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Title: Separation of silicon carbide-coated fertile and fissile particles by gas classification

Abstract

The separation of /sup 235/U and /sup 233/U in the reprocessing of HTGR fuels is a key feature of the feed-breed fuel cycle concept. This is attained in the Fort St. Vrain (FSV) reactor by coating the fissile (Th-/sup 235/U) particles and the fertile (Th-/sup 233/U) particles separately with silicon carbide (SiC) layers to contain the fission products and to protect the kernels from burning in the head-end reprocessing steps. Pneumatic (gas) classification based on size and density differences is the reference process for separating the SiC-coated particles into fissile and fertile streams for subsequent handling. Terminal velocities have been calculated for the +- 2 sigma ranges of particle sizes and densities for ''Fissile B''--''Fertile A'' particles used in the FSV reactor. Because of overlapping particle fractions, a continuous pneumatic separator appears infeasible; however, a batch separation process can be envisioned. Changing the gas from air to CO/sub 2/ and/or the temperature to 300/sup 0/C results in less than 10 percent change in calculated terminal velocities. Recently reported work in gas classification is discussed in light of the theoretical calculations. The pneumatic separation of fissile and fertile particles needs more study, specifically with regard to (1) measuring the recoveries andmore » separation efficiencies of actual fissile and fertile fractions in the tests of the pneumatic classifiers; and (2) improving the contactor design or flowsheet to avoid apparent flow separation or flooding problems at the feed point when using the feed rates required for the pilot plant.« less

Authors:
Publication Date:
Research Org.:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
OSTI Identifier:
7345989
Report Number(s):
ORNL/TM-5091
TRN: 76-018688
DOE Contract Number:  
W-7405-ENG-26
Resource Type:
Technical Report
Country of Publication:
United States
Language:
English
Subject:
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS; 21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS; COATED FUEL PARTICLES; SORTING; FERTILE MATERIALS; FISSILE MATERIALS; SPENT FUELS; HEAD END PROCESSES; PNEUMATICS; THORIUM CARBIDES; URANIUM 233; URANIUM 235; URANIUM CARBIDES; VRAIN REACTOR; ACTINIDE COMPOUNDS; ACTINIDE ISOTOPES; ACTINIDE NUCLEI; ALPHA DECAY RADIOISOTOPES; CARBIDES; CARBON COMPOUNDS; ENERGY SOURCES; ENRICHED URANIUM REACTORS; EVEN-ODD NUCLEI; FISSIONABLE MATERIALS; FLUID MECHANICS; FUEL PARTICLES; FUELS; GAS COOLED REACTORS; GRAPHITE MODERATED REACTORS; HEAVY NUCLEI; HELIUM COOLED REACTORS; HTGR TYPE REACTORS; ISOMERIC TRANSITION ISOTOPES; ISOTOPES; MECHANICS; MINUTES LIVING RADIOISOTOPES; NUCLEAR FUELS; NUCLEI; POWER REACTORS; RADIOISOTOPES; REACTOR MATERIALS; REACTORS; THORIUM COMPOUNDS; URANIUM COMPOUNDS; URANIUM ISOTOPES; YEARS LIVING RADIOISOTOPES; 050800* - Nuclear Fuels- Spent Fuels Reprocessing; 210802 - Nuclear Power Plants- Economics- Fuel Cycle

Citation Formats

Vaughen, V. C.A. Separation of silicon carbide-coated fertile and fissile particles by gas classification. United States: N. p., 1976. Web. doi:10.2172/7345989.
Vaughen, V. C.A. Separation of silicon carbide-coated fertile and fissile particles by gas classification. United States. https://doi.org/10.2172/7345989
Vaughen, V. C.A. 1976. "Separation of silicon carbide-coated fertile and fissile particles by gas classification". United States. https://doi.org/10.2172/7345989. https://www.osti.gov/servlets/purl/7345989.
@article{osti_7345989,
title = {Separation of silicon carbide-coated fertile and fissile particles by gas classification},
author = {Vaughen, V. C.A.},
abstractNote = {The separation of /sup 235/U and /sup 233/U in the reprocessing of HTGR fuels is a key feature of the feed-breed fuel cycle concept. This is attained in the Fort St. Vrain (FSV) reactor by coating the fissile (Th-/sup 235/U) particles and the fertile (Th-/sup 233/U) particles separately with silicon carbide (SiC) layers to contain the fission products and to protect the kernels from burning in the head-end reprocessing steps. Pneumatic (gas) classification based on size and density differences is the reference process for separating the SiC-coated particles into fissile and fertile streams for subsequent handling. Terminal velocities have been calculated for the +- 2 sigma ranges of particle sizes and densities for ''Fissile B''--''Fertile A'' particles used in the FSV reactor. Because of overlapping particle fractions, a continuous pneumatic separator appears infeasible; however, a batch separation process can be envisioned. Changing the gas from air to CO/sub 2/ and/or the temperature to 300/sup 0/C results in less than 10 percent change in calculated terminal velocities. Recently reported work in gas classification is discussed in light of the theoretical calculations. The pneumatic separation of fissile and fertile particles needs more study, specifically with regard to (1) measuring the recoveries and separation efficiencies of actual fissile and fertile fractions in the tests of the pneumatic classifiers; and (2) improving the contactor design or flowsheet to avoid apparent flow separation or flooding problems at the feed point when using the feed rates required for the pilot plant.},
doi = {10.2172/7345989},
url = {https://www.osti.gov/biblio/7345989}, journal = {},
number = ,
volume = ,
place = {United States},
year = {Thu Jul 01 00:00:00 EDT 1976},
month = {Thu Jul 01 00:00:00 EDT 1976}
}