IGCAR : Annual Report - Indira Gandhi Centre for Atomic Research

IGC
Annual Report 2007
solution in the concentration
range of 0.30-0.35M was
charged to three ion exchange
columns interconnected in
series to develop the required
length of borate band.
After commissioning the
plant, the displacement of
borate band in ABEP was
started. Once the column was
exhausted (ensured by the
absence of boric acid in the
sample drawn from the outlet of
the column), the resin was
hydraulically transferred to a
Regeneration Vessel (RV) for
regeneration.
After
regeneration and rinsing the
resin in RV, it was transferred
back to the same process ion
exchange column. The pressure
drop observed per column was
in the range of 1.5 to 2 bar
initially and later it stabilized to
1.2 bar per column. After
completion of 4 cycles of band
displacement, samples were
drawn from the rear end of the
borated band and sent for
isotopic analysis. As shown in
Fig. 3, the enrichment in 10 B to
40% was achieved in 2 months
of operation using fine resin
whereas with normal resin it
took 11 months to reach the
same level of enrichment in 10 B.
The operation of the plant has
given confidence in using fine
resin with manageable pressure
drop in columns, external
regeneration of the fine resin
after hydraulic transfer, and all
the more that enrichment could
be attained reach faster
compared to ion exchange
columns using normal resin.
III.D.2. Removal of Fluoride from the Effluent Generated
during Elemental Boron Production
Boron carbide containing 65%
enriched 10 B will be used as the
control rod material in FBRs.
R&D programme is being
pursued for enrichment of
isotopes of boron using ion
exchange chromatography,
production of elemental boron
from potassium fluoroborate
through molten salt
electrowining process. During
the production of elemental
boron from potassium
fluoroborate, effluents rich in
fluoride are generated. These
effluents cannot be disposed off
into water bodies due to the
disposal limit of less than 2
mg/litre of fluoride. Hence, a
method for effluent treatment
was developed to effectively
treat these fluoride effluents in
two stages. In the first stage,
the concentration is reduced to
less than 20 mg/litre using
chemical methods. This effluent
is further treated using
membrane filtration to reduce
the fluoride levels to