ML20246A464
| ML20246A464 | |
| Person / Time | |
|---|---|
| Issue date: | 05/08/1989 |
| From: | Scovill V, Rich Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-WM-39 NUDOCS 8907060297 | |
| Download: ML20246A464 (5) | |
Text
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NUCLEAR REGULATORY COMMISSION E
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URANIUM RECOVERY FIELD OFFICE
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0 0 00225 MAY 0 81989 URF0:VRS Docket No. 40-WM039 040WM039240E MEMORANDUM FOR:
Docket File No. 40-WM039 FROM:
Van R. Scov111, Project Manager Uranium Recovery Field Office Region IV
SUBJECT:
REVIEW 0F JUSTIFICATION FOR APPLICATION OF SUPPLEMENTAL STANDARDS AT VICINITY PROPERTY GJ-90006-0T (29 ROAD)
Background
By submittal dated March 8, 1989, the Department of Energy (DOE) provided a final Radiological and Engineering Assessment (REA) which requested the application of supplemental standards on the contaminated area (s) for vicinity property GJ-90006-0T.
This REA is an application for supplemental standards on a strip of land approximately 10 feet wide and 2,655 feet long, which is adjacent to the west edge of 29 Road, and is within the city limits of Grand Junction, Colorado.
The northern boundary of this strip of land is Orchard Avenue and the southern boundary is North Avenue.
The purpose of this assessment is to evaluate the extent of contamination in the area being considered for supplemental standards.
This assessment includes recommended remedial action, estimated volume of material to be removed and estimated cost alternatives.
Discussion The application for supplemental standards pertains to mill tailings
. contamination surrounding the water line on the west side of 29 Road.
The affected utility elements are a 6-inch diameter main water line, water valves and valve boxes, residential water taps, gas service lines and sanitary sewer service. lines.
The telephone, electric and cable television service lines are located overhead, along the 29 Road right-of-way.
There were five alternatives examined in the REA.
They are summarized as follows:
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Alternative 1 Complete remediation with replacement of existing pipe in the same
. location.
Health Risk'- Reduced to within EPA standards Construction Cost - $174,600
. Estimated Volume of Contaminated Materials Removed - 3,835 cy Alternative 2 Complete remediation, hand excavation with pipe in place.
Does not
. include remediation.at cross streets.
Health Risk -. Reduced to within EPA standards Construction Cost - $169,700 Estimated Volume of Contaminated Materials Removed - 3,688 cy.
Alternative 3 Complete remediation,-remove old pipe, install new at a 5-foot offset.
Health Risk - Reduced to within EPA standards Construction Cost - $242,000 Estimated Volume of Contaminated Materials Removed - 3,835 cy Alternative 4 Partial remediation by removal of tailings to a 30-inch depth. Does not include remediation of cross streets.
Health Risk - Gamma exposure rates reduced to background levels, radon gas migration not controlled.
Construction Cost - $66,400 i
Estimated Volume of Contaminated Materials Removed - 2,007 cy Estimated Volume of Contaminated Materials Remaining - 1,680 cy Alternative 5 Application of Supplemental Standards (No Remediation)
Health Risk - The REA data indicates no identifiable significant health risk Construction Cost - $0 Estimated Volume of Contaminated Materials Removed - O cy Estimated Volume of Contaminated Materials Remaining - 3,835 cy Radiological Data The area background is 16 pR/hr and 1.4 pCi/gm.
The highest gamma reading was reported at 69 pR/hr.
The exposure rate range at ground level, over the contaminated area, was reported between 14 to 69 pR/hr.
The average exposure rate at ground level, over the contaminated area was 27 pR/hr.
The Ra-226
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concentration in the soil, in contaminated areas, ranged from <1.0 to 182 pCi/gm.
The average Ra-226 concentration in the soil, in the contaminated area, was 52 pCi/gm.
Any contamination that was identified and is below or within 10 feet of a.
structure, the radon daughter concentration in that structure was estimated at 0.02 WL.
The data submitted supports the belief that the mill tailings were used during the construction of the water line.
Health Risk Analysis The analysis of health risks was presented in the REA utilizing two comparisons.
First was the examination of long-term exposures based on a 100 mrem per year exposure, and second was an assessment of short-term unusual exposures based on a 500 mrem per year exposure. The maximum gamma dose rate is 100 mrem / year to an individual member of the general public.
Doses which exceed 100 mrem / year are acceptable when the higher exposures do not persist for long periods and when the average annual dose over an individual's lifetime is. expected to be less than 100 mrem / year.
The health risk analysis presented background and maximum surface gamma rates that were measured, without consideration of the relative physical location of each.
DOE stated that in every case, the scenarios presented in the REA were described as unlikely but possible.
The scenarios did not create a model of likely situations, but rather to present-data that can be utilized to evaluate the potential for a health hazard if the application was approved.
The maximum gamma exposure rate, above background occurs in the area in front of 529 29 Road and is close to the worst case scenario.
The worst case scenario depicts occupation of.a site for an average of 5 hours5.787037e-5 days <br />0.00139 hours <br />8.267196e-6 weeks <br />1.9025e-6 months <br /> per day during a 1 year period. 00E stated that it is unlikely that this situation would occur in an area so close to the street without considerable changes in land ownership and uses.
Conclusion The DOE concluded that based on the examination of the health risks performed, i
there appears to be no identifiable significant health risk should the application be approved.* There is no change in land use expected within the foreseeable future.
Long range plans exist for widening and upgrading 29 Road, I
but construction is not anticipated until 1994; and, it was noted that there is a potential for future tailings migration from the 29 Road area.
l The DOE, in the REA, recommended that a long-term tailings management, disposal l
and migration control plan be developed and implemented.
The plan would I
address undiscovered deposits, deposits left in place through application of j
supplemental standards and deposits that are not within existing inclusion
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boundaries.
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1 Based on the above and the review of the subject REA and associated I
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correspondence, C'iterion "c" of 40 CFR 192.21 and the NRC's " Guidelines for Justifying the Use of Supplemental Standards," in 40 CFR Part 192, dated July 3,1986, DOE satisfied the criteria deemed necessary to apply supplemental 1
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standards.
It is recommended that concurrence be granted for the application of supplemental standards and that there be no removal of contaminated soils at the property designated as GJ-90006-0T (29 Road).
O Va R. Scovi
, Pr ject Manager Uranium Reco cry Field Office Region IV Approved by:
_.DaleSmith,Diqctor
h Uranium Recovery Field Office Region IV Case Closed:
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