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nium. 78 Tt?e original charge of fuel contains some 9-35 x IO4 moles of ura- If all this were supplied as W4, about 1840 moles (16,54 kg) of Beo would be required to reduce 5% of it to ?IF3.” While the fnitial preparation procedure could be modified so that some of the bTF3 would be present as the fuel was delivered, in situ production likely wouEd be more convenient, The delivered fuel could be made slightly deficient in BeF2 to accommodate that generated by m3 production. As indicated previously, the fissisn process occurring with Wb, is s8gnificantl.y oxidizing. During the 30-year reactor lifetime (22.5 full- pow€!% years asskuned) With 70% of the fiSSiQfnS occukring in uranim iso- topeso nearly 6.12 x 104 moles of uranium w ill have been fissioned. I C ~ the fissioning uranium fs 95% UF~, as much as 5.8 x 104 moles of U F ~ might be oxidized [at a generally unifom rate of 7 moles (-2-1 kg) per full- power day] during the reactor lifetime. 2.9 x IOb moles (261 kg) of metallic berylPim. Its reduction would require some The BeF2 produced in that manner represents about 3.0% of that present in the original fuel charge. Some additional reduction of UF4 to W3 will be required if the fuel must be treated to remove oxide ion. Accomplishing the reduction of UF4 to uF3 in situ w0ul.B certainly seem feasible By using metallic uranium in place of beryllium. Should the decision be made to add the fissionable and fertile uranium as UFks reduction performance by use of uranium would have the advantage of not appreciably diluting the fuel. Removal of inadvertent oxide contamination, Treatment of complex molten fluorides with anhydrous HF-Ifz mixtures has been used COIIUSIQE~~Y to reduce the oxide concentration to completely innocuous levels. 84% 85 real doubt exists that such treatment could be used if required for purification of DMSR fuel mixtures. However, there is little basis to assess the necessity of such purification. Operation of the MSRE during a four- year period with many shutdowns and several minor repair operations showed no evidence of oxide contamination. In early versions, equipment should be included in which HF-PI2 mixtures and then H2 could be used to remove “~n additional 9.63 x 104 moles of uranium tetraflusride %sill be added during the reactor lifetime. Reduction of 5% of this will require 81% additional 2.41 x IO3 moles (21.7 kg) of beryllium. NO y,. . . :. L
such contamination. For a demonstration reactor, this relatively sinple equipment probably should be sized to pernit treatment of the fuel on a 300-d cycle; if it were pessimistically assmed that 3.3 d would be required to ~ P Q C ~ a ~ batch, S the equipment should be sized to assomodate 1% of the fuel charge (-1 m3)0 Some fission products would be affected by this treatment; iodine, in particular, would be evolved and would have to be managed in the off- gas. ~elenim and tellurium (if they are soluble as ~e2- and ~ e in ~ the - molten fuel) might also evolve. kidation of pa49 to pas+ could be avoided by inelusion of a few percent of H2 with the HF. However, oxidation of a large fraction of the UF3 to UF4 would re- sult unless the IIF-H2 mixture contained so large a fraction of M2 that it would be relatively inefficient at oxide removal. Accordingly9 to allow for additional (beryllium or uranium) reduction of this UF4 would be necessary to maintain the desired ~ J F ~ / Uratio. P ~ For example, in the unlikely event that the fuel must be treated for oxide removal each 1000 full-power clays, the inventory would require treatment 8.2 times during the reactor lifetime. The inventory of uranium isotopes (see Table 9) increases regu%arly during the reactor lifetime and may average 1.07 x 105 moles during the 30 years. not true) all the UF~ were oxidized each time and if 5% of the uranium inventory were to be reduced, some 2.2 x IO4 moles of BeQ would be required during the reactor lifetime. nis, when added to the 2.9 x 104 moles of beryllium estimated previoulsy to be required to overcome the oxidative effect of uranium fission, would total some 5.1 x 104 moles of BeF2 generated or near 5.4% of the BeF2 3n the original feed. BeF2, though added at a slowly increasing rate during reactor life, is a good match for the 6.8% of 7 ~ needed i ~ to add the uranium as ~ i 3 ~ ~ A 7 . perfect match of LiF and BeFz additions is certainly not requ-ired; the maintenance processes briefly indicated above might provide a sufficiently good addition rate for LiF and BeF2. ~f (as is This added Possible addition of thorium. If making a few additions of thorim to the reactor fuel during its lifetime is necessary, then adding it as a liquid containing %iF and TRF4 should be possible. A possibility would be a melt containing about 70 nole % LiF and 30 mole X ThF4 melting wear
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i *w . . I
Page 5 and 6:
P iii CONTENTS ....................
Page 7 and 8:
CONCEPTUAL DESIGN CHARACTERISTICS O
Page 9 and 10:
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.
Page 17 and 18:
!I \.... . , . ~ .... .. . . / I I
Page 19 and 20:
... .. ...... . . . $i 13 Table 1.
Page 21 and 22:
15 Initial scoping studies showed t
Page 23 and 24:
.. . E 6> I S N 0.45 k- 0.50 B --.
Page 25 and 26:
:.:..y ,. . . w, E9 The code calcul
Page 27 and 28:
h 3. Additional 238Y is added as re
Page 29 and 30:
...z,y .. . c .A, Table 9. Actinide
Page 31 and 32:
';x.w' .... Relative power distribu
Page 33 and 34: ........ . . . :..i 27 a Inner 2.54
Page 35 and 36: 29 Table 16. Effect of neutron spec
Page 37 and 38: ob E 2 a 4 5 6 7 8 9 10 11 12 13 14
Page 39 and 40: .. . . . . . . . . . 'a# 0.1 0.2 0.
Page 41 and 42: 35 (Doppler effect), (2) changing t
Page 43 and 44: where Ci = relative delayed-neutron
Page 45 and 46: .... . . . . , c.y..p c "
Page 47 and 48: .... :...w . . . . . :, %. , dimens
Page 49 and 50: ,. ::.y ~. . .... , 40 0 43 1 2 3 4
Page 51 and 52: .,.,. . . ., , .. . . . . . . . %..
Page 53 and 54: .... ... . ....... . .%.W 3.3.1.1 C
Page 55 and 56: 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: 77 4 will apparently be necessary (
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 and 108: .,.. w .." by removing some uranium
Page 109 and 110: , . . . . . . , -c%w probably still
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
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_... ..&/ ; .; with reactor scram m
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137 includlng $900 million for the
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139 The authors want to acknowledge
Page 147 and 148:
. ... . .,.,.,.,.,. . , i.rc- q....
Page 149 and 150:
.:. _.i .. ..... -.=* 45. A. L. Mat
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...... &;.& 3 14 5 74. W, R. Grimes
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p 103. 6. Re Hudson 11, CQNCEPT-5 U
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... . . . . . . . , . ,.Y&fl 149 ap
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Account No. -0- Three- digit digit
Page 160 and 161:
.... ..
Page 162:
156 77. He 6. MacPherson, Institute
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