ML20247C584
| ML20247C584 | |
| Person / Time | |
|---|---|
| Issue date: | 05/26/1989 |
| From: | Hawkins E, Heyer R NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-WM-39 NUDOCS 8907240390 | |
| Download: ML20247C584 (4) | |
Text
.
g.
- _- %.~. 4 _
..y.-..._w-o,,-
- r (d '
?+2 i
- UNITED STATES'
,,[phier\\'
- y NUCLEAR REGULATORY COMMISSION
~E REGION IV
~\\
Y URANIUM RFCOVERY FIELD OFFICE
,o
- DENVER, L
Do 80225 MAY 2 61989 URFO: RSH
-Docket No. 40-WM039 040WM039320E 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-97007-0T (ORCHARD AVENUE, INDIAN WASH TO 29 ROAD)
.o
Background
By submittal date'd April.5, 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-9700~7-0T.
This REA is for an application for supplemental standards and is in the City limits of Grand Junction, Colorado.
The area is a strip of land approximately 12-feet wide and 1,962 feet long, adjacent to the south edge of Orchard Avenue.
The eastern boundary of this strip of land is 29 Road and the western boundary is Indian Wash.
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 application for supplemental standards pertains to the mill tailings contamination surrounding the water line on the south side of Orchard Avenue
.between Indian Wash and 29 Road.
The water line is an 8-inch diameter cast iron pipe, which lies within the public right-of-way for Orchard 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 follows:
N [ hk h 890526
~
i WN-39 PNU s
.E_L_._.__________________.-__
-.____.-._.________...______m_
m._
_____s-
_._m.__._
_____-m_
O _.... m a _.. m._
_.u
, _ ~_
Z.1
~ - ~ ~
.w 2
MAY 2 61989 Alternative 1 Complete remediation (Installation of new pipe and removal of old pipe)
Health Risk - Reduced to within EPA standards Estimated Construction Cost - $311,000 Approximate Volume of Contaminated Materials Removed - 2,813 cy Alternative 2 Complete remediation (Hand excavation and remediation with existing pipe left in' place)
Health Risk - Reduced to within EPA standards Estimated Construction Cost - $338,000 Approximate Volume of Co.ntaminated Materials Removed - 2,813 cy Alternative 3 Complete remediation (Remove existing pipe, perform remediation, and install new pipe at the existing location)
Health Risk - Reduced to within EPA standards e
Estimated Construction Cost - $259,000 Approximate Volume of Contaminated Materials Removed - 2,998 cy Alternative 4 Partial remediation (Removed tailings to a 30 inch depth)
Health Risk - Gamma exposure rates reduced to background levels, radon gas migration not controlled Estimated Construction Cost - $140,000 Approximate Volume of Contaminated Materials Removed - 1,790 cy Approximate Volume of Contaminated Materials Remaining - 1,023 cy Alternative 5
-Supplemental Standards Application (No remediation)
Health Risk - See " Health Risk Analysis" Section to this report.
Approximate Volume of Contaminated Materials Remaining - 2,813 cy.
Radiological Data The area background is 16 pR/hr and 1.7 pCi/gm.
The highest gamma reading was reported at 27 pR/hr.
The exposure rate range at ground level, over the coni.sminated area, was reported between 14 to 27 pR/hr.
The average exposure rate at ground level, over the contaminated area was 18 pR/hr.
The Ra-226 concentration in the soil, in contaminated areas, ranged <2.8 to 134.0 pCi/gm.
The average Ra-226 concentration in the soil, in the contaminated area, was 31 pCi/gm.
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 exposures do not persist for long
-~
-o 3
MAY 2 61989 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 in this application for supplemental standards has compared the dose rates measured at ground level with the recommendatioris of the ICRP and DOE regarding waist level exposures.
This procedure ensures a conservative evaluation.
The maximum gamma exposure rate, above background, occurs in the area in front of l
2885 Orchard Avenue (but it is a lower gamma exposure rate than described in the worst case scenario).
The worst case scenario depicts occupation of a site for an average of 21 hours2.430556e-4 days <br />0.00583 hours <br />3.472222e-5 weeks <br />7.9905e-6 months <br /> to 30 hours3.472222e-4 days <br />0.00833 hours <br />4.960317e-5 weeks <br />1.1415e-5 months <br /> per day during a one (1) year period to receive the 100 mrem dose.
DOE stated that it is unlikely that this situation would occur in an area so close to the street unless considerable changes occur in land ownership and uses.
Conclusion The DOE concluded that based on the examination of the health risks performed i
there are no identifiable significant health risks if this application for supplemental standards were to be approved.
The cost of remediation is excessive when no significant health risks exist.
No change in land use is I
expected within the foreseeable future.
The DOE stated that there is a potential for future migration of tailings from the Orchard Avenue area during street improvement / repair work or repair / replacement work on the water line, if either the partial remediation alternative or the supplemental standards application is approved.
The DOE, in the REA, does recommend 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 my 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.
I recommend 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-97007-0T (Orchard Avenue - Indian Wash to 29 Road).
Ralp S. Heye, Project Manager Uran'um Reco y Field Office Region IV Approved By:
p' d/ard F. Hawfins~, Branch Chief
/ Uranium Recovery Field Office Region IV l
Case Closed:
040WM039320E i
a_____
MAY 2 61999 WM039/320E/RSH/89/05/11/M DISTRIBUTION Docket File No. WM-039 PDR/DCS ABBeach, C1V RHeyer BFranz, RCPD, CO LLO Branch, LLWM URF0 r/f d
CONCilRRENCE:
DATE:
RHeyer/URF0/db S
6-76'%
k)h
$ 97 PGarcia/URF0 EFHawkins/URF0 2-/ f I
I f
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _