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Hydroxylamine Purex process

The Purex process, ie, plutonium uranium reduction extraction, employs an organic phase consisting of 30 wt % TBP dissolved in a kerosene-type diluent. Purification and separation of U and Pu is achieved because of the extractability of U02+2 and Pu(IV) nitrates by TBP and the relative inextractability of Pu(III) and most fission product nitrates. Plutonium nitrate and U02(N03)2 are extracted into the organic phase by the formation of compounds, eg, Pu(N03)4 -2TBP. The plutonium is reduced to Pu(III) by treatment with ferrous sulfamate, hydrazine, or hydroxylamine and is transferred to the aqueous phase U remains in the organic phase. Further purification is achieved by oxidation of Pu(III) to Pu(IV) and re-extraction with TBP. The plutonium is transferred to an aqueous product. Plutonium recovery from the Purex process is ca 99.9 wt % (128). Decontamination factors are 106 — 10s (97,126,129). A flow sheet of the Purex process is shown in Figure 7. [Pg.201]

As U is the major component of a SNF see Table 1.2, its initial separation in reprocessing alleviates the mass burden of following steps and is considered preferable. The UREX process developed in the AFCI program of the United States is based on the PUREX process (30 vol % TBP in n-dodecane) and suppression of extractions of Pu and Np by reduction/complexation (175-182). Plutonium and Np are reduced by acetohydroxamic acid (AHA, CH3CONHOH) to Pu(III), Np(V), and Np(IV). U is kept in an extractable U(VI) state. Although Np(IV) is also extractable, AHA forms a complex with Np(IV) that is soluble in the aqueous phase. In the case where reoxidation of Pu(III) occurs, the Pu(IV) also transfers to the aqueous phase by forming a Pu(IV)-AHA complex. Thus, U is exclusively extracted. AHA decomposes to hydroxylamine and acetic acid (176). [Pg.12]

Anyun, Z., Jingxin, H., Xianye, Z., Fangding, W. 2001. Hydroxylamine derivatives in PUREX process, VI. Study on the partitioning of uranium/neptunium and uranium/ plutonium with N,N-diethylhydroxylamine in the purification cycle of uranium contactor. Solvent Extr. IonExch. 19 (6) 965-979. [Pg.41]

Plutonium trifluoride. Plutonium trifluoride can be converted directly to plutonium metal, or it is an intermediate in the formation of PUF4 or PUF4 -PUO2 mixtures for thermochemical reduction, as described in Sec. 4.8. The stabilized Pu(III) solution, produced by cation exchange in one of the Purex process options for fuel reprocessing, is a natural feed for the formation of plutonium trifluoride, as is shown in the flow sheet of Fig. 9.9 [03]. A typical eluent solution from cation exchange consists of 30 to 70 g plutonium/liter, 4 to 5 Af nitric acid, 0.2 Af sulfamic acid, and 03 Af hydroxylamine nitrate. The sulfamic acid reacts rapidly with nitrous acid to reduce the rate of oxidation of Pu(III) to about 4 to 6 percent per day. Addition of ascorbic acid to the plutonium solution just before fluoride precipitation reduces Pu(IV) rapidly and completely to Pu(III). [Pg.443]

The next step in the Purex process after primary decontamination is separation of plutonium from uranium. This is done by reducing plutonium to the trivalent state, in which it is inextractable by TBP, while leaving the uranium in the extractable hexavalent condition. Reductants that have been used for this purpose include Fe, U, hydroxylamine, or cathodic reduction. [Pg.486]

Figure 10.29 Principal steps in Purex process for LMFBR fuel. F.P. = fission products HAN = hydroxylamine nitrate ... Figure 10.29 Principal steps in Purex process for LMFBR fuel. F.P. = fission products HAN = hydroxylamine nitrate ...
R7. Richardson, G. L, and J. L. Swanson Plutonium Partitioning in the Purex Process with Hydrazine-Stabilized Hydroxylamine Nitrate, Report HEDL-TME-75-31, June 1975. [Pg.561]

Once plutonium and uranium are coextracted and codecontaminated, plutonium is separated from uranium in the partitioning contactor by reduction to Pu(III) with a reduc-tant. Over the years, a number of plutonium reductants have been proposed. The most widely used reductant to partition plutonium from uranium in the PUREX process was (Fe(S03NH2)2) other alternates were proposed such as hydrazine-stabilized ferrous nitrate or uranous nitrate, and hydroxylamine salts. [Pg.413]

HNA was incorporated into many nuclear fuel reprocessing plants in the early 1970s replacing the ferrous sulfamate and hydroxylamine sulfate for plutonium reduction because it possessed the proper Pu(IV) to Pu(III) reduction attributes and the gaseous reaction products N2, N2O, and water contributed to the minimization of the volume of solid wastes produced. The French PUREX process at the La Hague site safely uses a mixture of HNA and nitric acid for the reductive stripping phase of plutonium. The British also used HNA in the thermal oxide reprocessing plant (THORP) for over several years (Barney, 1998). [Pg.415]

Me Kibben, J.M. and J.E. Bercaw, 1971. Hydroxylamine nitrate as a plutonium reductant in the PUREX solvent extraction process. Report DP-1248. Aiken, SC Savannah River Laboratory. [Pg.465]


See other pages where Hydroxylamine Purex process is mentioned: [Pg.201]    [Pg.142]    [Pg.491]    [Pg.940]    [Pg.949]    [Pg.840]    [Pg.940]    [Pg.7085]    [Pg.7197]    [Pg.135]    [Pg.414]   
See also in sourсe #XX -- [ Pg.949 ]

See also in sourсe #XX -- [ Pg.949 ]

See also in sourсe #XX -- [ Pg.6 , Pg.949 ]




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