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Uranium Aerosol Act...
Uranium Aerosol Activity Size Distributions at a Nuclear Fuel Fabrication Plant
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- Hansson, Edvin (författare)
- Linköpings universitet,Avdelningen för diagnostik och specialistmedicin,Medicinska fakulteten,Westinghouse Elect Sweden AB, Sweden
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- Pettersson, Håkan (författare)
- Linköpings universitet,Avdelningen för diagnostik och specialistmedicin,Medicinska fakulteten,Region Östergötland, Medicinsk strålningsfysik
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- Eriksson, Mats (författare)
- Linköpings universitet,Avdelningen för diagnostik och specialistmedicin,Medicinska fakulteten,Swedish Radiat Safety Author, Sweden
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(creator_code:org_t)
- LIPPINCOTT WILLIAMS & WILKINS, 2020
- 2020
- Engelska.
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Ingår i: Health Physics. - : LIPPINCOTT WILLIAMS & WILKINS. - 0017-9078 .- 1538-5159. ; 119:3, s. 327-341
- Relaterad länk:
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https://liu.diva-por... (primary) (Raw object)
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https://urn.kb.se/re...
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https://doi.org/10.1...
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Abstract
Ämnesord
Stäng
- Inhalation of uranium aerosols is a concern in nuclear fuel fabrication. Determination of committed effective doses and lung equivalent doses following inhalation intake requires knowledge about aerosol characteristics; e.g., the activity median aerodynamic diameter (AMAD). Cascade impactor sampling of uranium aerosols in the breathing zone of nuclear operators was carried out at a nuclear fuel fabrication plant producing uranium dioxide via ammonium uranyl carbonate. Complementary static sampling was carried out at key process steps. Uranium on impaction substrates was measured using gross alpha counting and alpha spectrometry. Activity size distributions were evaluated for both unimodal and bimodal distributions. When a unimodal distribution was assumed, the average AMAD in the operator breathing zone at the workshops was 12.9-19.3 mu m, which is larger than found in previous studies. Certain sampling occasions showed variable isotope ratios (U-234/U-238) at different impactor stages, indicating more than one population of particles; i.e., a multimodal activity size distribution. When a bimodal distribution (coarse and fine fraction) was assumed, 75-88% of the activity was associated with an AMAD of 15.2-18.9 mu m (coarse fraction). Quantification of the AMAD of the fine fraction was associated with large uncertainties. Values of 1.7-7.1 mu m were obtained. Static sampling at key process steps in the workshops showed AMADs of 4.9-17.2 mu m, generally lower than obtained by breathing zone sampling, when a unimodal distribution was assumed. When a bimodal distribution was assumed, a smaller fraction of the activity was associated with the coarse fraction compared to breathing zone sampling. This might be due to impactor positioning during sampling and sedimentation of large particles. The average committed effective dose coefficient for breathing zone sampling and a bimodal distribution was 1.6-2.6 mu Sv Bq(-1)for(234)U when Type M/S absorption parameters were assumed (5.0 mu Sv Bq(-1)for an AMAD of 5 mu m). The corresponding lung equivalent dose coefficient was 3.6-10.7 mu Sv Bq(-1)(29.9 mu Sv Bq(-1)for an AMAD of 5 mu m). The predicted urinary excretion level 100 d after inhalation intake was found to be 13-34% of that corresponding to an AMAD of 5 mu m. Uranium aerosols generated at a nuclear fuel fabrication plant using ammonium uranyl carbonate route of conversion were associated with larger AMADs compared to previous work, especially when sampling of aerosols was carried out in the operator breathing zone. A bimodal activity size distribution can be used in calculations of committed effective doses and lung equivalent doses, but parameters associated with the fine fraction must be interpreted with care due to large uncertainties.
Ämnesord
- MEDICIN OCH HÄLSOVETENSKAP -- Klinisk medicin -- Radiologi och bildbehandling (hsv//swe)
- MEDICAL AND HEALTH SCIENCES -- Clinical Medicine -- Radiology, Nuclear Medicine and Medical Imaging (hsv//eng)
Nyckelord
- aerosols; contamination; internal; lungs; human; nuclear workers
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
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