ML19256F467
| ML19256F467 | |
| Person / Time | |
|---|---|
| Issue date: | 12/02/1979 |
| From: | Eadie G NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| To: | Scarano R NRC OFFICE OF NUCLEAR MATERIAL SAFETY & SAFEGUARDS (NMSS) |
| Shared Package | |
| ML19256F468 | List: |
| References | |
| FOIA-80-529, FOIA-81-8, REF-WM-28 NUDOCS 7912190184 | |
| Download: ML19256F467 (3) | |
Text
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NUCLEAR REGULATORY COMMisslON
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MEMOPANDUM FOR: Ross A. Scarano, Chief Uranium Recovery Licensing Branch FROM:
Gregory Eadie Uranium Recovery Licensing Branch
SUBJECT:
DOSE ESTIMATES FROM INGESTION OF CHURCH ROCK LIVESTOCK At the present time, limited analytical data exists of the actual radio-active concentrations in various ti sues of livestock raised locally near the areas of the Rio Puerco affected by the UNC uranium mill tailings dam fai l ure. Data reported by the US EPA-LVF in a letter dated October 12, 1979 (attachment #1) appears to be the only available pertinent data.
In order to estimate the dose received by an individual who might possibly ingest meat contamination to the highest concentration level as reported by the EPA, the following parameters and assumptions have been made:
1.
The adult meat ingestion rate is 78.3Xg per year (U.S. NRC, May 1979).
2.
The adult dose conversion factors for meat ingestion are as follows (see U S. NRC, May 1979):
DOSE PER YEAR (IN MREM)PER PCI INGESTED Oroan U-238 U-234 Th-230 Ra-226*
Pb-210*
-5 5
- 5. 70x10-5 3
Whole Body 4.54x10 5.17x10 4 2.06x10-34.60x10 2 5.44x10-4
~4
-4 4.60x10 6 1.53x10-2 Bone 7.67x10 8.36x10-3 Liver 0
0 1.17x10
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1.23x10-Kidney 1.75x10 1.99x10~4 5.65x10~4 5.74x10 4 4.37x10 2
~4 1.63x10
- Note the relatively higher dose conversion factors for bone dose for radium-226 and lead-210.
U.S. NRC, May 1979, " Calculational Models for Estimating Radiation Doses to Man from Airborne Radioactive Materials Resulting from Uranium Milling Ope rati ons."
L62UT53 7912100
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. 3.
The highest radioactivity concentrations were reported for cow liver (sample #210874):
DOSE PER YEAR IN MREM U-238 U-234 Th-230 Ra-226 Pb-210 Concentration (in pCi/kg) 4.4 4.3 1.7 no data no data Whole Body 0.016 0.017 0.0076-no data no data Bone 0.26 0.28 0.27 no data no data Liver 0
0 0.016 no data no data Kidney 0.060 0.067 0.075 no data no data 4.
The " control" cow liver results were (sample #210885):
DOSE PER YEAR IN MREM U-238 U-234 Th-230 Ra -226 Pb-210 Concentration (in pCi/kg)
<0.40
<0.34 0.18 no data no data Whole Body 0.0014 0.0014 0.00080 no data no data Bonc 0.024 0.022 0.029 no data no data Li ver 0
0 0.0017 no data no data Kidney 0,0055 0.0053 0.0080 no data no data 5.
The highest concentrations for sheep liver were (sample #210890):
DOSE PER YEAR IN MREM U-238 U-234 Th-230 Ra-226 Pb-210 Concentration (in pCi/kg) 2.0 2.1 2.1 no data no data Whole Body 0.0071 0.0085 0.0094 no data no data Bone 0.12 0.14 0.34 no data no data Liver 0
0 0.019 no data no data Kidney 0.027 0.033 0.093 no data no data 6.
The ".controT' Sheep liver results were (sample #210902):
DOSE PE.; YEAR IN MREM U-231__
U-234 Th-230 Ra-226 Pb-210 Concentration (in pCi/kg) 0.23 0.30 0.22 no data no data Whole Body 0.00082 0.0012 0.00098 no data no data Bone 0.014 0.020 0.035 no data no data Liver 0
0 0.0020 no data no data Kidney 0.0032 0.0047 0.0097 no data no data e
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1620 M4
Ross A. Scarano 7.
Therefore, from the above computations, it appears that the incremental bone dose would be about 0.74 mrem per year for the ingestion of cow's liver and about 0.53 mrem per year from sheep's liver due to the increase above " control" levels for the radionuclides U-238, U-234, and Th-230.
It should be noted that radium-226 and lead-210 have higher dose conversion factors than for uranium and thorium; therefore, the total dose calculations must considers the contribution from radium and lead in these livestock tissues. Unfortunately, at this time, the actual data for radium and lead concentrations is not available. The assumption that these radionuclides may be present at about 10 times the uranium content (i.e.,
radium and lead of 50 pCi/kg) has been made, and it is estimated that they would contribute less than 240 mrem additional bone dose. This assumption seems conservative in that the available data on radium in water and soil samples from the affected areas has been generally less than 10 times the uranium content.
Therefore, at this time, without confinnatory radium and lead data, it would seem prudent to refrain from eating livestock possibly contaminated by radioactive materials released from the uranium mill tailings dam failure. A complete dose assess-ment will be performed upon receipt of all the pertinent livestock tissue radiological analyses data.
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Gregory G. Eadie Uranium Recovery Licensing Branch Division of Waste Management Attachment
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