ML19331D003
| ML19331D003 | |
| Person / Time | |
|---|---|
| Issue date: | 08/12/1980 |
| From: | Eadie G, Scarano R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| References | |
| CON-FIN-B-2217, REF-WM-40 NUDOCS 8008270066 | |
| Download: ML19331D003 (10) | |
Text
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UNITED STATES
'3 8Y NUCLEAR REGULATORY COMMISSION s ghQ [' ^n E
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WASHINGTON, D. C. 20555 j
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~AUG 121980 MEMORANDUM FOR:
Edgemont Remedial Action Program Files (FIN No. B-2217)
FROM:
Greg G. Eadie Uranium Recovery Licensing Branch
SUBJECT:
REMEDIAL ACTION PROGRAM FOR EDGEMONT, SOUTH DAK0TA
Background
At the request of the U. S. Nuclear Regulatory Comission (NRC), the town of Edgemont, South Dakota and vicinity was surveyed in early November 1978 to determine if uranium mill tailings from the former Edgemont Uranium Mill had been used for off-site construction purposes.
The U. S. Environmental Protection Agency (EPA) conducted the surveys
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using a specially shielded gama radiatica detection system mounted in a van type motor vehicle. A similar survey had been conducted by the EPA 1971-72 and 1978) parison of results between the two surveys (i.e.,
in 1971-72 and comindicated a total of 60 possible tailings use locations in the area.
However, there is a possibility that additional tailings-use locations exist since the mobile van system has inherent detection problems, such as shielding and response time factors, which essentially limit this system's use and require more detailed gamma radiation surveys at each suspect location.
In December 1979, the EPA provided Radon Progeny Integrating Sampling i
Units (RPISU) to the State to conduct measurements of working levels l
(WL) inside those structures identified as gama anomalies (i.e., above l
background radiation levels). As of June 10, 1980, the following distribution of WL's has been reported for 31 structures surveyed (note l
that not all of these structures are gama anomalies).
l
>0.10WL -- 4 structures
>0.05WL -- 5 structures
>0.03WL -- 6 structures
>0.015WL -- 4 structures less than 0.015WL -- 12 structures i
l THIS DOCUMENT CONTAINS P00R QUAUTY PAGES UUo82700(oq
, Also, the Department of Housing and Urban Development (HUD) has become involved in requiring a grab-WL sampling at any structure in Edgemont prior to guarantying federal mortgage monies.
Therefore, in order to fully assess all possible locations having elevated radiological conditions, the following programs, as shown in Figure 1, shall be conducted in the vicinity of Edgemont, South Dakota:
I.
Grab Working Level Measurements (HUD/ EPA Protocol)
A grab (i.e., brief sampling time of about 5 minutes or a 10 to 20 liter volume) sample to determine the radon progeny concentrations (in WL) should be completed using the Thomas method for analysis.
This grab WL sampling shall be conducted based on the HUD/ EPA protocol (see Enclosure 2) in the following manner:
1.
The structure must be in the " closed-up" condition (i.e., all doors and windows shut, and no air conditioning or heating systems. in operation) for at 1. east 3 hours3.472222e-5 days <br />8.333333e-4 hours <br />4.960317e-6 weeks <br />1.1415e-6 months <br /> prior to sample collection.
2.
The grab WL sample shall be collected in the area of longest r
occupancy, e.g., the bedroom or finished basement area of a residence, or the main working area of a comercial building.
l 3.
If the inside grab WL exceeds 0.033 WL, such a structure shall then be resampled.
If upon confirmation of a value in excess i
of 0.033WL, that structure shall be considered for the engineering assessment.
t 4.
If the grab WL is between 0.01 and 0.033WL, a definitive gamma i
radiation survey and/or soil sampling programs shall be completed
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as discussed below.
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5.
If the. grab WL is less than 0.010WL, the structure shall be l
cleared and will not require further radiological assessments.
II.
Gamma Radiation Measurements A portable gamma survey meter (e.g., micro R meter.) shall be used to complete the gamma radiation measurements both inside and outside of the structure. This survey meter shall be cross-calibrated with a Pressurized Ionization Chamber (PIC) in order to provide realistic exposure measurements.
This survey shall be designed to detect the r
presence of any possible residual radioactive material under, L
within or around the structure. A map shall be provided indicating
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all locations having above background radiation levels. This survey need only be performed once far each structure.
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.. III. Long-term Radon Progeny Sampling Long-tenn radon progeny sampling using either the Radon Progeny Integration Sampling Unit (RPISU) or the Measurement of Daughters (MOD) sampling unit may be required in any structure having a. grab WL in the range 0.01 to 0.033WL and a radiation survey indicating the presence of residual radioactive material or an exposure rate less than ;0 pR/hr above background. Such long-term radon progeny samples shall be collected for at least 100 hours0.00116 days <br />0.0278 hours <br />1.653439e-4 weeks <br />3.805e-5 months <br />, every other month, for at least six samples during a yearly cycle.
IV.
Soil Sampling Soil sampling, both surface and at depth, shall be completed at specified locations to determine the concentrations of uranium decay chain series radionuclides (e.g., uranium, radium-226, thorium-230 and lead-210). The lower limit of detection shall be at least 0.50 pCi/ gram of soil for radium-226 analysis which shall be used to determine compliance to the regulatory standards.
Bore-hole logging to determine the presence of radium-226 at depths of up to 8 feet may also be required.
V.
Engineering Assessment An engineering assessment shall be completed at each stucture which exceeds the EPA's standards for uranium mill tailings cleanup (i.e., as proposed in 40 CFR 192 of an annual average WL_ greater than 0.015, or having radium in soil gama radiation exposure rate in exc. greater than 5 pCi/g, or a ess of background of 0.02 l
mR/hr). The assessment shall provide a detailed map of all residual l
radioactive material deposits and volume estimates.
Such information may be obtained by gamma radiation survey techniques, bore-hole l
logging techniques, or soi', sampling and analysis.
($~
l Gr.eg G. Eadie Uranium Recovery Licensing Branch Division of Waste Managment Approved by:/,4.dv rWe#
/'Ross A. Scarano, Chief
Enclosures:
1.
Figure 1 2.
Interim HUD/ South Dakota Radiation Survey Protocol l
ENCLOSURE 1
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FIGURE 1 REMEDIAL ACTinN PROGRAM FM EDGEMCNT, SOUTH DAKOTA i
p 1
Greater Than ENGINEERING ASSES. TNT EPA Standards REMEDIAL ACTION'!
i VERIFICATION
- GAF: - MAPPING PROGRAM i
SOL aAMPLING Less Than Pngeny
.. BORE HOLE. LOGGING JPA Standards NOACTIONl h,d 1
p 0.033 WI
)
g
/b
% 1..
RESAMPLE INDOOR RADON DAUGHTERS STATE e
TO CONFIRM CONSIDE R ATION Areas Where Soil 226Ra.
is 5 pCl/g or More Confirmatory Grab Samp e Less n 0.033 E Greater Than or Equal to 0.033 WL COLLECT SOIL V
CORE SAMPLES 1RAB SAMPLES, Greater Than 0.01 WL GAMMA RADIATION anna pose Rate FOR 22%A MAPPING RADON PROGENY to Less Than 0.033 WL J0pR/hr or More
)
SURVEY N AIR FILTERS,
WORKING LEVELS.
').01 WL or Less 4
T, lb ge,l is Less Than 5 pClig Areas Whwe Sot 1226h ~
4 eg,
\\>
Tern Radon Progeny 4
MAKE LONG-TERM
}Lon 0.0 $ WL or More INDOOR RADON PROGEN r
MEASUREMENTS (RPISU NO REMEDI AL ACTION Long-Term Radon Progeny N
Less Than 0.015 WL
- HUO/ EPA Protocol a,Ancealy may be natural terrestrial radioactivity resulting in radiological exposure 13 excess of EPA Standards.
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Enclosurs 2 1liTE RIM HL'0/ SOUTH DAKOT A P'DI ATION SURVEY PROTOCCL FEBRUARY 1980 I
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E " ll l ll l T " A "
A CRITERIA Basic criteria adopted for the South Dakota /HUD radiation level certification program will be drawn from two established sources.
A.
U.S. Surgeon General's Guidelines for Grand Junction, Colorado, dated July 27, 1970.
B.
U.S. Environmental Protection Agency's Recc=:encations to the State of Florida, dated June 8,1979.
Criteria #1 Any weighted indoor Working Level (WWL) determined tc :s above 0.02 WL (including background) shall be classificd as exces:'.g nat level the Administrator of the EPA has found acceptr.ble ir. :er : of the increased long term risk of lung cancer in the exp sed :::alation.
See Note below.
t Criteria 52 If ~ a weighted indoor working level measurement exceeds 0.015 WL, an additional set of measurements shall be made on another daj to verify All such a reading to determine acceptability of existing resictr.ces.
measurements taken will be averaged to determine the b 'L.
When annual average air concentrations of rador, decay products.
Note:
are less than 0.02 WL, remedial action recuirec tc recuce such concentrations to as low as reasonaoly achievable levels should be taken.
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2 METHODOLOGY l (For existing residences)
In determining acceptability of a residence for federally su:::rted financing in Edgemont, South Dak:ta and vicinity, the State will perform indoor radon daughter measurements in the following manner:
T:r ea:h measurement an air sample having a minimum volume of 1.
20 li.ters will be drawn through a 25 millimeter Miilipore Type AA filter having a pore size of 0.80 micrcns.
After an appropriate period of decay, the filter will be ccunted for alpha activity The radon daughter concentration in witn a scintillation counter.
K0rking Levels (WL) wili be calculated and recorded.
A M use Closed Reading (HCR) shall be made in a ground floor or 2.
basement room after the residence has been sealed for a minimum t
f peri:d of nree (3) hours.
Sealed means that all windcws, doors, an: 0;tside vents are closed. To make the measurement, The State Officer will enter the residence, opening the entry door only to 4
If the HCR exceeds the extent that equipment and staff may enter.
0.02 UL, ther a House Open Reading (HOR) will be taken.
The House Open Reading will be made in the same locaticn where the l
3.
The HDR will be made while the room is being venti-HCR v.as taken.
lated at a n:rmal level using available dcors, windows, fans, etc.,
tnat supply fresh outside air.
Such ventilation shall be in use for a minimum of 15 minutes before the HOR is taken.
Weichtine Precedure:
Each reating (HCR and HOR) will receive the following weighting:
7/12 HCR + 5/12 HOR = WWL c
Tr.5 L".? shall then be used to certify a given resident's acceptability h
In the Edgement area for furtner federal financing censideration.
seven months are chosen as precluding the use of outside ventilation due to inclement weather.
The weignted indoor working level procedure may be bypassed by making a " house closed reading" to maximize conditions (worst case) to deter-4.
mine acceptability directly if the working level determination falls below 0.02 WL.
An alternate method of determining acceptability of a residence is 5.
th2 use of data acquired by measuremen* with a Radon Indoor Progeny Integrating Sampling Unit (RIP!SU).
RIPISU data will be cerived RIPISU data acquired in from a minimum sampling time of 60 hours6.944444e-4 days <br />0.0167 hours <br />9.920635e-5 weeks <br />2.283e-5 months <br />.
the period between November 15 and April I can be substituted for RIPISU data acquired between June I and September 30 can the HCR.
be substituted for the HOR.
v
r 2
s._.i; (For Undeveloped Vacant Land)
Fu:ure raciatien exposures in structures built on a given tract of land can be influenced by certain conditions. These can be largely cnaracteri:ed by answering the foliewing questions.
Is the land minerali:ed with geological formaticas that contain 1.
uranium decay cnain elements in varying amounts?
Is ine. underlying gerlegy sufficier.:1y disturbed by fracturing, 2.
cr o ner perturbaticns which can enhance radon seepage tunnelir.;i:n to the ground's surface?
and diffus Has tne in.: cred tra: of land been reclai:2d, graded or previously 2.
it;a::ed wi:n de:: sits of ;hos;na e cnd/or copper slag that contains urania: de: y cnair. eierer.:s in varyin; at unts?
2 k'ill the buildi:.g cateriais used in subsequent construction of a stra::u-e cr-a ;iven trat cf vacant land contain a sufficiently icw enou;n level cf uranium decay chain elements?
(Normally, this
~
is tne case if non-waste materials are used in fabrication of building materials.)
Ir. de:ecnir.ing ac:e; ability of a given tract of land for its utili-aticr. as a~ federal'.y fir.an'ced project site in Edgement, South Dakota and vicinity, the State will handle each evaluation and certification en a casa by case basis, Tnis is due to the cc=plexity of parameters that need to be consicered in the process.
Methods tr.at can be employed by tne State to perform these evalua-tions will normally include:
1.
gamma scintillometer grid surveys; surface soil sac-ling and ground coring for radicanalytical deter-2.
mina:icns; char cci canister or scintil1$ tion cell monitoring of raden diffusion 3.
and seepage to grcund surfaces; use of aerial ra:icmetric cr other radicanalytical data to determine 4.
existin; back;rour.d gamma radiation.
See Figures 1 and 2 for clarifying data, cefinitions and depictions concerning this protocol.
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