Chemistry Reference
In-Depth Information
Feed U, Pu,
Np, Am, Cm,
FP 1 M HNO
3
0.1 M AHA
Scrub
0.5 M HNO
3
0.3 M AHA
Extractant
30 vol % TBP
U extraction
Scrub
Extractant
30 vol % TBP
Tc strip
6 M HNO
3
Cs/Sr
extraction
U strip
0.01 M HNO
3
U re-extract.
Tc-strip
NPEX
extraction
Cs/Sr
product
Separation by ion
exchange
Solvent
recycle
U-strip
Tc product
Pu/Np
product
Am/Cm
extraction/
separation
U product
FP,
Lns
Am/Cm
product
Hull, iodine
Decay
storage
Waste form
fabrication
Gen IV
reactor
LWR
ALWR
Low level
waste
Repository
FIGURe 1.7
Conceptual flowsheet of UREX+3 for processing of LWR spent fuel.
with Ce(III) was higher than 0.3 M at an aqueous acidity of 3 M HNO
3
and 0.08 M at
pH 3 (
471
). The isolation of FPs, namely
135
Cs, is not shown in the GANEX process.
Taking the CHON principle into consideration, a research group at JAEA proposed
the Amide-based Radio-resources Treatment with Interim Storage of Transuranics
(ARTIST) concept (
203, 472- 474
) for the Gen III+, IV reactor fuels (Figure 1.9). It
is comprised of the BAMA process for selective U(VI) extraction, TODGA-I and -II
processes for separation of all transuranics and separation of Sr, respectively, and
the DOC[4]C6 process for Cs recovery. Interim storage of all transuranics recovered
by the TODGA-I process was proposed. The admixture of TRUs and Lns satisfies
the IAEA's threshold for self-protection, 1 Sv/hr at 1 m, and thereby is actually a PR
product. From this admixture, Pu is to be separated, mixed with U, and fabricated to
MOX fuel for recycling to the Gen III+ reactors by PR modes in a combination of the
separation process and the fuel fabrication process. TRUs are to be separated from
Lns by an N-O hybrid donor,
N
-octyl-
N
-tolyl-1,10-phenanthroline-2-carboxyamide,
fabricated to MAs oxide fuel, and burned in the FBR.
The CFCs shown in Figures 1.7-1.9 are futuristic and therefore, will evolve
steadily in accord with circumstances. There are other well-known CFCs: NEXT
(
475
) in Japan and Total Partitioning Process in China (
476, 477
).
As described above, various separation processes and CFCs have been developed and
proposed, aiming at the modification of the current PUREX process and reformation of
the Improved PUREX and also aiming at the establishment of advanced reprocessing
processes. Figure 1.10 shows a classification scheme for these processes and CFCs.
