Radioactive Aerosols | ScienceGate

Particle size and fuming rate of radioactive aerosols generated during the heat cutting of activated metals

Applied Radiation and Isotopes ◽

10.1016/0969-8043(94)90197-x ◽

1994 ◽

Vol 45 (5) ◽

pp. 553-562 ◽

Cited By ~ 8

Author(s):

Yuichi Oki ◽

Masaharu Numajiri ◽

Takenori Suzuki ◽

Yukio Kanda ◽

Taichi Miura ◽

...

Keyword(s):

Particle Size ◽

Radioactive Aerosols

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The coagulation of radioactive aerosols

Journal of Aerosol Science ◽

10.1016/0021-8502(92)90370-b ◽

1992 ◽

Vol 23 ◽

pp. 145-148 ◽

Cited By ~ 4

Author(s):

C.F. Clement ◽

R.A. Clement ◽

R.G. Harrison

Keyword(s):

Radioactive Aerosols

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Observation of radioactive aerosols in chernobyl after the accident at the fukushima-1 npp

Atomic Energy ◽

10.1007/s10512-012-9543-4 ◽

2012 ◽

Vol 112 (3) ◽

pp. 199-206 ◽

Cited By ~ 2

Author(s):

A. K. Kalynovsky ◽

V. A. Krasnov ◽

B. I. Ogorodnikov ◽

V. N. Shcherbin

Keyword(s):

Radioactive Aerosols

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Radiation-Hygienic Investigations of Experimental Production of Mixed Nitride Uranium-Plutonium Fuel at JSC SChC. Part 1: Methods and Results

Medical Radiology and radiation safety ◽

10.12737/1024-6177-2021-66-5-23-32 ◽

2021 ◽

Vol 66 (5) ◽

pp. 23-32

Author(s):

L. Il'in ◽

A. Samoylov ◽

Aleksandr Tsoviyanov ◽

S. Shinkarev ◽

N. Shandala ◽

...

Keyword(s):

Physicochemical Properties ◽

Radiation Exposure ◽

New Technology ◽

Neutron Radiation ◽

High Reactivity ◽

Radioactive Material ◽

External Exposure ◽

Experimental Production ◽

Radioactive Aerosols ◽

Uranium Plutonium

Purpose: To present the methods and results of studies of the factors of radiation exposure to workers involved in the manufacture of mixed uranium-plutonium nitride (MUPN) fuel at the complex experimental installations CEI-1 and CEI-2 of JSC SChC. Material and Methods: Regularities of the formation of external exposure doses have been revealed based on the study of the dynamics of the ambient dose equivalent rate (ADER) of photon and neutron radiation at the CEI-1 and CEI-2 workplaces, as well as instrumental individual dosimetric control of the equivalent doses to workers. In order to assess the inhalation intake and possible doses from internal irradiation, studies of the physicochemical properties of radioactive aerosols were carried out. Results: It has been found that the main sources of penetrating radiation in the premises of CEI-1 are boxes where tablets are pressed, chips and rejected tablets are crushed, as well as temporary storage of products is occurred. The highest ADER values have been measured in those boxes, where the radiation exposure was due to radioactive contamination caused by past activity, and is not associated with fabrication of MUPN fuel. A significant contribution of neutron exposure to individual doses of workers was measured, which exceeded the contribution of gamma exposure at some workplaces of the CEI-1. At CEI-2, a non-functioning exhaust ventilation pipe passing over the premises was found to be a powerful source of external radiation. This pipe contained a significant amount of radioactive material. Assessment of the contribution of gamma exposure from the ventilation pipe to the external exposure of workers reached 85% at some workplaces. Studies of the physicochemical properties of radioactive aerosols have revealed a high reactivity of MUPN compounds, leading to instant oxidation of the thoracic fraction of MUPN fuel aerosols under contact with air. The complex morphological and dispersed composition of aerosol particles in combination with a complex chemical composition caused by the aging processes of aerosols, can lead to a fundamental difference in the biokinetics of MUPN aerosols, the process of dose formation and, consequently, the degree of radiological hazard compared to those adopted in the ICRP models for U and Pu. The results of the current radiation-hygienic research are of a preliminary nature, since the object of this research is an experimental installation, which was used to develop a new technology for the production of MUPN fuel. The instrumental and methodological approaches to assess the factors of radiation exposure to workers tested at these experimental installations, will be used in the future to conduct similar studies during the pilot industrial operation of new modules for fabricating and refurbishing of MUPN fuel.

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Modification of Filtered Air Intake Flowrate to Improve Control Room Habitability

Volume 7: Decontamination and Decommissioning, Radiation Protection, and Waste Management; Mitigation Strategies for Beyond Design Basis Events ◽

10.1115/icone26-81941 ◽

2018 ◽

Author(s):

Xinjian Liu ◽

Weipeng Shu ◽

Mengxi Wang

Keyword(s):

Extended Period ◽

Leakage Rate ◽

Design Parameters ◽

Source Terms ◽

Control Room ◽

Limit Operator ◽

Radioactive Aerosols ◽

Loss Of Coolant Accident ◽

Operator Dose ◽

Accident Conditions

Control room habitability (CRH) shall be maintained to provide adequate protection for control room operators, such that they can remain in the control room envelope (CRE) safely for an extended period and thus control the nuclear facility during normal and accident conditions. A critical objective of CRH systems is to limit operator doses and/or exposure to toxic gases. The CRH systems does this by the combination of the intake of filtered air, isolation of outside air, recirculation systems and etc. Among the parameters determining radioactivity in a control room (in proportion to radiation doses of operators), intake flowrate of filtered air is an important one. For different types of accident source terms, the evolution of operator doses in a control room versus intake flowrate were analyzed in this paper. It turns out that the increase of intake flowrate results in larger operator doses when inert radioactive gases are the dominant radioactive substances. On the contrary, increasing intake flowrate does good to lower the irradiation level of control room operators when radioactive aerosols dominate the source terms. The rationality behind this fact was interpreted in detail in this paper, with special attention paid to the unfiltered in-leakage rate. It can be inferred that an optimal intake flowrate probably exists leading to the minimum operator dose under an actual accident condition. This paper then performed a calculation analysis based on design parameters and source terms of design basis accident of LOCA (a large break loss of coolant accident) accident. The evolution of operator dose was found to be a U-curve versus increasing intake flowrate, which proved the existence of the abovementioned optimal intake flowrate of filtered air for CRH systems. Furthermore, the sensitivity analysis of intake flowrate was carried out to study the effects of unfiltered in-leakage rate and filtered recirculation. This study indicates that intake flowrate of filtered air can significantly influence the CRH. For different accidents, the intake flowrate should be properly modified rather than set as a fixed value. To optimize the radiological habitability of control rooms, the effects of unfiltered in-leakage must be taken into consideration. Besides, filtered recirculation is an effective way to control radiation exposure caused by iodine and radioactive aerosols.

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Studying the Impact of Radioactive Charging on the Microphysical Evolution and Transport of Radioactive Aerosols with the TOMAS-RC v1 framework

10.5194/gmd-2017-96 ◽

2017 ◽

Cited By ~ 1

Author(s):

Petros Vasilakos ◽

Yong-Ηa Kim ◽

Jeffrey R. Pierce ◽

Sotira Yiacoumi ◽

Costas Tsouris ◽

...

Keyword(s):

Background Radiation ◽

Atmospheric Transport ◽

Long Range Transport ◽

Radioactive Aerosol ◽

Computationally Efficient ◽

Radioactive Aerosols ◽

Model Studies ◽

Aerosol Mass ◽

Range Transport ◽

The Impact

Abstract. Radioactive charging can significantly impact the way radioactive aerosols behave, and as a result their lifetime, but such effects are neglected in predictive model studies of radioactive plumes. The objective of this work is to determine the influence of radioactive charging on the vertical transport of radioactive aerosols in the atmosphere, through its effect on coagulation and deposition, as well as quantifying the impact of this charging on aerosol lifetime. The TwO-Moment Aerosol Sectional (TOMAS) microphysical model was extended to account for radioactive charging effects on coagulation in a computationally efficient way. The expanded model, TOMAS-RC (TOMAS with Radioactive Charging effects), was then used to simulate the microphysical evolution and deposition of radioactive aerosol (containing the isotopes 131I and 137Cs) in a number of idealized atmospheric transport experiments. Results indicate that radioactive charging can facilitate or suppress coagulation of radioactive aerosols, thus influencing the deposition patterns and total amount of radioactive aerosol mass available for long-range transport. Sensitivity simulations to uncertain parameters affirm the potential importance of radioactive charging effects. An important finding is that charging of neutral, coarse mode aerosol from background radiation can reduce coagulation rates and extend its lifetime in the atmosphere by up to a factor of 2.

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