ML20236T602
| ML20236T602 | |
| Person / Time | |
|---|---|
| Issue date: | 11/10/1987 |
| From: | Starmer R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Fliegel M NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| REF-WM-43 NUDOCS 8712010392 | |
| Download: ML20236T602 (5) | |
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j NUCLEAR REGULATORY COMMISSION -
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WASHINGTON, D. C. 20555.
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NOV 101987L MEMORANDUM FOR: Myron Fliegel, Section Leader Uranium Recovery Section Operations Branch Division of Low-Level. Waste Management and Decommissioning, NMSS FROM:
R. John Starmer, Section Leader Siting Section. Technical Branch Division of Low-Level Waste Management and Decommissioning, NMSS
SUBJECT:
REVIEW 0F LOWMAN FINAL CADSAR l
Enclosed are our comments of.the Lowman, Idaho final Comparative Analysis of l
Disposal Site Alternatives Report (CADSAR). We also reviewed DOE's responses-l to our comments of the draft CADSAR.
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The surface water review was performed by Ted Johnson who found that all surface water problems are recognized and agreed to be resolved.
The groundwater review was performed by.Lynn Deering. Although groundwater had been considered a significant issue in the draft CADSAR, D0E.has. dropped groundwater from' consideration.for.'the final document. Since DOE has not determined seasonal'or maximum groundwater levels, and.since. levels could fluctuate into the disposed tailings, NRC considers the issue significant and suggests:its reinclusion in the.CADSAR.
The geology review was performed by Kristin Westbrook and is enclosed.
Please contact Kristin Westbrook at telephone extension.74543 if you have any questions or comments ~ about.this review.
j h $ h =o w R. John Starmer,.Section Leader Siting Section,. Technical Branch Division of Low-Level Waste Management and Decommissioning, NMSS
Enclosure:
As stated MA Hecarc fya y;y D:; '
B712010392 871110
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Site:
Lowman Date:
10/29/87 Commentor:
NRC Groundwater Comment:
CADSAR GW 1 Page:
21 DOE states in the preliminary final CADSAR (page 21) that the below grade l
design will be at a maximum depth of 35 feet below the existing ground surface, l
and that the bottom of the excavation will be maintained a minimum of five feet l
above the high seasonal groundwater levels. DOE has not yet characterized the seasonal variation in groundwater levels under the proposed stabilized pile or the site as a whole, hence it is premature to assign a fixed maximum depth of 35 feet for the excavation at this time considering that groundwater icvels could seasonally rise above this depth.
In addition, maintaining for only a i
five foot interval between the tailings and the water table is a highly nonconservative design, as maximum water level fluctuations may be difficult to adequately characterize within a one year sampling period. Placing the l
tailings within the zone of water table fluctuation could result in lateral leachate migration through the shallow, unconfined aquifer system toward Clear Creek, and subsequently, failure to comply with EPA standards.
DOE should revise the final CADSAR to indicate that the feasibility of the j
proposed below grade design is dependent upon the results of at least a full year of water leveT1 measurements to adequately characterize seasonal fluctuations, and that the details of the proposed design (i.e., maximum depth of excavation) will be determined based on these sampling results.
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LD/87/LOWMAN 2-Site:
Lowman Date:
10/29/87 Commentor:
NRC Groundwater Comment:
CADSAR GW 2 Page:
22 DOE has omitted groundwater as a significant issue in the preliminary final CADSAR (page 22). Based on NRC staff review of groundwater information provided in this document (e.g., water level measurements, flow direction, groundwater discharge, and groundwater use),'there appears to be no technical basis for deleting groundwater as significant. DOE should revise the final i
CADSAR to reinstate groundwater as a significant' issue, or provide justification as to why groundwater is ru) longer considered a significant-issue.
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.i LD/87/LOWMAN Site:
Lowman Date 10/29/87 Commentor:
NRC/ Groundwater Comment:
CADSAR GW 3 Page:
21 The DOE states in the preliminary final CADSAR (page 21) that if necessary, the proposed radon barrier on the stabilized tailings pile will be designed to inhibit. infiltration of water into and through the contaminated materials.
Given an ' average annual-precipitation at the site of. about 25 inches and a relatively shallow depth to groundwater, the proposed radon barrier on the tailings pile should definitely be designed to inhibit infiltration. DOE should revise the final CADSAR to indicate that the radon barrier will in fact be designed to inh' bit infiltration of water into and through the contaminated materials.
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. 1 LOWMAN, ID GE0 LOGY COMMENT
- Lowman, Idaho NRC Staff Geology - Seismology Final Cadsar 1 Page: 22 Section 5.1 (Seismicity) refers to Section 3.2 regarding bedrock accelerations of 0.45g to 0.50g. Nothing is contained in.Section 3.2 about these accelerations or ataut earthquake magnitudes that could cause the accelerations.
The comment responses document (comment 2,.page 9) states that a Richter I
magnitude of 7.3 is to be used as the design event. However, no mention is made of the 7.3 event in the text of the final CADSAR. Consideration should be given to having Section 3.2 of the final CADSAR contain comprehensive information about earthquake accelerations and the Richter magnitudes.
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