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102 developed far enough to lead to an integrated process. Further, after dPSCQVery Of the s@ductiVe-eXtractisn/metal-~ra~S~er process, Which, though cmplbex, involved handling only liquids and gases, studies of all other separations were largely abandoned. An ion-exchange process €or selective removal of lanthanide ions f r~m the molten fuel has long seemed attractive in principle,B9 but no attractive ion exchanger €or these materials has been demonstrated. An obvious dfffi~ulty is posed by the aggressive tendency of the molten LiF-BeF2- ThF4-WF4 system to react wdth most materials that are likely to be useful, Certain refractory lanthanide compounds (such as carbides, nitrides, or sulfides) could conceivably be useful and sufficiently stable. The only candidate materials to date have been materials such as CeF3 and LaF3. By virtue of the fomati~~~ sf nearly ideal solid soluti~ns among the rare earth trifEuorides, these compounds are capable of removing other (higher cross-section) lanthanides from the molten fluorides. The ~leutro~~ cross sections of cerium and Pantharem are not negligible; because such an exchange process saturates the treated fuel with CeF3 or LaF3, the resulting fuel solution still has substantial parasitic neutron absorbers .19 CeF3 (or LaF3) exchanger also would presumably remove trivalent actfnides (including plutonium) from the molten fuel, ThPs would be unacceptable fQP EbMSR. No overall chemical process based on such sepa~~tfo~s has been de- scribed e Obviously, much development would be necessary before such a process could be demonstrated, hkaso, several solids-handling operations apparently would be required and no process based QII these operations could be capable of processing a DMSR on a short time cycle. However, given the present state of knowledge, the following process can be visu- alized to operate m relatively large (1- to 2-hn3) batches of DMSR fuel, possibly after coding for 5 or 6 de The following steps would be necessary * me . w.9 . . . . . . .
, . . . . . . , -c%w probably still be mostly tri€%u~ride~, This oxidized system will be corrosive, but it should be manageable in equipment of nickel or nickel-elad Hastelloy. Step 2. Precipitate the insoluble oxides ushg water vapor diluted in helium. 'RE oxides UO2% Pa205, Pu02, Ce02, probably Np02, and possibly Am02 and @m02 should be obtairped, With the exception of %r02 and Pa205, these will be largely in solid SUPU~FQ~. The oxide solid solution is likely to contain 15 to 20% of Tho2; this WQUP~ correspond to a few (less than 5) percent of the T%F4 present in the fluoride. Recover the oxides by decantation and filtration. Step 3. Hydrofluorinate the oxides from step 2 into the purified LIP- Step 4. Step 5. Step 6, BeP2-ThF4 melt from step 7 and reduce the melt with H2 and then with lithium, thorim, or beryllium to reconstitute fuel with the desired UF~/UF~ ratio. Hydr~fluo~inate the liquid from step 2 to remove excess oxide ion. kidize to get samarium and (if possible) europium to SmF3 and EuF3. Treat the melt from step 4 with an excess of CeF3. This might be done in a column or in a two- or three-batch countercurrent operation. This T ~ ~ Q V a ~ major S fraction of the rare earths but does essentially nothing for cesium, rubidium, strontium, and barium. (If neptunium, americium, and curium are appreciably harder to oxidize than plutonium, they should remain in the salt in step 2 and should be removed on the CeF3 in step 5.) The LfF-BeF2-ThF4 melt from step 5 contains sdy a fraction of the rare earth poisons but, of course, is saturated with CeF3. oxidize the ee* to ~e4+. Step 7. ~recipitate the ce4+ as c~o~. some will accompany the Step 8. Ce02, but the quantity should be small. by decantation and filtration. the fissile material recovery operation in step 3. Dissolve the solid &F3 (contaminated with rare earths) from step 5 in some suitable salt (preferably not SLiF-BeP2) and oxidize the Ce3+ to @e4'@ Separate the precipitate Feed the molten LiP-BeP2-ThF4 to
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P iii CONTENTS ....................
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CONCEPTUAL DESIGN CHARACTERISTICS O
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3 The primary purpose of this study
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.. .... . w..w c Y ... . r 5 2. GEN
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ii.... :.: ..... .,. \ ..... %& . 3
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addition StathQR would be required.
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!I \.... . , . ~ .... .. . . / I I
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... .. ...... . . . $i 13 Table 1.
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15 Initial scoping studies showed t
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.. . E 6> I S N 0.45 k- 0.50 B --.
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:.:..y ,. . . w, E9 The code calcul
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h 3. Additional 238Y is added as re
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...z,y .. . c .A, Table 9. Actinide
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';x.w' .... Relative power distribu
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........ . . . :..i 27 a Inner 2.54
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29 Table 16. Effect of neutron spec
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ob E 2 a 4 5 6 7 8 9 10 11 12 13 14
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.. . . . . . . . . . 'a# 0.1 0.2 0.
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35 (Doppler effect), (2) changing t
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where Ci = relative delayed-neutron
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.... . . . . , c.y..p c "
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.... :...w . . . . . :, %. , dimens
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,. ::.y ~. . .... , 40 0 43 1 2 3 4
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.,.,. . . ., , .. . . . . . . . %..
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.... ... . ....... . .%.W 3.3.1.1 C
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49 Variation of fuel composition wi
Page 57 and 58: .. .*,p. . . . . . . . Table 25. Ph
Page 59 and 60: ;: c.... x. . w ..i 53 Table 26, St
Page 61 and 62: would be expected to have an equili
Page 63 and 64: .... . . . . :i ,.*,&s 57 Corrosion
Page 65 and 66: . ;;..,..I . . . . . . "LW 0 9 m -
Page 67 and 68: of the fissioned atom. ea ~arly ass
Page 69 and 70: 63 n e results of a program of solu
Page 71 and 72: 65 Table 27. Sources and rates Sf p
Page 73 and 74: operation of the PISRE. 67 analyses
Page 75 and 76: UP3/UF4 ratio would be possible. DM
Page 77 and 78: $ .p9 3.3.3.1 Preparation of initia
Page 79 and 80: 73 Contamination of fuel by seconda
Page 81 and 82: *w- through the walls of the primar
Page 83 and 84: 77 4 will apparently be necessary (
Page 85 and 86: such contamination. For a demonstra
Page 87 and 88: 8% 3.4 Reactor Materials Although s
Page 89 and 90: : ....., . .’ -. ..WY used in the
Page 91 and 92: ..... i.. ....., . .Yd 85 QRPIL-DWG
Page 93 and 94: ... w . . .y and to salt containing
Page 95 and 96: With the different ~Bjectives of ns
Page 97 and 98: t.;$- ... quite different from thos
Page 99 and 100: 93 during noma1 operation. Minor am
Page 101 and 102: ............. . . .. . .=w as SSm,
Page 103 and 104: . . . :.w . . . . , 4. ALTERNATIVE
Page 105 and 106: .. . ... . . . . . . .. . . "W 3. T
Page 107: .,.. w .." by removing some uranium
Page 111 and 112: and the ~ dvent (or carrier) salt a
Page 113 and 114: BO 7 TPle fuel makeup requirements
Page 115 and 116: 5. CQPIPIERCIWLPZATION CONSIDERATIO
Page 117 and 118: 11% At the close of MSRE operation,
Page 119 and 120: 12YS 75 22”” 955 30” 1””
Page 121 and 122: 115
Page 123 and 124: aa 7 some components in common with
Page 125 and 126: Ae eo un t No * Table 3%. Capital c
Page 127 and 128: - ,.,.,.,., p .. ..... . G is based
Page 129 and 130: 123 Table 34. Summary of annual non
Page 131 and 132: ...... . . . . ., x.:w* 4 i.. ... _
Page 133 and 134: E2 7 There are no detailed estimate
Page 135 and 136: 129 particularly if such activities
Page 137 and 138: . ~.........* . . . . . :*. ... . -
Page 139 and 140: . .. . . . . . . . ;.:w b 133 the i
Page 141 and 142: _... ..&/ ; .; with reactor scram m
Page 143 and 144: 137 includlng $900 million for the
Page 145 and 146: 139 The authors want to acknowledge
Page 147 and 148: . ... . .,.,.,.,.,. . , i.rc- q....
Page 149 and 150: .:. _.i .. ..... -.=* 45. A. L. Mat
Page 151 and 152: ...... &;.& 3 14 5 74. W, R. Grimes
Page 153 and 154: p 103. 6. Re Hudson 11, CQNCEPT-5 U
Page 155: ... . . . . . . . , . ,.Y&fl 149 ap
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Account No. -0- Three- digit digit
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.... ..
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156 77. He 6. MacPherson, Institute
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