ORNL-4191 - the Molten Salt Energy Technologies Web Site

The chemical research and development effort
in close support of the MSBR program includes, as
described in this chapter, a variety of studies.
A major share of this effort is still devoted to the
immediate and anticipated problems of the operating
Molten-Salt Reactor Experiment.
Sampling of the MSRE fuel and coolant salts and
interpretation of the analyses for major and minor
constituents of the melt, and examination of metal
and graphite surveillance specimens from the core
and of specimens exposed to the pump bowl gases,
continue as routine, though obviously necessary,
portions of the total effort. Minor fractions of
several fission products continue to appear in the
pump-bowl gas space. The possibility that these
may occur as volatile compounds has prompted
examination of the chemistry and the vaporization
behavior of the little--known intermediate valence
fluorides of molybdenum.
Oxide-fluoride equilibria in the LiF-BeF system
and its more complex counterparts with added
UF, and ThF, are under study, since such
equilibria may well lead to separation processes
of value and seem to have shown us container
e
W. R. Grimes
K. E. Thoma
materials that will greatly aid our experimental
program.
The plans to substitute a lower melting and more
economical coolant for the LiF-BeF mixture in
the MSRE have requid examination of phase hehavior
among the alkali fluoroborates and of
ancillary questions of the decomposition pressure
of these materials and of possible undesirable
interactions of BF, with metals and lubricants to
which it would be exposed.
While recovery of uranium by fluorination (both
from fuel and blanket) and recovery of fuel salt
by vacuum distillation remain as the design reprocessing
methods, the recovery of protactinium
from the blanket and the removal of fission products
from the fuel by reductive extraction into
molten metals continue to show promise and ace
actively pursued.
Development studies in analytical chemistry
have been directed primarily to improvement in
analysis of radioactive samples of fuel for oxide
and uranium trifluoride and for impurities in the
helium gas from the MSR'E.
8.1 MSRE SALT COMPOSITION AND FURlTY signify that generalized corrosion in the fuel and
coolant circuits is practically absent, and that
Molten fuel, flush, and coolant salts have been
. intermittently circulated and stored in the MSRE
. .. . -
for approxirnately two years. In use, these salts 'Chemical analyses performed under the supervision
of C. E. X,atnb, Analytical Chemistry Division; spechave
been subjected to chemical analysis on a
trochemical data were obtained by W. R. Musick,
regular basis. The results of these analyses Analytical Chemistry Division.
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