TAM-D.1 - Waste Management Woodrow Wilson D 08:00 - 08:45
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| Chair(s): Mike Stewart
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TAM-D.1.1
08:00 DOE Radiation Protection of the Public and the Environment: Recent Guidance Documents HM Stewart*, Department of Energy
Abstract: The Atomic Energy Act of 1974 gives the U.S. Department of Energy (DOE), the authority to self-regulate the management of radioactive waste generated by DOE. DOE manages radioactive waste under DOE Order (O) 435.1 Chg. 2, Radioactive Waste Management, 2021. During operations and disposal of radioactive waste activities within the DOE complex, DOE O 435.1, invokes DOE O 458.1, Chg. 4, Radiation Protection of the Public and the Environment, 2020. DOE O 458.1 provides the policies and regulation required to protect the public and the environment during DOE activities. This session will discuss recently published Standards (STD) that support DOE O 458.1. The documents include recently published DOE STD XXXX-2023, Implementing Release and Clearance of Property Requirements, which provides guidance consistent with requirements for Department and contractor personnel who must determine the disposition of property. This update includes recently issued pre-approved authorized limits for volumetric radioactivity in material based upon ANSI/HPS N13.12-2013, Surface and Volume Radioactivity Standards for Clearance. DOE recently reaffirmed two Handbooks (HDBK) with administrative changes for reference updates: DOE HDBK-1215-2014, Chg. 1, Optimizing Radiation Protection of the Public and the Environment for use with DOE O 458.1, ALARA Requirements and DOE HDBK-1216-2015, Chg. 1, Environmental Radiological Effluent Monitoring and Environmental Surveillance.
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TAM-D.1.2
08:15 Exploring Radiation Effects on Extraction Chromatographic Materials RB Borhan*, University of Massachusetts Lowell, Massachusetts
; ER Bertelsen, University of Massachusetts Lowell, Massachusetts
Abstract: The recovery of target nuclides from nuclear waste streams provides an avenue for increasing the inventory of valuable radionuclides for industrial use. Extraction chromatography, a subset of liquid–liquid chromatography, is a separation technique in which an extractant is physically adsorbed on porous solid support that may offer high-purity separation. Extraction chromatography support materials used for the separation of value radionuclides from nuclear waste streams must be able to withstand the high radiation environments of the waste stream matrix. In this work, two chromatographic supports, diatomaceous earth, and carbon-coated diatomaceous earth were functionalized with bis-(2-Ethylhexyl) phosphoric acid (HDEHP) and examined for their radiation stability. The partitioning of europium was evaluated after the supports were exposed to the Co-60 gamma source at increasing absorbed doses, preceding and following extractant physisorption. Using scanning electron microscopy (SEM), it was observed that there were no significant changes to the particle morphology for either support material. Both the diatomaceous earth and carbon-coated diatomaceous earth exhibited similar europium distribution profiles—before and after irradiation—indicating that both materials remain robust up to 2,500 kGy.
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TAM-D.1.3
08:30 Regulatory Approach for discharge of liquid radioactive effluents. MM Majali*, Federal Authority for Nuclear Regulation
; BS Al Ameri, Federal Authority for Nuclear Regulation; Mu Majali
Abstract: The criteria and options for the selection of appropriate technology for either discharge of liquid radioactive effluents into the sewer system directly or concentrate and store for decay is a very important regulatory decision due to the exposure raised and costs involved and the potential complexity of technical and environmental considerations.
The “delay- stored” and “dilute- disperse” approaches have been investigated. The production source term (P) was used by assuming that the production is constant and continuous over time. The buildup activity (A(T)) during a period (T) will depend on the total removal rate (K) which is equal to the physical decay rate and any other removal factor if any. In this case, the buildup activity would be increased up to a certain value and reach equilibrium while the activity concentration is most likely to remain the same if not combined with an additional dilution, and would be substantially decreased when the dilute and disperse approach is applied. The decrease in the activity concentration depends on the dilution volume and hence decreasing in the occupational exposure in the facility. Usually, a large amount of diluted volume is available for direct discharge due to mixing it with other liquid effluent or water streams. By the time the effluent reaches the environment, concentrations of the radionuclides would be reduced to acceptable release levels.
The presented production source term model can be used effectively for estimating and evaluating the impact of the liquid radioactive effluents discharged into the sewage system either directly by examining the adequacy of the sewage system. In addition, it can also demonstrate that the concentrate and store approach can increase unnecessary occupational exposures and potential of contamination after delay and store to involved staff and workers without producing any net benefit, in addition to the cost involved. Furthermore, provides the regulatory discussion maker with a straightforward method to ensure that the selected option will be identical to the exemption criteria, the radiation risk is sufficiently low as not to warrant any further control, inherently safe, and has no regulatory concern with no appreciable likelihood of scenarios that could lead to a failure to meet both no concern and no regulatory control.
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