ML20245K777
| ML20245K777 | |
| Person / Time | |
|---|---|
| Issue date: | 06/26/1989 |
| From: | Heyer R, Rich Smith NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-WM-39 NUDOCS 8907050252 | |
| Download: ML20245K777 (4) | |
Text
_ - - _ - - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . ._ _ -
POR p$ eso UNITED STATES p .
'[ NUCLEAR REGULATORY COMMISSION g REGION IV
,g' URANIUM RECOV FIELD OFFICE
- DENVER, COLORADO 80225 JUN 2 61989 URF0:RSH Docket No. 40-WM039 040WM039310E MEMORANDUM FOR: Docket File No. 40-WM039 FROM: Ralph S. Heyer, Project Manager Uranium Recovery Field Office, Region IV
SUBJECT:
REVIEW 0F JUSTIFICATION FOR APPLICATION OF SUPPLEMENTAL STANDARDS AT VICINITY PROPERTY GJ-97009-0T (NORTH AVENUE BETWEEN 28 ROAD TO 29 ROAD, SOUTH SIDE)
Background
By submittal dated March 20, 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-97009-0T.
This REA is for an application for supplemental standards in a strip of land approximately 10 feet wide and one-half mile long containing a 10-inch diameter water main.
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 This supplemental standards application pertains to the mill tailings contamination surrounding the water line on the south side of North Avenue between 28 Road and 29 Road. The water line.is'a 10-inch diameter cast iron-pipe, which lies within the Colorado Department of Highways (CDH) right-of-way for North Avenue. Mill tailings have been found near this pipe in sufficient..
quantities to suggest that tailings were used as bedding and backfill materials-during the water line construction.
There were five alternatives examined in the REA. .They are summarized as I follows:
O f*
g 8907050252 890626 g PDR W AS~I E PNV l
I 2 JUN 2 61989 .J Alternative 1 Complete remediation (installation of new pipe and removal of old pipe)
Health Risk - Reduced to within EPA standards. l Estimated Construction Cost - $661,000 l Estimated Volume of Contaminated Materials Removed - 4,417 cy Alternative 2 Complete remediation (hand excavation and remediation with existing pipe i left in place) l Health Risk - Reduced to within EPA standards.
Estimated Construction Cost - $624,000 Estimated Volume of Contaminated Materials Removed - 4,417 cy Alternative 3 3 Complete remediation (remove existing pipe, perform remediation, and i install new pipe at the existing location) j Health Risk - Reduced to within EPA standards.
Estimated Construction Cost - $442,000 Estimated Volume of Contaminated Materials Removed - 4,610 cy I Alternative 4 Partial remediation (remove tailings to a 30-inch depth)
Health Risk - Gamma exposure rates reduced to background levels.
Estimated Construction Cost - $227,000 Estimated Volume of Contaminated Materials Removed - 2,410 cy Estimated Volume of Contaminated Materials Remaining - 2,007 cy
)
Alternative 5 Supplemental standards application (No Remediation) l Health Risk - See " Health Risk" Section.
l Estimated Volume of Contaminated Materials Remaining - 4,417 cy Radiological Data The area background is 15 pR/hr and 1.6 pCi/gm.- The highest gamma reading was I reported at 109 pR/hr. The exposure rate range at ground level, over the contaminated area, was reported between 17 to 109 pR/he. The average exposure ;
rate at ground level, over the contaminated area was 43 pR/hr. The Ra-226 1 concentration in the soil, in contaminated areas, ranged from 1
<1.3 to 176.1 pCi/gm. The average Ra-226 concentration in the soil, in the 1 contaminated area, was 35 pCi/gm. .
i Health Risk Analysis i i
The analysis of health risks was presented in the REA utilizing two i 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- i 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 ,
s !
l i
~
3 JllN 2 6 1989 is expected to be less than 100 mrem / year. The health risk analysis presented in the application described the worst case scenario based on the minimum 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 aescribed 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 2865 North Avenue and is equal to the worse case scenario. The worst case scenario depicts occupation of a site for an average of three to four hours per day during a one year period. DOE 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 there appears to be no identifiable significant health risks should the application be approved. There is no change in land use expected within the foreseeable future. However, it was noted that there is a potential for future tailings migration from the North Avenue area during street improvement or repair wo k.
The 00E, in the REA, recommended that a long-term tailings management, disposal, and migration control plan be developed and implemented. The plan would address undiscovered deposits, deposits left in place through application of supplemental standards, and deposits that are not within existing inclusion boundaries.
Based on the above and the review of the subject REA and associated correspondence, Criterion "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 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-97009-0T (North Avenue between 28 Road to 29 Road, South Side).
( () 6
/ &
Ra1 i S. Heye , Project Manager Urahium Recove Field Office I r Region IV I Approved By: ;
R. Dale Smith, Director Uranium Recovery Field Office l t
Region IV l Case Closed: 040WM039310E
?.. i
~
JUN 2 61989 WM39-310E/RSH/89/06/16/M DISTRIBUTION Docket File No. 40-WM039 PDR/DCS ABBeach, RIV RHeyer PGarcia BFranz, RCPD, C0 ,
LLO Branch, LLWM URF0 r/f CONCURRENCE: DATE:
RHeyer/URF0/db V 5-[? _g PGarcia/URF0 Mr/LPs (,-n -e)
RDSmith/URF0 x
_ _ _ _ _ _ _ _