The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
James G Yusko - One of the best experts on this subject based on the ideXlab platform.
-
Radioactive Materials in recycled metals an update
Health Physics, 1998Co-Authors: Joel O Lubenau, James G YuskoAbstract:AbstractIn April 1995, Health Physics published a review paper titled “Radioactive Materials in Recycled Metals.” At that time, 35 accidental meltings of Radioactive sources in metal mills were reported, including 22 in the U.S., along with 293 other events in the U.S. where Radioactive Material was
-
Radioactive Materials in recycled metals
Health Physics, 1995Co-Authors: Joel O Lubenau, James G YuskoAbstract:In recent years, the metal recycling industry has become increasingly aware of an unwanted component in metal scrap-Radioactive Material. Worldwide, there have been 35 instances where Radioactive sources were unintentionally smelted in the course of recycling metal scrap. In some cases contaminated metal consumer products were distributed internationally. In at least one case, serious radiation exposures of workers and the public occurred. Radioactive Material appearing in metal scrap includes sources subject to licensing under the Atomic Energy Act and also naturally occurring Radioactive Material. U.S. mills that have smelted a Radioactive source face costs resulting from decontamination, waste disposal, and lost profits that range from 7 to 23 million U.S. dollars for each event. To solve the problem, industry and the government have jointly undertaken initiatives to increase awareness of the problem within the metal recycling industry. Radiation monitoring of recycled metal scrap is being performed increasingly by mills and, to a lesser extent, by scrap processors. The monitoring does not, however, provide 100% protection. Improvements in regulatory oversight by the government could stimulate improved accounting and control of licensed sources. However, additional government effort in this area must be reconciled with competing priorities in radiation safety and budgetary constraints.more » The threat of Radioactive Material in recycled metal scrap will continue for the foreseeable future and, thus, poses regulatory policy challenges for both developed and developing nations.« less
Joel O Lubenau - One of the best experts on this subject based on the ideXlab platform.
-
Radioactive Materials in recycled metals an update
Health Physics, 1998Co-Authors: Joel O Lubenau, James G YuskoAbstract:AbstractIn April 1995, Health Physics published a review paper titled “Radioactive Materials in Recycled Metals.” At that time, 35 accidental meltings of Radioactive sources in metal mills were reported, including 22 in the U.S., along with 293 other events in the U.S. where Radioactive Material was
-
Radioactive Materials in recycled metals
Health Physics, 1995Co-Authors: Joel O Lubenau, James G YuskoAbstract:In recent years, the metal recycling industry has become increasingly aware of an unwanted component in metal scrap-Radioactive Material. Worldwide, there have been 35 instances where Radioactive sources were unintentionally smelted in the course of recycling metal scrap. In some cases contaminated metal consumer products were distributed internationally. In at least one case, serious radiation exposures of workers and the public occurred. Radioactive Material appearing in metal scrap includes sources subject to licensing under the Atomic Energy Act and also naturally occurring Radioactive Material. U.S. mills that have smelted a Radioactive source face costs resulting from decontamination, waste disposal, and lost profits that range from 7 to 23 million U.S. dollars for each event. To solve the problem, industry and the government have jointly undertaken initiatives to increase awareness of the problem within the metal recycling industry. Radiation monitoring of recycled metal scrap is being performed increasingly by mills and, to a lesser extent, by scrap processors. The monitoring does not, however, provide 100% protection. Improvements in regulatory oversight by the government could stimulate improved accounting and control of licensed sources. However, additional government effort in this area must be reconciled with competing priorities in radiation safety and budgetary constraints.more » The threat of Radioactive Material in recycled metal scrap will continue for the foreseeable future and, thus, poses regulatory policy challenges for both developed and developing nations.« less
Eunmi Choi - One of the best experts on this subject based on the ideXlab platform.
-
remote detection of Radioactive Material using high power pulsed electromagnetic radiation
Nature Communications, 2017Co-Authors: Dongho Yu, Ashwini Sawant, Mun Seok Choe, Eunmi ChoiAbstract:Remote detection of Radioactive Materials is impossible when the measurement location is far from the Radioactive source such that the leakage of high-energy photons or electrons from the source cannot be measured. Current technologies are less effective in this respect because they only allow the detection at distances to which the high-energy photons or electrons can reach the detector. Here we demonstrate an experimental method for remote detection of Radioactive Materials by inducing plasma breakdown with the high-power pulsed electromagnetic waves. Measurements of the plasma formation time and its dispersion lead to enhanced detection sensitivity compared to the theoretically predicted one based only on the plasma on and off phenomena. We show that lower power of the incident electromagnetic wave is sufficient for plasma breakdown in atmospheric-pressure air and the elimination of the statistical distribution is possible in the presence of Radioactive Material. Detection of hazardous Radioactive Material far from its source is challenging. Here the authors demonstrate a method with higher sensitivity by utilizing high-power pulsed electromagnetic-wave-induced plasma breakdown, which has potential uses in security and defence.
-
First experimental observation of plasma breakdown for detection of Radioactive Material using a gyrotron in real-time
2017 Eighteenth International Vacuum Electronics Conference (IVEC), 2017Co-Authors: Dongho Yu, Ashwini Sawant, Mun Seok Choe, Eunmi ChoiAbstract:A gaseous plasma avalanche phenomenon is one of candidates to discover a radioactivity in long-distance. A minimum lag time composed of mainly formative delay time and statistical delay time is essential to initiate the plasma volume discharge. Based on the delay time distribution, the existence of Radioactive Material is determined. In this paper, we present experimental results on the reduced delay time with Radioactive source.
-
Real-time, remote detection of Radioactive Material using a high-power millimeter/THz wave vacuum device
2017 47th European Microwave Conference (EuMC), 2017Co-Authors: Dongho Yu, Ashwini Sawant, Mun Seok Choe, Eunmi ChoiAbstract:We present the first experimental demonstration of the remote-detection of a concealed Radioactive Material using a high-power millimetre-wave vacuum device, a gyrotron. A 95 GHz, 30 kW pulsed gyrotron was used for detecting a 0.64 mCi 60Co Radioactive Material via plasma breakdown. We observed the obvious difference in the measured plasma formation delay time in the presence of Radioactive Material compared to without the Radioactive Material. The plasma breakdown threshold electric field was measured with the Radioactive Material and compared to without it. The presented experimental results support a strong detection capability of the concealed Radioactive Material using the invisible electromagnetic wave source, a highpower vacuum device.
Dongho Yu - One of the best experts on this subject based on the ideXlab platform.
-
remote detection of Radioactive Material using high power pulsed electromagnetic radiation
Nature Communications, 2017Co-Authors: Dongho Yu, Ashwini Sawant, Mun Seok Choe, Eunmi ChoiAbstract:Remote detection of Radioactive Materials is impossible when the measurement location is far from the Radioactive source such that the leakage of high-energy photons or electrons from the source cannot be measured. Current technologies are less effective in this respect because they only allow the detection at distances to which the high-energy photons or electrons can reach the detector. Here we demonstrate an experimental method for remote detection of Radioactive Materials by inducing plasma breakdown with the high-power pulsed electromagnetic waves. Measurements of the plasma formation time and its dispersion lead to enhanced detection sensitivity compared to the theoretically predicted one based only on the plasma on and off phenomena. We show that lower power of the incident electromagnetic wave is sufficient for plasma breakdown in atmospheric-pressure air and the elimination of the statistical distribution is possible in the presence of Radioactive Material. Detection of hazardous Radioactive Material far from its source is challenging. Here the authors demonstrate a method with higher sensitivity by utilizing high-power pulsed electromagnetic-wave-induced plasma breakdown, which has potential uses in security and defence.
-
First experimental observation of plasma breakdown for detection of Radioactive Material using a gyrotron in real-time
2017 Eighteenth International Vacuum Electronics Conference (IVEC), 2017Co-Authors: Dongho Yu, Ashwini Sawant, Mun Seok Choe, Eunmi ChoiAbstract:A gaseous plasma avalanche phenomenon is one of candidates to discover a radioactivity in long-distance. A minimum lag time composed of mainly formative delay time and statistical delay time is essential to initiate the plasma volume discharge. Based on the delay time distribution, the existence of Radioactive Material is determined. In this paper, we present experimental results on the reduced delay time with Radioactive source.
-
Real-time, remote detection of Radioactive Material using a high-power millimeter/THz wave vacuum device
2017 47th European Microwave Conference (EuMC), 2017Co-Authors: Dongho Yu, Ashwini Sawant, Mun Seok Choe, Eunmi ChoiAbstract:We present the first experimental demonstration of the remote-detection of a concealed Radioactive Material using a high-power millimetre-wave vacuum device, a gyrotron. A 95 GHz, 30 kW pulsed gyrotron was used for detecting a 0.64 mCi 60Co Radioactive Material via plasma breakdown. We observed the obvious difference in the measured plasma formation delay time in the presence of Radioactive Material compared to without the Radioactive Material. The plasma breakdown threshold electric field was measured with the Radioactive Material and compared to without it. The presented experimental results support a strong detection capability of the concealed Radioactive Material using the invisible electromagnetic wave source, a highpower vacuum device.
J J Cheng - One of the best experts on this subject based on the ideXlab platform.
-
data collection handbook to support modeling impacts of Radioactive Material in soil and building structures
2015Co-Authors: C Yu, S Kamboj, Cheng Wang, J J ChengAbstract:This handbook is an update of the 1993 version of the Data Collection Handbook and the Radionuclide Transfer Factors Report to support modeling the impact of Radioactive Material in soil. Many new parameters have been added to the RESRAD Family of Codes, and new measurement methodologies are available. A detailed review of available parameter databases was conducted in preparation of this new handbook. This handbook is a companion document to the user manuals when using the RESRAD (onsite) and RESRAD-OFFSITE code. It can also be used for RESRAD-BUILD code because some of the building-related parameters are included in this handbook. The RESRAD (onsite) has been developed for implementing U.S. Department of Energy Residual Radioactive Material Guidelines. Hydrogeological, meteorological, geochemical, geometrical (size, area, depth), crops and livestock, human intake, source characteristic, and building characteristic parameters are used in the RESRAD (onsite) code. The RESRAD-OFFSITE code is an extension of the RESRAD (onsite) code and can also model the transport of radionuclides to locations outside the footprint of the primary contamination. This handbook discusses parameter definitions, typical ranges, variations, and measurement methodologies. It also provides references for sources of additional information. Although this handbook was developed primarily to support the application ofmore » RESRAD Family of Codes, the discussions and values are valid for use of other pathway analysis models and codes.« less
-
manual for implementing residual Radioactive Material guidelines using resrad version 5 0
1993Co-Authors: C Yu, A J Zielen, J J ChengAbstract:This manual presents information for implementing US Department of Energy (DOE) guidelines for residual Radioactive Material. It describes the analysis and models used to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil and the design and use of the RESRAD computer code for calculating doses, risks, and guideline values. It also describes procedures for implementing DOE policy for reducing residual radioactivity to levels that are as low as reasonably achievable. Two new pathways, radon inhalation and soil ingestion, have been added to RESRAD. Twenty-seven new radionuclides have also been added, and the cutoff half-life for associated radionuclides has been reduced to six months. Other major improvements to the RESRAD code include the ability to run sensitivity analyses, the addition of graphical output, user-specified dose factors, updated databases, an improved groundwater transport model, optional input of a groundwater concentration and a solubility constant, special models for tritium and carbon-14, calculation of cancer incidence risk, and the use of a mouse with menus.
-
data collection handbook to support modeling the impacts of Radioactive Material in soil
1993Co-Authors: C Yu, J J Cheng, L G Jones, Y Y Wang, E Faillace, C Loureiro, Y P ChiaAbstract:A pathway analysis computer code called RESRAD has been developed for implementing US Department of Energy Residual Radioactive Material Guidelines. Hydrogeological, meteorological, geochemical, geometrical (size, area, depth), and Material-related (soil, concrete) parameters are used in the RESRAD code. This handbook discusses parameter definitions, typical ranges, variations, measurement methodologies, and input screen locations. Although this handbook was developed primarily to support the application of RESRAD, the discussions and values are valid for other model applications.
