ORNL-5388 - the Molten Salt Energy Technologies Web Site

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Table 4.2-1. Fuel Utilization Characteristic2 for SSCRs
Under Various Fuel Cycle Optionsa*
Initial
Equilibrium Cycle
Fissile Fissile 30-Yr Cumulative
30-Yr Cumulative
Separative Work
Fuel Type
Fissl le Inventory
(kg/GWe 1
Makeup
(kg/GWe-yr)
Discharge
(kg/GWe-yr)
U30, Requirement
(ST/GWe)
Requirement'
(lo3 kg SW/GWe)
Dispersible Resource-Based Fuels
LEU, no recycle 1577 23511 713 235U 182 23%
196 Puf
MEU/Th. 23sU feed, 2540
U recycle
371 2ssU 228 235U
371 233U
65 Puf
Dispersible Denatured Fuel
Denatured 233U02/Th02, 1663 233U 236 233U
U recycle
PuO2/ThOz, Pu recycle 2354 Puf
4; E;
72 Puf
Energy-Center-Constrained Fuel
791 Puf 780
273
Puf
233U
3 235u
5320 3010
3220 3077
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'1290-MWe SSCR; IO-MWe additional power required to run reactor coolant pumps and 020 upgrader facility.
bAs~umes 75% capacity factor, annual refueling, and 0.2 w/o tails assay.
mode of operation. Because the basic PWR NSSS* is used, the utilization of the denatured
thorium fuel cycles will pose no additional problems or R&D needs beyond those required
to implement this type of fuel in the conventional PWR. Although the general feasibility
of spectral-shift control appears relatively well established, nevertheless there are a
number of aspects of SSCR design which must be evaluated in order to fully assess the
conercial practicality of spectral-shift-controlled reactors. The more significant of
these are briefly discussed below.
1. Resource Utilization - A more accurate assessment of resource utilization is
required to more definitively establish the economic incentives for spectral-shift control
on the LEU cycle.
water reactors, the savings in Uj08 and separative work for 235U-based systems must be
demonstrated to be sufficiently large to compensate for the additional capital cost of
equipment required to implement spectral-shift control. A similar assessment for
denatured 233U fuel is also required.
If the concept is to be economically competitive with conventional
2. Plant Modifications - The plant modifications necessary to realize spectral-
shift control must be identified, and the cost of these modifications established, The
practicality and cost of these modifications, of course, bear directly on the economics
and commercial feasibility of the concept. Of particular concern are modifications which
may be required to limit the leakage of primary coolant (from valve stems, seals, etc.)
and the equipment required to recover unavoidable primary coolant leakage. Primary
coolant leakage is important both from the standpoint of economics, because of the high
cost of D20, and from the standpoint of radiation hazard, because of the problem of occu-
pational exposures to tritium during routine maintenance, Other possible modifications to
current'designs which result from the presence of D20, such as the increased fast fluence
on the reactor vessel and possible changes in pumping power, will also have to be addressed.
NSSS = Nuclear Steam supply 'System.