ML20214K580
| ML20214K580 | |
| Person / Time | |
|---|---|
| Issue date: | 09/26/1986 |
| From: | Fliegel M NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Martin D NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| REF-WM-68 NUDOCS 8612020363 | |
| Download: ML20214K580 (6) | |
Text
.
DISTRIBUTION WM sf,(W68) JGrimm WMGT rf AIbrahim NHSS rf TMo REBrowning JTrapp WM68 HF/86/9/24 MBell KJackson 1
J0 Bunting GGnugnoli PS Justus SBilhorn w ra & rf SEP 2 6 1986 MFliegel MEMORANDUM FOR: Dan Martin, Section Leader PDR WMLU M ""8 TJohnson FROM: Myron Fliegel, Section Leader WMGT
SUBJECT:
WMGT DRAFT COMMENTS ON THE GREEN RIVER FINAL CADSAR, TECHNICAL ASSISTANCE RE0 VEST DATED SEPT. 11, 1986 As per your request, our draft connents on the Green River Final CADSAR are enclosed. At this stage our comments are preliminary and may change pending further review and additional information gained during site visits.
Furthermore, as per agreement between the project manager and my technical lead individual corrents have not been reviewed as part of our quality assurance procedures, in order to meet your schedule needs. Contributors to this review were Michael Young (ground water), Joel Grimm (geology) and Tin Mo (geochemistry). Joel Grimm's comments were provided verbally in a meeting with WMLU on September 26, 1986. Geophysics did not have any comments, since there was ro geophysics to review in the document. Due to vacation schedules and other Low Level Waste commitments Ted Johnson (surface water) did not have time to prepare draft cerments on the Final CADSAR, but as agreed with the project manager, he will provide final comments to be sent to DOE after the site visit.
Should you have any cuestions please contact William Ford (74697).
f a
Myron Fliegel, Section Leader WMGT Enclocures: /
As Stated M7MW M Proic:t._!v/
_ _ _.___ Docket f,'o.__ _ _
A% - - - - - . - _ . . _ . . ._
m m U WM. Gli SS) .. _ - - _. -
kR hhh860926 WM-68
, PDR
( , ,
JFC :WMGT :WMGT J .
____:_______ g. _:_____..,_ ___:____________:____________:____________:____________:___________
1AME :WFord D : : : : :
h _ _ _ _ : _ _ __ _ _ _ _ _ _ _ _ :: M Fl i e ge l DATE:86/9/4 :86/9/ h _::____________::____________.____________:__
6
~ BRAff GRN FINAL CADSAR/MHY GROUNDWATER COMMENTS GREEN RIVER FINAL CADSAR Section8.2,PreferredAlternative,Page2p The final CADSAP states that only SIP and S S cptions were considered because both options provided technically feasible disposal areas for acceptable costs; of these, the SOS option was chosen. There are several factors, however, pertaining to the hydrogeology of the preferred site that are of particular concern to NRC staff. When considering these factors, NRC concludes that the decision to utilize the SOS option did not take in account all the available information on the hydrogeology and present grour.dwater quality. Finalizing the SOS option could, result in increased characterization and monitoring activities to be specified in the RAP, and increased difficulty in meeting the proposed water resources protection criteria set by CCE. The following factors form the bases for this conclusion.
- 1. The proposed disposal site is located atop alluvium that "... would most likely be highly permeable, [and] highly variable in both extent and composition ...". This type of medium for disposal of centaminated tailings may premete migration of contaminants due to higher groundwater velocity.
- 2. Although many other UMTRA project sites are lccated within the Mances Shale, a well-known strata in the area, the proposed disposal site "...
may or may not directly overlie the low-permeability Mancos Shale found nearby." In fact, from ficure 3.3 of the CADSAR, it appears that the Mancos Shale (called Tununk Shale in the figure) consists primarily of sandstone / shale interbeds, and thus cannot be considered a confining layer. Therefore deeper aquifers will not be protected from potential contamination.
- 3. The CADSAR, spending considerable time detailing the location and depths of monitor wells, states that alluvial, shale and deep (Burro Canyon Formation) wells already sFew signs of centamination; concentrations of uranium in the Marcos Shale and Burro Canyon Formatico are 1.4 mg/l and 0.02 mg/1, respectively. Thus, downward migration of contaninants is probably occurring into an aquifer system that "may be suitable for irrigation and stock wa+rrirg".
- 4. Jccc.rding to the CADSAR, unlined pits were fornally used for the disposal of wastes from a nearby launch facility. However, the type of wastes disposed of in these unlined pits were not discussed. These pits
GRN FINAL CADSAR/MHY
-?
are located north, and downgradient of the proposed uranium mill tailings
. disposal area. Therefore, potential groundwater contamination from the launch facility's disposal area may sicnificantly mask the results of groundwater monitoring activities initiated by D0E. In this case, it may be difficult to determine the source of groundwater pollution and the responsible party.
- 5. The tailings pile has already impacted water quality in Brown's Wash.
According to the CADSAR (page 14), water quality results show uranium concentration as high as 1.3 mg/1, indicating recharge of the wash by contaminated groundwater.
Based on these conditions, disposal of tailings using the SOS option, may lead sto increased contamination of usable groundwater in the Green River area, and Mfficulty in determining who was responsible for the pollution. It does not app ar that these factors were taken into consideration during the d m p on-making process. Therefore, i' 00E goes ahead with the SOS option, they'@ould consider the hydrogeolcgical characteristics of the site and vicinity during the design phase of the remedial action and anticipate increased characterization and monitering activities that will be needed to fully understand the grcundwater system, and ensure compliance with water quality criteria specified in DOE's proposed plan.
Section 2, Alternative Site Selection, Pace.3 The final CADSAR indicates that several groundwater characteristics are undefined and that efforts are under way to better understand and quantify the hydrogeologic system. However, in the DOE memorandum (November 19,1985) titled, " Implementation of New Planning / Development Process", DOE states "The CADSAR will be firelized after full site characterization activities have been completed." The fact that several critical hydrogeolegical characteristics (as listed in the previous comment) are unknown, underscores the concern that the decision to go final on the CADSA.R was premature, and not in the spirit of the intent of this new planning / development precess. Therefore, DOE should evaluate the decision-making process at Green River, in light of this memorandum, and determine whether the results from additional characterization efforts should be considered in the final site selection.
Section 4.2, " Stabilization on Site, Page 20 The CADSAD states that "+he excaveted pit may or may not require a 1cw-permeability liner." Fewever, the decision not to roovire a lire has apparertly been nade, since the cost of constructing the liner wasn't considered in the SOS cost summary found in Table 6.2. If the decisicn not to l
t
F $
P .
GP.tl F111FL CfDSPR/Mt4Y - 3-h SOS option use a liner has been trade it is without basis, ble, highly considering that t e '
proposes to dispose of contaminated tailings on "hichly h permeaDOE variable" material.
SOS option is excercised, and include the ccst of liner construction i cost of the remedial action, i
+
4
--p ,- n -,3 , _ - , - - r y yn -,,-w, , . . - - , , r - .<,.- ----- -- ---,
P 4
DRDT M/09/T?/TP DRAFT GE0 CHEMISTRY COMMENTS ON THE FINAL GREEN RIVER UNTRAP CADSAR AND DOE RESPONSES TO NRC CCEMENTS ON THE GREEN RIVER DRAFT CADSAR Section 4.0, Site Conceptual Design, Page 19 The final CADSAR does not address the effects of salts on tailings stabilization and contaminant transport. It has recently come to the staff's attention that studies of about twenty inactive uranium mill tailings sites by a CCE contractor (Markos and Bush; 1983, 1981a, 1981b, 1980 and Markos 1979) indicate that the unevenly distributed high salt content of tailings constitutes the major aspects of geochemical disequilibria. The salts impart geochemical reactions and redistribution of materials within the tailings piles which, in turn, result in the physical instability of the tailings and cover naterials and breach of the contaminant / radon barriers throJgh passage of time.
Many of the manifestations of physical instability indicate rapid cFanges within relatively short intervals of time (of the order of several months to a year)'and forecast a problem on current or proposed practices of containment of contaminants'from mill tailings sites. For a long lasting and safe rehabili-tation/ stabilization of tailings the irracts of the geochemical processes within the tailings on the physical stability of the tailings ano cover materials and barriers cannot be it;rored.
The overall effect of soluble salts in the tailings is very important. They establish a water circulator system in the opposite direction to gravity. They create an environment where many metals are highly mobile. The salts tend to move to the surface of the tailings carrying centaminants which can enter into the surroundings by surface erosional processes such as wind and runoff. The salts are corrosive, and they can move through cover materials and tend to destroy vegetation en the surface of the tailings.
The NRC staff's position is that any containment techrelogy proposed by DOE in their Draft Remedial Action Plan (DRAP) for Green River and in future DRAPs for other sites should assess and consider the above results of the geochemical study of the twenty inactive uranium millirn sites conducted by Markos and Bush for DOE (Markos and Bush, 1983, 1981a,b, 1980 and 1979). Engineering designs for protective actions must be designed to withstand physical forces caused by chemical reactions in the tailings. Containment practices, designed in a wav te circumvent or eliminate the forces produced by the chemical interactiers ir tailings, are necessary fcr adecuate prctection of the envircrrert.
Please src imC staff's draft comments on the Grand Junction Draft Remedial Action Plan transmitted to COE en September 19, 1986 for a more ccrprehensive
r r
86/09/25/TM discussion of the implications of the results of the DOE studies referenced above on the engineered design or control technology to contain effluents /centaminants from uranium mill tailings sites.
~~*^~"-~w-w,._, __,_ ___ _