WPM-E2 - Air Montioring Orange B 16:15 - 17:15
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| Chair(s): Matthew Barnett, Dave Fuehne
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WPM-E2.1
16:15 Visualization Of Radioiodine Distribution In Silver Zeolite Cartridges With Gamma-Ray Imaging DJ DiMarco*, Louisiana State University
; KL Matthews, Louisiana State University; WH Wang, Louisiana State University
Abstract: Radioactive iodine is a major fission product from nuclear reactors and has significant implications for human health and the environment. Iodine-131 is of particular concern because it is a beta emitter with an 8.02-day half-life and a high fission yield, resulting in potentially large exposures to the thyroid. Due to its potential adverse health effects on humans, air sampling following an unplanned release from a nuclear power plant is a necessary step of emergency management. This sampling is done in the field by drawing a known volume of air through a cartridge packed with silver zeolite as the adsorbing media, which is well known to retain gaseous iodine but not noble gases. These cartridges are taken from the field and then counted typically by placing a detector on the top face of the cartridge. Current calibration techniques do not account for the spatial distribution of gaseous iodine within the cartridge. This practice can lead to inaccurate measurements of gaseous radioiodine concentration. Gamma-ray imaging potentially is a method for visualizing the I-131 distribution. Here we report an evaluation of the suitability of a gamma-ray imaging system for visualizing the distribution of I-131. Both planar imaging and single-photon emission computed tomography (SPECT) were assessed. The low level of activity that can be collected in an air sampling cartridge substantially limits the achievable image quality.
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WPM-E2.2
16:30 Operational Health Physics Challenges: From Discovery to Recovery of a Leaking Transuranic Glovebox at Idaho National Laboratory’s Materials and Fuels Complex RL Case*, Idaho National Laboratory
; K Konzen, Idaho National Laboratory; CS Brower, Idaho National Laboratory; TA Hyde, Idaho National Laboratory; JD Johnston, Idaho National Laboratory; JJ Lopez, Idaho National Laboratory; CD Morgan, Idaho National Laboratory; PL Nelson, Idaho National Laboratory; BJ Schrader, Idaho National Laboratory
Abstract: This presentation describes the fifteen months spent recovering the Advanced Fuel Cycle Initiative Glovebox after retrospective air sample analysis identified the presence of Am-241 in August of 2014. The event received local and national media attention and nine people received internal dose. A multidisciplinary effort developed a testing and recovery plan to identify and correct the source of the leak. Lengthy investigation into the how the releases occurred under normal working conditions where all glovebox and radiological monitoring systems were fully operational was conducted. The radiological air monitoring that was being performed by continuous air monitors (CAM) did not result in any alarms during any work evolution even though there was enough airborne activity to trigger an alarm. CAM data reconstruction was performed to identify why the alarms did not trigger and helped to identify the times and magnitudes of the releases. As a result, CAM configuration was optimized for better monitoring capabilities, and a new helium leak testing method was developed.
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WPM-E2.3
16:45 Military and American National Standards Institute Testing of a Tritium In Air Monitor AJ Ramey*, Ludlum Measurements Inc.
Abstract: Contractual requirements of a purchase of tritium in air monitors from Ludlum Measurements in 2017 specified a large amount of rigorous military standard testing as well as radiological testing. Much of the radiological testing was performed following the requirements of ANSI N42.30. A concise description of the various tests, including MIL-STD-810G, MIL-STD-461G, MIL-STD-901D, MIL-STD-1399, and others is given. The tests include vibration, shock, RF/EMI, temperature, humidity, salt fog, transportation, durability, and blowing rain tests. All testing required traceability to national standards. Purchasing decisions were made involving test equipment, or whether outside testing was the preferred route. Details of the acquired equipment is given. Preparations for these tests are described, as well as problems that occurred during the testing. A discussion of the results and some lessons learned is given. Some of the topics covered are military standard compliant test equipment, test fixtures, data collection, and design aspects affected by testing. A timeline of the testing regime is also given, as well as testing hours required for each type of test.
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WPM-E2.4
17:00 Investigation of the Airborne Release Fraction During Rapid Oxidation of Depleted Uranium Metal PB Bragg*, Idaho National Laboratory
Abstract: The Idaho National Laboratory (INL) performs research and development activities for the Department of Energy (DOE). Some research is to investigate new and alternative manufacturing methods for nuclear fuel fabrication. In doing so, metal-based (uranium) fuel fabrication techniques are investigated, where an inherent hazard is the pyrophoricity of uranium metal. Therefore, a desire exists to understand the airborne release fraction under the conditions of ignition (rapid oxidation), extinguishing and clean-up. To investigate the airborne release fraction an experiment was designed in which 11 air samples were collected during six separate oxidation evolutions for various depleted uranium (DU) masses, geometries and application methods of an extinguishing agent. The null hypothesis for DU oxidation with and without the application of extinguishing media assumes the highest airborne release fraction occurs during the oxidation process. The null hypothesis for the application method of the extinguishing media assumes the application method directly affects the airborne release fraction. For each oxidation evolution (with or without extinguishing media application) an air sample was collected. One sample during the oxidation process and one sample during clean-up and set-up for the next evolution giving two air samples per oxidation evolution. Health physics technicians (HPTs) ensured all experimental equipment was returned to a radiologically clean status before continuing to the next evolution to reduce the potential of cross contamination. On the fourth evolution only one air sample was collected due to a very rapid extinguishing of the oxidation process. Field counts performed at the completion of the experiment demonstrated a definite change in the airborne release fraction dependent on if extinguishing media was applied and the method of application. Comparison of the alpha activity per air sample for oxidation evolutions in which no extinguishing media was used requires rejection of the null hypothesis. Comparison of the alpha activity per air sample for oxidation evolutions in which extinguishing media was applied requires accepting the null hypothesis. Finally comparison of the alpha activity per air sample for the application method of extinguishing media requires acceptance of the null hypothesis.
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