium to prevent its release to the environment. The fluoride salt–cooled high-temperature reactor (FHR) uses clean fluoride salt coolants and the same graphite-matrix coated-particle fuel as high-temperature gas-cooled reactors. Molten salt reactors (MSRs) dissolve the fuel in a fluoride or chloride salt with release of fission product tritium into the salt. In most FHR and MSR systems, the baseline salts contain lithium where isotopically separated 7Li is proposed to minimize tritium production from neutron interactions with the salt. The Chinese Academy of Sciences plans to start operation of a 2-MW(thermal) molten salt test reactor by 2020. For high-magnetic-field fusion machines, the use of lithium enriched in 6Li is proposed to maximize tritium generation—the fuel for a fusion machine. Advances in superconductors that enable higher power densities may require the use of molten lithium salts for fusion blankets and as coolants. Recent technical advances in these three reactor classes have resulted in increased government and private interest and the beginning of a coordinated effort to address the tritium control challenges in 700°C liquid salt systems. In this paper, we describe characteristics of salt-cooled fission and fusion machines, the basis for growing interest in these technologies, tritium generation in molten salts, the environment for tritium capture, models for high-temperature tritium transport in salt systems, alternative strategies for tritium control, and ongoing experimental work. Several methods to control tritium appear viable. Finally, limited experimental data are the primary constraint for designing efficient cost-effective methods of tritium control.

Research Organization:
Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Office of Nuclear Energy (NE), Reactor Fleet and Advanced Reactor Development. Nuclear Reactor Technologies
Grant/Contract Number:
AC05-00OR22725
OSTI ID:
1394392
Journal Information:
Nuclear Technology, Vol. 197, Issue 2; ISSN 0029-5450
Publisher:
Taylor & Francis - formerly American Nuclear Society (ANS)Copyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 71 works
Citation information provided by
Web of Science

References (50)

The molten salt reactor (MSR) in generation IV: Overview and perspectives journal November 2014
Molten salts database for energy applications journal November 2013
Assessment of Candidate Molten Salt Coolants for the Advanced High Temperature Reactor (AHTR) report March 2006
Assessment of Candidate Molten Salt Coolants for the NGNP/NHI Heat-Transfer Loop report June 2006
Basis for Fluoride Salt–Cooled High-Temperature Reactors with Nuclear Air-Brayton Combined Cycles and Firebrick Resistance-Heated Energy Storage journal October 2016
Thermal hydraulics analysis of the Advanced High Temperature Reactor journal December 2015
Liquid Fuel Molten Salt Reactors for Thorium Utilization journal May 2016
ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets journal November 2015
Reheat-Air Brayton Combined Cycle Power Conversion Design and Performance Under Nominal Ambient Conditions
  • Andreades, Charalampos; Scarlat, Raluca O.; Dempsey, Lindsay
  • Journal of Engineering for Gas Turbines and Power, Vol. 136, Issue 6 https://doi.org/10.1115/1.4026506
journal February 2014
Reheat Air-Brayton Combined Cycle Power Conversion Off-Nominal and Transient Performance journal February 2014
Advanced Nuclear Open Air-Brayton Cycles for Highly Efficient Power Conversion journal October 2015
Tritium release behavior from Li2BeF4 molten salt by permeation through structural materials journal November 2000
In-Situ Tritium Release Experiment from Molten Li 2 Bef 4 Salt Under Neutron Irradiation at Elevated Temperatures (Intrexflibe) journal December 1996
An integrated model of tritium transport and corrosion in Fluoride Salt-Cooled High-Temperature Reactors (FHRs) – Part I: Theory and benchmarking journal December 2016
Tritium Production, Releases and Population Doses at Nuclear Power Reactors journal September 1985
In situ measurement of tritium permeation through stainless steel journal June 2013
Graphite: Properties and Characteristics book February 2012
Graphite behavior and its effects on MSBR performance journal February 1969
Protection of nuclear graphite toward liquid fluoride salt by isotropic pyrolytic carbon coating journal November 2013
Sealing nuclear graphite with pyrolytic carbon journal October 2013
Degradation of carbon materials by intercalation journal January 1999
The retention of deuterium and tritium in POCO AXF‐5Q graphite
  • Causey, R. A.; Baskes, M. I.; Wilson, K. L.
  • Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, Vol. 4, Issue 3 https://doi.org/10.1116/1.573392
journal May 1986
Absorption and desorption of deuterium on graphite at elevated temperatures journal July 1988
Mechanism of Hydrogen Trapping and Transport in Carbon Materials journal January 2003
Thermal desorption of hydrogen from carbon and graphite at elevated temperatures journal July 2013
Desorption of hydrogen trapped in carbon and graphite journal November 2013
H2 Dissociative Adsorption at the Zigzag Edges of Graphite journal January 2004
First principles studies for the dissociative adsorption of H2 on graphene journal March 2003
A novel approach to fabricating fuel compacts for the next generation nuclear plant (NGNP) journal October 2008
Practical aspects for characterizing air oxidation of graphite journal October 2008
Spent Nuclear Fuel and Graphite Management for Salt-Cooled Reactors: Storage, Safeguards, and Repository Disposal journal August 2015
Hydrogen diffusion and solubility in pyrolytic carbon journal January 1979
Bulk hydrogen retention in neutron-irradiated graphite at elevated temperatures journal June 2009
Hydrogen behavior in carbon and graphite before and after neutron irradiation – Trapping, diffusion and the simulation of bulk retention– journal October 2011
Trapping State of Hydrogen Isotopes in Carbon and Graphite Investigated by Thermal Desorption Spectrometry journal March 2015
Investigation of morphology and hydrogen adsorption capacity of disordered carbons journal December 2014
Atypical hydrogen uptake on chemically-activated, ultramicroporous carbon journal April 2010
Hydrogen trapping in neutron-irradiated graphite journal April 2009
Kinetic effect of Pd additions on the hydrogen uptake of chemically-activated ultramicroporous carbon journal July 2010
Fission product behavior in the Molten Salt Reactor Experiment report October 1975
Pore structure of carbon adsorbents and the adsorbability of gases and vapors. 2. Analysis of the results of a study of krypton and xenon adsorption in light of the bulk micropore filling theory
  • Dubinin, M. M.; Nikolaev, K. M.; Polyakov, N. S.
  • Bulletin of the Academy of Sciences of the USSR Division of Chemical Science, Vol. 29, Issue 7 https://doi.org/10.1007/BF00949148
journal July 1980
Unique hydrogen adsorption properties of graphene journal November 2010
Study on the Air Core Formation of a Gas–Liquid Separator journal September 2015
Survey of advanced nuclear technologies for potential applications of sonoprocessing journal September 2016
Helium-cooled molten-salt fusion breeder report December 1984
JUPITER-II molten salt Flibe research: An update on tritium, mobilization and redox chemistry experiments journal February 2006
A Vacuum Disengager for Tritium Removal from HYLIFE-II Reactor Flibe journal May 1992
Design of a Helium-Cooled Molten-Salt Fusion Breeder journal July 1985
Tritium production, releases and population doses at nuclear power reactors journal July 1985
ARC: A compact, high-field, fusion nuclear science facility and demonstration power plant with demountable magnets text January 2014

Cited By (5)

Impurities in Primary Coolant Salt of FHRs: Chemistry, Impact, and Removal Methods journal July 2019
Numerical simulation of tritiated bubble trajectory in a gas-liquid separator journal October 2017
Verification of Modelica-Based Models with Analytical Solutions for Tritium Diffusion journal March 2018
Fusion Blankets and Fluoride-Salt-Cooled High-Temperature Reactors with Flibe Salt Coolant: Common Challenges, Tritium Control, and Opportunities for Synergistic Development Strategies Between Fission, Fusion, and Solar Salt Technologies journal December 2019
Source Term Study on Tritium in HTR-PM: Theoretical Calculations and Experimental Design journal January 2017