ML20202G094
| ML20202G094 | |
| Person / Time | |
|---|---|
| Issue date: | 12/11/1985 |
| From: | Starmer R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Clark A NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML20198M712 | List:
|
| References | |
| FOIA-86-396, REF-PROJ-M-32 NUDOCS 8607150299 | |
| Download: ML20202G094 (7) | |
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DEC 111985 NOTE TO TOM CLARK /A
- Note To:
A. Thomas Clark, Jr., Project Manager, FCAF From:
R. John Starmer, Section Leader, WMLU
Subject:
WEST VALLEY COMMENTS Please add the following coment (1F) to the December 4,1985 note addressing the review of the advance Draf t EA for West Valley. Also, an additional observation is included as a further elaboration on the original statement of 2J3.
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It appears that additional erosion protection is needed to adequately stabilize the site. While it is feasible that site integrity could be maintained under i
normal rainfall conditions, occurrences of large, intense storms could cause a significant amount of erosion to occur in the nearby gullies and on the trench and tumulus covers. During such events, waste isolation and site integrity may not be maintained. Therefore, it is suggested that additional discussion be provided regarding designs which would be developed to mitigate the erosion problems that would be produced by intense stonn events.
Under 2J3)
In regard to the schematic of the tumulus, this emphasizes the need to provide drainage away from the waste.
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R. John Starmer, Section Leader, WMLU d
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ENCLOSURE 2 ADDITIONAL STAFF COMMENTS ON ADVANCE DRAFT EA DISPOSAL OF PROJECT LLW AT WEST VALLEY 1.
Evidence / references should be provided to support assertions regarding the integrity of disposal unit covers.
2.
The proposed disposal method for Class A waste will quite likely result in a water accumulation problem similar to that already observed at the Maxey Flats and West Valley sites.
Since most of the waste will exist as compressible trash, " miscellaneous dry solids," and failed equipment disposed in 55 gallon drums and steel boxes, these drums and boxes will begin failing within a few years and create large voids within the trenches. Experience from other disposal facilities has shown that trench voids can result in large sinkholes (i.e., several feet in diameter) being created in the trench caps.
Such voids and sinkholes will increase water infiltration in the trenches and disrupt any drainage system built into the trench caps.
Given the impermeable nature of the site soils, the infiltrating water will collect in the trenches and will have to be removed and treated.
3.
It is conceivable that subsidence will also be observed in the Class B/C tumulus. Although this subsidence will apparently not result in a bathtub problem, there may be contaminated leachate generated which would need to be handled and treated.
There are at least two sources that can be identified as contributors to subsidence:
unstable waste forms and; excessive void space within catainers.
Staff suggests referencing process control programs that address solidification / stabilization processes and void space elimination.
4.
The Draft EA is deficient in that DOE has not provided an economic analysis to support their preferred option.
In particular, DOE has not considered the full life cycle costs that would be associated with any disposal method.
Following the costs associated with waste disposal, there will be continuing costs associated with active maintenance of the.
disposal facility. Additional money spent during disposal may result in a requirement for less money being spent over the long term. Therefore, DOE should attempt an analysis which tries to balance and compare these costs.
5.
The on-site alternatives considered by DOE are of insufficient scope.
Staff suggests expanding the range of alternatives considered to include other engineered disposal methods (e.g., concrete bunkers, the Westinghouse SUREPAK system, deep trenches, etc.) which may be more likely to provide stability and isolation over the long term.
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> 6.
Kerosene TBP and various other chemicals are either located within the West Valley Nuclear Service Center or will be utilized in various facets of the disposal operations.
Potential affects of these chemicals on the geotextile.should be considered for impacts on fabric and drain performance throughout the long term.
7.
The affects of the proposed disposal units (trenches and tumulus) on the existing disposal areas (NRC licensed site and New York state site) have not been addressed.
Due to the close proximity of the proposed disposal units to the existing disposal areas and the potential role that the proposed disposal units will play in the overall stabilization of the West Valley site, WM staff suggests that the EA include a discussion on the affects that the proposed units may have on the entire W.V.
site (i.e., NRC and NY state sites).
It is perceived that failure to consider this issue may mask potential environmental problems.
8.
The predicted dose an individual may receive will depend on the assumptions that were incorporated into the modeling exercise I
(e.g., infiltration rates, water-waste contact time, leach rates, Kd values).
Two different sets of assumptions were incorporated into the EA l
dose analysis (one for trench disposal and one for tumulus disposal).
Staff concludes that a comparative dose assessment cannot be conducted between trench and tumulus disposal since two different sets of assumptions were utilized.
If the intent is to conduct a comparative analysis, the same assumptions should be incorporated into each concept.
9.
The Draft EA should provide individual pathway evaluations for the Class A waste (trenches) and the Class B/C waste (tumulus).
The Class 8/C waste (tumulus) evaluation should then be compared to the Class B/C (trench) pathway evaluations that were utilized in the Draft and Final Environmental Impact Statements for 10 CFR Part 61 (NUREGs 0782 and 0945).
This will provide a comparative basis for justifying or denying the decision to utilize tumulus disposal for B/C waste.
- 10. Recent information (see Quarterly Progress Report for " Properties of Radioactive Waste and Waste containers. FIN-A3027, 1985) reported by Brookhaven National Laboratory indicates that during dry periods of leaching, when intermittent leaching occurs, leach specimens may experience movement of material from the enriched subsurface zone of the specimen towards the depleted surface with subsequent release of this material during the next period of contact with water.
This appears to cause an increased release of radionuclides depending on the length of the dry period (the longer the dry period, the greater the release of radionuclides).
WVDP should consider this phenomenon when assessing the leaching of waste material from the tumulus.
- 11. The radioactive waste source term is apparently estimated in a crude manner.
The program description addressing waste stream sampling and i
characterization should be referenced, e
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._ 12. The following statement was included in the Draft EA:
" Migration of contamination was not considered feasible during the active institutional control period because engineered features such as low permeability clay caps and surface drainage systems prevent the infiltration of surface water into the waste" (p. G-75).
However, comments that were generated during the 12/12/85 briefing (i.e., TBP plume migration) indicate that migration in the weathered till is occurring.
Because there may be additional factors besides infiltration of water through the engineered trench caps, it is suggested that the assumption that states that no migration will occur during the 100 year period of active institutional control should be reevaluated and incorporate additional factors.
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- 13. The geotechnical staff of the Division of Waste Management does not support the proposed action for the disposal of project low-level waste, cited in the Draft EA (DEA) for West Valley.
This is based on technical considerations addressing long-term isolation of waste at the proposed location at the West Valley facility.
Specific phenomena that may well jeopardize long-term waste isolation are erosion and gullying in the site area and a fluctuating near-surface ground-water table.
These phenomena are among those that have been codified through the promulgation of 10 CFR i
Part 61, Subpart D, Technical Requirements.
Although it is understood that 10 CFR Part 61 may not apply to the i
proposed action at the West Valley site, the concerns are presented in terms of their compliance with the technical requirements of 10 CFR Part 61.
These concerns address only the action proposed in the DEA and should not necessarily be construed as an indictment of the entire West Valley site.
However, there are sufficient concerns regarding disposal of low-level waste at West Valley to seriously question continued investigations to that end.
Although other disposal site locations or designs may be more suitable for disposal of project low-level waste, it is recommended that alternatives to continued disposal at West Valley receive more thorough consideration.
A.
PERFORMANCE OBJECTIVES
$61.41 Protection of the General Population from Releases of Radioactivity Insufficient documentation and supporting information in the DEA modeling (risk assessment) preclude any judgment as to whether this objective has been met.
661.44 Long-Term Stability l
The active and well-documented erosion problems of the site 1
area indicate that this objective would not appear to be l
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B.
TECHNICAL REQUIREMENTS 661.50 Site is Capable of Being Modeled, Characterized, etc.
(a)(2)
This condition may be met at the site however the lack of documentation of the hydrogeology of the site precludes an assessment by the staff.
$61.50 Site Unaffected from Future Population Growth (a)(3)
There is no apparent evidence that this condition could not be met.
Q61.50 Natural Resources (a)(4)
There is no 6, parent evidence that this condition could not be met.
661.50 Site is Well-Drained (a)(5)
There are marshy areas throughout the WNYNSC property as was nbserved on a site visit.
The presence or absence of these areas on the site itself and how they might relate to the ground-water system has not been addressed in the EA.
$61.50 Upstream Drainage Areas Minimized (a)(6)
There is no apparent evidence that this condition could not be met.
661.50 Sufficient Depth to the Water Table (a)(7)
This condition does not appear to be met in terms of the Class A ' trenches.
On the contrary, it appears that these trenches are designed to be emplaced directly in the zone of water table fluctuation based on the information in Herbes and Clapp, 1984, concerning the location of the o
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_ water table.
The history of water accumulation in the trenches at West Valley will likely continue in the proposed trenches as the unstable Class A wastes collapse causing trench cap failure.
961.50 No Ground-water Discharge to the Site (a)(8)
This condition does not appear to be met since the weathered till zone apparently discharges to the on-site gullies as was observed during a staff site visit.
In any case, there is insufficient hydrogeologic information provided in the DEA on ground-water flow through the weathered till zone to make a proper assessment.
%61.50 Tectonic Processes (a)(9)
There is no apparent evidence that this condition could not be met.
561.50 Surface Geologic Processes (a)(10)
This conditic + does not appear to be met due to the active erosion problems in the disposal site area such as landsliding, headcutting, etc. and the apparent lack of adequate engineering designs to adequately mitigate the problems.
561.50 Impacts from Nearby Facilities (a)(11)
This condition does not appear to be met.
The past disposal history and other activities at this site would likely cause a significant impact on the environmental monitoring program for the new LLW disposal area.
C.
SITE DESIGN 961.50 Erosion Protection (a)(1) and (a)(5)
These requirements do not appear to have been met.
While site integrity could possibly be maintained under normal rainfall conditions, an occurrence of a large, intense storm could cause significant lateral and headward erosion to occur in the nearby gullies toward the trench and tumulus covers.
In such an event, waste isolation could o
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,, not be maintained with the current design.
Our review of the design presented in the EA indicates that inadequate erosion protection has been provided for the gullies and the trenches to meet these requirements.
The designs are based on historic rates of erosion and gullying which may not be representative of expected future erosion rates, particularly if an intense storm were to occur.
Based on such an occurrence we conclude that a significant amount of additional erosion protection is needed to adequately stabilize the site.
In order to meet these requirements (particularly the longevity requirements with no planned maintenance), we further conclude that the required erosion protection should be designed to withstand the occurrence l
of very rare and intense local stonn events, not just historic events.
g61.53 Environmental Monitoring The monitoring program presented in the EA does not contain much of the basic information necessary to judge its adequacy.
This information includes, but is not limited to, location of sampling points, methods of sampling, establishment of baseline in relationship to the site characteristics, setting of action levels, and contingency planning.
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