ML20207S931
| ML20207S931 | |
| Person / Time | |
|---|---|
| Issue date: | 03/09/1987 |
| From: | Justus P NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Martin D NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| REF-WM-68 NUDOCS 8703200414 | |
| Download: ML20207S931 (2) | |
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0000 TM/87/03/05 MEMORANDUM FOR:
Dan Martin, Section Leader Low-Level Waste and Uranium Recovery Proiects Branch FROM:
Philip S. Justus, Acting Chief Geotechnical Branch
SUBJECT:
WMGT (GE0 CHEMISTRY) COMMENTS ON REVIEW 0F THE GREEN RIVER DRAFT RAP AND DRAFT EA, TECHNICAL ASSISTANCE REQUEST DATED JANUARY 30, 1987
.As per your request, our geochemistry comments on the Green River Draft L
RAP and Draft EA are enclosed. Tin Mo coordinated this review with
]
f:
Michael. Young of your staff.
Should you have any questions please contact
-Tin Mo (x74693).
M PhilipS.Justus,ActnfChief Geotechnical Branch
Enclosure:
As stated i
WM Reccrd File WM Pro,icct --. dh Docket 110.
PDR d l
LPDR_ _ _
l Distribution:
B703200414 870309 i
PDR WASTE
__(Retur.n to WM, Usd4)
L
.s 0000 TM/87/03/05 NRC GE0 CHEMISTRY COMMENTS ON THE GREEN RIVER DRAFT REMEDIAL ACTION PLAN, RAP (JAN. 1987)
DRAFT ENVIRONMENTAL ASSESSMENT, EA (DEC. 1986) 0F REMEDIAL ACTION 1.
Upon completion of the review of the Green River DRAP and DEA, the NRC staff found that the DOE has given very little or inadequate consideration for the geochemical aspects of the remedial action proposed at the Green River site.
Both of the above subject 00E documents lacked a pertinent discussion of the geochemistry of the site soil and the supporting quantitative and representative site specific geochemical data (e.g.
dispersion coefficients, attenuative capacities and solubilities) for site characterization as required by the DOE's Technical Approach Document (TAD,1986).
Future revisions of the Green River RAP and EA should correct this deficiency.
2.
During the reviews of the Grand Junction Draft Remedial Action Plan, (DRAP) and the Green River UMTRAP - Final CAOSAR, the NRC staff expressed their concerns about the effects of geochemical disequilibria due to salts, on tailings stabilization and contaminant transport (Letters from D. E. Martin, NRC to J. G. Themelis, DOE dated October 29, 1986 and September 18, 1986 andenclosures). The staff commented that in any containment technology proposed by the DOE in their future remedial action plans and environmental assessments (EA)s for remedial actions, the DOE should assess and consider the impacts of the geochemical processes and disequilibria within the tailings on the long-term (200-1000 years) physical stability of the tailings and cover / barrier materials.
Relevant to this point, NRC staff have reviewed DOE's response to NRC comments on the RAP for Grand Junction, and agree with DOE that, under certain site conditions, disruptive geochemical processes may be moderated or slowed down. These conditions may include, but are not limited to, a water table far (> 10 feet) below the tailings, salt concentrations in the tailings Tow enough so that dissolution will not promote settlement of the pile, and a moist cover system which will preclude the possibility of strong upward hydraulic gradients.
The NRC staff therefore request that DOE quantitatively address these conditions for the Green River site, and demonstrate that instability due to salt dissolution and related processes will be negligible.
Specifically 00E should procure representative salt concentrations in the tailings, or measure them representatively, and evaluate the potential for shallow ground water accumulating beneath the pile in the pediment gravels and Dakota sandstone.
Furthermore, DOE should demonstrate that the long-term hydraulic gradients in the tailings will be downward.
Subsequent versions of the Green River RAP and EA should provide the necessary information for NRC staff to conclude that the geochemical processes will not cause long-term physical instability of the pile.