ORNL-TM-7207 - the Molten Salt Energy Technologies Web Site
ORNL-TM-7207 - the Molten Salt Energy Technologies Web Site ORNL-TM-7207 - the Molten Salt Energy Technologies Web Site
600°C (see Fig. 11). veloped for addition of solid ThFbe Alternatively, a procedure presumably could be de- Partial removal of noble and seminoble metals. The behavior of these insoluble fission-product species, as indicated previously, is not under- stood in detail. If they precipitate as adherent deposits on the DMSR heat exchanger, they would cause no particularly difficult problems. How- ever, should they f~l^ta only loosely adherent deposits that break away and circulate with the fuel, they would be responsible for appreciable para- sitic neutron captures. If these species were to deposit on the moderator graphite, they would constitute an even worse neutro~~ic situation. To the extent that they circulate as particulate material in the fuel, insoiuble fission-product species could probably be usefu~iy re- moved by a small bypass flow through a relatively slmple Hastell~y-~ool filter system. Presumably, such a system would need to have a reasonably Isw pressure drop and probably would need to consist of sections in paral- le1 88 that units whose capacity was exhausted could be reasonably re- placed o 3.3.3.4 Summaryp, constraints, and uncertainties Very Ifke%y, a number of optkn-is for fuel maintenance are avaflable. Some of these have been demonstrated and others couEd be made available if there were good reasons why they were needed. Several uncertainties also exist. Present%y, we do not hiow whether (1) treatment to remove inadvertent ~ont~~~ninati~n by oxide will be neces- sary$ (2) addition of uranium to the DMSR fuel will be done by use of ' L ~ ~ U(3) F ~ the ~ oxidative ~ effect of fission is near 1 oxidative equiva- lent per mole of uranium fissioned, or (4) the removal of noble and semf- noble metals from the DNSR fuel is necessary or desirable. ShQu%d 'they prove desirable, a relatively large number of: QptiOHlS could be made available. A great amount of further optimization of the fuel cycle for DNSR will be required before we know which, if any, of these options are necessary 0% desirable.
8% 3.4 Reactor Materials Although special, high-quality materials probably would Re used throughout in the construction of a BMSR, most of them Could be obtained from cowmerical sources that routinely supply such materials using cur- rently available technology. Two notable exceptions to this generaliza- tion are the Structural alloy that would have to be used for components normally exposed to molten salt and the graphite for the reactor core moderator and reflector. Both of these materials would require specifi- cations peculiar to the MSW system. 3.4.1.1 Requirements 3.4.1 Structural allov The metallic structural material used in constructing the primary circuit of a molten-salt reactor will sperate at temperatures up to about 700°C. The inside of the circuit will be exposed to salt that contains fission products and will receive a maximum thermal fluence of about 6 X neutrons/m2 over the operating ldfetime of about 30 years. This fluence will cause some embrittlement because of helium formed by trans- mutation but will not cause swelling such as is noted at higher fast flu- ences. The outside of the primary circuit will be exposed to nitrogen that contains sufficient ajir from inleakage to make it oxidizing to the metal. Thus, the m etal must (1) have moderate oxidation resistance, (2) resist corrosion by the salt, and (3) resist severe embrittlement by thermal neutrons. In the secondary circuit, the metal will be exposed to the coolant salt under much the same conditions described for the primary circuit. The main differences will be the lack of fission products and uranium in the coolant salt and much lower neutron fluences. This material must have moderate oxidation resistance and must resist corrosion by a salt not eon- taining fission products or uranium. The primary and secondary circuits involve numerous structural shapes ranging from several centimeters thick to tubing having wall thicknesses of only a millimeter or so. These shapes must be fabricated and joined
- 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 and 84: 77 4 will apparently be necessary (
- Page 85: such contamination. For a demonstra
- 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
600°C (see Fig. 11).<br />
veloped for addition of solid ThFbe<br />
Alternatively, a procedure presumably could be de-<br />
Partial removal of noble and seminoble metals. The behavior of <strong>the</strong>se<br />
insoluble fission-product species, as indicated previously, is not under-<br />
stood in detail. If <strong>the</strong>y precipitate as adherent deposits on <strong>the</strong> DMSR<br />
heat exchanger, <strong>the</strong>y would cause no particularly difficult problems. How-<br />
ever, should <strong>the</strong>y f~l^ta only loosely adherent deposits that break away and<br />
circulate with <strong>the</strong> fuel, <strong>the</strong>y would be responsible for appreciable para-<br />
sitic neutron captures. If <strong>the</strong>se species were to deposit on <strong>the</strong> moderator<br />
graphite, <strong>the</strong>y would constitute an even worse neutro~~ic situation.<br />
To <strong>the</strong> extent that <strong>the</strong>y circulate as particulate material in <strong>the</strong><br />
fuel, insoiuble fission-product species could probably be usefu~iy re-<br />
moved by a small bypass flow through a relatively slmple Hastell~y-~ool<br />
filter system. Presumably, such a system would need to have a reasonably<br />
Isw pressure drop and probably would need to consist of sections in paral-<br />
le1 88 that units whose capacity was exhausted could be reasonably re-<br />
placed o<br />
3.3.3.4 Summaryp, constraints, and uncertainties<br />
Very Ifke%y, a number of optkn-is for fuel maintenance are avaflable.<br />
Some of <strong>the</strong>se have been demonstrated and o<strong>the</strong>rs couEd be made available if<br />
<strong>the</strong>re were good reasons why <strong>the</strong>y were needed.<br />
Several uncertainties also exist. Present%y, we do not hiow whe<strong>the</strong>r<br />
(1) treatment to remove inadvertent ~ont~~~ninati~n by oxide will be neces-<br />
sary$ (2) addition of uranium to <strong>the</strong> DMSR fuel will be done by use of<br />
' L ~ ~ U(3) F ~ <strong>the</strong> ~ oxidative ~ effect of fission is near 1 oxidative equiva-<br />
lent per mole of uranium fissioned, or (4) <strong>the</strong> removal of noble and semf-<br />
noble metals from <strong>the</strong> DNSR fuel is necessary or desirable.<br />
ShQu%d '<strong>the</strong>y prove desirable, a relatively large number of: QptiOHlS<br />
could be made available. A great amount of fur<strong>the</strong>r optimization of <strong>the</strong><br />
fuel cycle for DNSR will be required before we know which, if any, of<br />
<strong>the</strong>se options are necessary 0% desirable.
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