2020 Health Physics Society Midyear Meeting & ExhibitionTAM-B
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| Chair(s): Michael Lewandowski, Edward Tupin |
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TAM-B.1 10:00 A Health Physics Perspective on Prevention Through Design - Modernization of a World-Class Radiation Physics Facility. Mejias Manuel*, NIST nukemanny@gmail.com
An overview of the health physics considerations in the design of new facilities which include radioactive material laboratories, industrial/research x-ray devices, and health physics support areas. The presentation will include a discussion of hazards elimination and/or mitigation during the design phase of a new facility and the renovation of an existing facility. Topics will include shielding design, travel paths between laboratories, personnel contamination check points, and liquid and gaseous effluent monitoring design. Lessons learned from the Modernization of the Radiation Physics building at NIST will be discussed. |
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TAM-B.2 10:15 The Value Of A Health Physicist To Industrial Radiation Safety. Lewandowski Michael A.*, 3M mike.lew.chp@gmail.com
Ionizing radiation emitting devices are widely used at industrial facilities. Radiation safety activities are performed by individuals who do not identify themselves as health physicists. Under what circumstances is this acceptable? When is having a health physicist responsible for radiation safety the better alternative? These questions will be explored during this presentation with recommendations given for specific situations in a subset of industrial facilities where radioactive material and radiation generating machines are used to develop or manufacture consumer or industrial products. Excluded from consideration are electric power generation and manufacture and distribution of medical imaging machines. |
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TAM-B.3 10:30 Exemption from 10 CFR 71.5 for Relocation of a Radioactive Material Quantity of Concern. Rubin Wendy M*, National Institutes of Health wendy.rubin@nih.gov
The National Institutes of Health (NIH) received an exemption from the requirements in 10 CFR 71.5 to transport a self-shielded irradiator across a public road. The NIH utilized the allowance in 49 CFR 171.1(d)(5) for moving a self-shielded irradiator by a government employee solely for noncommercial purposes without conforming to DOT requirements. The request was made due to the circumstances of the very short distance involved, the uncertain availability of a Type B transport container, and the anticipated significant cost of a transport container should one be available. There was also a security concern since there was not a Type B container available that could hold the specific model of irradiator with the in-device delay hardening in place. The in-device delay hardening would have to be removed before the irradiator could fit in an existing Type B container, which would make the source more vulnerable to theft and increase the risk for potential radiation exposure. Furthermore, the NIH was in the unique position of being able to meet the conditions of 49 CFR 171.1(d)(5), since NIH is a federal facility. Nonetheless, significant challenges were faced and dealt with. |
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TAM-B.4 10:45 The N.S. Savannah from Crown Jewel of the Atoms for Peace Program to Decommissioning Project. Tupin Edward A*, Consultant etupin@yahoo.com
The NS (for Nuclear Ship) was the first and so far only nuclear powered ship to sail in the U.S. Merchant fleet. Nuclear powered vessels have long been a staple fo the U.S. Navy. Shortly after the USS Nautilus, the first nuclear powered submarine, entered service in the Navy, the NS Savannah was designed and built. She was powered by a single pressurized water nuclear reactor that produced steam for the steam turbine that drove her by a single propeller. She was in service in the US Merchant fleet from 1962 to 1971, when she was defueled. Her nuclear reactors were made permanently inoperable in1975. The Nuclear Regulatory Commission (NRC) Operating License was converted to a possession only license for the residual radioactivity. The career of the Savannah was shortened by several unforeseen events. She was built as a combination cargo and passenger ship. Cargo shifted from break bulk to containerized. Because of the configuration of the Savannah, she was not able to handle containers. Shortly after her launch, Boeing debuted the 707 jet which greatly shortened transoceanic flight.For the past several years, the N.S. Savannah has been in Baltimore Harbor, at the Canton Marine Terminal, where many projects related to decommissioning have been accomplished. One of these was cutting an access door into the side of containment through the reactor crash protection shield. This past fall, she was relocated to Philadelphia and put into dry dock. The goal of the project is to reduce the residual radioactivity so the ship can be free released and the NRC license can be terminated. |
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TAM-B.5 11:00 Integrated Model for Internal Radiation Field in an LEO Vehicle. Zimmerman Charles A*, Louisiana State University; Chancellor Jeffery C, University of Texas Medical Branch; Zimmerman Charles charlesazimmerman@hotmail.com
The historical method of choice for manned low-Earth orbit (LEO) spaceflight missions typically uses orbital inclinations less than approximately 56 degrees. This takes advantage of the geomagnetic field’s innate shielding from the radiation hazards of space flight. Higher inclination polar orbital paths (e.g. ~90 degrees) can be more desirable for future commercial and manned military space flights. These orbital profiles result in a greater degree of radiation exposure and will require a clear understanding of the crew’s expected dose. It is currently feasible, though inconvenient, to model the internal radiation field of a particular space vehicle following a polar LEO orbit. Here we present an integrated method that utilizes high performance computer systems (e.g. supercomputers), 3D Monte Carlo particle transport and advanced numerical methods to determine the intravehicular radiation environment for any vehicle shielding configuration and mission orbit profile. This will facilitate a method for rapid and accurate health risk assessment for any vehicle along any orbital path in LEO. |
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TAM-B.6 11:15 Neutrons in Internal Dosimetry: Is Spontaneous Fission All There Is? Hertel Nolan E.*, Georgia Tech and ORNL Center for Radiation Protection Knolwedge; Samuels Caleigh, ORNL Center for Radiation Protection Knowledge; Eckerman Keith , ORNL Center for Radiation Protection Knowledge; Hertel Nolan, ORNL Center for Radiation Protection Knowledge nolan.hertel@me.gatech.edu
International Commission on Radiological Protection (ICRP) Publication 133 provides specific absorbed fractions (SAFs) for spontaneous fission neutrons. This is in keeping with the ICRP formalism that SAFs are only produced for radiations emitted directly in the decay of radionuclides. However, there are alpha-emitting radionuclides which could potentially lead to higher levels of neutron doses outside the source organ due to (alpha,n) neutron emission. The generation of (alpha,n) neutron sources also could occur in radionuclides that decay solely by alpha emission. According to ICRP formalism, the dose due to those neutrons would technically be included in the SAF value for alpha particle emission. As a first level attempt at trying to assess the order of magnitude of this impact, the authors have performed SOURCES-4C computations of neutron emission for Am-241, Pu-238, Pu-239 and Pu-240 placed in bone, liver and lung material elemental compositions taken from ICRP Publication 110. For this initial study, only the activity of the parent radionuclide was considered and not their progeny. The number of neutrons emitted per cm3 of the source organ/tissue were computed with the code assuming equal activity concentrations, Bq/cm3. Future calculations will be performed to compute the energy deposition magnitudes in other organs and include any alpha decay by the progeny. As an example of the comparison of (alpha,n) neutrons produced per cm3 in the source organ to the number of neutrons emitted in spontaneous fission, there are 14-15 times more (alpha,n) neutrons emitted in these organs for Pu-238 than by spontaneous fission. By contrast Pu-40 which has a “large” spontaneous fission emission probability, produces about 0.3-0.4 (alpha,n) neutrons per spontaneous fission neutron. The presentation will further discuss whether this phenomenon is an interesting physics study or whether it needs to be included in internal dosimetry studies. |
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TAM-B.7 11:30 Challenges associated with the management of radiologically-contaminated wounds. Davis Jason E*, ORAU; Davila Anthony, LSU jason.davis@orau.org
Radiologically-contaminated wounds are relatively rare events, which limits the number of healthcare and health physics professionals with experience in handling these cases. General principles and biokinetic models are available through NCRP and ICRP publications, which provide a basic framework for response, but lack details sought by operational health physicists and medical professionals in dealing with specific cases. Practical aspects of evaluating the extent of contamination, determining appropriate therapeutic actions based on extent and type of contamination, follow-up monitoring, evaluation of therapy effectiveness, and the equivalent or effective dose associated with the wound are currently being researched. The foci of this presentation are the difficulty in determining the precise location of contamination in a wound, and the dosimetric complications of such wounds. |
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TAM-B.8 11:45 Status of the Science Support Committee. Krieger Kenneth*, Science support Committee kvkrieger@netzero.net
The Science Support Committee has the responsibility to provide material and equipment to chapters that want to hold a science teachers workshop. we also have a science workshop kit that can be used. but in the past it has been difficult to get materials and equipment for workshops. purpose of this presentation to bring visibility to the committee and tell all what services are available through the committee. |