ORNL-4191 - the Molten Salt Energy Technologies Web Site

FROM REACTOR
t Li+, ~e*+ F-
I Th4: U": Po'.' !
I
COIJNTFRCURRFNT
CON [ACTOR
137
c l
ORNL-DWG 67--1,!920
H20, H* --------pp
HYDROFI. UDRlNATlON
Fig. 10.1. Suggested Flow Diagrams for Protactinium Removal by Oxide Extraction.
controlled initial composition is equilibrated with
the blanket. salt. It is expected that 23 3Pa will
distribute strongly to the oxide phase, while the
amount of 233U removed will be controlled by the
iirariium contenl. of the influent oxide phase. Subsequently,
the oxide phase might be stored while
the 233Pa decays and then largely recycled to the
contactor with some adjustment of the composition
and with removal of a portion of the (Th-U)O, solid
solution as product. Before returning the salt to
the reactor, the dissolved oxide could be removed
by HF-H sparging. 'This processing concept
might be applicable to a one-region breeder fuel.
Kt should only be necessary to adjust the uranium
content of the oxide phase upward iii order to be
compatible with the higher uranium content necessary
for a fuel salt.
It is planned to continue the present rneasuremerit
of the distribution of U4'., and perhaps Pa4+,
between fluoride and oxide phases as a function
of composition and temperature. In these measurements,
vigorous agitation will be used in the
hope of shortening the equilibration times. If the
results should warrant, a more detailed study of
the rate-controlling factors in the distribution of
U4-' and Pa4' will then he made.
Chemistry
e. E. I,. Bamberger R. B. Allen
J. P. Young C. F. Baes, Jr.
The advantages of silica as a container material
for molten salts in spectrophotometric, emf, and
other measurements include high thermal shock
resistance, good ultraviolet transmittance, high
electric resistivity, low price, arid ease of fabri-
cation. Fur the containment of molten LiF-BeF ~
mixtures, an obvious disadvantage is possible
chemical attack as a result of the reaction
However, when the equilibrium partial pressure of
SiF, was calculated for this reaction from avail-
able formation free energies for crysialline SiO,,
crystalline BeO, gaseous SiF,, and dissolved
JA NA F Th ermochenzic a 1 Ta b les , Cle :