ORNL-TM-7207 - the Molten Salt Energy Technologies Web Site

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a Inner 2.548 2.44 7.86 3*22
A &Iter 2.032 2.51 7.96 3.17
B Inner 2.540 2.42 7.96 3.29
B Outer 1.022 3,14 18.6 3.38
5.8 2. I4 6.6 3.08
B
of zone A, as judged by the two zones with 1 = 25.4 me To estimate the
effect on neutron yield, the 232~h chain laas an ultimate yma in a par-
ticular situation of 1.06 neutrons per capture in 232~h, while the yield
of 23% fs only 0.84 (Ref. 9). With -40% of the fertile capture in 2%!,
as it is for the present system, a 10% increase tn the 238-to-232 capture
ratis would reduce neutron yield by -8.5%. Accordingly, the variation in
Table 12 is not a large effect. Even though cell geometry changes the
cross sections significantly the 232~h ana 2 3 8 ~ changes approximately
cancel each other.
nucIides.
hother variable of interest is the densi%y of the fuel-salt heavy
the life of the system, and this is not accompanied by a corresponding
change in 232.~h.
data vs density are shown in Table 14 for the case of core zone A with =
25.4 mw.
Table 3 shows that 238U density apprsx%mately doubles during
varying QV~P a range of reasonable interest, resonance
While the 232Th density increases by 51%, the product of den-
sity and cross section increases by only 28%.
For 238U, the density in-
creases by 129%, and the product increases by only 57%, thus illustrating
that nuclide density and its effect on resonance cross section are both
large, but partially caneelling, effects. A similar table % ~ other r nu-
clides for which resonances were calculated shows relatively less influ-
ence of nuclide density on cross section (Table 15).