Some reactor components, systems or modules are entirely factory-fabricated and are subsequently transported and assembled on-site. For example, some small capacity nuclear plants foresee factory fabrication of the full nuclear steam supply system. In this case, the above-mentioned parameters y and z cannot apply and the productivity effect (factor k) becomes dominant.

Figure 6.6 presents the OKBM Afrikantov experience data on cost reduction in serial factory production of the nuclear propulsion plants [6.9]. After a certain number in the series, no additional gain in productivity is supposed.

1.1 -| 1 — 0.9 — 0.8 — I 0.7 —

CD

.>

0.6 —

CD

0.5 —

о

О

0.4 — 0.3 — 0.2 — 0.1 0

0

Using the data presented in Figure 6.6 and the equations (6.6) and (6.7):

, T

T = (1+ x) To and Tn = (n = 2),

and assuming that for the fully factory fabricated plants the only relevant factor is к (6.7) one could derive the values of x and к for the marine propulsion reactor case of Figure 6.6:

x=15%

k=5-7% (6.11)

Although к is the principal factor for full factory assembled propulsion (as well as barge — mounted power) reactors, and the evaluated value of this factor is ~3 times higher than that
recommended in [6.4] (see equation [6.11]), the overall cost reductions for each subsequent factory — fabricated nuclear propulsion plant shown in Figure 6.6 appear to be well within the ranges defined by equations (6.6) and (6.7) for conventional land-based plants built mostly on the site. This fact is independently confirmed by the OKBM Afrikantov in reference [6.9].