Actinide removal from spent salts

Patent · Tue Jan 01 00:00:00 EST 2002

OSTI ID:874838

Hsu, Peter C ^[1]; von Holtz, Erica H ^[2]; Hipple, David L ^[2]; Summers, Leslie J ^[2]; Adamson, Martyn G ^[3]

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1. Pleasanton, CA
2. Livermore, CA
3. Danville, CA

A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• Assignee: The Regents of the University of California (Oakland, CA)
• Patent Number(s): US 6471922
• OSTI ID: 874838
• Country of Publication: United States
• Language: English

Related Subjects

actinide
removal
spent
salts
method
removing
contaminants
uranium
thorium
salt
molten
oxidation
mso
reactor
described
removed
analyzed
determine
carbonate
concentration
dissolved
water
reagents
added
precipitate
oxide
andor
diuranate
precipitated
materials
filtered
dried
packaged
disposal
radioactive
waste
90
filtration
solutions
&gt;20
returned
re-use
containing
&lt;20
require
clean-up
exchange
column
yields
contain
01
ppm
molten salt
radioactive waste
salt solution
/423/588/