ML20214S238
| ML20214S238 | |
| Person / Time | |
|---|---|
| Issue date: | 05/27/1986 |
| From: | Knapp M NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Themelis J ENERGY, DEPT. OF |
| References | |
| REF-WM-39 NUDOCS 8612080228 | |
| Download: ML20214S238 (7) | |
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W1108/DMG/86/05/20 MY 2 719%
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J Kane MLU r/f M Nataraja NMSS s/f J Valdes Mr. John G. Themelis, Project Manager J0 Bunting M Fliegel Uranium Mill Tailings Project Office DM Gillen P Justus U.S. Department of Energy DE Martin G Gnugnoli 5
Albuquerque Operations Office MR Knapp E Ha'wkins, URF0 Post Office Box 5400 RE Browning Albuquerque, New Mexico 87115 MJ Bell
Dear Mr. Themelis:
Enclosed for your consideration are our comments on your March,1986 document entitled " Alternate Site Selection Process for UMTRA Project Sites." Although the document establishes an orderly process for alternate site selection, we find (as indicated in our comments) that the process as presented is lacking in its description of procedures and bases for selection of exclusionary criteria.
If you have any questions regarding this review, please contact Daniel M..
Gillen of my staff.
(FTS 427-4160).
O Sincerely,
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WM Record fue Docket th -7 PDR
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- ~~ Malcolm R. Knapp, Acting Chief
.- Low-Level Waste and Uranium Dis'r$@.c0, Recovery Projects Branch
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- Division of Waste Management
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- Office of Nuclear Material Safety and Safeguards
Enclosures:
As stated 8612030228 860527
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PDR WASTE WM-39 PDR IOFC :WMLU:r
- WML
- WMLU NAME :DM Gillen
- DE r n
- MR Knapp DATE:86/05/91
- 86/05/c7
- 86/05/p
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o ENCLOSURE 1
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, WM-39/JV/5/6/86/ ALT ggy
GENERAL COMMENT
S A) The present document is not rigorous or detailed enough to meet its stated O
purpose of providing procedures for selecting technically sound alternateIn t disposal sites.
document have been identified:
- 1) Though it is stated that different factors will be " considered," no description of the methodology that will be employed to consider these factors is presented.
In its present form, the document is merely an outline of the process by which alternate sites will be chosen and does not include a description of the procedures that will be used.
The revised document should either include or provide references to such procedures.
- 2) Exclusionary criteria are presented without providing any basis or justification for their selection.
The revised document should clarify the rationale used for selecting the specific guidelines presented.
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B) The staff considers that the site selection process should lead to at least the following conclusions:
- 1) the alternate site (s) selected are among the best that can reasonably be found and; (2) the alternate site (s) are better/ worse than, or as good as, the existing site.
NRC suggests that reaching these conclusions become a part of the UMTRAP alternate site selection process.
SPECIFIC COMMENTS Figure 1.1, Page 2 It is stated in section 2.1 (pg. 3) that "it should be recognized that the ASSP That
[ Alternate Site Selection Process) (see Figure 1.1) is one of iteration.
is, [if no suitable sites are found] the evaluation process [will] be i
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W-39/JV/5/6/86/ ALT i
Contrary to this statement, however, Figure 1.1 portrays the repeated."
screening process as a unidirectional sequence of steps with no loops for Figure 1.1 in the revised document should reflect that iterations i
iterations.
(Also see comment on Section 2.3, pg. 6).
can occur in the screening process.
i Section 2.2, Page 3 It is stated that Table 2.1 provides "the basic list of regional screening A)guidelines" but that these "... will be modified as site conditions dictate."
The NRC staff considers that to change the rating guidelines arbitrarily from site to site would defeat the purpose of attempting to establish a systematic-The guidelines selected should and uniform alternate site selection process.
be sufficiently generic to apply uniformly to all sites under consideration.
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The staff recommends that DOE revise this section to address the concerns 3
noted.
B) It is stated that guidelines for Phase II preliminary screening of search regions "will be identified... from existing information and [ areas excluded
- However, based on these guidelines] will be plotted on the topographic maps."
the document does not describe the process that will be used to locate 4
4 The revised document should describe the pertinent " existing information."
methodology that will be used by DOE to ensure that all relevant information l C has been obtained.
Table 2.1, Pages 4-5 A) The bases for selection of the guidelines (including numerical values) cited are not stated and the definitions provided tend to be equivocal.
For example, in addition to being deficient in its interpretability, the definition of
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" slopes and escarpment" includes specific numerical values that are cited As without stating the reasons why these values are considered significant.
4 another example, the definition of " erosive soils" is ambiguous as it does not include a justified range of soil erodibility factor values that would be DOE should provide the rationale considered unacceptable for a candidate area.
used for selecting specific criteria and clarify the meaning of the definitions presented.
B) The recharge and isolation of sole source aquifers is identified as one of the guidelines for rejecting or accepting areas within a region for possible I
l alternative disposal sites.
The definition of the screening guideline for areas directly overlying, or recharge areas for,
" aquifers" is given as:
sole-source aquifers or aquifers containing potable water; unless... those i
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aquifers are hy'drologically isolate,d... by low permeability geologic formations." However, in many areas within a region there may not be sufficient information available to reach a conclusion on confinement or The document does not indicate how areas will be classified if potability.
sufficient information is not available, i.e., will the area be included for further detailed investigation during site selection or will it be eliminated l
DOE should indicate how they will deal with the situation of as unsuitable?
inadequate data with regard to the aquifer system.
C) Accordir.g to the definition of the screening guideline for " aquifers", areas that a-e located above " potable" groundwater supplies will be excluded.
However, the meaning of " potable" water is ambiguous as the concentration of l
The staff l
constituents that determine potability can vary from state to state.
recommends that DOE explicitly define how the term is being used in the l
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D) No guidelines for chemical attenuation or availability of suitable rock for i
riprap are included in the table.
Given the primary importance of these parameters, the staff recommends including and adequately defining criteria for the same in the list of regional screening guidelines.
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Section 2.3, Page 6 The need for Phase III of the screening process is not apparent.
As presently structured, Phase III involves selecting three candidate areas based on reexamination of the literature and application of extremely subjective l
criteria (Table 2.2) very similar to those employed for Phase II area-screening. The staff considers that a more efficient approach would be to i
eliminate Phase III and divide Phase IV into two steps:
Step 1.
This step would involve the preparation of " factor maps" for the study areas not eliminated during Phase II.
The data for the maps would
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j be obtained from the available literature and rated in accordance to the criteria in Table 2.3.
The result of this exercise would be maps of the
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study areas displaying composite rankings that could be easily contoured 4
to produce " suitability maps." Based on such maps, a minimum of three l
sites within the most suitable areas would be selected for further investigation and unsuitable areas eliminated from further consideration.
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This step would consist of rating the three or more sites Step 2.
selected in step 1 by applying the criteria in Table 2.3 to the The procedures applied to i
site-specific field data obtained for each.
l collect the appropriate field data should be presented or adequately l
referenced in the document.
DOE should consider revising the document to reflect these recommendations.
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. WM-39/JV/5/6/86/ ALT
-4.
Table 2.3, Pages 8-15 A) Many of the criteria specified for rating the different factors in the table are not specific or quantitative enough to allow reproducible results to be reached by independent site-raters.
For example, in rating chemical attenuation (factor #13), the significance of " low," " moderate," and "high"
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clay content is subjective and would be subject to different interpretations by different individuals. This problem would be solved by specifying numerical ranges of clay content for each rating category based on reasonable and adequate justifications.
As another example, in rating conflict with mineral resources, the interpretation of " serious," " moderate," and " minor" conflicts is very ambiguous.
Application of the principles of a resource / reserve classification scheme similar to that outlined by the U.S. Geological Survey and the Bureau of Mines (U.S. Geological Survey Circular 831, 1980) would minimize the ambiguities noted.
The staff recommends that DOE revise the table to address the concerns noted.
B) A particularly desirable characteristic for any site is its proximity to a source of good quality rock for riprap.
The staff recommends including and adequately defining this criterion in Table 2.3.
C) Though the presence and quality of groundwater is included as a
" hydrological" rating factor, the use of the resource is not considered.
Presumably, sites that overlie " potable" groundwater would have been excluded in Phase II.
However, there are several uses of non potable drinking water that may affect the safety of the public and the environment.
For example, water that is not adequate for drinking by humans may be fine for livestock watering or irrigation.
Contamination of water used for these and other purposes will eventually impact the public health.
The staff recommends, therefore, that DOE introduce a factor into Table 2.3 that deals with the situation of non potable groundwater use.
D) Factor #10 in the site ranking matrix deals with the relative permeability of soil and/or rock formations.
Although permeability is an important characteristic that affects the ability of the porous medium to transmit fluid, the staff takes issue with the use of the term " relative permeability." As defined in the Dictionary of Geological Terms (American Geological Institute, 1976), the term is commonly used in reference to:
"The permeability to one fluid phase when two or more fluid phases are present in the porous medium."
Thus, as used in the table, the term can be misleading given that it is The staff unlikely that fluid phases will be considered in characterization.
therefore suggests that 00E use' the term " hydraulic conductivity" in describing characterization of rock properties rather than fluid properties.
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~5-E) Though it.ts stated (section 2.4, p. 6) that the criteria presented are based in part on the geotechnical ranking matrix used by the Colorado Geological Survey (CGS), many modifications have been made to the latter without technical justification. For example, in evaluating surficial materials thickness as a factor, the CGS rating matrix gives the highest ("best") ranking to sites that are underlaid by clay or silty clay or by 0 to 2 ft. of other types of surficial material; sites underlaid by more than 20 feet of non-clayey O
deposits are given the lowest ranking for this particular factor.
By contrast, v
in evaluating surficial materials thickness as a factor (factor #2), the DOE rating matrix would assign the highest ranking to sites having 20 or more feet of any type of surficial sediments.
As another example, the CGS rating matrix rates the land slope factor (factor #1) as highest for sites with slopes of 2%
to 5%, thus striving for a compromise between the requirements for slope stability and minimization of on-site ponding.
The DOE rating matrix, on the other hand, would rate the land slope factor as highest for sites with slopes 4
of 2.5% to 0%. The bases for selection or modification of specific criteria should be presented in the revised document.
F) The ranges of distances to be rated in evaluating the hazards to a site from the " nearest seismic risk capable fault" (factor #4) should depend on the magnitude of the earthquakes anticipated.
The fixed distance ranges specified in the table may not be adequate in all cases.
For example, an earthquake of j
magnitude 6.5 or greater may pose significant hazards to a site 20 km away.
j O The staff recommends modifying this rating parameter to be dependent of earthquake magnitude and shortening the term " seismic risk capable fault" to
" capable fault."
G) In rating the "present erosion / depositional environment" (factor #6) the highest ranking is given to sites with: "No erosion or undergoing deposition."
This criterion appears to have been adopted from the rating matrix used by the i
Colorado Geological Survey.
It should be emphasized, however, that the rating matrix used by the Colorado Survey was designed to select sites for below grade disposal (i.e., burial) of tailings.
By contrast, the DOE's rating matrix is l
intended to select locations for above ground disposal of tailings piles.
Given the importance of maintaining drainage ditches around such piles free of sediments and debris, it is questionable whether sites located in depositional 4
settings should be given a high ranking.
The staff recommends revising this ranking factor to reflect the concern noted.
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ENCLOSURE 2 JK 05/19/86 M1 MARTIN REVIEW COMENTS ON DOE'S " ALTERNATE SITE SELECTION PROCESS FOR UMTRA PROJECT SITES" O
REFERENCES:
1.
Letter from J.G. Themelis, Project Manager, 00E, to D. Martin, Section Leader, NRC, March 14, 1986 with Enclosure.
REVIEW COMENTS:
1.
The following coments are made to clarify statements contained in the Enclosure to Reference 1 above.
(a) Page 6, Paragraph 2.3, 3rd sentence. Change "by design engineering" to "for design".
(b) Page 6, Paragraph 2.4, 3rd sentence.
In first sentence of third O
paragraph, change " test pitting is" to " test excavations are".
(c) Page 6, Paragraph 2.4, last two sentences. The stated number of site-specific characteristics and the total number of points in this paragraph should be revised to agree with Table 2.3.
(d) Page 7, Table 2.2.
To adequately allow consideration of the difficulties, problems and costs associated with the construction of a stabilized tailings system at a relocated site, it is suggested i
that a characteristic, "Constructibility of stabilized tailings system", be added under Engineering in Table 2.2.
The inclusion of this characteristic is intended to allow consideration of factors such as the extent or difficulty of earthwork operations or site specific requirements for proper drainage or dewatering during construction etc., in order to weigh these factors when assessing the suitability of an alternate site. Similar to the other characteristics, I
Table 2.3 should then be revised to allow for rating of the factor '
i on constructibility.
(e) Page 15, Table 2.3, Footnote c.
The technical evaluation reflected in Table 2.3 ranking is to be completed in Phase'IV of the alternate site selection process. At the Phase IV stage explorations and test pit excavations may have already been completed, where logging of explorations and laboratory test results on encountered materials will have become available. For this reason it is suggested the word " visible" be deleted from footnote c in recognition of the data base beyond visible which would be available in the ranking of the pertinent factors.
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