ML20205K998
| ML20205K998 | |
| Person / Time | |
|---|---|
| Issue date: | 10/27/1988 |
| From: | Deering L, Grimm J, Wastler S NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Lohaus P, Surmeier J NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| REF-WM-39, REF-WM-54, REF-WM-62, REF-WM-68, REF-WM-86 NUDOCS 8811010433 | |
| Download: ML20205K998 (5) | |
Text
E,
's SW/ TRIP REPORT 00T 2 71998 MEMORANDUM FOR:
Paul H. Lohaus, Chief Operations Branch John J. Surmeier, Chief Technical Branch THROUGH:
Myron Fliagel, Section Leader Uranium Recovery Section, LLOB John R. Starmer, Section Leader Siting Section, LLTB FROM:
Sandra L. Wastler, Project Manager Uranium Recovery Section, LLOB Joel Grim, Geologist Siting Section, LLTB Lynn Deering, Hydrologist Siting Section, LLTB
SUBJECT:
FIELD TRIP TO THE GRAND JUNCTION, RIFLE AND SLICK ROCK REMEDIAL ACTION SITES DATES:
August 1-5, 1988 PLACES:
Grand Junction processing and disposal sites Old and New Rifle processing and disposal sites Slick Rock site Green River site PURPOSE:
The purpose of the UMTRAP site visit was to familiarize the NRC staff with the sites designated above in order to aid the staff in their review of the DOE's remedial action plans.
ATTENDEES:
August 2, 1988 - Grand Junction and Green River L.Ste)p(TAC)
S.Wastler(RC) f D. Lesce (00E)
J. Grim (NRC)
L. Coons (TAC)
L.Derring(NRC)
J. Lindsay (TAC)
August 3, 1988 - Old and New Rifle processing and disposal sites Grand Junction processing site L. Stepp (TAC) )
- 5. Wastler (NRC)
T.Goering(TAC J. Grim (NRC)
J. Lindsay (TAC)
L. Derring (NRC)
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e SW/ TRIP REPORT 2-August 4. 1988 - Slick Rock Mill site M. Jackson TAC S. Wastler (NRC)
T. Goering TAC J. Grimm (NRC))
L. Derring (NRC J. Lindsay TAC DISCUSSION:
GRAND JUNCTION / CHENEY DISPOSAL SITE The Cheney disposal site was visited on the mornings of August 2 and 5.
Participants arrived via an existing dirt road from U.S. Highway 50, two miles southwest of the proposed disposal area. The following are observations of surficial features related to previous issues:
(1) A well developed pavement exists, which previously was suspected to be simply an erosional lag deposit.
(2) Dark desert varnish exists on most.surficial stones.
(3) Near-surface soil consists of a vesicular A horizon and a thin argillic B horizon with abundant calcic material. Holes were dug by hand, and neither underlying C horizons nor buried profiles were observed.
Each observed feature generally. supports assertions made in the RAP. These features collectively support a conclusion that pediment surfaces in the Cheney area have experienced geomorphic stability for a considerable period of time, perhaps since late Pleistocene time, or earlier.
Participants inspected and walked along various portions of Whiting's ditch.
The inspection of Whiting's ditch resulted in the following observations:
(1) The ditch was created to divert runoff in Creek D (called East Creek in design documents), and does not extend to Indian Creek as shown in the RAP. Therefore, the ditch does not divert water from Indian Creek.
(2)
In addition a diversion ditch exists between Indian Creek and Creek D approximately one mile upstream from Creek D's diversion. However, the levee across Indian Creek that would create this diversion is breached in two places, and therefore runoff to the ditch would not likely occur during average runoff events.
(3) Since Whiting's ditch is dry, and does.not capture water from Indian Creek, the hypothesis presented in the RAP that Whiting's ditch is the major source of recharge to the shallow perched aquifer, and that the aquifer is only present downgradient of the ditch, should be reassessed.
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k SW/ TRIP REPORT I GREEN RIVER PROCESSING AND DISPOSAL SITE f
A short unplanned side trip was taken on August 2nd to visit the Green River site. The purpose of this visit was to provide the NRC's Green River project manager with an opportunity to become familiar with the site. DOE providea the
' NRC project manager with a tour of the remedial action site discussing both specific site features and proposed remedial actions. The remaining open i
issues at this site concerns the site hydrology. Since the NRC hydologist for this site was not on the site visit, no significant technical observations were made.
GRAND JUNCTION PROCESSlhG SITE The Grand Junction processing site was visited on August 3 and the following
. observations were made:
(1) Entry gate has been destroyed by vandals and has not been replaced, thereby allowing unlimited access to the site.
The pile showed evidence of bikers and ATV's on the pile.
In fact, during our visit, two minors on ATV were caught on the site and were told to leave by L. Stepp.
L. Stepp indicated that the appropriate DOE. personnel responsible would be notified.
e (2) Subsidence and surface sinks were still noted on the pile.
(3) Vicinity property disposal is ongoing to the east. Contaminated material is delivered by regular dump trucks and arrives covered by tarps. At least three deliveries arrived during the 45 minutes on the site.
(4) The nitrate and asinonia plumes were discussed.
The feed lot at the west side of the pile is a potential source of the pollution.
(5) On the south side of the river it was noted that the Mancos Shale crops out along.~the bank as stated in the RAP.
The existance of the Mancos shale on the south bank confirms that an alluvial aquifer connection does not occur. Therefore, contaminants are not transporte'd southward or southwestward from the site beneath the river.
OLD AND NEW R'IFLE PROCESSING SITES On August 3 the site visit participants went to both the old and new Rifle processing sites.
The participants briefly visited the site office at the new processing site.and then drove around the site observing the state of the buildings and the condition of the pile cover. The pile,
was noted to have a good vegetative cover, but some minor rills due te' erosion were noted on the side slupes near the base of the pile.
The participants also drove to the old Rifle processing site which was observed from an overlook imediateiy above the site. This site is completely overgrown with vegetation ;nd the pile is almost indistinguishable from the surrounding areas.
F s
SW/ TRIP REPORT 4
RIFLE /ESTES GULCH DISPOSAL SITE The first stop was in the central portion of the proposed disposal area. The area is underlain by relatively young valley f111 deposits which were formed after incision of the main piedmont surface.
H1gher ridges around and through the area consist of older and very coarse-grained colluvium, probably correlative to the massive colluvium better exposed in small canyons upstream of the site. Older culluvium has clasts in excess of one-meter diameter, is unstratified, is matrix supported, and supports a much denser growth of juniper and pinon woodland. The younger valley fills are relatively fine-grained, no gravel was observed, and it supports only grasses shrubs, and cacti. Gully exposures indicate weak or no soil development in the young deposits.
SLICK ROCK PROCESSING AND DISPOSAL SITE The Slick Rock site was visited August 4,1988. The first stop was on the cliff across tne Dolores River from the site, for an overview of the area. The pile appeared unchanged from earlier visits, except for a few rills having formed on the interim cover and a small amount of vegetation that established itself.
Exposures of the foundation materials, shown in the dRAP as QT2 and Qe, were observed in Corral Draw. It was observed that deposits denoted as Qe (eolian) include a large amount of gravelly material. The gravel clasts are up to 20 cm in diameter, are composed mostly of sandstone, and appear to occur mostly in the upper portion of unit Qe and, perhaps as paleochannels in the deposit. The unit is clearly derived from bedrock which lies upstrean in Corral Draw. These relations suggest that unit Qe is predominantly fluvial in origin, most of its volume representing fine-grained overbank deposits. The unit does not appear to be eolian in origin.
Unit QT2 underlies Qe and consists of coarse-grained volcanic clasts, persumably derived f rom the San Juan Mountains, 60 miles to the southeast.
Unit QT2 crops out in Cprp l Draw and is found in a topographic saddle above the tunnel outlet of Corra'l Draw. The gravels are also extensively exposed in Sumit Canyon. The. unit'sttains a thickness of at least 6 meters, but appears to pinch out of approximately the same distance from the Dolores as the cliffs which form the valley's southwestern side. Drilling data show that the thickness of Quaternary deposits in the southwestern part of the site is much greater than previously-expected. Occurrence, thickness, and lithology of QT2 grovels show that the Dolores River formerly meandered through the site.
Observations made in hydrology include:
(1) The outcrops of Entrada Sandstone on the site were observed. The outcrop is described in the dRAP as a contact separatir.9 the ancient Dolores River alluvium (contaminated) from the modcen Sumit Canyon allwium. A water supply well is located northwest of the
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SW/ TRIP REPORT
.S.
2 7 1988 existing tail-ings in the Sumit Canyon Wash Alluvium.
The TAC stated during the site visit that the supply well will not become contaminated because it is separated stratigraphically from the Dolores River alluvium by the Entrada Sandstone and there is no hydraulic gradient from the Dolores River alluvium to the well.
Examination of water quality results for the supply well (#634) does not suggest that the well has been contaminated to date.
(2) Well 510 was observed during a previous NRC site visit to be completed without grout cement at the surface, and the well casing extended only a few feet below land surface. As a result of the previous site visit, the NRC staff prepared a written coment to 00E recomending replacement of the well and collection of new water quality sarrples. At the time of our site visit, the well had not yet been replaced.
P Sandra L. Wastler, Project Manager Uranium Recovery Section, LLOB
/5 Joel Grim, Geologist Siting Section, LLTB 1
Lynn Deering, Hydrologist 4
f,5 Siting Section, LLTB as DISTRIBUTION:
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DATE:/0/# 7/88
- 4/.7/88
- is / 21/88 0FFICIAL RECORD COPY