The Mayak Worker Dosimetry System (Mwds-2013) for Internally Deposited Plutonium: An Overview

Birchall, А.; Востротин, В. В.; Puncher, Mathew L.; Efimov, Alexander; Dorrian, M.-D.; Sokolova, A. B.; Napier, Bruce A.; Суслова, К. Г.; Miller, Scott C.; Zhdanov, Alexey; Strom, Daniel J.; Scherpelz, R.I.; Schadilov, A. E.

doi:10.1093/rpd/ncx014

Cited by 26 publications

(37 citation statements)

References 14 publications

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“…For example, the particle transport model has been revised (ICRP 2015). Default absorption parameters for UO 2 and U 3 O 8 are now considered intermediate Type M/S (rapid fraction, f r = 0.03; rapid rate, s r = 1 An add-on to IMBA has previously been used to model urinary excretion according to the ICRP 130 recommendations (Birchall et al 2017). This add-on was acquired and used in the present work to model the urinary excretion following inhalation of 1 Bq of 234 U according to the ICRP 130 particle transport model.…”

Section: Internal Dosimetrymentioning

confidence: 99%

Uranium Aerosol Activity Size Distributions at a Nuclear Fuel Fabrication Plant

2020

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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 μm, which is larger than found in previous studies. Certain sampling occasions showed variable isotope ratios ( 234 U/ 238 U) 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 μm (coarse fraction). Quantification of the AMAD of the fine fraction was associated with large uncertainties. Values of 1.7–7.1 μm were obtained. Static sampling at key process steps in the workshops showed AMADs of 4.9–17.2 μm, 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 μSv Bq −1 for 234 U when Type M/S absorption parameters were assumed (5.0 μSv Bq −1 for an AMAD of 5 μm). The corresponding lung equivalent dose coefficient was 3.6–10.7 μSv Bq −1 (29.9 μSv Bq −1 for an AMAD of 5 μm). The predicted urinary excretion level 100 d after inhalation intake was found to be 13-34% of that corresponding to an AMAD of 5 μm. 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.

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Section: Internal Dosimetrymentioning

confidence: 99%

Uranium Aerosol Activity Size Distributions at a Nuclear Fuel Fabrication Plant

2020

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“…From the excretion rates, systemic and organ dosimetry estimates can be obtained from biokinetic and dosimetry models. Such models that have been applied to exposed Russian nuclear workers include the Mayak Worker Dosimetry System-2008 (MWDS-2008) [ 8 ], MWDS-2013 [ 9 ] and MWDS-2016 [ 10 ] models. Prior analyses of data obtained from workers at the Mayak Production Association (Mayak PA), Ozersk, Russia, have demonstrated considerable variability in plutonium excretion rates [ 11 ].…”

Section: Introductionmentioning

confidence: 99%

The effects of chronic diseases on plutonium urinary excretion in former workers of the Mayak Production Association

et al. 2020

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The radiochemical analysis of plutonium activity in urine is the main method for indirect estimation of doses of internal exposure from plutonium incorporation in professional workers. It was previously shown that late-in-life acute diseases, particularly those that affect the liver, can promote accelerated rates of release of plutonium from the liver with enhanced excretion rates. This initial study examines the relationships of some chronic diseases on plutonium excretion as well as the terminal relative distribution of plutonium between the liver and skeleton. Fourteen cases from former workers at the Mayak Production Association (Mayak PA) who provided from 4–9 urine plutonium bioassays for plutonium, had an autopsy conducted after death, and had sufficient clinical records to document their health status were used in this study. Enhanced plutonium excretion was associated with more serious chronic diseases, including cardiovascular diseases and other diseases that involved the liver. These chronic diseases were also associated with relatively less plutonium found in the liver relative to the skeleton determined by analyses conducted after autopsy. These data further document health conditions that affect plutonium biokinetics and organ deposition and retention patterns and suggest that health status should be considered when conducting plutonium bioassays as these may alter subsequent dosimetry and risk models.

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“…Workers employed at the nuclear enterprise Mayak PA and exposed to long-term irradiation turned out to run elevated risks of malignant neoplasms; however, data related to stomach cancer are rather ambiguous [20][21][22]. Up to now, a period of observations performed on Mayak PA workers has been extended considerably and there are new improved techniques for assessing doses of occupational internal alphairradiation [23] and it creates better conditions for refining previously obtained results on influence exerted by ionizing irradiation on stomach cancer risk.…”

mentioning

confidence: 99%

“…Personnel employed at all the basic works of Mayak PA were exposed to general external gamma-irradiation, and those who were employed at radiochemical and plutonium works were additionally exposed to alpha-active aerosols of plutonium-239. In our research we used estimations of occupational irradiation doses calculated on the basis of up-to-date dosimetric systems, "Dosimetric system for Mayak PA workers -2008" for external gamma-irradiation doses and "Dosimetric system for Mayak PA workers -2013" for doses of internal alpha-irradiation caused by incorporated plutonium [23,24].…”

mentioning

confidence: 99%

“…External irradiation has been monitored since PA Mayak started its operations and individual gamma-irradiation doses are known for each worker. Monitoring over internal irradiation has been introduced gradually since the late 1960ties; therefore, internal alpha-irradiation doses are detected for 31% workers exposed to plutonium-239 aerosol at their work places as the activity of this nuclide in their urine has been measured [23,24]. 55% workers in the examined cohort were employed by Mayak PA in 1948-1958 when radiation exposure on personnel was the highest.…”

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confidence: 99%

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Risk of morbidity with stomach cancer among workers employed at radiation-hazardous enterprise

Zhuntova¹,

Григорьева²,

Azizova³

2019

Health Risk Analysis

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We performed retrospective research among a cohort made up of workers employed at "Mayak" Production Association (Mayak PA), a state nuclear enterprise, who had been exposed to long-term external gamma-irradiation and internal alpha-irradiation caused by plutonium-239 under inhalation introduction. Our research goal was to assess impacts exerted by occupational irradiation and non-radiation factors on a risk of morbidity with stomach cancer (SC) in workers employed at Mayak PA.We used individual data on occupational irradiation doses obtained from "Dosimetric system for Mayak PA workers -2008" for external gamma-irradiation, and "Dosimetric system for Mayak PA workers -2013" for internal alpha-irradiation. We applied Poisson regression to calculated odds ratio (OR) for morbidity with stomach cancer among the examined cohort both for radiation and non-radiation factors.We detected statistically significant influence exerted on risk of morbidity with SC among workers employed at Mayak PA by the following factors: age, sex, attitudes towards to smoking and alcohol intake, stomach and duodenum ulcer, and external gamma-irradiation. Taking into account adjustments as per non-radiation factors, we detected a statistically significant increase in OR of morbidity with SC which was equal to 1.48 (95 % CI 1.10; 1.98), when a dose of external gamma-irradiation accumulated in the stomach walls was more than 1.0 Gy. We didn't detect any correlation between risk of morbidity with CS among the examined cohort and internal alpha-irradiation.Given that data obtained in epidemiologic research concerning impacts exerted by occupational irradiation on SC risks are ambiguous, it is necessary to clarify the obtained results and to perform more profound analysis of dose -response relationship among a more extended cohort of workers employed at Mayak PA.

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The Mayak Worker Dosimetry System (Mwds-2013) for Internally Deposited Plutonium: An Overview

Cited by 26 publications

References 14 publications

Uranium Aerosol Activity Size Distributions at a Nuclear Fuel Fabrication Plant

Uranium Aerosol Activity Size Distributions at a Nuclear Fuel Fabrication Plant

The effects of chronic diseases on plutonium urinary excretion in former workers of the Mayak Production Association

Risk of morbidity with stomach cancer among workers employed at radiation-hazardous enterprise

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