ML20059E489
| ML20059E489 | |
| Person / Time | |
|---|---|
| Issue date: | 08/31/1990 |
| From: | Jacoby D NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| To: | NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV) |
| References | |
| REF-WM-48 NUDOCS 9009100213 | |
| Download: ML20059E489 (4) | |
Text
IT h n -.
. _sa. W _...
_A_.w
.a., :: - a
..-...ha----
p Mrg
. UNITED STATES y
~ NUCLEAR REGULATORY COMMISSION D
j REolON IV 3
,e URANIUM RECOVERY FIELD OFFICE DENVER.
D o 80225 AUG 31 1990 URF0:DLJ Docket No. WM-48 040WM048970E MEMORANDUM FOR:
Docket File No. WM-48 l
FROM:
Dawn L. Jacoby Project Manager i
SUBJECT:
REMEDIAL ACTION PLAN' MODIFICATION NO. 3:
SUPPLEMENTAL STANDARDS APPLICATION FOR~THE RIVER BANK AREA AT THE DURANGO P.% CESSING SITE 1
BACKGROUND 1
The EPA standards for remedial actions, under 40 CFR 192.12(a), require that the concentration of radium-226-in land averaged over:any area of 100 square meters shall not exceed the background level by more than-5 pti/g,; averaged i
over the first 15 cm of soil below.the surface and 15 pCi/g averaged over 15 cm thick. layers of, soil more than 15 cm below the surface. The radon flux standard,:40 CFR 192.02(b)(1), requires that the release of radon-222 not-exceed an average release rate of 20 pCi/m2s. The' regulations' allow for adjustment of these standards where circumstances require. ' Acceptance criteria for applying supplemental. standards are outlined in 40 CFR 192.21..
During cleanup operations at the Durango processing site in 1989, elevated Ra-226 concentrations were encounterud immediately_ adjacent to the' Animas River at depths greater than the normal river stage.
An evaluation by DOE showed that the environmental damage and risk to' workers associated with removal of the contamiliated soil would be unreasonable relative to the long-term benefits and that the contamination did not pose a clear hazard to the public health and safety.
As a result., DOE, in~ a Remedial Action Plan Modification (RAP Mod 1) i dated July 18, 1989, proposed that supplemental standards be used generically for all contaminated areas along the river.
The supporting data in RAP Mod 1
.however, was for one specific area identifisd as Region I.
NRC reviewed the 9
~
r PM:URF0
- DD:URF0e AD:URF0: RIV
~
DJacob
'v EHawkin LAYandel b 08/ff/
08Q/90 08/St/90[
n f,
lh '
+,
9009100213 900831 L. (' %
PDR WASTE 1
m WM-48 PNU 15'
(
e AUG 31 1990 2
I DOE submittal and concurred in the application of supplemental standards for only the specific area, Region I, for which supporting data had been provided.
The date of this concurrence was September 19, 1989.
A second area of elevated Ra-226 concentrations was later identified along the river bank.
By letter dated February 28, 1990, DOE requested concurrence on the application of supplemental standards in this area on the basis of the the approval cf RAP Mod 1.
NRC did not consider the approval of RAP Mod 1 to be generic as NRC's concurrence was only applicable to one specific area.
Therefore, at the request of NRC, this application was resubmitted as RAP Mod 3 on May 7, 1990.
This submittal, however, was not acceptable because the proposed modifications to the Remedial Action Plan were identical to the modifications made by RAP Mod 1.
As a result, DOE provided a revised RAP Mod 3 on June 19, 1990.
This document was found acceptable for supplemental standard application as it contained wording that was specific for the second contaminated area.
However,'a problem still remained in that the modifications i
made to the Remedial Action Plan as a result of RAP Mod I were still in effect, i.e. the language that DOE had interpreted as generic approval for supplemental standard application at all areas along the river bank remained in place.
NRC requested that RAP Mod 3 remove this generic wording that resulted from RAP Mod 1.
In lieu of revising the RAP Mod 3 document 00E, in letter dated August 10, 1990, committed to clarifying the application of supplemental standards in the final Remedial Action Selection Report.
DISCUSSION During a site visit on September 6,1989, the RAP Mod 3 region of contamination along the river bank was informally observed and solutions discussed with DOE representatives of the RAC and TAC, and the State of Colorado.
The area of discussion is identified as Region II, comprised of Areas 2A, 28, and'20, and is located on the river bank below the old tailings pile, adjacent'to the slag area (Figure 1).
Areas 2A and 2C have been excavated to 1 foot below the existing water elevation.
At this elevation, water reportedly. began entering the excavation.
The estimated depth of the contamination that remains in these areas is 2 feet.
The contaminated material in Area 2B is beneath 5 to 7 feet of clean riprap and backfill.
The estimated thickness of the contaminated i
material below this area is 2.5 feet.
The estimated total volume of contaminated material that remains in place is 65 cubic yards, with Ra-226 concentrations ranging from 35 to 295 pCi/g.
The complete excavation of these three areas would require destroying 120 linear feet of the river bank causing excessive environmental harm.
DOE-is requesting that the remaining contaminated material-be left in place in these three areas, leaving the river bank undisturbed.
Areas 2A and 2C will be
~-
- a _ c_
c_u_ _ _. -
3 j.
J AUG 31 1990 3
covered with 10 feet of clean fill.
Area 28 will remain as is.
Radiological modeling of these areas by DOE indicated that leaving the remaining material in place would have negligible health effects.
CONCLUSION The proximity of the areas to the Animas River and the levels of contamination associated with them, provides a low public health hazard.
The staff therefore finds that the location meets supplemental standard criteria 40 CFR 192.21(a),
. producing environmental harm that is excessive compared to the associated health benefits from cleanup to EPA standards.
Also, the proposed cleanup meets the intent of the low as reasonably achievable philosophy of 40 CFR 192.22.
The staff concurs with DOE that supplemental standards be applied for the area described.
The June 19, 1990, RAP Mod 3' document does not delete the generic language contained in RAP Mod 1.
Rather than further revising the RAP Mod 3 document, DOE requested in their letter dated August 10,-1990, that NRC accept the supplemental stant4ard application for the specific area described in RAP Mod 3 and let the generic issue be resolved in the final Remedial Action Selection Report.
This approach was discussed and agreed to during the DOE /NRC conference call on August 20, 1990.
NRC responded to DOE's August 10, 1990, request by letter dated August 22, 1990.
As surface cleanup at the processing site is now complete, the concerns associated with a perceived NRC generic concurrence in supplemental-standards can be considered moot, b
Dawn L. Ja y
/
Project M n ger V
Case Closed:
040WM048970E bcc:
'POR/DCS" '
URF0 r/f ABBeach, RIV LLO Branch, LLWM DJacoby j
RGonzales J
RCPD, CO-4
ti f lJ *.
t 4y&g?w?$l(:Whj
, i REGIONIl-0R j\\
pays
^'
~~A-a
~.,.n.'A m
,(
' qjq o
~
-.' fr.
a
- w. $?'
U*.
-./.l,'
i o
~
. = -
- Hl2,
(/6 JM).
g
/
T
' Ns*
f Y
f asff. )
au,,;,
ss Itt38 REGION 11
@ AREA :2A
=s-ern : 44-~ CYS
,,y,,
m
~
x Y
5 L Ws.
...,,. a f ~ "
m m.m.7 g
4A REA.2B
[t&4,,
19.CYS
~p
- " h 2
REA 2C l
L l
g T.....,- 2 cvs bOID n1(10 4
BOO!5.5 i)' 'l
.m f
}
7=>
5 1
PWERn' Leur
-N na WALL
$ a b /ai/
$"'" I Han be)
..