ML20248J831
| ML20248J831 | |
| Person / Time | |
|---|---|
| Issue date: | 06/03/1998 |
| From: | William Ford, Hooks K, Johnson T NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | |
| Shared Package | |
| ML20248J820 | List: |
| References | |
| REF-WM-64 WM-64-98-201, NUDOCS 9806090326 | |
| Download: ML20248J831 (9) | |
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U.S. NUCLEAR REGULATORY COMMISSION DIVISION OF WASTE MANAGEMENT Docket No.: WM-64 Report No.: WM-64/98201 Licensee: U.S. Department of Energy Facility: Lakeview Disposa! Site Location: Lake County, Oregon (north of town of Lakeview)
Date: May 5,1998 Inspectors: Kenneth R. Hooks, inspection Team Leader Division of Waste Management (DWM)
Uranium Recovery Branch (URB)
T. L. (Ted) Johnson, Surface Water Hydrologist Division of Waste Management (DWM)
Uranium Recovery Branch (URB)
W.!!iam H. Ford, Hydrologist i Division of Waste Management (DWM) !
Uranium Recovery Branch (URB) l Banad N. Jagannath, Geotechnical Engineer Division of Waste Management (DWM)
Uranium Recovery Branch (URB)
Approved by: Joseph J. Holonich, Chief Uranium Recovery Branch, Division of Waste Management Attachments: Partial List of Persons Contacted List of items Opened, Closed, and Discussed Partial List of References Enclosure 9006090326 980603 -
L_________._____ . _ _ _ _ _ . _ _ . _ _ . _ _ _
, Report Details Insoection Ssspg The U.S. Nuclear Regulatory Commission (NRC) inspectors conducted an announced inspection of the Lakeview uranium mill tailings disposal site in Lake County, Oregon, approximately 7 miles north of the town of Lakeview, Oregon, on May 5,1998. The purpose of the NRC inspection was: to observe the inspection being conducted by personnel from the l.
U.S. Department of Energy (DOE) Grand Junction, Colorado, office (the licensee) and its contractors;, to inspect surface features of the site; and to review hydrologic records brought to the site by the DOE personnel.
[: Although there are no NRC Inspection Manual Chapters (MC's) or inspection Procedures (IP's)
! directly applicable to the inspection of uranium mill tailings disposal sites which have been l licensed for long-term care under the general license in Title 10 Code of Federa' o.egulations
- (10 CFR) Part 40.27, the NRC inspectors reviewed and used the applicable portions of the
!- . MC's and IP's in the attached Partial List of References. The NRC had previously verified that reclamation of the site was adequate in its review and acceptance of the DOE's site Completion Report. The adequacy of DOE's plans for post-licensing inspections of the site to evaluate
- changes in site conditions was previously verified by the NRC through its acceptance of the DOE's Long-Term Surveillance Plan (LTSP). Thus the bases for evaluation of the DOE
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- On May 6,1998, the NRC inspectors observed the Lakeview uranium mill processing site, l which has been reclaimed and released for unrestricted use. Nothing requiring further review was observed.
Site Status I The Lakeview disposal site is located on the Collins Ranch, approximately 7 miles north of I
Lakeview,' Oregon, in semiarid or high desert country, at an elevation of about 4750 feet above sea level.' The tailings pile contains about 926,000 cubic yards of radioactively-contaminated material, relocated to the disposal site, mainly from the Lakeview uranium processing mill. The land surrounding the disposal site is privately owned (Collins Ranch).
Reclamation of the Lakeview disposal site by DOE was completed in 1989. The site was placed under the general license in 10 CFR Part 40.27 when the NRC accepted the DOE's final LTSP for the site by letter dated September 15,1995. The NRC letter noted two areas of
- l. . concem, related to erosion protection rock (riprap) durability and water seepage from the disposal cell (tailings impoundment), which were identified by both NRC and DOE personnel during pre-licensing site visits. DOE performed annual pre-licensing inspections of the site starting in 1990, and annual post-licensing inspections in accordance with the requirements of the LTSP starting in 1995. Due to continued NRC and DOE concern about rock durability, DOE instituted a data-gathering program to evaluate the extent of and rate of rock deterioration at the site.
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. General Observations and Findinas Following a brief entrance meeting to define the inspection scope and to obtain site background information, the inspection began with a walkdown of the top and riprapped sides of the tailings pile (disposal cell) and the riprapped diversion channel on the north and west sides of the impoundment. The top of the impoundment, which was visibly damp, is covered with a rock / dirt mulch, which has been seeded and displayed considerable clump vegetation. There was no visible erosion of the top cover. There was standing water visible at the toe of the diversion channel, and a small amount of water flowing from the trench (finger) drains away from the site.
i Flow from each of the finger drains had created some visible erosion of the surface, generally at
- l. .the site fence line. Specific details of site conditions are given in the following paragraphs.
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. Geotechnical Observations and Findinas During the inspection, NRC staff observed : (1) condition of the top of the tailings pile; (2) riprap covered slopes and drainage ditches; (3) finger drains; (4) settlement monitoring stations; and (5) fence, signs, ,d permanent markers at the site. J l
l The top of the tailings disposal cell is a vegetated cover on a rock mulch and soil mixture base.
! ' The surface was damp, probably be :ause of rain preceding the site inspection. There were no i gullies but only a few minor rills, probably caused by shrinkage of clayey material in the cover. 1 The top was partially covered with grass planted as part of the vegetative cover, and local sage and tumble weed bushes that have established on the cover. As seeps were noticed in the
. finger drains at the toe of the riprapped slope, DOE had conducted field permeability tests to determine the hydraulic conductivity of the cover. DOE did not perform any permeability tests l 'during this inspection. However, DOE stated that it plans to evaluate the permeability of the cover in connection with investigating the source of the seeps observed in the finger drains. 3
! DOE also plans to assess the impact of changes in permeability on the long-term performance 1 of the disposal cell. l
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The riprapped slopes and drainage ditches are generally in the as-constructed configurations.
The DOE conducted field gradation tests to determine the D 3a size of the riprap in an effort to quantify the rate of riprap degradation. This item is discussed in detailin the Surface Water Hydrology and Erosion Protection section of this report. j The riprap on the slope terminates in a toe drain which drains into the diversion ditch at the northern end of the disposal cell. There are five finger drains from the toe drain leading towards the western boundary of the site (fence). The staff observed seepage from four of the five finger drains, and also minor gullying as a result of flow from the finger drains (see Figure 2).
The DOE inspection tea n measured and photographed the gullies. The source of the seep could not be established by visual observation; DOE stated that it would attempt to establish the source of the seepage by further investigations.
The staff saw the permanent settlement monitoring devices, which appeared to be in working condition.- Settlement monitoring was not part of this inspection, and DOE stated that it intends
- to inspect and monitor them in the 1999 annual inspection. The NRC inspectors observed the l 3
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. DOE team inspecting the fence, signs, and permanent site markers. The fence and other items were allin good condition.
Geotechnical Conclusions
- 1. DOE committed to investigate the source of the seepage observed in the finger drains.
Tests will be conducted to determine if the seepage is water coming out of the disposal cell or surface water flowing down through the riprap and flowing into the finger drains. If water is seeping out of the disposal cell, then the source of the water (surface water infiltrating into the disposal cell through the cover or ground water migrating into the disposal cell) will be investigated.
- 2. DOE stated that additional permeability tests will be performed to establish the in-situ permeability of the as-built cover. This information will be important in the investigation to determine the source of the seep observed in the finger drains.
Hydroloaic Observations and Findinas The NRC inspectors observed: (1) upgradient, downgradient, and point of compliance wells; (2) toe drains; (3) recharge areas for the pile; (4) the pile drainage diversion; (5) areas around the pile; and (6) hydrologic data for the site which had not been submitted to the NRC.
Generally wet conditions existed in the recharge areas up hill from the pile and one ground water seep was found within the security fence on a hill slope north of the pile. Water was seen flowing and leaving the site from four of the five toe drains. Standing water was observed in the diversion channel (see Figure 3). Geologic cross-sections and monitor well completion reports brought by DOE personnel were inspected. From these reports it was learned that the point of compliance wells are twinned, because they monitor two different sands, it could also be seen that the two seeps encountered during the construction of the pile occurred at a sandstone siltstone contact above the water table.
In Section 5.3.1 of the LTSP, DOE recommended sampling ground water only once every five years, based on ground water travel time. In response to an NRC staff comment on the LTSP, which recommended annual sampling for the firct five years, DOE proposed to evaluate the data collected through 1994, and, if no significant changes were apparent, to implement sampling once every five years as proposed in the LTSP. This issue does not appear to have been resolved, based on the DOE hydrologic data reviewed by the NRC staff during the inspection. Therefore, DOE committed to perform sampling and analyses as required to close the issue.
Hydroloaic Conclusions i
- 1. DOE agreed to provide the NRC with an analysis of the sampling data as discussed in the l 1994 DOE responses to NRC comments on the LTSP.
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- 2. It could not be determined by either the NRC or DOE inspectors whether or not the water flowing out of the toe drains is from ground water that has flowed through the disposal cell 4
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l or if it is from surface water that has been captured by the toe drain and diversion channel. Therefore, water quality samples must be collected from the toe drains to confirm that there is no threat to the public from contamination moving off the site.
- 3. DOE committed to providing the NRC with copies of DOE reports DOE /AL/62350-69F Rev 1., "UMTRA Project Water Sampling and Analysis Plan, Lakeview, Oregon, dated September 1995 and September 1993. These documents contain the geologic cross-sections and well completions for the disposal site, and are not currently in the NRC files.
- 4. DOE committed to investigate and report to the NRC if the point of compliance monitor wells have been correctly located in the uppermost aquifer on the down gradient side of the pile.
Surface Water Hydroloav and Erosion Protection Observations and Findinas During the inspection, the NRC staff observed DOE activities to measure the size of rock currently present on the slopes of the disposal cell. Using a new procedure that was submitted for NRC staff review by letter dated March 25,1998, DOE performed the measurements using a series of sieves and counting of rocks that passed through specific sieves (see Figure 1).
Preliminary calculations indicated that the D3a size of the riprap currently present is about 2.8 inches. If these measurements are accurate, the rock size has deteriorated significantly in the !
last 10 years. However, DOE has previously provided calculations to show that a rock size of about 2.7 inches is sufficient to resist the flow rates associated with the Probable Maximum !
Flood (PMF), and, thus, the rock is still acceptable, due to the, over design of the original rock size and thickness.
The staff also observed DOE activities to monitor changes of the large rock in the diversion channel area. Using a series of photographic stations and detailed observations of specific large rocks, DOE is using a program that will detect changes in the individual rock masses, such as cracks, fractures, or decrease in size. Based on the observations and comparisons with photographs taken previously, some minor changes have occurred to some of the rocks over the last year. Thus, it appears that the large rocks in the diversion channel are undergoing rapid weathering processes. The changes to the rock sizes are hardly detectable, but it is !
obvious that some changes have occurred. '
l Surface Water Hvdroloav and Erosion Protection Conclusions ;
Construction of erosion protection was conducted in accordance with the NRC-approved design, and the riprap layers appeared adequate, based on the observed condition of the rock on the side slope and in the diversion channel. Although observation and evaluation of the riprap indicate that the rock is still large enough to resist the design flow rates, significant deterioration of the rock has already occurred over the last 10 years. DOE recognizes the need to conduct detailed monitoring of the rock and is continuing its efforts to do so. The current LTSP program is considered sufficient to detect and correct any problems with rock l deterioration.
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, Overall Conclusions
. Surface reclamation of the Lakeview Site appeared to have been conducted in accordance with l
the NRC-approved design, and construction appeared adequate based on the condition of the top cover and diversion ditch. Although observation of the side slope riprap and the DOE inspectors evaluation of the rock indicate that the rock is still within specification, significant deterioration of the rock has already occurred. Seepage is still evident, and data gathering and evaluation by DOE are required to determine the source.
The inspection performed by the DOE team was in accordance with the commitments in the Lakeview LTSP.
No deviations from the commitments in the LTSP were identified, and no violations were identified. f During the inspection, DOE committed to the following:
- 1. Investigate the source of the seepage observed in the finger drains.
l 2. Provide the NRC with ground water sampling data and analyses to justify the sampling schedule proposed in the LTSP (every five years), or revise the sampling schedule.
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- 3. Perform additional permeability test of the as-built cover.
! 4. Re-evaluate the location of the POC wells.
- 5. Formally transmit to the NRC the hydrologic reports reviewed by the NRC staff during the inspection.
- 6. Continue the monitoring and testing of the riprap.
Exit Meeting An exit meeting was conducted at the conclusion of the inspection on May 5,1998. During this j meeting, the inspectors reviewed the scope and findings from the inspection. DOE did not l disagree with any findings or conclusions stated by the NRC inspectors, and did not identify any information provided to, or reviewed by, the inspectors, as proprietary.
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. PARTIAL LIST OF PERSONS CONTACTED Licensee:
Russel Edge, DOE Grand Junction Office Mark Plessinger, MACTECH-ERG Gregory M. Smith, MACTECH-ERS ITEMS OPENED. CLOSED. AND DISCUSSED Ooened None were opened in this report.
Closed None Discussed None PARTIAL LIST OF REFERENCES
( DOE /AL/62350, "Long-Term Surveillance Plan for the Collins Ranch Disposal Site, Lakeview, Oregon," August 12,1994. ,
DOE "1996 Inspection of the Lakeview, Oregon, Title I Site," August 30,1996.
{
DOE "1997 Inspection of the Lakeview, Oregon, Title l Site," July 10,1997.
NRC Trip Raport, Lakeview, Oregon, UMTRCA Title i Disposal Site. October 31,1995.
NRC Inspection Manual Chapter (MC) 2620, "On-Site Construction Reviews of Remedial Action at inactive Uranium Mill Tailings Sites," February 11,1993.
l MC 2801, " Uranium Mill and 11e.(2) Byproduct Material Disposal Site and Facility inspection Program," September 2,1997.
NRC Inspection Manual inspection Procedure (IP) 35702, " Inspection of Quality Verification Function,"
April 14,1992.
, IP 88001,"On-Site Construction," April 15,1994.
IP 92701, "Fc:lowup," March 14,1994.
J Attachment j i
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Figure 2: Water From Footer Drains Leaving Site and Eroding Beneath Site Fence.
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Mr. Jrck Tillm:n :
U.S. Department of Energy Grand Junction Office
-2597 8 3/4 Road Grand
- Junction, CO 81503
SUBJECT:
INSPECTION REPORT WM-64/98201 FOR THE LAKEVIEW, OREGON DISPOSAL SITE
Dear Mr. Till,
man:
On May 5,1998, U.S. Nuclear Regulatory Commission (NRC) staff performed an inspection of the Lakeview uranium mill tailings disposal site located near Lakeview, Oregon. The Lakeview site was reclaimed by the U.S. Department of Energy (DOE) under Title i of the Uranium Mill Tailings Radiation Control Act of 1978, and is now subject to long-term care by DOE under the general license in Title 10 Code of Federal Regulations Part 40.27. The enclosed report presents the results of the inspection.
The inspection examined the condition of the site and the inspection activities of the DOE inspection team performing the annualinspection required by the Long-Term Surviellance Plan approved by the NRC. No violations or deviations were identified; therefore, no response to this letter is required.
In accordance with 10 CFR 2.790 of the NRC " Rules of Practice," a copy of this letter and its enclosures will be placed in the NRC Public Document Room.
Bhould you have any questions concerning this inspection, please contact Ken Hooks, the inspection team leader, at (301) 415-7777, or Ted Johnson, the NRC Project Manager for the Lakeview site, at (301) 415-6G58.
Sincerely, Joseph J. Holonich, Chief Uranium Recovery Branch Division of Waste Management Office of Nuclear Material Safety and Safeguards Docket Number: WM-64
Enclosure:
NRC Inspection Report WM-64/98201 cc: Russel Edge, DOE-Grand Junction George Rael, DOE Albuquerque DISTRIBUTION (w/ encl): File Center URB r/f PUBLIC CCain, RIV BJagannath TLJohnson ACNW CNWRA WFord (w/o encl): MFederline CAbrams MLayton DOCUMENT NAME: S:\DWMiURB\KRH\lakeview. ins
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NAME KHooks k DGillen JHolonich DATE I/I98 N 6/ /98 6/ /98 l OFFICIAL RECORD COPY l
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