Radiation protection of melting of radioactive contaminated metal

An integral component of modern technogenic activities using nuclear energy is the accumulation of radioactively contaminated metals. Solving the issues of recycling or returning these metals to reuse is inextricably linked to ensuring the radiation safety of people and the environment at all stages of the technological cycle using radioactive metal. Possible consequences of the effect of ionizing radiation on the human body are considered, the features of radioactively contaminated metal as a possible source of radiation for production personnel are investigated, as well as the analysis of radiation safety of the utilization of radioactively contaminated metal by its melting using self-deactivation effect. It is noted that an important element of the complex of measures for radiation safety of production personnel is the assessment of the radiation situation, and its main purpose and overall content is indicated. The basic principles of radiation safety are formulated. The choice of rational options for the actions of production personnel in the disposal of radioactive contaminated metal eliminates the exposure of people to radiation levels that exceed standard values. Additional radiation exposure to the environment is also excluded. It is shown that the criterion of radiation safety of a metal is the maximum dose rate of gamma radiation from its surface, which ensures that the limit of the individual annual effective radiation dose is not exceeded. It is reasonable to review the permissible levels of radiation exposure of personnel performing operations with radioactively contaminated metal in accordance with the procedure established by the Ministry of Health of Ukraine. A multistage system for cleaning ventilation emissions from a melting furnace using an electrostatic filter at the last stage, which directly cleans gas aerosol emissions from radionuclides, is proposed. The results of the study can contribute to the return to production of large volumes of radioactively contaminated metal, significantly improve the technical and economic performance of metal production and help to prevent environmental disturbances.

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Comparative Analysis of Approaches to Regulation and Monitoring of Workers for Internal Radiation Exposure

Medical Radiology and radiation safety ◽

10.12737/1024-6177-2021-66-6-102-110 ◽

2021 ◽

Vol 66 (6) ◽

pp. 102-110

Author(s):

A. Molokanov ◽

B. Kukhta ◽

E. Maksimova

Keyword(s):

Radiation Exposure ◽

Effective Dose ◽

Human Body ◽

Radiation Safety ◽

Urine Excretion ◽

Internal Radiation ◽

Dose Limits ◽

Daily Urine ◽

Permissible Levels ◽

Committed Effective Dose

Purpose: Harmonization and improvement of the system for regulating the internal radiation exposure of workers and the basic requirements for ensuring radiation safety with international requirements and recommendations. Material and methods: Issues related to the development of approaches to regulation and monitoring of workers for internal radiation exposure in the process of evolution of the ICRP recommendations and the national radiation safety standards, are considered. The subject of analysis is the standardized values: dose limits for workers and permissible levels as well as directly related methods of monitoring of workers for internal radiation exposure, whose purpose is to determine the degree of compliance with the principles of radiation safety and regulatory requirements, including non-exceeding the basic dose limits and permissible levels. The permissible levels of inhalation intake of insoluble compounds (dioxide) of plutonium-239 are considered as a numerical example. Results: Based on the analysis of approaches to the regulation and monitoring of workers for internal radiation exposure for the period from 1959 to 2019, it is shown that a qualitative change in the approach occurred in the 1990s. It was due to a decrease in the number of standardized values by introducing a single dose limit for all types of exposure: the effective dose E, which takes into account the different sensitivity of organs and tissues for stochastic radiation effects (WT), using the previously accepted concepts of the equivalent dose H and groups of critical organs. From the analysis it follows that the committed effective dose is a linear transformation of the intake, linking these two quantities by the dose coefficient, which does not depend on the time during which the intake occurred, and reflects certain exposure conditions of the radionuclide intake (intake routes, parameters of aerosols and type of radionuclide compounds). It was also shown that the reference value of the function z(t) linking the measured value of activity in an organ (tissue) or in excretion products with the committed effective dose for a reference person, which is introduced for the first time in the publications of the ICRP OIR 2015-2019, makes it possible to standardize the method of measuring the normalized value of the effective dose. Based on the comparison of the predicted values of the lung and daily urine excretion activities following constant chronic inhalation intake of insoluble plutonium compounds at a rate equal annual limit of intake (ALI) during the period of occupational activity 50 years it was shown that the modern biokinetic models give a slightly lower level (on average 2 times) of the lungs exposure compared to the models of the previous generation and a proportionally lower level (on average 1.4 times) of plutonium urine excretion for the standard type of insoluble plutonium compounds S. However, for the specially defined insoluble plutonium compound, PuO2, the level of plutonium urine excretion differs significantly downward (on average 11.5 times) compared to the models of the previous generation. Conclusion: With the practical implementation of new ICRP OIR models, in particular for PuO2 compounds, additional studies should be carried out on the behavior of insoluble industrial plutonium compounds in the human body. Besides, additional possibilities should be used to determine the intake of plutonium by measuring in the human body the radionuclide Am-241, which is the Pu-241 daughter. To determine the plutonium urine excretion, the most sensitive measurement techniques should be used, having a decision threshold about fractions of mBq in a daily urine for S-type compounds and an order of magnitude lower for PuO2 compounds. This may require the development and implementation in monitoring practice the plutonium-DTPA Biokinetic Model.

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Cumulative radiation doses from recurrent PET/CT examinations

British Journal of Radiology ◽

10.1259/bjr.20210388 ◽

2021 ◽

pp. 20210388

Author(s):

Makoto Hosono ◽

Mamoru Takenaka ◽

Hajime Monzen ◽

Mikoto Tamura ◽

Masatoshi Kudo ◽

...

Keyword(s):

Radiation Exposure ◽

Imaging Modality ◽

Tracking System ◽

Radiation Doses ◽

Effective Radiation Dose ◽

Positron Emission ◽

Pet Ct ◽

Tissue Contrast ◽

Key Issues ◽

Effective Radiation

Positron emission tomography (PET)/computed tomography (CT) is an essential imaging modality for the management of various diseases. Increasing numbers of PET/CT examinations are carried out across the world and deliver benefits to patients; however, there are concerns about the cumulative radiation doses from these examinations in patients. Compared to the radiation exposure delivered by CT, there have been few reports on the frequency of patients with a cumulative effective radiation dose of ≥100 mSv from repeated PET/CT examinations. The emerging dose tracking system facilitates surveys on patient cumulative doses by PET/CT because it can easily wrap up exposure doses of PET radiopharmaceuticals and CT. Regardless of the use of a dose tracking system, implementation of justification for PET/CT examinations and utilisation of dose reduction measures are key issues in coping with the cumulative dose in patients. Despite all the advantages of PET/MRI such as eliminating radiation exposure from CT and providing good tissue contrast in MRI, it is expensive and cannot be introduced at every facility; thus, it is still necessary to utilise PET/CT with radiation reduction measures in most clinical situations.

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Management of personnel of fire and rescue garrisons taking into account radiation exposure

Technology of technosphere safety ◽

10.25257/tts.2021.2.92.94-105 ◽

2021 ◽

Vol 92 ◽

pp. 94-105

Author(s):

A. G. Zavorotnyy ◽

Keyword(s):

Mathematical Model ◽

Radiation Dose ◽

Radiation Exposure ◽

The State ◽

Reference Points ◽

Effective Radiation Dose ◽

Risk Of Death ◽

Radiation Accidents ◽

Stochastic Effect ◽

Effective Radiation

Introduction. At present, despite the efforts made by the state, the state of radiation protection does not reach the level at which there is no unacceptable risk of harm to the life or health of people, the environment, the property of individuals and legal entities, state and municipal property on the territory of the Russian Federation in the event of implementation of radiation treats. The readiness of management bodies, forces and means of fire and rescue garrisons to eliminate the consequences of radiation accidents is a very urgent problem. Goals and objectives. The aim of the work is to improve the management of the personnel of fire and rescue garrisons, taking into account the radiation exposure in preparation for liquidation and during the elimination of radiation accidents. Tasks include the creation and justification of a model that allows you to convert the exit risks of the deterministic effects into the risks of stochastic effects. Methods. To create a model for the management of fire and rescue garrisons’ personnel, taking into account the radiation exposure, we used the literature experimental data and used the probabilistic-statistical method and the method of least squares. Results and discussion. The calculated model of management of the fire and rescue garrisons’ personnel, taking into account radiation exposure in preparation for liquidation and in the course of liquidation of radiation accidents, is developed. The probabilistic mathematical model allows us to estimate the exit of stochastic and deterministic effects depending on the effective radiation dose. The excellent convergence of the predicted (calculated) value EAR1 = 0,000607 and the statistical value EAR0 = 0,000724 is due to the fact that the reference points LD10 = 2 Gy , LD50/60 = 4 Gy , LD90 = 6 Gy are based on repeatedly verified statistical data on radiation accidents and deaths of more than 1000 people in radiation accidents [1]. This indicates that the mathematical model adequately reflects the exit of stochastic and deterministic effects observed during the operation of nuclear facilities both in normal mode and in radiation accidents. Conclusions. The probability of exit of stochastic and deterministic effects depending on the radiation dose received by the personnel of fire and rescue garrisons is presented. The threshold of the stochastic effect for humans is in the vicinity of the equivalent dose of 10 mSv for radiation with low linear energy transfer. At the same time, the probability of a stochastic effect is 3 · 10-6 on average after 15 years. This model of radiation exposure management for the personnel of fire and rescue garrisons could be a good tool for the emergency response manager (fire extinguishing manager) during preparation for the elimination and during the elimination of radiation accidents. Keywords: management, personnel, fire and rescue garrison, radiation exposure, effective radiation dose, risk of death

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Four-Year Cumulative Radiation Exposure in Patients Undergoing Computed Tomography Angiography for Suspected Pulmonary Embolism

Radiology Research and Practice ◽

10.1155/2013/482403 ◽

2013 ◽

Vol 2013 ◽

pp. 1-5 ◽

Cited By ~ 5

Author(s):

Edwin A. Takahashi ◽

Hyo-Chun Yoon

Keyword(s):

Pulmonary Embolism ◽

Radiation Dose ◽

Radiation Exposure ◽

Ct Scans ◽

Suspected Pulmonary Embolism ◽

Effective Radiation Dose ◽

Medical Radiation ◽

Medical Radiation Exposure ◽

Effective Radiation ◽

Acute Pe

Purpose.The objective of this study was to determine the estimated effective radiation dose of pulmonary CT angiography (CTA) for suspected pulmonary embolism (PE) contributing to total medical radiation exposure over a 4-year period.Materials and Methods.This investigation retrospectively reviewed 300 patients who presented to the emergency department and received a pulmonary CTA scan for suspected PE. We evaluated these patients' electronic medical record to determine their estimated radiation exposure to CT scans during the following four years. Using DLP toEconversion coefficients, we calculated the cumulative effective radiation dose each subject received.Results.A total of 900 CT scans were reviewed in this study. Pulmonary CTA delivered an average effective radiation dose of 10.7 ± 2.5 mSv and accounted for approximately 65% of subjects' 4-year cumulative medical radiation dose. Only 6.3% of subjects had a positive acute PE according to their radiology report.Conclusion.Pulmonary CTA accounted for the majority of subjects’ medically related effective radiation dose over a 4-year period. With only a minority of subjects having positive findings for acute PE, increased efforts should be made to clinically assess pretest probability before the consideration of imaging.

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Perspective technology of recycling of radioactive contaminated metal based on its melting

Nuclear and Radiation Safety ◽

10.32918/nrs.2018.2(78).07 ◽

2018 ◽

pp. 43-48 ◽

Cited By ~ 1

Author(s):

V. Balakin ◽

V. Mashinistov ◽

A. Koveria

Keyword(s):

Gamma Radiation ◽

Radiation Power ◽

Beta Radiation ◽

Volume Distribution ◽

Effective Radiation Dose ◽

Surface Distribution ◽

Safety Criterion ◽

The Individual ◽

Effective Radiation ◽

Melted Metal

Melting of the radioactively contaminated metal converts it as a source of ionizing radiation from a surface distribution of radionuclides into the source with their volume distribution. From the surface of the melted metal gamma radiation of a part of radionuclides is emitted, which are in its scope. Alpha and beta radiation are absorbed completely in the metal. To obtain a radiation-safe metal it is necessary that the amount of gamma-emitting radionuclides, which are loaded into the furnace together with the charge, did not exceed the established allowable level. The radiation safety criterion of the melted metal is the maximum value of the gamma radiation power from its surface, the established limit of the individual annual effective radiation dose is not exceeded. There is a need for experimental verification of theoretical results was obtained. The use of this technology will allow the return to industrial production of large amounts of accumulated radioactively contaminated metal and creates conditions for the prevention of environmental violations.

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Effective Radiation Dose in a Skeletal Survey Performed for Suspected Child Abuse

The Journal of Pediatrics ◽

10.1016/j.jpeds.2016.01.017 ◽

2016 ◽

Vol 171 ◽

pp. 310-312 ◽

Cited By ~ 15

Author(s):

Rachel P. Berger ◽

Ashok Panigrahy ◽

Shawn Gottschalk ◽

Michael Sheetz

Keyword(s):

Child Abuse ◽

Radiation Dose ◽

Skeletal Survey ◽

Effective Radiation Dose ◽

Effective Radiation

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Simulated Radiation Dose Reduction in Whole-Body CT on a 3rd Generation Dual-Source Scanner: An Intraindividual Comparison

Diagnostics ◽

10.3390/diagnostics11010118 ◽

2021 ◽

Vol 11 (1) ◽

pp. 118

Author(s):

Andreas S. Brendlin ◽

Moritz T. Winkelmann ◽

Phuong Linh Do ◽

Vincent Schwarze ◽

Felix Peisen ◽

...

Keyword(s):

Image Quality ◽

Radiation Dose ◽

Dose Reduction ◽

Whole Body ◽

Reference Standard ◽

Diagnostic Confidence ◽

Effective Radiation Dose ◽

Intraindividual Comparison ◽

Dual Source ◽

Effective Radiation

To evaluate the effect of radiation dose reduction on image quality and diagnostic confidence in contrast-enhanced whole-body computed tomography (WBCT) staging. We randomly selected March 2016 for retrospective inclusion of 18 consecutive patients (14 female, 60 ± 15 years) with clinically indicated WBCT staging on the same 3rd generation dual-source CT. Using low-dose simulations, we created data sets with 100, 80, 60, 40, and 20% of the original radiation dose. Each set was reconstructed using filtered back projection (FBP) and Advanced Modeled Iterative Reconstruction (ADMIRE®, Siemens Healthineers, Forchheim, Germany) strength 1–5, resulting in 540 datasets total. ADMIRE 2 was the reference standard for intraindividual comparison. The effective radiation dose was calculated using commercially available software. For comparison of objective image quality, noise assessments of subcutaneous adipose tissue regions were performed automatically using the software. Three radiologists blinded to the study evaluated image quality and diagnostic confidence independently on an equidistant 5-point Likert scale (1 = poor to 5 = excellent). At 100%, the effective radiation dose in our population was 13.3 ± 9.1 mSv. At 20% radiation dose, it was possible to obtain comparably low noise levels when using ADMIRE 5 (p = 1.000, r = 0.29). We identified ADMIRE 3 at 40% radiation dose (5.3 ± 3.6 mSv) as the lowest achievable radiation dose with image quality and diagnostic confidence equal to our reference standard (p = 1.000, r > 0.4). The inter-rater agreement for this result was almost perfect (ICC ≥ 0.958, 95% CI 0.909–0.983). On a 3rd generation scanner, it is feasible to maintain good subjective image quality, diagnostic confidence, and image noise in single-energy WBCT staging at dose levels as low as 40% of the original dose (5.3 ± 3.6 mSv), when using ADMIRE 3.

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A Call to Define Stereotactic Radiosurgery

Neurosurgery ◽

10.1227/01.neu.0000143613.13759.d4 ◽

2004 ◽

Vol 55 (6) ◽

pp. 1371-1373 ◽

Cited By ~ 18

Author(s):

Bruce E. Pollock ◽

L Dade Lunsford

Keyword(s):

Radiation Therapy ◽

Stereotactic Radiosurgery ◽

Single Session ◽

Short History ◽

Effective Radiation Dose ◽

The Past ◽

Radiation Delivery ◽

History Of ◽

Effective Radiation ◽

And Training

Abstract STEREOTACTIC RADIOSURGERY IS the single-session, precise delivery of a therapeutically effective radiation dose to an imaging-defined target. Conceived and developed during the past 5 decades, stereotactic radiosurgery has involved significant advances, which have improved patient outcomes and made it a critical component of modern neurosurgical practice and training. In this article, a short history of stereotactic surgery and radiosurgery are presented, and radiosurgery is contrasted to radiation therapy. Adherence to accepted, descriptive terms in defining stereotactic radiosurgery and radiation therapy permits a clear distinction among the results of the different radiation delivery techniques for patients, physicians, and other interested parties.

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