ORNL-5388 - the Molten Salt Energy Technologies Web Site

5-1 4
The first aspect of large plant design and licensing R&D, identified as component
R&D, is related primarily to the extension of the CANDU to 1,000 MWe, the use of slightly
enriched fuel, and possible increases in system pressure so as to reduce effective capital
cost.
In general, increasing the power output of the HWR to 1,000 MWe should be more readi-
ly accomplished than with other concepts such as the LWR, since it can be accomplished
simply by adding additional fuel channels and an additional coolant loop. The use of
slightly enriched fuel and higher operating pressures should result in no fundamental
changes to CANDU design, but nevertheless will necessitate some development in order to
accommodate the higher interchannel peaking expected with slightly enriched fuels and the
effect of higher system pressures on pressure-tube design and performance. Modifications
for U.S. siting are somewhat difficult to quantify since a thorough licensing review of
the HWR has yet to be completed. Although there is no doubt of the fundamental safety of
the CANDU, modifications for U.S. siting and licensing are nevertheless anticipated for
such reasons at differing seismic criteria (due to the differing geology between the U.S.
and Canada) and because of differing licensing traditions.
tion on the performance of slightly enriched uranium fuel should also be developed by ir-
radiating such fuel in existing HWRs (such as in Canada's NPD plant near Chalk River) to
the discharge burnups anticipated for the reference design (about 21,000 MWe/TeM). Methods
of analyzing the response of the HWR to anticipated operational occurrences and other
postulated accidents will have to be developed and approved by the Nuclear Regulatory
Commission, and a safety analysis report in conformance with NRC criteria will have to be
devel oped and defended.
Additional experimental informa-
As is the case for the HTGR, the cost for a power demonstration plant for the HWR
would be significantly higher than the cost for a DUTH-fueled LWR.
stration costs shown in Table 5.1-2 have been estimated under the same set of assumptions
used for estimating the HJGR plant.
The large plant demon-
The cost of a program to convert an HWR from its reference uranium cycle to denatured
fuel would be approximately equal to that previously described for the LWR.
5.1.4. Spectral-Shift-Controlled Reactors
As was noted in Chapter 4, the SSCR consists basically of a PWR whose reactivity
control system utilizes heavy water instead of soluble boron to compensate for reactivity
changes during the operating cycle.
Since the SSCR proof-of- principle has already been
demonstrated by the operation of the BR3 reactor in Belgium, and since various components
required for heavy-water handling and reconcentration are well established by heavy-water
reactor operating experience, the SSCR is considered to be at a stage where either a
prototype or a large power plant demonstration is required.
For most alternative reactor concepts at this stage of development, a prototype
program would be necessary because of the capital cost and high risk associated with
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