Radiation Exposure for Uranium Industry Residents
(last updated 24 Nov 2020)
Contents:
> see also:
| The general radiation dose standard for the public is 1 mSv/a, and the fatal cancer risk for the public is 0.05 per Sv, according to [ICRP60]. |
Exposure to 1 mSv/a over a lifetime of 70 years results in an excess fatal cancer risk of 0.35% (1 : 286). (see Radiation Dose to Risk Converter)
In some cases, regulators apply fractions of the 1 mSv/a standard for doses caused from single facilities.
U.S. EPA standard for drinking water [40 CFR 141.15] - excerpt:
| Combined radium-226 and radium-228 | 5 pCi/l (0.185 Bq/l) |
| Gross alpha particle activity (including radium-226 but excluding radon and uranium) | 15 pCi/l (0.555 Bq/l) |
| uranium | 30 µg/l |
|
| WHO guideline for uranium in drinking-water [WHO2004]
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U.S. EPA recommendation for radon in homes (EPA  )
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Source Term
The release of radon-222 from the mine as well as the specific emission per tonne U3O8 produced shows high variations:
| Total Annual Radon Emission [TBq] | Specific Radon Emission [GBq/t U3O8] |
| Ranger Mine (Australia) | 130 | 22 |
| former Panel Mine (Canada) | 96 | 110 |
| former Ronneburg Mine (Germany) | 690 | 210 |
| former Denison Mine (Canada) | 1100 | 540 |
| Rabbit Lake Mine (Canada) | 1600 | 760 |
| former Aue Mine (Germany) | 650 (?) | 2000 |
GBq stands for 109 Bq, TBq stands for 1012 Bq
1 t U3O8 is equivalent to 0.848 t U
[UNSCEAR1993], all figures for 1989
U.S. EPA effluent limitations for mine drainage from open-pit and underground uranium mines [40 CFR 440.32] (excerpt):
| Maximum for any one day | 30 day average |
| Ra-226 (dissolved) | 10 pCi/l (0.37 Bq/l) | 3 pCi/l (0.111 Bq/l) |
| Ra-226 (total) | 30 pCi/l (1.11 Bq/l) | 10 pCi/l (0.37 Bq/l) |
| U | 4 mg/l | 2 mg/l |
|
Exposure of Residents
- External radiation from ore piles and waste rock dumps:
for a person standing on the surface (based on [FGR12] dose factors):
- 415 nSv/h (= 3.6 mSv/a for continuous occupation) from low grade ore with a uranium contents of 100 ppm (0.01%) U.
- 67 nSv/h (= 0.59 mSv/a for continuous occupation) from material with a radium-226 activity of 0.2 Bq/g, a frequently applied standard for unrestricted access. For equilibrium, this corresponds to 16.2 ppm U.
- Inhalation of ore dust from mine and waste rock dumps
The effective dose from inhalation of 1 mg uranium ore of an ore grade of 0.1% U is 0.7 µSv (for higher ore grades, the dose increases correspondingly). The 1 mSv annual standard for the public is equivalent to 1.43 g. For continuous exposure, this corresponds to a uranium ore concentration in air of 180 µg/m3. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for insoluble compounds, adults, breathing rate of 0.9 m3/h, U-238 in equilibrium with progeny)
- Inhalation of radon from mine and waste rock dumps
| U.S. EPA standard for excess effective dose from emission of radon-222 from an underground uranium mine to any member of the public [40 CFR 61.22]:
|
See also: Uranium Mine and Mill Resident Individual Dose Calculator, Radon Individual Dose Calculator, and, for collective dose calculations, Nuclear Fuel Population Health Risk Calculator
- Ingestion of food grown on contaminated soil or irrigated with contaminated water
(See also Uranium Toxicity)
- Ingestion of contaminated water
The effective dose from ingestion of 1 g pure natural uranium is 1.23 mSv. The 1 mSv annual standard for the public is equivalent to 0.813 g. For consumption of 500 l/a, this corresponds to a uranium concentration in drinking water of 1.6 mg/l. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for adults)
In this case, uranium toxicity is the limiting factor.
(see also Health Impacts for Residents)
Source Term
Annual airborne emissions of uranium mills
| U3O8 produced | Annual emission |
| Rn-222 | Ra-226 | Th-230 | U-238 |
| [t] | [GBq] | [GBq] | [GBq] | [GBq] | [kg] |
| Ranger (Australia) | 4000 | 54,000 | | | 2 | 161 |
| Olympic Dam (Australia) | 1200 | 16,000 | 0.1 | 0.1 | 0.2 | 16 |
| Nabarlek (Australia) | 1700 | 21,000 | | | 0.7 | 56 |
| Key Lake (Canada) | 5832 | ? | 0.024 | 0.041 | 0.85 | 69 |
| Rabbit Lake (Canada) | 1900 | 9,200 | | | | |
GBq stands for 109 Bq
1 t U3O8 is equivalent to 0.848 t U
[UNSCEAR1993], all figures for 1989 (Nabarlek: 1987)
The release of radon-222 from the mill per tonne U3O8 produced is typically 13 GBq/t U3O8. (GBq stands for 109 Becquerels.) [UNSCEAR1993]
Annual emissions in liquid effluents of uranium mills
| U3O8 produced | Annual emission |
| Pb-210 | Ra-226 | Th-230 | U-238 |
| [t] | [GBq] | [GBq] | [GBq] | [GBq] | [kg] |
| Amok (Canada) | 741 | 0.05 | 0.01 | 0.029 | 7.6 | 613 |
| Key Lake (Canada) | 5832 | 0.07 | 0.17 | 0.07 | 0.7 | 56 |
GBq stands for 109 Bq
1 t U3O8 is equivalent to 0.848 t U
[UNSCEAR1993], all figures for 1989
U.S. EPA effluent limitations for discharges from uranium mills and in-situ leach mines [40 CFR 440.32]:
| Maximum for any one day | 30 day average |
| Ra-226 (dissolved) | 10 pCi/l (0.37 Bq/l) | 3 pCi/l (0.111 Bq/l) |
| Ra-226 (total) | 30 pCi/l (1.11 Bq/l) | 10 pCi/l (0.37 Bq/l) |
|
U.S. EPA standard for cleanup of land contaminated with residual radioactive material from inactive uranium processing sites [40 CFR 192.12]; concentration of radium-226 in soil:
- 5 pCi/g (0.185 Bq/g) for the top 15 cm of soil;
- 15 pCi/g (0.555 Bq/g) for soil deeper then 15 cm.
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A radium-226 concentration of 0.185 Bq/g corresponds to an uranium concentration (before eventual extraction) of 15 ppm.
U.S. NRC standard for soil containing radionuclides other than radium [64 FR 17506 , April 12, 1999]:
- the dose must not exceed the dose from cleanup of radium contaminated soil to the 5 pCi/g (0.185 Bq/g) standard for the top 15 cm, excluding the dose from radon
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The dose from soil contaminated with radium-226 at 0.185 Bq/g, that is used as a reference in the above standard, seems to be a mystery, however:
- According to EPA, the 0.185 Bq/g radium-226 standard is consistent with a 15 mrem/a (0.15 mSv/a) dose limit for a residential scenario.
- According to NRC, the 0.185 Bq/g radium-226 standard results in potential doses between 22 and 34 mrem/a (0.22 and 0.34 mSv/a), depending on the scenario.
- The external dose alone from standing on soil contaminated with radium-226 at 0.185 Bq/g is 0.54 mSv/a) for continuous exposure, using the [FGR12] dose factors and assuming equilibrium between radium and its decay products.
All these calculations exclude the dose from radon.
Exposure of Residents at Uranium Mill
U.S. EPA dose limit for uranium fuel cycle facilities (excluding radon) [40 CFR 190.10]:
- 25 mrem/a (0.25 mSv/a) to the whole body,
- 75 mrem/a (0.75 mSv/a) to the thyroid, and
- 25 mrem/a (0.25 mSv/a) to any other organ
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- Inhalation of radon from operating mill
See also: Radon Individual Dose Calculator, and Uranium Mine and Mill Resident Individual Dose Calculator,
- Inhalation of radon from contaminated soil
According to U.S. EPA, a radium-226 concentration of 0.185 Bq/g in soil can readily lead to indoor levels of radon decay products of 0.02 WL (74 Bq/m3 EEC, corresponds to radon concentration of 185 Bq/m3 for F=0.4, results in 3.3 mSv/a for 80% occupancy) [48 FR 590].
See also: Radon Individual Dose Calculator
- Inhalation of dust from ore and concentrate
| U.S. EPA dose limit for emissions of radionuclides (excluding radon) to the air from facilities licensed by the NRC [40 CFR 61.102]:
|
The effective dose from inhalation of 1 mg uranium ore of an ore grade of 0.1% U is 0.7 µSv (for higher ore grades, the dose increases correspondingly). The 1 mSv annual standard for the public is equivalent to 1.43 g. For continuous exposure, this corresponds to a uranium ore concentration in air of 180 µg/m3. EPA's 0.1 mSv annual standard is equivalent to 143 mg. For continuous exposure, this corresponds to a uranium ore concentration in air of 18 µg/m3. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for insoluble compounds, adults, breathing rate of 0.9 m3/h, U-238 in equilibrium with progeny)
The effective dose from inhalation of 1 mg pure natural uranium (as contained in the uranium ore concentrate) is 0.22 mSv. The 1 mSv annual standard for the public is equivalent to 4.5 mg. This corresponds to a uranium concentration in air of 0.58 µg/m3. EPA's 0.1 mSv annual standard is equivalent to 0.45 mg. For continuous exposure, this corresponds to a uranium concentration in air of 58 ng/m3. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for insoluble compounds, adults, breathing rate of 0.9 m3/h)
- Ingestion of contaminated water
The effective dose from ingestion of 1 g pure natural uranium is 1.23 mSv. The 1 mSv annual standard for the public is equivalent to 0.813 g. For consumption of 500 l/a, this corresponds to a uranium concentration in drinking water of 1.6 mg/l. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for adults)
In this case, uranium toxicity is the limiting factor.
> See also [NRC1982]
Source term
A rule-of-thumb value for the Specific Radon Exhalation Rate from the bare surface of unsaturated tailings is 1 Bq/m2s per BqRa-226/g [EPA1986]; this applies for "infinite" (in terms of radon exhalation) thickness of the tailings, that is more than 4 meters.
In case of bare tailings from ore with an ore grade of 0.1% U, the radon exhalation rate would be approx. 12 Bq/m2s.
| U.S. EPA standard for radon-222 emission rate from surface of inactive uranium mill tailings piles [40 CFR 61.222, 40 CFR 192.02]:
|
U.S. EPA design standard for effectiveness of cover on inactive uranium mill tailings [40 CFR 192.02]:
- 1000 years to the extent reasonably achievable,
- at least 200 years in any case
|
Exposure of Residents at Uranium Mill Tailings
- External radiation on tailings surface:
The dose rate from standing on bare tailings from ore with an initial ore grade of 0.1% U is 4.1 µSv/h (=36 mSv/a for continuous occupation) (based on [FGR12] dose factors).
- Inhalation of radon from tailings
The maximum radon concentration in air at the edge of a uranium mill tailings pile releasing 280 pCi/m2s (10.36 Bq/m2s) is 4 pCi/l (148 Bq/m3), according to [EPA1983]. For continuous exposure and F=0.4, this corresponds to an annual dose of 3.3 mSv/a.
| U.S. EPA standard for excess radon-222 concentration outside inactive uranium mill tailings piles [40 CFR 192.02]:
|
For continuous exposure and F=0.4, this standard corresponds to an annual dose of 0.41 mSv/a.
> See also: Uranium Mine and Mill Resident Individual Dose Calculator, and Radon Individual Dose Calculator, and, for collective dose calculations, Nuclear Fuel Population Health Risk Calculator
- Inhalation of tailings dust
The effective dose from inhalation of 1 mg uranium mill tailings left over from an ore with a grade of 0.1% U is 0.5 µSv (for higher ore grades, the dose increases correspondingly). The 1 mSv annual standard for the public is equivalent to 2 g. For continuous exposure, this corresponds to a uranium mill tailings concentration in air of 253 µg/m3. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for insoluble compounds, adults, breathing rate of 0.9 m3/h)
- Ingestion of food grown on contaminated soil or irrigated with contaminated water
- Ingestion of contaminated water
U.S. EPA standards for radionuclides in groundwater at inactive uranium mill tailings site [40 CFR 192.02]:
| Combined U-238 and U-234 | 30 pCi/l (1.11 Bq/l, equiv. to 44 µg/l for secular equilibrium) |
| Combined Ra-226 and Ra-228 | 5 pCi/l (0.185 Bq/l) |
| Gross alpha-particle activity (excluding radon and uranium) | 15 pCi/l (0.555 Bq/l) |
|
The effective dose from ingestion of 1 g pure natural uranium is 1.23 mSv. The 1 mSv annual standard for the public is equivalent to 0.813 g. For consumption of 500 l/a, this corresponds to a uranium concentration in drinking water of 1.6 mg/l. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for adults)
In this case, uranium toxicity is the limiting factor.
- Radiation exposure in buildings contaminated from tailings material:
In Grand Junction, Colorado, about 700 buildings were contaminated with enough tailings to increase indoor radon decay product levels by at least 0.01 WL; a few houses had levels higher than 0.5 WL [EPA1983].
U.S. EPA standard for buildings contaminated with residual radioactive materials from inactive uranium processing sites (40 CFR 192.12):
- objective of 0.02 WL, including background
(74 Bq/m3 EEC, corresponds to radon concentration of 185 Bq/m3 for F=0.4, results in 3.3 mSv/a for 80% occupancy), and
- limit of 0.03 WL, including background
(111 Bq/m3 EEC, corresponds to radon concentration of 277.5 Bq/m3 for F=0.4, results in 5 mSv/a for 80% occupancy);
- limit for gamma radiation: 20 µR/h above background
(122.6 nSv/h, or 0.86 mSv/a for 80% occupancy)
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See also: Radon Individual Dose Calculator
- Inhalation of radon in homes built on top of a tailings deposit:
Considering inhalation of Rn-222 (and progeny) alone, the increase in the effective dose would be between 6 to 10 mSv/a for a repository with a cover, or about 75 mSv/a for a repository without a cover. [Goldschmidt1999]
(Assumptions: house with an unventilated cellar; time spent in the house = 7,000 h/year in a main room and 100 h/year in an unventilated cellar; thickness of cover considered 4 m and 3 m; average specific activity of the tailings = 16 Bq/g [obviously means Ra-226] - this corresponds to an original ore grade of 0.13% U.
For calculation principles, see: IPSN/DPRE report No. 98/16: Simplified model of radon accumulation in dwellings built on repositories containing 226Ra - Calculation of the associated radiological impact).
> See also [NRC1982]
Source term
Annual emissions of uranium conversion plants
| Capacity | Annual emission |
| airborne | liquid effl. |
| U-238 | U-238 |
| [GBq] | [kg] | [GBq] | [kg] |
| Blind River refinery (Ontario) | 18,000 t U as UO3 | 0.9 | 73 | 0.1 | 8 |
| Port Hope UF6 plant (Ontario) | 10,000 t U as UF6 | 0.7 | 56* | 2.6 | 210 |
* 1998 figure was 143 kg (AECB BMD 99-123)
GBq stands for 109 Bq
other non-radioactive emissions include fluorine, among others
[UNSCEAR1993], all figures for 1989
Annual emissions of uranium enrichment plants
| Capacity | Annual emission |
| airborne | liquid effl. |
| uranium | uranic alpha | uranic beta |
| [GBq] | [kg] | [GBq] | [GBq] |
| Capenhurst (UK) | | 0.02 | ? | 1.7 | 1.7 |
GBq stands for 109 Bq
other non-radioactive emissions include fluorine, among others
[UNSCEAR1993], all figures for 1989 (Capenhurst 1988)
Annual emissions of nuclear fuel fabrication plants
| Capacity | Annual emission |
| airborne | liquid effl. |
| uranic alpha | uranic beta | uranic alpha | uranic beta |
| [GBq] | [GBq] | [GBq] | [GBq] |
| KNFC (Korea) | | 0.3 | 0.1 | 0.03 | 0.013 |
| Springfields (UK) | | 1 | 2 | 400 | 114,000 |
GBq stands for 109 Bq
other non-radioactive emissions include fluorine, among others
[UNSCEAR1993], all figures for 1989
Exposure of Residents at Conversion and Enrichment plants
U.S. EPA dose limit for uranium fuel cycle facilities (excluding radon) [40 CFR 190.10]:
- 25 mrem/a (0.25 mSv/a) to the whole body,
- 75 mrem/a (0.75 mSv/a) to the thyroid, and
- 25 mrem/a (0.25 mSv/a) to any other organ
|
- Inhalation of uranium dust
| U.S. EPA dose limit for emissions of radionuclides (excluding radon) to the air from facilities licensed by the NRC [40 CFR 61.102]:
|
The effective dose from inhalation of 1 mg pure natural uranium is 0.22 mSv. The 1 mSv annual standard for the public is equivalent to 4.5 mg. This corresponds to a uranium concentration in air of 0.58 µg/m3. EPA's 0.1 mSv annual standard is equivalent to 0.45 mg. For continuous exposure, this corresponds to a uranium concentration in air of 58 ng/m3. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for insoluble compounds, adults, breathing rate of 0.9 m3/h)
- Ingestion of food grown on contaminated soil or irrigated with contaminated water
- Ingestion of contaminated water
The effective dose from ingestion of 1 g pure natural uranium is 1.23 mSv. The 1 mSv annual standard for the public is equivalent to 0.813 g. For consumption of 500 l/a, this corresponds to a uranium concentration in drinking water of 1.6 mg/l. (See also: Uranium Radiation Individual Dose Calculator)
(based on ICRP72 dose factors for adults)
In this case, uranium toxicity is the limiting factor.
At COVRA's storage buildings for depleted uranium (as U3O8) in Vlissingen, The Netherlands, the excess radiation dose rate at the fence (next to a public road) was in 2012 measured as 79.5 nSv/h (0.696 mSv/a for continuous occupancy), of which 69% are from gamma radiation, and 31% from neutron radiation. [COVRA 2014]
The excess gamma dose rate in front of a hotel located near Areva's storage buildings for depleted uranium (as U3O8) in Bessines-sur-Gartempe (Haute-Vienne) was in 2009 measured as 0.25 µSv/h (2.19 mSv/a for continuous occupancy). [DRIRE2009]
[COVRA 2014] Bijlagen 3-5 bij Aanvraag Revisievergunning, COVRA N.V., 6 Feb. 2014
[DRIRE2009] Rapport d'inspection - Site industriel de Bessines-sur-Gartempe (87), Le 17 juin 2009, DRIRE Limousin
[EPA1983] U.S. EPA: Final Environmental Impact Statement for Standards for the Control of Byproduct Materials from Uranium Ore Processing (40 CFR 192), Vol. 1, September 1983, Report No. EPA/520/1-83-008-1
[EPA1986] Final Rule for Radon-222 Emissions from Licensed Uranium Mill Tailings. Background Information Document, U.S. Environmental Protection Agency, Office of Radiation Programs, Washington, DC, August 1986, 226 p. Report No. EPA/520/1-86/009
[FGR12] U.S. EPA: Federal Guidance Report No. 12: External
Exposures to Radionuclides in Air; Water; and Soil, EPA 402-R-93-081, September 1993
> download
full text (1081k - PDF format)
> online lookup of FGR 12 dose factors for external exposure
> download database DFEXT of FGR 12 dose factors, contained in the DFACT package
[The FGR 12 dose factors are based on ICRP26. The DFEXT software also allows computing of the effective dose according to ICRP60: these values have been used here.]
[Goldschmidt1999] Radiological Impact Assessment Of A Uranium Mill Tailings Repository, by Frédéric Goldschmidt and Jean Marc Peres, IPSN/Environment Protection Department, paper presented at Eurosafe in Paris, Nov. 18-19, 1999
> Download full text (207k, PDF format)
[ICRP60] 1990 Recommendations of the International Commission on Radiological Protection, ICRP Publication 60, Oxford 1991
[Mudd2008] Radon Releases From Australian Uranium Mining and Milling Projects : Assessing the UNSCEAR Approach, by Gavin M Mudd, in: Journal of Environmental Radioactivity, Vol. 99 (2008) No. 2, pp 288-315.
[NRC1982] U.S. NRC: Regulatory Guide 3.51, Calculational Models for Estimating Radiation Doses to Man from Airborne Radioactive Materials Resulting from Uranium Milling Operations, 1982
> Download full text (2.3M PDF)
[UNSCEAR1993] Sources and Effects of Ionizing Radiation, United Nations Scientific Committee on the Effects of Atomic Radiation, UNSCEAR 1993 Report to the General Assembly, with Scientific Annexes, United Nations, New York, 1993, 922 p. (see also [Mudd2008])
[WHO2004] World Health Organization: WHO Guidelines for drinking-water quality, third edition, 2004
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[xx FR yyyy] U.S. Federal Register , xx = volume, yyyy = page