ML20202G061
| ML20202G061 | |
| Person / Time | |
|---|---|
| Issue date: | 12/16/1985 |
| From: | Roles G NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Saraka L NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML20198M712 | List:
|
| References | |
| FOIA-86-396, REF-PROJ-M-32 NUDOCS 8607150293 | |
| Download: ML20202G061 (10) | |
Text
__
e
- o UNITED STATES 8
NUCLEAR REGULATORY COMMISSION o
i E
WASHINGTON, D. C. 20555 9.
8 4 +.... #,
r -,. 6 ggc
'5 MEMORANDUM FOR: Lawreace Saraka low-level Waste and Uranium Recovery Projects Branch Division of Waste Management THROUGH:
Michael Tokar, Section Leader Engineering Branch Division of Waste Management FROM:
G. W. Roles Engineering Branch Division of Waste Management
SUBJECT:
REVIEW 0F PRELIMINARY ORAFT ENVIRONMENTAL ASSESSMENT (EA) FOR DISPOSAL OF WEST VALLEY DEMONSTRATION PROJECT LOW-LEVEL WASTE In response to your December 13 note, we have prepared and enclosed some additional comments on the oreliminary draft EA. Given the unusually short time review time, our comments are provided by three individual members of the Engineering Branch. Those from LeRoy Person address the specific points raised in your December 13 note, while those from myself and Stan Neuder are more general in nature.
Please call me at 74791 if you have questions.
N-O
~
G. W. Roles Engineering Branch Division of Waste Management
Enclosures:
Connents from L. Person, G. Roles, and S. Neuder.
8607150293 e60708 PDP FOIA REENIK086-396 PDR o
)
LSP 12/16/85
- Comments by Roy Person on West Valley EA Briefing of December 12, 1985 3.
Recent information (see Quarterly Progress Report for " Properties of Radioactive Waste and Waste Containers, FIN A-3027, 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 increased release of radionuclides depending on the length of the dry period (the longer the dry period, the greater the release of radionuclides).
Has WVDP considered this phenomenon when assessing the leaching of waste material from the tumulus?
4 Will the geotextile be affected by volatile chemicals (e.g., kerosene tributyi phosphate, or other organic radiolytic degradation products)?
6.
Do the WVDP pathway evaluations represent the proposed disposal concept?
i o
w.
201.3/SN/12/17/85 r Neuder's Comments on West Valley i*
1.
Page G-75, Paragraph 2: The statement was made in the document that
" Migration of contamination was not considered feasible during the active institutional control period because engineered features such as low penaeability clay caps and surface drainage system prevent the infiltration of surface water into the waste." At the briefing of 12/12/85, 00E stated that there exists significant subsurface water flow in the lateral direction near or at the trenches. This characteristic of the site precludes anyconfidence in the assumption that no migration will occur during the 100 year period of active institutional control.
2.
Page G-ll2, last Paragraph:
It's difficult to believe that the drinking water pathway is less controlling than the fish-ingestion pathway.
i This is critically dependent on the assumptions made regarding migration, migration pathways and receptor locations.
3.
General Comment Regarding Dose Assessment:
Th'e projected dose to an individual will depend strongly on assumptions made regarding infiltration rates, water-waste contact time, leach rates K values.
d Uncertainties may easily exceed the reported difference between the l
trench vs. tumulus disposal modes.
1
l t
,i 1
i
~
j WV COM f
d General Comments on Draft West Valley EA G. Roles - 12/16/85 1
i i
4 These are comments of a general nature based on a rapid review of the subject
{
document.
Insufficient time exists for a more extensive review.
This review i
furthermore principally focuses on items of fundamental concern in regard to low-level waste disposal -- i.e., the long term structural stability of the 1
1 waste and disposal method.
During the development of 10 CFR Part 61, NRC i
concluded that structural stability was of sufficient importance to warrant 1
inclusion as one of the four performance objectives for land disposal.
]
As stated in 10 CFR 61.44, "the disposal facility must be sited, designed, used, j
operated, and closed to achieve long tern stability of the disposal site and to 1
eliminate to the extent practicable the need for ongoing active maintenance i
following closure so that only surveillance, monitoring, or minor custodial care are required."
In 10 CFR 61.2, active maintenance is defined to include ongoing activities such as the pumping and treatment of water from a disposal i
i unit or one-time measures such as replacement of a disposal unit cover.
Some of the history which led to the adoption of this performance objective is l
provided below as a background, i
Background
i l
10 CFR Part 61 was developed in order to correct a number of institutional and technical problems which had been identified in connection with low-level waste i
disposal.
Action") of the draft Part 61 EIS (NUREG-0782).Thes i
As stated in the draft EIS:
)
At the coninercial sites, the difficulties were principally evident at the
{
Maxey Flats. KY and West Valley, NY sites.
The problems were 1
j predominately attributed to three factors: (1) the trench cap or coverint over the trench was of a higher permeability than the surrounding soil i
which allowed precipitation to e' nter and collect in the trenches; (2)
I disposal trenches were completed when they contained appreciable quantities of rainwater; and (3) the compressible, degradable, unstable j
nature of the waste being buried led to subsidence of the trench cap creating pathways for precipitation to readily enter the trenches.
1 These L
factors led to the filling of trenches with water and to small releases of j
radioactivity through surface and groundwater pathways.
i i
i,
+
I l
\\
WV COM l '
1 l
I Studies and remedial actions were initiated at both sites.
These studies and remedial actions have proven to be expensive -- e.g., greater than
$1,000,000/yr at the Maxey Flats site -- and are continuing to this day.
In the final EIS on the Part 61 rule (NUREG-0945), NRC strongly emphasized the importance of waste and site stability in minimizing both long tenn releases and institutional control maintenance activities.
10 CFR 61.44 was identified as one of four necessary performance objectives, and a number of technical requirements were imposed to help ensure that the performance objectives would be met.
These requirements are in Subpart 0 and include those on waste form, waste facility design and operation, closure, etc.
A classification system was established which requires that the higher activity (Class 8 and C) waste be stabilized according to stringent standards. presented in 10 CFR 61.56.
Class A waste is not generically required to meet the stabilty requirements.
It is important to understand, however, that NRC did not mean to imply that stability was not important for Class A waste disposal.
In fact, NRC staff stated in the final PArt 61 EIS that the " preferred solution in terms of minimizing groundwater migration and reducing institutional control maintenance activities would be to extend waste stability requirements to all waste (p.
5-10). However, NRC staff also indicated that they believed that extension of waste stability requirements to all waste would have too great of an economic impact to require generically at the time of the rulemaking, particularly to small entities.
The decision, then, was to require on a generic basis segregation of the unstable Class A waste, and to consider further stability requirements on a site-specific basis. As stated on page 5-11 of the final Part 61 EIS:
NRC staff, therefore, intends that the site operator give particular attention to means of achieving greater stability to the design of that portion of the facility used for disposal of Class A waste.
Innovative designs should be considered in order to provide long term stability of i
the site, considering the inherent instability of the Class A waste and the potential for waste accumulation problems where there is potential for such problems to occur.
NRC staff highlighted their concerns with the potential for water acculation problems at some sites at a number of other points in both the draft and final Part 61 EIS (e.g., pp. 4-36 and 4-37 of the final EIS).
i One particular statement is of particular interest (p. 5-19 of the final Part 61 EIS):
Ouring licensing of specific disposal facilities, however, special attention will be given to the possibility of leachate accumulation within disposal cells.
At specific sites where such a possibility can occur, e
e WV COM
. i additional measures intended to eliminate this possibility will be i
considered.
)
Although it is not specifically stated in the EIS, the authors of the above quote defihitely had sites such as West Valley in mind.
Comments I
1.
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 the West Valley sites, and so it is highly doubtful that the performance objective set forth in section 61.44 will be met. Almost 100% of the waste exists as compressible trash, " miscellaneous dry solids", and failed equipment disposed in SS-gallon drums and steel boxes. These drums and boxes should begin failing within a few short years, and large voids will be created within the trenches.
This will result in subsidence of the trench caps and significantly increased infiltration of water into the trenches.
Given the impermeable nature of the site soils, the infiltrating water will collect in the trenches.
This water will have to be continuously and periodically removed and treated.
1 Trench voids will result from (1) degradation of the organic material (paper, wood, etc.) that comprises much of the waste, and (2) void spaces remaining within the containers after packaging.
apparent for failed equipment packaged in boxes.This second problem will be especially Experience from other disposal facilities has shown that these trench voids can result in large sinkholes (i.e., several feet in diameter) being created in the trench caps.
i Such voids and sinkholes will surely disrupt any drainage system built into the trench caps. No evidence is provided to suggest that the use of filter fabric layers will significantly reduce the generation of these sinkholes.
2.
Subsidence will also be observed in the Class B/C tumulus. Although this subsidence will apparently not result 1,n a bathtub problem, there will be contaminated leachate generated which will need to be handled and treated.
This subsidence will result from at least two sources.
First, although DOE proposes to solidify some of the waste, experience has shown that " solidified" is not the same as " stable." Cement waste forms that are merely " solidified", as opposed to " stable", frequently crumble and i
fracture extensively.
I am aware of no tests performed by 00E to qualify their solidification processes to meet the stability requirements in Section 61.56, nor of any process control programs to ensure that waste processing will be 1
carried out correctly, t
h
e WV COM i
4 Second, voids will exist in the containers following packaging. 00E has stated that solidified waste containers are expected to be at least 95% full.
I am aware of no process control program to ensure that this expectation becomes reality. Furthermore, about 30% of the Class 8/C waste will exist as trash and failed equipment within steel boxes.
I would anticipate that at least 50% of i
j the volume within the boxes will be void space.
4 Similar to the Class A waste trenches, the waste containers will rust and fail
{
within a few years.
Waste and soil (and crumbling cement waste forms)~will consolidate within the tumulus, leading to slumping and subsidence of.the i
tumulus covers.
This slumping and subsidence will surely disrupt internal drainage networks within the tumulus covers.
Again, no evidence is provided to t
indicate that the use of filter fabric layers will significantly reduce the 1
generation of the sinkholes within the tumulus covers.
I 3.
DOE has provided no evidence to supoort their assertions regarding the i
integrity of the disposal covers during the active institutional control periods.
These covers are presumed to work essentially perfectly for time periods ranging from 100 to several hundred years. On the other hand, there is considerable evidence which suggests that the disposal will not perform I
adequately for even a few years. Some of this evidence has been provided in I
the above two comments. Also of interest is the attached abstract of a USGS paper on collapse and erosion of trench covers at the Sheffield disposal site l
(presented at the Seventh Annual DOE Lt.WMP Participants' Infonnation Meeting, Las Vegas, Nevada, Sept. 1985).
i 4
The draft EA is deficient in that 00E has provided no economic analysis to 1
i support their preferred option.
In particular, 00E has not considered the full j
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 will result in a requirement for less money being spent over the tong term.
00E should attempt an analysis which tries to balance and-
{
compare these costs j
y i
5.
The alternatives considered by DOE in the EA are of insufficient scope.
t suggest expanding the range of alternatives considered to include more highly engineered disposal methods (e.g., concrete bunkers, the Westinghouse SllREPAK system, etc.) which may be more likely to truly provide structural stability over the long term.
This would be consistent with NRC's intentions as stated i
in the final Part 61 EIS regarding the application of the regulation and classification system to specific disposal sites.
4 i
l i
r
. - - - - - - - - - - - " - - - - ' - - ^ ^ - - - - - ' - -
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - ' - - - - ^ ^ - ~ ~ -
WV COM 6.
The radioactive waste source term is estimated in a very crude manner --
i.e., waste volumes and gross activities are postulated, and then an isotopic distribution based on the activity within one of the high level waste tanks is applied.
I am surprised that, given 00E's resources, a more accurate estimate has not been provided.
In any case, such estimates should not be considered acceptable for actual disposal operations.
Individual waste streams should be characterized and isotopic distributions estimated based on actual sampling data.
7 Given the apparent potential for significant impacts, either environmental or economic or both, an argument could be made that an environmental impact sta tement is necessary, i
l
. ~
4
~
COLLAPSEANDEROS!0NATTHEL0id-LE"ElRADI0 ACTIVE-WASTE
. DISPOSAL SITE NEAR SPEFFIEL3, ILLINOIS J. R. Gray and L. L. McGovern U.S. Geological Survey, WRD, Urbana, Illinois ABSTRACT Collapse and erosion are the dominant landform-modification processes at the Sheffield low-level radioactive-waste disposal site.
Records on collapse have been collected by the site contractor since 1978 and include date of inspection, location, and void dimensions.
Fluvial sediment yield has been measured by the U.S. Geological Survey beginning July 1982 from three gaged areas which drained two-thirds of the 20-acre site, and from a gaged 3.5-acre area in undisturbed terrain 0.3 mile south of the site.
Three hundred and two collapses were recorded from October 12, 1978, to July 12, 1985.
Based on the weight of earth material equivalent to void volume, an annual average.of 9 tons of sediment per acre of site area has moved downward due to collapse.
Void volume was log-normally distributed around a median of 10 cubic feet.
The depth of one collapse was estimated to be 20 feet; two collapses exceeded 18 feet in diameter. Sixty-two per-cent of the collapses occurred near waste-disposal trench boundaries, while the remainder occurred in earth material covers over the trenches.
Two-thirds of the 302 collapses occurred during the months of February, March, and April. These collapses represent 58 percent of the total collapse weight. Three collapses during the spring of 1979 comprised 22 percent of the total collapse weight for the period of record.
Onsite fluvial sediment yield average 2 tons per acre annually from July 1982 through July 1984.
Although this yield was approximately 200 times the sediment yield from the undisturbed area, it is less than one-third the. statewide average annual sediment yield.
Unvegetated areas, rills, and gullies contribute the bulk of sediment measured at the gages. Annual collapse yields are over 4 times greater than fluvial sediment yield.
N l0
a m ;i. ':
+
Arv :: SEVENTH O
LWMP
^
PARTICIPANTS' INFORMATION MEETING DOE LOW-LEVEL WASTE MANAGEMENT PROGRAM Las Vegas, Nevada September 10-13, 1985 h
'*f*e y
ep
- .g*
eag g,,
a p, [k
'= QmT 4
"g
.