ML20039B407

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Forwards Draft Radiological Assessment of Impact from Operation of UCC Uravan Milling Facility.Doses Are Well in Excess of 40CFR190 Std Compliance Will Be Determined Through Environ Monitoring Program at Nearby Mill
ML20039B407
Person / Time
Issue date: 10/15/1981
From: Scarano R
NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS)
To: Hazle A
COLORADO, STATE OF
References
REF-WM-34 NUDOCS 8112220676
Download: ML20039B407 (37)
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Dear Mr. Hazle:

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J-Enclosed for your review is a draft of the radiological assessment'ef J

j the impacts from the operation of the Union Carbide Corporation (UCCh g sc//

Uravan milling facility.

It can be seen that the dose cocinitments computed in this radiological assessr.ent are higher than in the assessment performed by the iMS Corporation for UCC. The NUS assessment is described in "40 CFR 190 Related Radiological Doses Due to the Operation of the Uravan Uranium Hill" (NUS-3582). Following are several basic differences in initial assumptions and inputs contributing to the discrepancies in dose commitments:

Meteorology

-The NRC employ (ed the Grand Junction Colorado joint frequency distribution JFD). The NUS methodology split the facility with the Grand Junction JFD and a modified local meteorology. Since the local meteorology did not distinguish stability classes, the NUS methodology modified the local meteorology using the stability class frequencies of the Grand Junction JFD. Consequently, the NRC placed more confidenca in using the Grand Junction JFD.

Source Tems Although ore and tailings specific activities are identical in both approaches, the estimated source terms for the ore pad and tailings emissions in the NUS and HRC assessments disagreed significantly.

The NRC emission rates for the ore pad and tailings were larger than those used by NUS by factors of 2.75 and 12.8; respectively.

The NRC methodology for source terms is described in the detailed radiological assessment appendix to the enclosed document.

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Mr. Albert J. llazie 5 1981 The NRC also included contributions frem other area sources, such as the Club Hesa Spray Area, which ranged from a maximum of 9.7 x 10 1 Curies / year (Th-230) to a minimum of 6.6 x 10 s Curies / year (Pb-210). These sources were not considered in the NUS report.

Dose Conversion Factors The dose conversion factors (DCF) for inhalation presented in NUS-3582 are not identical to those employed in llRC assessment. Although, the NUS methodology claims to include NRC mechanisms such as mass-average lung weighting, the resultant dose commitment for the lung did not appear to reflect this.

The liRC modeling effort indicates that the mill operations appear to be the primary contributors to the doses at the nearby residences. The most critical pathway at nearby residences is inhalation. The inhalation doso comitments to the lung at the Block D receptor (0.18 km SE) is 615 mrem / year (HRC). The 1105 as:essment computed a lung dose comitment of 120 mrem / year, which is below the liRC estimate by a factor of 5.

It should be understood that this factor of 5 is not unusual in light of the uncertainties of computer modeling. Of the NRC estimate, approximately half is attributable to the uranitsn released from the yellowcake stack.

The tailings, spray and evaporation pond areas contribute less than 4f.

of the total lung inhalation dose. Although the mill plant is the primary contributor, it should be noted that the resultant bone dose comitment from the tailings and spray areas is still a factor of 4 over the 40 CFR Part 190 standard.

Although there are discrepancies between the predicted impacts of HRC and NUS, it is quite evident that both assessments describe doses well in excess of the 40 CFR Part 190 standard. Ultimately, the determination of compliance or the degree of noncompliance will be determined through the environmental monitoring program at and nearby the Uravan mill.

We look forward to any coments which you might have on tnis assessment.

Sincerely.

Origi..m.,1,;u by:

R. A. Scarono Ross A. Scarano, Chief Uranium Recovery Licensing Branch Division of Waste 11anagement

Enclosure:

Radiological Assessment for tie Union Carbide Uravan Uranium Hill 10/15/81 WG II Revision No. 1 a"'cHMu,Rj.(g,,,.w.mj.jf.,,,,,

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RADIOLOGICAL ASSESSMENT FOR THE UNION CARBIDE URAVAN URANIUM MILL 1.1 Introduction The purpose of this report is to present the NRC Staff's assessment and method-ology which were used to describe the incremental radiological impacts which would result from continued operation of the Uravan Mill at its present location.

This assessment contains estimates of the annual releases of radioactive materials from the mill and tailings management system, the resulting concen-trations at the restricted area boundaries from the mill and tailings management system, and the dose commitments to nearby individuals and the general population (as defined by NRC, Ref. 1) within 80 km (50 miles).

The calculated concentra-tions and doses are compared to regulatory standards and measured background radiation.

All potential pathways that were considered to contribute a signif-icant fraction of the dose commitments have been examined The results of this radiological assessment are dependent on and sensitive to

.many input design parameters.

In particular, Grand Junction meteorology was used in the absence of detailed, site specific, meteorology which was not available to NRC at the time this assessment was performed.

However, it is believed that the Grand Junction, Colorado meteorology is reasonable and a comparison of Grand Junction and San Miguel river valley data indicates that 3

stability conditions would be similar at both sites (Ref. 2).

Where actual values have been obtained from environmental monitoring data (Ref. 2) these values have been used.

J Changes in parameter values used in the estimation of radioactive releases (Table 1.1) would result in different calculated dose commitments.

Therefore, future significant modifications to the facility's design or operation which would affect the assumptions made here concerning effluent releases would require a revised analysis.

1.1.2 Estimated releases The assumptions and data used and the estimates of overall releases of radio-active material from the mill and the tailings management system are presented in Tables 1.2 and 1.3.

More detailed descriptions of release estimates are provided in Appendices A and B.

A schedule of operation based on 20 years' production of tailings was used in estimating the parameters and releases for the tailings management system.

1.. 3 Exposure pathways 1.1.3.1 Airborne pathways Potential airborne environmental pathways by which people can be exposed to radioactive materials from this project are shown in Fig. 1.1.

These pathways include exposure from inhalation of radioactive materials in the air,

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Table 1.1 Principal parameter values used in the radiological assessment of the Union Carbide Corporation Uravan mill Parameter Value*

Average ore grade, % V 0 0.17 3 3 Ore concentration of U-238 562.5 Th-230 542.0 pCi/g Ra-226 595.0 Pb-210 617.0 Ore processing rate, MT/ year 432,000 Operation schedule, days / year 360 Ore storage pile Actual Area, ha 1.42 Annual average dust loss rate, g/m year 269.2 2

Dust-to-ore activity ratio 2.5 Release rate for truck dumping and other 5.5 x 10 3 ore pad activities, %

Specific radon flux from ore piles, 1.0 2

pCi/m -sec per pCi/g Ra-226 Tailings impoundment system General parameters Tailings area activities, pCi/g U-238 83.0 Th-230 485.0 Ra-226 573.0 Pb-210 666.0 Annual average dust loss rate, 2692.45 2

g/m. year Dust-to-tails activity ratio 2.5 Dusting raduction factor for water cover, moisture, and chemical agents, %

80.0 Specific radon flux from exposed 2

beach, pCi/m.tec per pCi/g Ra-226

1. 0 Tailings areas Pile 1 & 2, ha 23.0 Pile 3, ha 9.3

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3 Table 1.1 (continued)

Parameter Value*

Evaporation ponds and spray areas TDS, g/L 140 Concentrations in discharge to ponds, pCi/L U-238 3459 Th-230 148300 Ra-226 1004 Pb-210 1004 Concentrations in solids in ponds, pCi/g U-238 24.7 Th-230 1057.4 Ra-226 7.2 Pb-210 7.2 Evaporation pond and spray areas, ha Club Ranch ponds 13.0 Club Mesa spray area 13.0 Emergency ponds 0.5

  • Parameter values presented here are those selected by NRC staff after careful review of the applicants submittals.

In instances where available data have been insufficient and/or not specific, reasonably conservative estimates have been made.

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4 Table 1.2 Estimated annual releases of radioactivity resulting from the Uravan uranium mill during operations Annual releases of radioactivity (Curies / year)*

Release Source U-238 Th-230 Ra-226 Pb-210 Rn-222**

Ore storage 4.38E-2t 4.22E-2 4.64E-2 4.81E-2 2.67E+2 Yellowcake stack #

5.36E-1 8.51E-3 3.54E-4 4.00E-3 0.0 1

Aerofall crushing stacks #

4.93E-2 7.58E-2 3.07E-2 6.42E-2 1.08E+2 AK leach #

4.79E-2 1.94E-1 7.09E-2 3.23E-1 0.0 Leach #

6.26E-4 6.39E-4 2.39E-3 1.56E-3 0.0 Fine ore storage area #

5.33E-3 8.45E-3 1.64E-2 1.27E-2 0.0 Tailings area pile 1 & 2S 2.57E-2 1.51E-3 1.78E-1 2.06E-1 8.34E+2 Tailings area pile 35 1.04E-2 6.06E-2 7.16E-2 8.32E-2 3.36E+2 3

Club Ranch Evaporation Ponds 1.08E-3 4.62E-2 3.14E-4 3.14E-4 5.92E+0 4

Club Mesa Spray Area 2.16E-2 9.23E-1 6.29E-3 6.29E-3 2.95E+1 Emergency PondsS 4.15E-5 1.78E-3 1.21E-5 1.21E-5 2.20E-1

  • Releases of all other isotopes in the U-238 decay series are also included in the radiological impact analysis.

Thest releases are assumed to be identical to those presented here for parent isotopes.

For instance, the release rate of U-234 is assumed identical to that for U-238.

Release rates of Pb-210 and Po-210 are assumed equal to that for Ra-226.

    • Rn-222 emissions are estimated using the Ra-226 content in the ore or tailings.

tread as 4.38 x 10 2 or 0.0430.

  1. Particulate emissions of U-238, Th-230, Ra-226 and Pb-210 were measured by the NUS Corporation and reported in NUS-3582 in 1980.

STailings ponds presently reflect an 80% reduction due to water cover and i

water or chemical spraying.

Evaporation ponds reflect a 95% reduction, since very little, if any, beach areas are exposed during operation.

During post-operation drying, the reduction factors are assumed to be 0.

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Table 1.3 Annual dose commitments to individuals in the vicinity of the Uravan uranium mill Dose commitments

  • to body organs (mrem per year of exposure) 1 Exposure Whole Bronchial pathway body Bone Lung epithelium Nearest residence, BLOCK D, 0.18 km SE Inhalation **

11.1 324.0 615.0 82.9 i

External ground 24.6 24.6 24.6 24.6 External cloud 0.108 0.108 0.108 0.108 Vegetable ingestion 10.3 141.0 10.3 10.3 Meat ingestion #

4.00 57.1 4.00 4.00 Milk ingestion 2.17 24.4 2.17 2.17 Total 52.3 571.0 656.0 124.0 Nearest residence in prevailing wind direction, BLOCK C, 0.50 km NW Inhalation **

9.17 266.0 512.0 59.3 External ground 21.8 21.8 21.8 21.8 External cloud 0.058 0.058 0.058 0.058 Vegetable ingestion 9.12 124.0 9.12 9.12 Meat ingestion #

4.00 57.1 4.00 4.00 Milk ingestion 1.92 21.5 1.92 1.92 Total 46.1 490.0 549.0 96.2 Mining camp #2, 1.74 km WSW Inhalation **

4.97 159.0 190.0 94.7 External ground 17.5 17.5 17.5 17.5 External cloud 0.255 0.255 0.255 0.255 Vegetable ingestion 7.23 98.4 7.23 7.23 Meat ingestion #

4.00 57.1 4.00 4.00 l

Milk ingestion 1.51 16.4 1.51 1.51 iotal 35.5 349.0 220.0 125.0

  • 0oses are integrated over a 50 year period from one year of exposure

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    • Doses to the whole bc,dy, lungs, and bone are those resulting from the inhalation of U-238, U-234, Th-230, Ra-226, Pb-210, l

and Po-210 particulates.

Doses to the bronchial epithelium are those resulting from the inhalation of radon daughters.

  1. Ingestion doses result from the consumption of the meat of cattle grazing 1.03 km WNW of the mill.

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from radioactive materials deposited on the ground, and from ingestion of contaminated food (i.e., vegetables, meat, and milk).

1.1.3.2 Liquid pathways The potential for contamination of drinking water at the Uravan site was not considered to be significant due to the relatively large depth to usable groundwater and the presence of intervening strata (domestic a ter for the town of Uravan is obtained from a well 2 miles East-Southeast of the site and tops an aquifer 150-200 feet below the level of the canyon floor).

Geologic formations below the tailings disposal site and above the San Miguel River are aquifers of poor quality due to their relatively low permeability and their topographically high position. The primary aquifer in the area is the Windgate Sandstone which is located 800 feet below the site.

Impacts associated with contamination of surface water, however, were investi-gated due to the proximity of the Uravan Mill (and associated Club Ranch Ponds) to the San Miguel River.

Results of this investigation, however, indicate that the liquid pathway is not significant compared to other pathways shown on Figure 1.4.

1.1.4 Radiation dose commitments to individuals The nearest known resident is located about 0.2 km (0.1 mile) southeast of the mill.

The nearest known residence in the prevailing wind direction is located about 0.5 km (0.3 miles) northwest of the mill.

The nearest population center is Uravan, Colorado which is located less than 0.2 km (0.1 mile) directly east or the mill.

Table 1.3 presents a summary of the individual dose commitments calculated for these locations.

It was assumed that milk, meat, and vegetables were consumed from cattle grazing at the two nearest locations (0.2 km directly east of the mill) to the site boundary, and from locally grown vegetables.

1.1.5 Radiation dose commitments to populations Table 1.4 shows the predicted annual environmental population dose commitments which were calculated within 80 km (50 miles) of the site using the Mill Dose Code (Reference 1).

The estimated annual population dose commitments to the same population from natural background radiation sources is presented in Table 1.4.

Population distribution data (Table 1.5) projected for the year 2000 were used to do the estimation.

This population is projected for what is estimated to be the last year of operation and is based on a density of 3 persons per square mile, except for known population centers.

Population dose commitments resulting from the operation of the Uravan uranium mill represent a fraction of the doses from natural background sources.

Releases of radon gas yield radiological impacts ranging thousands of miles from a release source.

Impacts of radon releases from the facility which occur within 80 km (50 miles) of the site have been included in the tabulation

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Table 1.4 Annual environmental dose commitments (EDCs) to regional population

  • within 50-mile radius resulting from the operation of the Uravan uranium mill 100 year EDC'(person-rem per year of exposure)**

Exposure Whole Bronchial pathway body Bone Lung epithelium #

Inhalation r

2.13 65.4 93.3 36.3

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External ground 16.3 16.3 16.3 16.3 External cloud 0.399 0.399 0.399 0.399 f

Vegetable ingestion 3.34 41.6 3.34 3.34 Heat ingestion 0.112 1.49 0.112 0.112 Milk injestion 0.250 2.62 0.250 0.250 Total 22.5 128.0 114.0 56.7 Estimated population dose 3881.0 4858.0 3908.0 14786.0 from natural backgroundt Ratio of total annual 0.006 0.026 0.029 0.004 regional population j

dose to that from i

natural background

  • Population is estimated to the last year of operation (2000) based on an approximate density of 3 persons per square mile, (ER p. 2-8), except for known population centers.
    • Doses to the whole body, lung, and bone are those resulting from the releases of U-238, U-234, Th-230, Ra-226, and Pb-210 particulates.
  1. Inhalation doses to the bronchial epithelium are those resulting from the j

inhalation of radon daughters.

tBackground doses are based on the regional population size of 26,404.

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Table 1.5 Population distribution projected for the final year of the Uravan uranium mill's operation i

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NME NE ENE E

ESE SE SSE S

S3W SW WSW W

WNW NW NNW KILOMETERS 0.0 22.5 45.0 67.5 90.0 112.5 135.0 157.5 180.0 202.5 225.0 247.5 270.0 292.5 315.0 337.5 1.0- 2.0 1

1 1

1 1

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1 1

1 1

1 1

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1 1

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2 2

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10.0-20.0 69 1050 1025 69 69 69 69 69 69 69 69 69 69 59 69 69 20.0-30.0 115 115 115 115 115 115 115 115 115 115 115 115 115 115 115

.115 30.0-40.0 160 160 370 160 160 160 160 160 160' 160 160 160 160 160 160 160 h

1 40.G-50.0 208 208 370 208 208 208 208 208 208 208 208 208 20e 208 208 208 50.0-60.0 253 253 253 253 253 253 253 253 253 253' 253 253 253 253 253 253 60.0-70.0 299 299 299 299 299 299 299 299 299 299 299 299 299 299 299 299 t

V 70.0-80.0 344 344 344 344 344 344 344 344 344

344, 344 344 344 344 344 344 1471 2452 2799 1471 1471 1471 1471 1471 1471 1471 1471 1471 1471 1471 1471 2030 TOTALS TOTAL 1-80 KM POPULATION IS 26404 PERSONS 8

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g of the regional population dose commitments (Table 1.4).

Transcontinental radon-222 impacts have also been evaluated.

Table 1.6 includes total environ-mental dose commitments received by both regional and extraregional popula-tions, as well as a grand total of 100 year environmental dose commitments i

received by all populations.

1.1.6 Evaluation of radiological impacts on the public Examination of the estimated doses from milling operations at the-Uravan Uranium Project indicate that annual environmental doses to the regional population from this site are a fraction of those from natural background radiation (Table'1.4).

However, a comparison of the dose commitments to individuals at the nearest locations and the nearest location in the pre-vailing wind direction (noted in Section 1.1.4) with the limits specified in the Environmental Protection Agency's 40 CFR 190 (" Radiation Protection Standards for Normal Operations of the Uranium Fuel Cycle" effective December 1980) regulations indicates that both of these locations receive doses which signifi-cantly exceed the standard of 25 millirems total dose to any organ of an offsite individual (18 to 25 times the allowable dose).

Table 1.7 compares the 40 CFR Part 190 limits with calculated dose commitments to individuals.

Doses in this. table are actuilly lower than total doses (Table 1.3) because it does not include doses from radon and its daughters.

As indicated in Table 1.7, the radiation dose commitments to the bones and lungs of individuals living at the nearest residence and the nearest residence in the prevailing wind direction are respectively 21.9 and 25.4 times the EPA limits.

The calculated bone doses result primarily from the inhalation of particulates, and closer examination of releases appears to indicate that these doses are due to isotopes of uranium.

The dose proximity (0.2 km) of these residences to mill operations appears to have significantly influenced the calculated doses.

Radiological monitoring perf ormed by the NUS Corporation in the vicinity of the mill (Ref. 2) seems to confirm the estimated high doses calculated for the site vicinity.

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Table 1.6 Total. environmental dose commitments resulting from the Uravan uranium mill operations * (person-rem)

Bronchial Location of population Whole body Bone Lung epitheliut Within 80 km of the mill 7.354E+02** 3.727E+03 2.704E+03 2.086E+03 Beyond 80 km of the mill 8.737E+02 1.079E+04 8.737E+02 8.737E+02 Total 1.609E+03 1.451E+04 3.578E+03 2.959E+03 Fraction of background #

1.932E-06 1.742E-05 4.296E-06 7.106E-07

  • Calculated for the operational and postoperational periods totaling l

20 years.

    • Read as 7.354 x 102 or 735.4.
  1. Ratio of total environmental dose commitments resulting from Uravan mill operations to doses from natural background sources, which are-estimated on the basis of a North American continental population projected for the year 2000 at 416.4 million persons, each receiving 100 millrems per year to the whole body, bone, and lung and 500 millirems per year to the i

bronchial epithelium.

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i Table 1.7 ' Annual dose commitments to individuals compared with EPA radiation protection standards 40 CFR 190 Dose commitments (mrem per year of exposure)

Exposure pathway Whole body Bone Lung EPA 40 CFR 190 limits

  • 25-25 25 Nearest residence, BLOCK D, 0.18 km SE Inhalation 11.1 324.0 615.0 External 2.09 2.09 2.09 Vegetable ingestion 10.3 141.0 10.3 Meat ingestion **

4.0 57.0 4.00 Milk ingestion 2.17 24.4 2.17 Total 29.7 548.0 634.0 Fraction of limit 1.19 2.19 25.4 Nearest residence in prevailing wind, BLOCK C, 0.50 km NW Inhalation 9.17 266.0 512.0 External 1.75 1.75 1.75 Vegetable ingestion 9.12 124.0 9.12 Meat ingestion **

4.00 57.0 4.00 Milk ingestion 1.92 21.5 1.92 Total 26.0 47.0 529.0 Fraction of limit 1.04 18.8 21.2 Mining camp #2,1.74 km WSW Inhalation 4.97 159.0 190.0 External 0.777 0.777 0.777 Vegetable ingestion 7.23 98.4 7.23 Meat ingestion **

4.00 57.0 4.00 Milk ingestion 1.51 16.4 1.51 Total 18.5 332.0 204.0 Fraction of inmit 0.74 13.3 8.16

  • Values from 40 CFR Part 190, which specifically excludes doses and dose commitments arising from l

releases of radon and daughters.

    • Meat ingestion doses result from the consumption of i

the meat of cattle grazed 1.03 km WNW of the mill.

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References 1.

Environmental Report, Uravan Uranium Project; Prepared by Dames and Moore for the Union Carbide Corporation.

August 31, 1978.

2.

40 CFR 190 Related Radiological Doses due to the Operation of_the Uravan Uranium Mill.

NUS-3582.

61ay 30, 1980.

3.

Descriptions of the United States Uranium Resource Areas.

NUREG/CR-0597.

June 1979.

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Appendix The radiological assessment using the MILDOS computer code does not include impacts from liquid pathways.

Generally, the liquid pathways to humans are not significant in miiling regions; however, the proximity of the San Miguel River to the Uravan mill raises the question of possible seepage into the river and to water wells.

The specific pathways that will be discussed are:

1.

Humans drinking contaminated water.

2.

Humans consuming meat from cattle drinking contaminated water.

3.

Humans drinking milk from dairy animals consuming contaminated water, d

The concentration levels which are to be considered correspond to three points of interest along the San Miguel River Upstream, between the mill and the Club Ranch evaporation ponds, and downstream of the mill.

Monitored concentrations Data was collected during 1979 and reported in "The 1979 Annual Summary, Environmental and Health Physics Monitoring, Uravan, Colorado", published by the Union Carbide Corporation Metals Division.

Tnis data is summarized in Table 1.

Dose commitments to individuals by the three liquid pathways above will be based on contamination levels listed in Table 1.

Impacts to humans from direct consumption Table 2 presents the dose conversion factors for human consumption of contaminated water.

Using the concentration levels in Table 1 and the dose conversion factors in Table 2, the auman impacts from water consumption at the various points of the San Miguel River are displayed in Table 3.

Impact to Humans from Consumption of Meat The calculational model for this pathway is taken from References 1 and 2.

The computation consists of two steps:

1.

The meat concentration is the product of the following:

Animal uptake of liquid (liters / day).

Environmental transfer coefficients pCi/kg pCi/ day Water concentration of the nuclide of interest (pCi/ liter).

2.

The dose commitment to a given organ is computed as a product of the following:

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-2 Table 1 1979 annual average concentrations of radionuclides in the San Miguel River (pCi/L) 4 Location U-Nat Th-230 Ra-226 Upstream 7.0 1 19.0*

3.0 1 1.0 0.62 1 0.92 l

Below mill and above Club Ranch Ponds 8.0 t 10.0 3.0 1 2.0 0.64 1 0.39 Downstream 9.0 1 12.0 8.0 1 15.0 0.65 1 0.20

  • The numbers following i are the annual sample standard 3

deviations for the monthly samples.

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Table 2 Dose conversion factors for human consumption of contaminated water (mrem per pCi/L)*

l Radionuclide Whole body Bone Liver Kidney U-Nat**

3.59E-2.

5.93E-1 0.0 1.38E-1 Th-230 2.11E-2 7.62E-1 4.33E-2 2.09E-1 i

Ra-226 1.70E+0 1.70E+1 2.12E-3 6.03E-2

  • The 50 year dose commitment for each year of ingestion j

of contaminated water.

The above values are based on J

an average adult consumption rate of 370 liters / year (Regulatory Guide 1.109) and adult ingestion dose conversion factors (Regulatory Guide RH 802-4).

    • 0ose conversion factors for U-238 and U-234 were summed to obtain U-Nat dose factors.

. Read as 3.59 x 10-2 or.0359.

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Table 3 Dose commitments to humans from co..sumption of contaminated water.

(mr6m/ year of ingestion)

Location Whole body Bone Liver Kidney Upstream 1.37 17.0 0.131 1.63 Between mill and I

-Club Ranch Ponds 1.44 17.9 G.143 1.77 Downstream 1.60 22.5 0.348 2.95 L

Table 4 Pertinent environmental parameters J

Description Value Reference Uptake rate of water 50 (cattle)

Ref. 1 (liters / day)

Transfer coefficients U 3.4 x 10-4 (cattle)

Ref. 1, 2, 3 1

y ested Th 2.0 x 10-4 (cattle)

Ref. 1, 2, 3 l

Ra 5.1 x 10-4 (cattle)

Ref. 3 Pb 7.1 x 10-4 (cattle)

Ref. 3 Adult Meat. Ingestion Rate 78.3 (meat)

Ref. 3 l

kg/yr 4

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Annual rate of meat consumption (kg/yr),

Meat concentration of the nuclide (pCi/kg).

This was computed in 1 above.

The dose conversion factor for the particular nuclide and organ i

mrem /yr pCi ingested To permit flexibility, the parameters in Tables 4 and 5 are utilized so as to leave the initial water concentration variable.

Table 6 lists factors which convert water concentration directly to dose.

Using Table 6 and the concen-trations in. Table 1,- doses to the various organs are computed and listed in Table 7.

Impacts to humans from ingestion of milk from dairy animals consuming contaminated water Table 8 presents the dose conversion factors used to determine the human impacts from the milk ingestion liquid pathway.

The values in the table are prepared so that only the concentrations in the water of the radionuclides need to be known.

Generic uptake values are used, in lieu of more specif1c informa-tion. The values in Table 8 are in reality multipliers which take into account the dose conversion factors in Table 6, the assumed annual ingestion rates of the animals and humans and the environmental transfer coefficients.

Dose commitments to humans are presented in Table 9 for the milk pathways.

Again the impacts are computed for the 3 different points along the San Miguel River.

Summary The total impact from the liquid pathways is presented in Table 10.

These values are the sum of the dose impacts from Tables 3, 7 and 8.

The impacts of humans drinking water directly are the largest, but it should be noted that the potability of the water from the river may be questionable.

Likewise, the concentrations from the wells may not correspond to the concentrations reported for the river.

If the upstream concentrations are taken to represent the background radionuclide content of the San Miguel River, the downstream concentrations contributs no more than 6 mrem to the total impact of the liquid pathway.

i I) reft 5

1 Table 5 Adult dose conversion factors for ingestion (ref. 3) mrem /pCi ingested.U-238 U-234 Ra-226 Th-230 Pb-210 i

Whole Body.

~4.54x10-5 5.17x10-5 4.60x10-3 5.70x10-5

~5.44x10-4 Bone 7.67x10-4 8.36x10-4 4.60x10-2 2.06x10-3 1.53x10-2 1.

Liver 0.0 0.0 5.74x10-6 1.17x10-4 4.37x10-3 Kidney 1.75x10-4 1.99x10-4 1.63x10-4 5.65x10-4 1.23x10-2 i

t Table 6 dult dose factor multipliers

'"#**f{'t,"

'for ingestion of meat rom cattle consuming contaminated water 5-Beef i

U-Nat*

Th-230 Ra-226 i

Whole Body 1.29x10-4 4.46x10-5 9.18x10-3 Bone 2.13x10-3 1.61x10-3 9.18x10-2 4

Liver 0.0 9.16x10-5 1.15x10-5 Kidney 4.98x10-4 4.42x10-4 3.25x10-4 j

  • Factors for U-238 and U-234 were summed to obtain the U-Nat multiplier.

1

l Bradn l

6 Table 7 Annual organ dose to adults resulting from the ingestion of meat from cattle drinking contaminated water.

(mrem per year of ingestion)

Location Whole body Bone Liver Kidney Upstream 0.007 0.077 0.0003 0.005 Between mill and Club Ranch Ponds 0.007 0.081 0.0003 0.006 Downstream 0.007 0.092 0.001 0.008 Table 8 Dose conversion factors for human consumption of milk from dairy cows watered on contaminated water mrem pCi/L*

Radionuclide Whole Body Bone Liver Kidney U-Nat 4.62E-04 7.63E-03 0.0 1.78E-03 Th-230 2.22E-06 8.03E-05 4.56E-06 2.20E-05 Ra-226 2.12E-02 2.12E-01 2.64E-05 7.50E-04

  • The 50 year dose commitment for each year of ingestion of milk. The above values are based on the following:

i) Dairy animal intake rate:

60 liters / day ii) Adult ingestion milk rate:

130 liters / year pCi 1i er iii) Environmental transfer coefficients:

p U - 6.1 x 10-4 l

Th 5.0 x 10-6 Ra - 5.9 x 10-4 iv) Adult ingestion dose conversion factors from Table 5.

I l

1)cade 7

Table 9 Gose: commitments to individuals from the ingestion of milk from animals drinking water from the San Miguel River.

(mrem / year of ingestion) 1 Location Whole body Bone Liver Kidney Upstream 0.016 0.185 0.00003 0.013 i

Between mill and Club Ranch Ponds 0.017 0.197 0.00003 0.015 Downstream 0.018 0.207 0.0001 0.017 1.

i 4

I 4

Table 10. Dose commitments-from the liquid pathway to humans.

(mrem /yr_of ingestion) i 4

j Location Whole Body Bone Liver Kidney 1

Upstream 1.39 17.3 0.131 1.65 Between mill and

.i Club Ranch Ponds 1.46 18.2 0.143 1.79 l

Downstream 1.63 22.8 0.349 2.98 i

l

ry 1)po Appendix B DETAILED RADIOLOGICAL ASSESSMENT i

.~

4 Appendix B DETAILED RADIOLOGICAL ASSESSMENT

-This assessment describes the models, data, and assumptions used by the staff l

to perform its radiological impact assessment of the Union Carbide Corporation's Uravan uranium mill.

The primary calculational tool employed is MILDOS,1 an l

NRC-modified version of the UDAD (Uranium Dispersion and Dosimetry) computer

]

code originated at Argonne National Laboratory.2 j

. B.1 ANNUAL RADI0 ACTIVE MATERIAL RELEASES 4

Table 1.2 lists estimated annual activity releases for the Uravan Mill. All data except for the annual average dusting rate for exposed tallings sands are based on the data and assumptions given in Table 1.1 and described elsewhere in Section. 1.

This dusting rate is calculated in accordance with the following equation:

M=3.15j F

0 ss.

(B-1) i where F = annual average frequency of occurrence of wind speed group 3

i s, dimensionless; R = dusting rate for tailings sands at the average wind speed for s

wind speed group s for particles <20 pm diam, g/m.s; 2

M = annual dust loss per unit area, g/m. year; 2

).

3.156 x 107 = number of seconds per year; 0.5 = fraction of total dust loss constituted by particles <20 pm l

diam, dimensionless.1 The values of R and F used by the staff are as given in Table B.l.

s s

i t

'j.

B-1 i

c,,. - -., _ _. - + - -.,., _,

t-1

-.v we e

c-

+--

h B-2 Table B.1 Parameter values for calculation of annual dudting rate for exposed tailings sands

  • Wind speed group Average wind speed Dusting rate Annual frequency of (knott)

(mph)

(g/m.s) occurrence 2

I 0-3 1.5 0

0 4-6 5.5 0

0 7-10 10.0 3.92E-7**

0.14338 11-16 15.5 9.68E-6 0.02179 17-21 21.5 5.71E-5 0.00551

>21 28.0 2.08E-4 0.20228

  • Dusting rate as a function of wind speed is computed by the MILDOS code.1 Wind speed frequencies obtained from annual joint frequency data presented in Table B.2.

4 or.000000392.

Read as 3.92 x 10 7, t

The calculated value of the annual dusting rate, M, is 2692.5 g/m. year.

2 Annual curie releases from the tailings piles are then given by the following relationship:

S = MA(1 - f )I (C) (2.5 x 1072),

(B-2) c t where A = assumed beach area of the pile, m ;

2 f = fraction of dusting rate controlled by mitigating actions, c

1 dimensionless; f = fraction of ore content of particular nuclide present in the t

]

tails; 5 = annual release for the particular beach area, Ci/ year; C = assumed raw ore activity, pCi/g; 2.5 = dust-to-tails activity ratio; 10 12 = C1/pci.

There are two main tailings disposal areas at the Uravan site.

The largest one is approximately 23 hectares and is composed of the old tailings piles and an active tailings disposal area.

The smaller impoundment is 9.3 hectares of tailings and is actively being used for disposal of tailings.

The NRC staff has assumed a dusting loss reduction factor of 80% or better for water cover, moisture and other mitigation procedures.

Should the moisture levels in the solids not be sufficient

,7

,/

)NO 8-3 Table 8.2 Joint relative wind frequency data from Grand Junction, Colorado

hf.W}/

g.4 to reduce dusting to this level, then the estimates presented in the dose assessment portion of this document could be significantly higher.

The activities of U-238, Th-230, Pb-210 and Ra-226 in the tailings solids were measured and dccumented by the NUS Corporation for the Uranium mill.3 These activities are 83 pCi/g, 485.0 pCi/g, 573.0 pCi/g and 666.0 pCi/g for U-238, Th-230, Ra-226 and Pb-210, respectively.

These activities were assumed to be representative of all solid tailings disposal areas.

In addition to the teilings impoundments, the Uravan mill site has approximately 30 hectares of evaporation ponds or spray areas.

These areas are designed to accelerate the evaporation of the liquid waste from the mill.

Activities of the solids which are suspended in the liquids are estimated to be:

24.7 pCi/g, 1057.4 pCi/g, 7.2 pCi/g, and 7.2 pCi/g for U-238, Th-230, Ra-226 and Pb-210.

The reduction factor for the evaporation ponds is assumed to be approximately 95%, since no more than 5% of beach would be exposed during operation.

How-ever, the spray areas are assumed to have 0% reduction of dusting, since the solids would " plate out" upon shallow evaporation.

Dust losses from the ore storage piles were estimated by assuming that they would be about 10% of those from an equivalent area of tailings beach.

a B.2 ATMOSPHERIC TRANSPORT 1he staff analysis of offsite air concentrations of radioactive materials has been based on four years of meteorological data collected at the Grand Junction, Colorado, site during the period 1960 through 1964.3 The collected meteoro-logical data are entered into the MILDOS code as input in the form of a joint frequency distribution by stability class, wind speed group, and direction.

I The joint frequency data employed by the staff for this analysis are presented in Table B.2.

The dispersion model employed by the MILDOS code is the basic straight-line Gaussian plume model. Ground-level, sector-average concentrations are computed using this model and are corrected for decay and ingrowth in transit (for radon-222 and daughters) and for depletion caused by deposition losses (for particulate matter). Area sources are treated using a virtual point source technique.

Resuspension into the air of particulate material initially 4

deposited on ground surfaces is computed using a resuspension factor that depends on the age of the deposited material and its particle size.1 For the isotopes of concern here, the total air concentration including resuspension is about 1.6 times the ordinary air concentration.

The assumed particle size distribution, particle density, and deposition velocities for each source are presented in Table B.3.

-w

yEr B-5 Table B.3 Physical characteristics assumed for particulate material releases Deposition Diameter Density Velocity AMAD*

Activity source (pm)

(g/cm )

(cm/s)

(pm) 3 Crusher dusts 1.0 2.4 1.0 1.55 Yellow cake dusts 1.0 8.9 1.0 2.98 Tailings, ore pile dusts 30%

5.0 2.4 1.0 7.75 70%

35.0 2.4 8.8 54.2 Ingrown radon daughters 0

1.0 0.3 0.3

  • Aerodynamic equivalent diameter, used in calculating inhalation doses.1 B.3 CONCENTRATION IN ENVIRONMENTAL MEDIA Information provided below describes the methods and data used by the staff to determine the concentrations of radioactive materials in the environmental media of concern in the vicinity of the site.

These include concentrations in the air (for inhalation and direct external exposure), on'the ground (for direct external exposure), and in meat and vegetables (for ingestion exposure).

Concentration values are computed explicitly by the MILD 05 code for U-238, Th-230, Ra-226, Rn-222 (air only), and Pb-210.

Concentrations of Th-234, Pa-234, and U-234 are assumed to equal that of U-238.

Concentrations of Bi-210 and Po-210 are assumed to equal that of Pb-210.

B.3.1 Air concentrations Ordinary, direct air concentrations are computed by the MILDOS code for each receptor location from each activity source by particle size (for particulates).

Direct air concentrations computed by MILD 05 include depletion by deposition (particulates) or the effects of ingrowth and decay in transit (radon and daughters).

To compute inhalation doses, the total air concentration of each isotope at each location, as a function of particle size, is computed as the sum of the direct air concentration and the resuspended air concentration:

C,g (t) = Caipd + Caipr(t),

(B-3) p where Cag (t) = total air concentration of isotope i, particle size p, at time p

3 t, pCi/m ;

aipd = direct air concentration of isotope i, particle size p, for C

3 the time constant, pCi/m ;

I

({

v B-6 j.

Ca9pr(t) = resuspended air concentration of isotope 1, particle size p, 3

at time t, pCi/m.

-The resuspended air concentration is computed using a time-dependent resuspen-sion factor, R (t), defined by p

~A t

~

R (t) = (1//p)10 S e R for t $ 1.82 year j

p

~

= (1/V )10 8 for.t > 1.83 year,

(B-4) p I

where R (t) = ratio of the resuspended air' concentration to the ground concen-p l

tration, for a ground concentration of age t years, of particle l

size p, m 1; j

V = deposition velocity of particle size p, cm/s; p

AR = assumed decay constant of the resuspension factor (equivalent to a 50-d half-life), 5.06 years;

~

10 5 = initial value of the resuspension_ factor (for particles with a deposition velucity of 1 cm/s), m 1;

~

10 8 = terminal value of the resuspension factor (for particles with a deposition velocity of I cm/s), m 1; 1.82 = time required to reach the terminal resuspension factor, years.

The basic formulation of the above expression for the resuspension factor, the initial and final values, and tne assigned decay constant derive from experi-l-

mental observations.4 The inverse relationship to deposition velocity elkinates mass balance problems involving resuspension of more than 100% of the initial I

l ground deposition for the 36 pm particle size (see Table B.3).

Based on this l

formulation, the resuspended air concentration is given by l

_ - (1 - exp[-(A * + A ) (t - a)]

g R

Caipr(t) =

0.01 C x 10 aipd (g,

3) j p

exp[-A *(t - a)] - exp(-A *t) g g

l

+ 10 46(t)

(3.1.56 x 107),

(B-5) 3, i

l where a = (t - 1.82) if t i 1.82, years; 6(t) = 0 if t < l.82 and is unity otherwise, dimensionless; l

ph

+ '

B-7 Ay=effectivedecayconstantforisotopeionsoil, year ~1; 0.01 = deposition velocity for the particle size for which the initial -resuspension factor value is 10 5 per meter, m/s; 3.156 x 107 = s/ year.

-Total air concentrations are computed using Eqs. B-3 and B-5 for-all particulate effluents.

Radon daughters that grow in~from released radon are not depleted because of deposition losses and are therefore not assumed to resuspend.

1 B.3.2 Ground concentrations Radionuclide ground concentrdions are computed from the calculated airborne particulate concentrations arising directly from onsite sources (not includ ng air concentrations resulting from resuspension).

Resuspended particulate concentrations are not considered for. evaluating grcund concentrations.

The direct deposition rate of radionuclide i is calculated, using the following relationship:

Ddi =

C V

(B-6) adip p, where C

= direct air concentration of radionuclide i, particle size p, adiE 3

pC1/m ;

Ddi = resulting direct deposition rate of radionuclide i, pCi/m.s; 2

4' V = deposition velocity of particle size p, m/s (see ref. 4).

p The concentration of radionuclide i on a ground surface resulting from constant deposition at the rate D ver time interval t is obtained from di 1 - exp[-Ai + Ae)t]

g (t) = Ddi C

(B-7) g l

where Cg (t) = ground surface concentration of radionuclide i at time t, pCi/m ;

2 j

t = time interval over which deposition has occurred, s; A = assumed rate constant for environmental loss, s-1; e

Ag = radioactive decay constant for radionuclide i, s-1 5

l l

l

B-8 The environmental loss constant Ae corresponds to an assumed half-time for loss of environmental availability of 50 years.4 This parameter accounts for downward migration in soil and loss of availability caused by chemical binding.

It is assumed to apply to all radionuclides deposited on the ground.

Ground concentrations are explicitly computed only for U-238, Th-230, Ra-226, and Pb-210.

For all other radionuclides, the ground concentration is assumed equal to that of the first parent radionuclide for which the ground concentration is explicitly calculated.

For lead-210,. ingrowth from deposited radium-226 can be significant.

The concentration of lead-210 on the ground caused by.

radium-226 deposition is calculated by the staff, using the standard Bateman formulation and assuming that radium-226 decays directly to lead-210.

If i

i_= 6 for radium-226 and i = 12 for lead-210 (ref. 1), the following equation is obtained:

A D 1-exp(-A{2)4 exp(-Agt)-exp(-A*2) t t

12 d6 Cg12(Pb+---Ra) =

(B-8) 1 A

A$2 A -A$2 6

6 i

where Cg12(Pb:

Ra) = incremental lead-210 ground concentration resulting from radium-226 deposition, pCi/m ;

2 A* = etfective rate constant for loss by radioactive decay and migration gf.a ground-deposited radionuclide and is equal to A + ^e' 8

n B.3.3 Vegetation concentrations Vegetation concentrations are derived from ground concentrations and total deposition rates.

Total deposition rates are given by the following summation:

9=[C,$pp, 0

V (B-9)

P where D is the total deposition rate, including deposition of resuspended j

activity, of radionuclide i, pCi/m

.s.

2 I

Concentrations of released particulate materials can be environmentally transferred to the edible portions of vegetables or to hay or pasture grass consumed by anirals by two mechanisms - direct foliar retention and root uptake.

Five categories of vegetation are treated by the staff:

edible aboveground vegetables, potatoes, other edible belowground vegetables, pasture grass, and hay. Vegetation concentrations are computed using the following equation:

a 1 - exp(-A,t )

y Cyj=DEEjry gg(Byg/P),

(B-10)

+C Y A, y

)dt B-9 where Byg = dimensionless; soil-to plant transfer factor for isotope i, vegetation type v, C

= resulting concentration of isotope i, in vegetation v, pCi/kg; 4

yg E = fraction of foliar deposition reaching edible portions of y

vegetation v, dimensionless; F = fraction of total deposition retained on plant surfaces, 0.2, 7

dimensionless; P = assumed areal soil density for surface mixing, 240 kg/m ;

2 t = assumed duration of exposure while growing for vegetation v, s; y

Y = assumed yield density of vegetation v, kg/m ;

2 y

A* = decay constant accounting for weathering losses (equivalent to a 14-d half-life), 5.73 x 10 7 per second.

The value of Ev is assumed to be 1.0 for all aboveground vegetation and 0.1 for all below ground vegetables.8 The value of t is taken to be 60 days, exceptforpasturegrass,whereavalueof30daylisassumed.

The yield dan-sity, Y is taken to be 2.0 kg/m, except for pasture grass, where a value of 2

0.75kg/m,2 is applied.

Values of the soil to plant transfer coefficients, B are provided in Table B.4.

yg, Table B.4 Environmental transfer coefficients Material U

Th-Ra Pb Plant / soli, Bvi Edible sooveoround 2.5E-3*

4.2E-3 1.4E-2 4.0E-3 Potatoes 2.5E-3 4.2E-3 3.0E-3 4.0E-3 Other belowground 2.5E-3 4.2E-3 1.4E-2 4.0E-3 Pasture grass 2.5E-3 4.2E-3 1.8E-2 2.8E-2 Stored feed (hay) 2.5E-3 4.2E-3 8.2E-2 3.6E-2 Beef / feed, F 3.4E-4 2.0E-4 5.IE-4 7.lE-4 pCi/kgperhCi/ day b,

Milk / feed, Fmi, 6.1x10 4 5.0x10 8 5.9x10 4 1.2x10 4

  • Read as 2.5 x 10'3, or.0025.

Source:

U.S. Nuclear Regulatory Commission, Calculational Models for Estimating Radiation Doses to Man from Airborne Radioactive Materials Resulting from Uranium Operations, Report Task RH 802-4, Washington, D.C., May 1979.

h B-10 B.3.4 Meat and milk concentrations Radioactive materials can be deposited on grasses, hay, or silage, which is eaten by meat animals, which are, in turn, eaten by man.

It has been assumed that meat animals obtain their entire feed raquirement by grazing nine months per year and consuming non-local stored hay for the remaining feed requirement.

The equation used to estimate meat cons :ntrations is Cbi = QFbi(0.75 Cpg 4 + 0.0 Chi),

(B-11) where Cpgj = concentration of isotope i in pasture grass, pCi/kg; Cg = concentration of isotope i in hay (or other stored feed), pCi/kg; Cbi = resulting concentration of isotope i in meat, pCi/kg; Fbi = feed-to-meat transfer factor for isotope i, pCi/kg per pCi/d (see Table B.4);

Q = assumed feed ingestion c=.te, 50 kg/d; 0.75 = fraction of total annual feed requirement assumed to be satisfied by pasture grass; 0.0 = fraction of the total annual feed requirement ass e d to be satisfied by locally grown stored feed (hay).

The above grazing assumptions are also reflected in the following equation for milk concentrations:

Cg = QF,j(0.75Cpgg + 0.00Cg),

(B-12) where Cg = average concentration of isotope i in milk, pCi/L; Fg = feed-to-milk activity transfer factor for isotope i, pCi/L per pCi/ day ingested (see Table B.4).

B.4 DOSES TO INDIVIDUALS Doses to individuals have been calculated for inhalation; external exposure to air and ground concentrations; and ingestion of veget&1es, meat, and milk.

Internal doses are calculated by the staff, using dosc :.onversion factors that yield the 50 year dor.e commitment, that is, the entire dose insult received over a period of 50 years following either inhalation or ingestion.

Annual doses given are the 5) year dose commitments resulting from the one year exposure period when environmental concentrations resulting from plant operations are expected to be near their highest level.

)

c..

~.

B-11 B.4.1 Inhalation doses Inhalation doses have been computed using air concentrations cotained by Eq. B-3 (resuspended air concentrations are included) for particulate materials and the dose conversion factors presented in. Table B.5.

Dose to the bronchial epithelium from radon-222 and short-lived daughters were

. computed based on the assumption of indoor exposure at 100% occupancy.

The dose conversion factor for bronchial epithelium exposure from radon-222 derives as follows:

~

1.

1 pCi/ma radon-222 = 5 x 10 6 working levels (WL).*

2.

Continuous exposure to 1 WL = 25 cumulative working level months (WLM) per year.

3.

1 WLM = 5000 mrem.8 Therefore, m

~

radon-222) x 5 x 10 6 x

25 x 5000 rems =

(1 pCi/m3 pCi/m3 WL WLM 0.625 millirems, and the radon-222 bronchial epithelium dose canversion factor is taken to be q

0.625 millirems per year per pCi/m.

3 B.4.2 External doses External doses from air and ground concentrations are computed using the dose conversion factors provided in Table B. 6.

Doses are computed based on 100%

occupancy at the particular location.

Indoor exposure is assumed to occur 14 hours1.62037e-4 days <br />0.00389 hours <br />2.314815e-5 weeks <br />5.327e-6 months <br /> / day at a dose rate of 70% of the outdoor dose rate.

B.4.3 Ingestion doses Ingestion doses are computed for vegetables and meat (beef and-lamb) on the basis of concentrations obtained using Eqs. B-9-B-12, ingestion rates given in Table B.7, and dose conversion factors 8 given in Table B.8.

Vegetable ingestion doses were computed assuming an average 50% activity reauction caused by food preparation.1 Ingestion doses to children and teenagers were computed but were found to be equal to or less than doses to adults.

i

  • 0ne WL concentration is defined as any combination of short-lived radioactive decay products on radon-222 in 1 L of air that will release 1.3 x 105 MeV of alpha particle energy during radioactive decay to lead-210.

K B-12 Table B.5 Inhalation dose conversion factors.

Values are given in millirems per year per pCi/m3 Organ U-238 U-234 U-230 Ra-226 Pb-210 Po-210 Particle size = 0.3 pm Whole body 7.46E+0 1.29E+0 a

Bone 2.32E+2 5.24E+0 Kidney 1.93E+2 3.87E+1 Liver 5.91E+1 1.15E+1 Mass average' lung 6.27E+1 2.66E+2 Particle size = 1.0 pm Whole body 9.82E+0 1.12E+1 1.37E+2 3.58E+1

4. 66E40 5.95E+1 Bone 1.66E+2 1.81E+2 4.90E+3 3.58E+2 1.45E+2 2.43E+0 Kidney 3.78E+1 4.30E+1 1.37E+3 1.26E+0 1.21E+2 1.79E+1 Liver 0.

O.

2.82E+2 4.47E-2 3.69E+1 5.34E+0 Mass average lung 1.07E+3 1.21E+3 2.37E+3 4.88E+3 5.69E+2 3.13E+2 Particle. size = 1.0 pm Whole body 4.32E+0 4.92E+0 1.66E+2 3.09E+1 4.36E+0 4.71E-1 Bone 7.92E+1 7.95E+1 5.95E+3 3.09E+2 1.35E+2

'1.92E+0 Kidney 1.66E+1 1.89E+1 1.67E+3 1.09E40 1.13E+2 1.42E+1 Liver 0.

O.

3.43E+2 3.87E-2 3.45E+1 4.22E+0 Mass average lung 1.58E+2 1.80E+2 3.22E+3 6.61E+3 7.72E+3 4.20E+2 Particle size = 5.0 pm Whole body 1.16E+0 1.32E+0 1.01E+2 4.00E+1 4.84E+0 7.10E-1 Bone 1.96E+1 2.14E+1 3.60E+3 4.00E+2 1.50E+2 2.89E+0 Kidney 4.47E+0 5.10E+0 1.00E+3 1.41E+0 1.25E+2 2.13E+1 Liver 0.

O.

2.07E+2 4.97E-2 3.83E+1 6.36E+0 Mass average lung 1.24E+3 1.42E+3 1.38E+3 2.84E+3 3.30E+2 1.88E+2 Particle size = 35.0 pm Whole body 7.92E-1 9.02E-1 5.77E+1 3.90E+1 4.43E+0 7.28E-1 Bone 1.34E+1 1.46E+1 2.07E+3 3.90E+2 1.38E+2 2.96E+0 Kidney 3.05E+0 3.47E+0 5.73E+2 1.38E+0 1.15E+2 2.19E+1 Liver 0.

O.

1.19E+2 4.85E-2 3.51E+1 6.52E+0 Mass average lung 3.33E+2 3.80E+2 3.71E+2 7.64E+2 8.70E+1 5.75E+1 aRead as 7.46 x 100, or 7.46.

I Sources:

M. Momeni et al., Uranium Dispersion and Dosimetry (UDAD) Code, Report ANL/ES-72, NUREG/CR-0553, Argonne National Laboratory, Chicago, May 1979 and D. R. Kalkwarf, Solubility Classification of Airborne Products from Uranium Ores and Tailings Piles, Report PNL-2830, NUREG/CR-0530, Pacific Northwest Laboratory, Richland, Wash., January 1979.

}.(h B-13 Table B.6 Dose conversion factors for external exposure Isotope Skin Whole body For air concentration doses, 3

millirems per year per pCi/m U-238 1.05E-5*

1. 57 E-6 Th-234 6.63E-5 5.24E-5 Pa(m)-234 8.57E-5 6.64E-5 U-234 1.36E-5
2. 49E-6 Th-230 1.29E-9 3.59E-6 Ra-226 6.00E-5 4.90E-5 Rn-222 3.46E-0 2.83E-6 Po-218 8.18E-7 6.34E-7 Pb-214 2.06E-3 1.67E-3 Bi-214 1.36E-2 1.16E-2 Po-214 9.89E-7 7.66E-7 Pb-210 4.17E-5 1.43E-3 For ground concentration doses, 2

millirems per year por pCi/m U-238 2.13E-6 3.17E-7 Th-234 2.10E-6 1.66E-6 Pa(m)-234 1.60E-6 1.24E-6 U-234 2.60E-6 4.78E-7 Th-230 2.20E-6 6.12E-7 Ra-226 1.16E-6 9.47E-7 Rn-222 6.15E-8 5.03E-8 Po-218 1.42E-8 1.10E-8 Pb '

3.39E-5 3.16E-5 Bi-

.4 2.18E-4 1.85E-4 Po-214 1.72E-8 1.33E-8 Pb-210 6.65E-6 2.27E-6

  • Read as 1.05 x 10 6, or.0000105.

Source:

U.S. Nuclear Regulatory Commission, Calculational Models for Estimating Radiation Doses to Man from Airborne Radioactive Materials Resulting from Uranium Milling Operations, Report Task RH 802-4,",Jashington, D.C., May 1979.

h

.,i.,

B-14 i

Table B.7 Assumed Tood ingestion rates

  • Infc..t Child Teen Adult Vegetables, kg/ year 48 76 105 Edible aboveground.

17 29 40 Potatoes 27.

42 60 Other belowground 3.4 5.0 5.0 Meat (beef,' fresh pork, 28

-45 78 and lamb), kg/ year Milk, L/ year 208 208 246 130 t

-* Ingestion rates are averages for typical rural farm householos.

No allowance is credited for portions of year when locally or homegrown food may not be available.

Source:

J. F. Fletcher and W. L. Dotson, HERMES - A Digital' Computer Code for Estimating Regional Radiological Effects from the Nuclear Power Industry, Report HEDL-TME-71-168, Hanford Engineering Development Laboratory, Hanford, Wash., December 1971 i

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i Table B.8 Ingestion dose conversion facters.

Values are in millirem /pci ingested.

Isotope Age group Organ U-238 U-234 Th-234 Th-230 Ra-226 Pb-210 B1-210 Po-210 Infant Whole body 3.33E-4 3.80E-4 2.00E-8 1.06E-4 1.07E-2 2.38E-3 3.58E-7 7.41E-4 fee 4.47E-3 4.88E-3 6.92E-7 3.80E-3 9.44E-2 5.28E-2 4.10E-6 3.10E-3 Liver O.

O.

3.77E-8 1.90E-4 4.76E-5 1.42E-2 2.680-5 5.93E-3 Kidney 9.28E-4 1.06E-3 1.39E-7 9.12E-4 8.72E-4 4.33E-2 2.08E-4 1.26E-2 Child Whole body 1.94E-4 2.21E-4 9.88E-9 9.91E-5 9.87E-3 2.09E-3 1.69E-7 3.67E-4 Bone 3.27E-3 3.57E-3 3.42E-7 3.55E-3 8.76E-2 4.75E-2 1.97E-6 1.52E-3 Liver 0.

O.

1.51E-8 1.78E-4 1.84E-5 1.22E-2 1.02E-5 2.43E-3 Kidney 5.24E-4 5.98E-4 8.01E-8 8.67E-8 4.88E-4 3.67E-2 1.15E-4 7.56E-3 Teenager Whole body 6.49E-5 7.39E-5 3.31E-9 6.00E-5 5.00E-3 7 01E-4 5.66E-8 1.23E-4 5

Bone 1.09E-3 1.19E-3 1.14E-7 2.16E-3 4.09E-2 1.81E-2 6.59E-7 5.09E-4 Liver 0.

O.

6.68E-9 1.23E-4 8.13E-6 5.44E-3 4.51E-6 1.07E-3 Kidney 2.50E-4 2.83E-4 3.81E-8 5.99E-4 2.32E-4 1.72E-2 5.48E-5 3.60E-3 Adult Wnole body 4.54E-5 5.17E-5 2.13E-9 5.70E-5 4.60E-3 5.44E-4 3.96E-8 8.59E-5 Bone 7.67E-4 8.36E-4 8.01E-8 2.06E-3 4.60E-2 1.53E-2 4.61E-7 3.56E-4 Liver 0.

O.

4.71E-9 1.17E-4 5.74E-6 4.37E-3 3.18E-6 7.56E-4 Kidney 1.75E-4 1.99E-4 2.67E-8 5.65E-4 1.63E-4 1.23E-2 3.83E-5 2.52E-3 Sources:

U.S. Nuclear Regulatory Commit

  • i.n, Calculational Models for Estimating Radiation Doses to Man from Airborne Radioactive Materials Resulting from Uranium Milling Operations, Report Task RH 802-4, Washington, D.C., May 1979 and G. R. Hoenes and J. K. Soldat, Age-Specific Radiation Dose Conversion Factors for a One-Year Chronic Intake, Report NUREG-0172, Battelle Pacific Northwest Laboratories, Richland, Wash., November 1977, i

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REFERENCES FOR APPENDIX B 1.

U.S. Nuclear Regulatory Commission, Calculational Models for Estimating Radiation Doses to Man from Airborne Radioactive Materials Resulting from Uranium Milling Operations, Report Task RH 802-4, Washington, D.C.,

May 1979.

2.

M. Momeni et al., Uranium Dispersion and Dosimetry (UDAD) Code, Report ANL/ES-72, NUREG/ CR-0553, Argonne National Laboratory, Chicago, May 1979.

3.

Cyprus Mines Corporation, letter to NRC, April 16, 1980, Docket No. WM-24.

4.

U.S. Nuclear Regulatory Commission, Final Generic Environmental Impact Statement on Uranium Milling, Report NUREG-07' 5, Washington, D.C.,

September 1980.

5.

D. C. Kocher, Nuclear Decay Data for Radionuclides Occurring in Routine Releases from Nuclear Fuel Cycle Facilities, Report ORNL/NUREG/TM-102, Oak Ridge National Laboratory, Oak Ridge, Tenn., August 1977.

6.

J. F. Fletcher and W. L. Dotson, HERMES - A Digital Computer Code for Estimating Regional Radiological Effects from the Nuclear Power Industry, Report HEDL-TME-71-168, Hanford Engineering Development Laboratory, Hanford, Wash., December 1971.

7.

D. R. Kalkwarf, " Solubility Classification of Airborne Products from Uranium Ores and Tailings Piles," Report NUREG/CR-0530; PNL-2830, Pacific Northwest Laboratory, January 1979.

8.

National Academy of Sciences - National Research Council, The Effects on Populations of Exposure to Low Levels of Ionizing Radiation, Report on the Advisory Committee on Biological Effects of Ionizing Radiation, U.S.

Government Printing Office, Washington, D.C.,

1972.

9.

G. R. Hoenes and J. K. Soldat, " Age-Specific Radiation Dose Conversion Factors for a One-Year Chronic Intake," Battelle Pacific Northwest Laboratories, U.S. Nuclear Regulatory Commission Report NUREG-0172, l

November 1977.

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