TUE-H - Technical Presentations Part 2 Including: Risk Assessment, Department of Energy Facilities, Emergency Response, Medical, and Radio-biology. Tuesday 10/06/20 2:00 PM - 5:20 PM
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| Chair(s): William Blakely, Mary Sproull
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TUE-H.1
2:00 PM Automated Reactor Primary Coolant Monitor Module for EPRI SMART Chemistry Project FL Bronson*, Mirion Technologies - Canberra
; C Gregorich, Electric Power Research Institute; Fr Bronson
Abstract: Currently, samples of primary coolant at a Nuclear Power Plant are extracted collected manually and analyzed for gamma emitters in the Chemistry laboratory on a HPGe system. This process is time consuming for the staff, creates risk of spills of radioactive fluid, and exposes the staff to radiation fields. Furthermore, potentially useful information from short-lived radionuclides and dynamic activity changes between the discrete sampling periods is lost. The automatic system built as part of the EPRI SMART Chemistry project is comprised of a coolant handling system, a detection system, and a data handling and analysis platform. The coolant handling system automatically monitors flow and temperature, controls the dual sample assay process, controls the filling process for the assay chambers, and controls the process to flush the chambers and to measure background. The detection system is a shielded HPGe detector optimized for high counting rates. There are dual sample chambers that can be alternately exposed to the detector. The unit could be configured to always measure a fresh flowing stream of coolant. Or the unit could be configured to periodically and repeatedly extract a sample, decay it, and count it. Or it can alternate between both modes, normally measuring the flowing fresh coolant stream continuously, but every 24 hours switch to assay a container that has decayed for 24 hours. Another unique aspect of the system is the ability to simultaneously execute parallel analyses with multiple counting times on each sample; short count times to record dynamic changes in activity, in parallel with long count times for lower detection limits. All spectra are immediately analyzed locally by the on-board Mirion Data Analyst module. The data handling system consists of a remote spectral and results display system with a relational data base to store all of the raw data and analyzed data. The presentation will describe the system in more detail and show factory testing results, prior to deployment.
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TUE-H.2
2:15 PM Premature Chromosome Condensation (PCC) Assay with Chromosomal Length Ratio (LR) and Cell-cycle Progression Index (CPI) Analyses R Sebastian, AFRRI/USUHS
; U Subramanian, AFRRI/USUHS; KH Hsiao, AFRRI/USUHS; DL Bolduc, AFRRI/USUHS; WF Blakely*, AFRRI/USUHS
Abstract: The purposes of this investigation were to establish radiation dose-response relationships using the premature chromosome condensation (PCC) assay. Several PCC endpoints were used, including cell-cycle progression index (CPI) (ratio of G2-PCC/G1-PCC), length ratio (LR) (ratio of longest to shortest chromosomes), and fraction of damaged cells based on the LR yields. The latter two endpoints were based on automatic image capture and analysis of LR. Blood samples from healthy human donors were exposed ex vivo to 137Cs gamma rays at ~0.6 Gy/min, samples were cultured for 48-hr with mitogen with calyculin A treatment for last 30 min, spreads were prepared on slides, stained, percentage of G2-PCC and G1-PCC scored, and individual spreads analyzed for LR. This study focused on a novel approach in log transforming LR results to enhance statistical analysis. Blind tests were performed and predicted dose and accuracies were determined using the aforementioned endpoints. In addition, an analytical approach for the determination of partial-body exposure doses and fraction of irradiated cells were established. Results show promising potential of various endpoints and provide a useful application of the PCC assay during mass-casualty triage situations. The views expressed in this abstract are those of the authors and do not necessarily reflect the official policy or position of DoD, AFRRI, USUHS, NDC, nor the U.S. Government. Funding support provided by USUHS (AFR-B4-4313 and AFR-B4-10971).
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TUE-H.3
2:30 PM Ultrasound Analysis of Acute Local Radiation injury RE Goans*, MJW Corporation
; CJ Iddins, REAC/TS
Abstract: Local radiation injury (LRI) is difficult to diagnose early, both in severity and extent, because of the prolonged time interval for the development of clinical signs and symptoms. High frequency ultrasound imaging has been shown to be useful in early detection of subcutaneous pathological changes not visible clinically. Two patients with LRI seen at the Radiation Emergency Assistance Center/Training Site (REAC/TS) will be presented, along with animal studies in a collaborative study at the University of Tennessee College of Veterinary Medicine (UTCVM). Patient S is a 46 year old female industrial radiologist from South Carolina whose left index finger briefly touched a 22 Ci Ir-192 source during a routine change-out procedure. Patient D is a 56 year-old male from Kentucky who developed two large necrotic lesions on his back from prolonged fluoroscopy procedures. Total dose to the lesions was estimated to be 40-50 Gy. In the UTCVM studies, two young Yorkshire pigs were irradiated locally in four 2x2 cm squares, 3 sites for analysis and one control site. Dose to the sites was 10 Gy and 20 Gy, respectively, using 6 MeV electrons from the UTCVM LINAC facility. A 12 MHz linear array ultrasound transducer with online tissue characterization using image and spectral analysis has been found to be useful to visualize the extent, depth, and time dependence of the human and animal radiation-induced lesions. Various algorithms in the National Institutes of Health computer image analysis suite, ImageJ version 1.51i, were evaluated. These include the grayscale distribution function, autocorrelation analysis, and calculation of image entropy. The grayscale distribution function is very sensitive to tissue edema, particularly in the first 5 days after irradiation. However, of these parameters, image entropy or average information content of the image, appears to be a very sensitive parameter to delineate late radiation-induced tissue changes.
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TUE-H.4
2:45 PM Establishing Pseudo Pelger-Huet Anomalies as Biodosimeters in Mammalian Species JM Hayes*, Colorado State University
; RE Goans, MJW Corporation; CJ Iddins, ORAU; JM Cline, Wake Forest School of Medicine; J Olson, Wake Forest School of Medicine; J Davis, ORAU; SM Bailey, Colorado State University; TE Johnson, Colorado State University
Abstract: Nuclear accidents, such as the Fukushima-Daiichi nuclear disaster in 2011, release a plume of radionuclides into the surrounding environment that include Iodine-131, Cesium-134, and Cesium-137. The contaminated environments continue to provide unique research opportunities related to chronic low dose radiation exposure to wildlife, which could serve as surrogates for human inhabitants of the Fukushima Prefecture and clean-up workers. Additionally, acute exposures can be a dangerous occupational hazard associated with handling high-level radioactive materials. Quantitative biomarkers of radiation exposure are being evaluated in chronically exposed free-ranging wild boar (Sus scrofa leucomystax) that inhabit Fukushima, and acutely exposed Rhesus macaques from the Wake Forest University Primate Center. Increased frequencies of abnormal neutrophils in peripheral blood, referred to as pseudo Pelger-Huët anomalies (PPHA), were determined to be present in both exposed wild boar and Rhesus macaques. PPHAs have been shown to be useful biomarkers of radiation exposure in several scenarios, including the 1958 Y-12 criticality accident, the radium watch dial painters, and thorium chronically exposed bats in South Africa. A PPHA dose response curve has been constructed for the wild boar, and biokinetics and dose response curves are currently being constructed utilizing peripheral blood smears for Rhesus macaques. Results have the potential to substantially reduce the cost – both in terms of time and resources – required for biodosimetric analyses in the event of future large-scale accidental or occupational exposures.
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TUE-H.
3:00 PM BREAK
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TUE-H.5
3:10 PM The False Narrative of Trinity JJ Shonka*, SRA
; JJ Shonka
Abstract: For 75 years there has been a narrative accepted by most Health Physicists, politicians and members of the public about the radiation received by downwinders from the Trinity bomb test on July 16, 1945. This narrative asserts that few people, if any, were impacted by the fallout from the Trinity test, and no significant exposure to the fallout occurred as compared to the fallout from other US tests and global fallout from the testing of nuclear weapons. This narrative also asserts that the "Cow-Grass-Milk" pathway dominated downwinder doses, and the worst case dose was much less than the doses received by the survivors of the atomic bombs used at Hiroshima and Nagasaki. A National Research Council of the National Academies, drawing on earlier work by the National Cancer Institute, continued this narrative in a report in 2005 to Congress that is still used by the Congressional Research Service and is accepted today.
A Working Group was formed in preparation for the 75th anniversary events of Trinity this year. The goal was to examine the narrative and determine its validity. If false, additional goals were to determine how and why this false narrative developed, and to begin to correct the longstanding differences between many scientists and downwinders. Working Group members included both scientists and representative downwinders. The process we used tried to express elements of the narrative from both sides of the issue and attempt to reach an agreement on what was false or true by reviewing the relevant literature. We hope to begin to correct, as needed, the long-term narrative. The process we used and success (and lack of success) in bringing divergent narratives together will be summarized. The results show that the widely accepted narrative is a false narrative that has been accepted by members of the Health Physics Society for 75 years.
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TUE-H.6
3:25 PM “Radiation Biodosimetry: A Mass Screening Tool for Radiological/Nuclear Events” M Sproull*, NIH/NCI/ROB
; T Kramp, NIH/NCI/ROB; U Shankavaram, NIH/NCI/ROB; K Camphausen, NIH/NCI/ROB
Abstract: Abstract
Purpose: In the event of a radiological or nuclear attack, advanced clinical countermeasures are needed for screening and medical management of the exposed population. Such a population will represent diverse heterogeneity in physiological response to radiation exposure. The current study seeks to compare the biomarker expression levels of five previously established proteomic biodosimetry biomarkers of radiation exposure including Flt3 Ligand (FL), Matrix metalloproteinase 9 (MMP9), Serum amyloid A (SAA), Pentraxin 3 (PTX3) and Fibrinogen (FGB), across multiple murine strains and to test a multivariate dose prediction model based on a single C57BL6 strain against other murine strains.
Material/Methods: Female mice from five different murine strains including C57BL6, BALB/c, C3H/HeJ, CD2F1, and outbred CD-1 mice were given a single whole body dose of 1-8 Gy
from a Pantak X-ray source at a dose rate of 3.59 Gy/min. Plasma was collected by cardiac puncture at days 1, 2, 3 and 7 post-IR. Plasma protein levels were determined via commercially available ELISA assay.
Results: Significant differences were found between radiation induced expression levels of FL, MMP9, SAA, PTX3 and FGB between the C57BL6, BALB/c, C3H/HeJ, CD2F1, and CD-1 strains (p < .05). The overall trends of dose dependent biomarker elevation however were similar between strains with FL and PTX3 showing the highest degree of correlation. Application of a previous C57BL6 multivariate dose prediction model using additional murine strains showed the limitations of a model based on a single strain and the need for data normalization for variance generated by technical assay variables. Accuracy of the tested dose prediction algorithm also increased with the number of biomarkers used.
Conclusion: Our findings indicate that strain specific differences do exist between expression levels of FL, MMP9, SAA, PTX3 and FGB in C57BL6, BALB/c, C3H/HeJ, CD2F1, and CD-1 murine strains and that use of multiple biomarkers for dose prediction strengthens the predictive accuracy of a model when challenged with a heterogeneous population. Our findings also illustrate the technical and biological variables which challenge translation of biodosimetry dose prediction models for application in the field setting.
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TUE-H.7
3:40 PM Comparative Evaluation (MCNP model and experiment) of Extremity Dose to Veterinarians from Sr-90 Ophthalmic Applicator at Texas A&M University Veterinary Teaching Hospital. L VASUDEVAN*, Texas A&M University
; SS CHIRAYATH, Texas A&M University; DL PHILLIPS, Texas A&M University
Abstract: Beta radiation delivered by Strontium-90 has been used successfully for treatment of small, superficial tumors. Strontium-90 surface applicator has been used in particular for ophthalmic use in veterinary patients. Beta radiation has a limited penetration and provides the required surface dose with a rapid fall-off beneath the surface. Texas A&M University Veterinary Teaching Hospital utilizes the Srontium-90 ophthalmic applicator for treatment of eye plaques/tumors on both small and large animals. The standard applicator utilizes the Sr-90 disc sealed in a welded stainless steel holder. The steel holder is attached to a handle which allows the active head to be rotated through 180 0 and which is fitted with a plastic shield to protect the operator. The Veterinarian who performs the treatment will hold the handle behind the plastic shield to minimize the external radiation exposure to the hands. The veterinarian wears the whole body and extremity (finger) dosimetry badge during therapy. The extremity dose reported from the badges have not been significant. In this study, a Monte Carlo N-Particle (MCNP) model of the Strontium-90 ophthalmic applicator was developed and a complete dose profile around the stainless steel holder and the handle was obtained. Experimental dose measurements were performed using TLD ring badges (Landauer, Inc.) arranged at specific distances on the handle. The dose calculated at different points across the handle from MCNP were compared against the TLD ring badge dosimetry results. Proper handling practices were discussed and implemented to reduce unnecessary radiation exposures to the hands.
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TUE-H.8
3:55 PM Determination of Buildup Factor, Linear Attenuation Coefficient and Half-Value Later of MCP-69 Alloy for Radiation Shielding and Protection M Maqbool, University of Alabama at Birmingham
Abstract: An investigation of the alloy MCP 69 was done using gamma ray sources ranging in energy of 0.662MeV to 1.333MeV for its possible use in radiation shielding and protection within this energy range. Narrow beam geometries were utilized to be able to determine the effective linear attenuation coefficient of MCP alloy. With this value, the mass attenuation coefficient and Half-Value Layer for the material were also determined. The theoretical component of the attenuation coefficient due to Compton interactions was also calculated and compared to the total effective attenuation coefficient as well as the mass attenuation coefficients and the mass energy-transfer coefficient. A broad beam geometry was used to determine the buildup factor of the alloy at these energy levels. It was observed that buildup factor varies with varying energy of gamma rays and thickness of attenuator.
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TUE-H.
4:10 PM BREAK
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TUE-H.9
4:20 PM Applying ALARA Design Principles SI Baker*, Argonne National Lab
; S Kamboj, Argonne National Lab
Abstract: The application of ALARA principles to the design of new radiological facilities at Argonne National Laboratory provides a consistent radiation safety basis for future facility operations. The Department of Energy mandates in 10 CFR 835 the use of a design criterion set at 20% of the applicable dose limits. For locations outside controlled areas this criterion corresponds to 0.2 mSv in a calendar year. In order to comply with this criterion, a set of bounding conditions was established for a new facility, the Materials Design Laboratory (MDL). A radiological facility for actinide research is being moved to the MDL third floor. Worst case radionuclides and their source strengths were determined for this facility. Local shielding was specified to reduce exposure rates to less than 0.05 mSv/hr at 30 cm from the radiation sources. The latest version, MCNP6, of the Los Alamos radiation shielding computer program MCNP was then used to calculate the exposure rates outside of controlled areas, and building materials were modified as necessary to meet the criterion. The results are discussed, including the impacts of penetrations for utilities, requirements for personnel dosimetry, and reduced occupancy. This work was supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11347.
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TUE-H.10
4:35 PM FEMA CBRN RadResponder Network; Transforming Radiological Dispersal Device Incident Response AE Leek*, Iowa Department of Public Health
; B Palmer, Chainbridge Technologies
Abstract: Rapid situational awareness and assessment early in radiation emergency response is critical to ensuring adequate and consistent public and responder protection actions. Significant efforts to enhance rapid protective action recommendations during radiological dispersal device incidents have been made by DHS S&T in the development of the Department of Homeland Security’s RDD Response Guidance; Planning for the First 100 Minutes (2017). This guidance coupled with the whole community data sharing platform provided by the FEMA CBRN RadResponder Network is having a transformative effect on the radiological/nuclear emergency response community by introducing novel solutions to enduring problems early in response. The integration of the DHS RDD response guidance into the RadResponder tool enables federal, state, local and private sector organizations to greatly improve their ability to quickly visualize recommended public and responder protection zones from the established guidance, as well as collect, manage and share real-time radiological data, maintain situational awareness, and establish a common operating picture in multijurisdictional response environments. This presentation will highlight the integration of the Department of Homeland Security’s RDD Response Guidance; Planning for the First 100 Minutes (2017) with the FEMA CBRN Responder Network to demonstrate how responding communities can leverage these resources to effectively respond during the earliest phases of a radiological dispersal device incident. The FEMA CBRN RadResponder is a free tool provided by FEMA allows a cost effect solution for federal, state, local, tribal, and territorial agencies of any size to collect and share data as well as view IMAAC predictions and federal response support products. *This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
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TUE-H.11
4:50 PM Radiation Induced Cancers, a Potential Liability of US Air Carriers JJ Shonka*, SRA
; SS McCoy, Bentley University; JJ Shonka
Abstract: US aircrew are among the highest exposed radiation workers on earth. Excess cancers attributable to the radiation exposure they receive have been observed in aircrew. Despite this, and despite international guidance to the contrary, the US imposes no regulatory requirements on US air carriers to address the radiation exposure of their employees. In lieu of regulations, the Federal Aviation Administration (FAA) issues a non-mandatory Advisory Circular as a training document intended for the aircrew themselves. The FAA also asserts that aircrew will not receive more than 100 millisieverts (mSv) of radiation when averaged over 5 years. The FAA also asserts that this method follows the guidance of the American Conference of Governmental Industrial Hygienists (ACGIH®). However, the ACGIH guidance requires the application of the “As Low As Reasonably Achievable” (ALARA) principle, which dictates that radiation exposure be measured and limited whenever possible. Thus the FAA program includes two requirements, justification and limitation, with no confirmatory measurements and no optimization.
The FAA assertion of 100 mSv averaged over 5 years is based on the most common form of radiation aircrew are subjected to (Galactic Cosmic Radiation (GCR)), and it does not consider other radiation from solar particle events, lightning or other sources of radiation. Since, unlike all other radiation workers in the US, aircrew radiation exposure is not measured, the FAA estimate is not based on measurements, but on the estimates of typical exposure to that one source of radiation by the FAA. These assertions have varied considerably over the years. In contrast, the European Union (EU), United Kingdom (UK), and other countries do regulate the radiation exposure of aircrew in their countries, including a requirement to monitor and control the radiation exposure. They also require enhanced annual medical follow-up if the exposure exceeds 6 mSv in one year. For carriers in the EU and UK, this 6 mSv forms an administrative limit that is followed to avoid the added requirements for exposures in excess of the 6 mSv. The actual limit of radiation for the EU and UK is 20 mSv in any one year, without averaging over 5 years. Because they actively roster their aircrew, this absolute limit is never exceeded. Aircrew expected to receive less than 1 mSv per year have no monitoring requirements, including most commuter or regional air routes.
It may be likely, in the future, that US aircrew will seek compensation for these illnesses and costs associated with these conditions. This study estimates the potential liability of US Air Carriers for radiation induced cancers using the precedent from prior exposed populations and litigation to establish an estimate of compensation. There have been compensation programs established for populations that were exposed to radiation as part of the US development of nuclear weapons, including downwinders from the Nevada Test Site, atomic veterans as well as Department of Energy workers. These programs have created an important precedent for addressing compensation for cancer from radiation exposure, which unlike typical workman’s compensation illnesses, can only be linked to the causes in a probabilistic manner. The compensation typically includes both medical care as well as a cash payment. Other estimates of the potential liability were obtained from consideration of other well-known litigation cases such as asbestos litigation.
The proper accounting under US Generally Accepted Accounting Principles (GAAP) is discussed and the potential financial and accounting implications to the four major US Air Carriers are presented. While the annual recurring cost to airlines may be immaterial to the major carriers, the initial expense associated with these potential lawsuits could significantly impact their financial statements due to the backlog of retirees.
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