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

Comment
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4-3
Comment
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It appears that the quick loading of the cavity is a practical alternative P.c.6 P. 3.4.10
to the prolonged loading suggested in the GEIS. Further variations should Figure 3.4.4 does not present the temperature profiles that are necessary
also be considered, such as the use of an array of cavities (a few to to completely characterize the extent and duration of the thermal load on
maybe 10's of cavities). This would, reduce the loading rate (in the case the host media. The maximum increase in temperature at the earth's
of the quick load) and distribute the heat load over a large volume. surface can occur hundreds of thousands of years later than shown.
(Numerical models can be very costly to run for long times and distances
4.c.2 General required, however an analytic model is available. See Reference 3 of
The treatment of "Rock Melt" in the GEIS misleads the reader as to the Appendix C of TID-28818 (Draft), "Subgroup Report on Alternative
depth of investigation which has been completed. For example in the first Technology Strategies for the Isolation of Nuclear Waste.)
paragraph on page 3.4.4 of the GEIS, it is stated: "The concept has been
assessed and reviewed (4,5) and preliminary laboratory scale 4.c.7 p
rivestigations have been performed (6,7)." The workshop referred to as The post sealing period environmental effects are assumed to be "the same
Reference 5, as productive as it may have been, fell far short of for (nonsalt) conventional and Rock Melt repositories." The basis for
assessing "Rock Melt." The laboratory scale investigations were designed this assumption should be given. If the thermal barrier effect protects
to study the descent of solid containers by rock melting, not the molten the HLW from groundwater leaching for possibly a few'thousand years, might
cavity concept.
not the post sealing performance be superior to that for conventional
geologic disposal?
).c.3 p.1.25
The introductory writeup on the rock melting concept does not present the
disadvantages for this alternative, which were presented for the very deep
4.c.8 A shortcoming of the description of the rock melt alternative is that no
mention is made of the need for or availability of the water that's
mention is made of the need for or availabiity of the water that's
hole concept, sub-seabed geologic disposal, etc. 'Equal treatment of all necessary for this alternative. Provide an estimate and discussion of the
alternatives should be demonstrated in the final EIS.
water requirements.
4.c.4 . 4.c.9 In the event that the cooling system for the waste fails while still
4.c.5
It is stated that retrieval of waste following emplacement would be needed, it will be very difficult to repair because of its proximity to
t is the waste.r
difficult. This is understated, and not adequately addressed.
the waste
34.
I. Information on the possible failure of the cooling system, mitigative
It is stated that the consequences of seismic activity appear minimal with actions, and environmental impacts should be provided.
proper facility design. Discuss the effects of seismic activity on
4.d Island Disposal
surface facilities supplying cooling water and cleaning up the steam, and 4 I
on the reliable supply of cooling water to the waste.
4.d.l Section 3.5
4-4
The discussion in Section 3.5 indicates that two options for island
disposal are being seriously considered. One option is disposal in