Management of Commercially Generated Radioactive Waste - U.S. ...

6.194
hole concept following package disengagement. The following order of decreasing preference
relative to corrective action is thus suggested: mined repository; island mined reposi-
tory; subseabed; space/very deep hole.
6.2.4.8 Long-Term Maintenance and Surveillance Requirements
None of the five concepts being considered here appear to require significant mainte-
nance and surveillance activities during the post-operational period.
6.2.4.9 Resource Consumption
Preliminary estimates of selected critical resources for mined repository, very deep
hole, subseabed and space disposal are provided in Table 6.2.8. Because of the very prelim-
inary state of development of most concepts as reflected in the apparent inconsistencies
among the estimates of Table 6.2.8, comparisons on the basis of these estimates would not
be meaningful.
6.2.4.10 Equity of Risk
None of the concepts appear to have significant differences in this respect. Subsea-
bed, ice sheet, island, and space disposal have the positive feature that no one must live
in close proximity to the final disposal location. This creates the initial impression that
the impact and risk are far less for those alternatives than for mined repositories. How-
ever a situation is established wherein the process of transportation of wastes is channeled
through one location. A judgement of the equity of risk and impact resulting from the focus
of transportation versus the focus of disposal is yet to be established.
6.2.5 Conclusions
Results of the comparisons on the assessment factors are depicted in Table 6.2.9 which
shows the preference rankings of the five concepts (mined repository, very deep hole, sub-
seabed, island repository, and space) on each of the assessment factors for which discrimi-
nation was found among the concepts. For each factor, the rankings of the five waste man-
agement concepts are plotted along a preference continuum, ranging from "most preferred" at
the extreme left to "least preferred" at the extreme right. Concepts are clustered where
no differences were observed.
6.2.5.1 Mined Repository
Examination of Table 6.2.9 supports selection of the mined repository concept as the
waste disposal concept for preferred development. This concept is a "most preferred" con-
cept on six of the seven comparisons of Table 6.2.9, ranking second on one consideration,
"Radiological Effects During the Post-Operational Period." Here, the apparent length of
isolation provided by space disposal results in the latter being preferred to mined reposi-
tories. An overall evaluation of the Radiological Effects attribute, however, might place