Spent flowsheets

Kraft pulping is a common process in the paper industry. Figure 8.4 shows a simplifled flowsheet of the process. In this process, wood chips are reacted (cooked) with white liquor in a digester. White liquor (which contains primarily NaOH, NaiS, Na2C03 and water) is employed to dissolve lignin from the wood chips. The cooked pulp and liquor are passed to a blow tank where the pulp is separated from the spent liquor weak black liquor which is fed to a recovery system for... 

The above information was used to develop conceptual flowsheets for the extraction of all of the actinides (U, Np, Pu, Am, and Cm) from high-level liquid waste from PUREX processing using 0.4 M 0fuel using 0.8 M DHDECMP in DEB. In both flowsheets, no oxidation state of Pu is necessary since the III, IV, and VI state extract into the organic phase. 

Conceptual flowsheet for the extraction of actinides from dissolved spent LWR fuel using 0.8 M DHDECMP in DEB. 

Nogueira, C. A. Delmas, F. New flowsheet for the recovery of cadmium, cobalt and nickel from spent Ni-Cd batteries by solvent extraction. Hydrometallurgy 1999, 52, 267-287. 

Figure 16 Process flowsheet of a GAC system with regeneration. In this complete GAC adsorption and regeneration system, four GAC columns can be operated in parallel or in series. Spent carbon is transferred to a multiple-hearth furnace for thermal regeneration. Regenerated carbon is mixed with virgin makeup and pumped back to the GAC columns. The GAC columns are backwashed periodically. (From Ref. 27.)...

FIGURE 1.7 Conceptual flowsheet of UREX+3 for processing of LWR spent fuel. 

Collins, E.D., Benker, D.E., Felker, L.K. et al. 2005. Development of the UREX + 3 flowsheet - An advanced separations process for spent fuel processing. ANS 2005 Winter Meeting, Washington, DC, November 17. 

Thanks to these promising results, two hot tests were further carried out in the hot cells of the ITU (181, 182) on a genuine highly active PUREX raffinate obtained by reprocessing 500 g of a U02 commercial reactor spent fuel (60 GWd/t). Oxalic acid and HEDTA were added to the PUREX high-activity raffinates, and its acidity was adjusted to 4.4 M. The flowsheet tested was... 

The CTH actinide separation process was developed as a possible means to reduce the expected long term dose to man from a geologic repository containing solidified radioactive waste from the reprocessing of spent nuclear fuel The distribution data for the elements present in significant amounts in the high level liquid waste (HLLW) from a Purex plant, the general principles and the flowsheet have been described in detail elsewhere A... 

Fig. 5.1. Spent sulfuric acid regeneration flowsheet. H2S04(f) in the contaminated spent acid is decomposed to S02(g), 02(g) and H20(g) in a mildly oxidizing, 1300 K fuel fired furnace. The furnace offgas (6-14 volume% S02, 2 volume% 02, remainder N2, H20, C02) is cooled, cleaned and dried. It is then sent to catalytic S02 + Vi02 —> S03 oxidation and H2S04 making, Eqn. (1.2). Air is added just before dehydration (top right) to provide 02 for catalytic S02 oxidation. Molten sulfur is often burnt as fuel in the decomposition furnace. It provides heat for H2S04 decomposition and S02 for additional H2S04 production. Tables 5.2 and 5.3 give details of industrial operations.

FIGURE 1. Simplified nuclear materials flowsheet to achieve the spent fuel... 

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