IRPA 16 - 2024 Meeting

PROFESSIONAL ENRICHMENT PROGRAM (PEP)

AAHP is evaluating the number of Continuing Education Credits awarded for each of the PEP (and CEL) courses based on technical content. Course instructors will be able to provide this information at the time of the presentation. This information will also be made available on the AAHP recertification site after data entry is completed.

All PEPs cost $105 each to attend. PEPs are only available in-person this year and will not be recorded.

Sunday, July 7, 8:00am – 10:00am

PEP 1-A: Case Studies in “Radiation Deception”: Practical Strategies for Avoiding Fraud Based on Lessons Learned

Robert Emery

The radiation protection profession has periodically experienced instances of purposeful deception practices that remained undetected for some period of time; upon discovery, the cases revealed gaps in confirmation or validation practices that the radiation protection community should note. This Professional Enrichment Program (PEP) presents summaries of actual “radiation deception” cases along with the process vulnerabilities they exploited. Recommended process improvements that the radiation safety community can consider will be discussed; ample time will be provided for discussion with the overall intent of improving the collective fidelity of radiation protection processes. e radiation protection profession has periodically experienced instances of purposeful deception practices that remained undetected for some period of time; upon discovery, the cases revealed gaps in confirmation or validation practices that the radiation protection community should note.

This Professional Enrichment Program (PEP) presents summaries of actual “radiation deception” cases along with the process vulnerabilities they exploited.

Recommended process improvements that the radiation safety community can consider will be discussed; ample time will be provided for discussion with the overall intent of improving the collective fidelity of radiation protection processes. The radiation protection profession has periodically experienced instances of purposeful deception practices that remained undetected for some period of time; upon discovery, the cases revealed gaps in confirmation or validation practices that the radiation protection community should note.

This Professional Enrichment Program (PEP) presents summaries of actual “radiation deception” cases along with the process vulnerabilities they exploited.

PEP 1-B: Becoming a science communicator in social media

Robert Hayes

The presenter (an associate professor of nuclear engineering and CHP) has been serving as a science communicator for many years doing public videos for TikTok with a focus on nuclear science and technology. Here he feilds at least 3 to 10 technical questions per day from the public with most questions focusing on radiological risk. The difficulties with developing a social media outreach following will be discussed from the lessons learned through generating a social media channel (TikTok) with over 100k followers having over 1M likes (https://www.tiktok.com/@nuclearsciencelover). Tips and ideas for easy but meaningful social media creation will be presented with the session ending with a practical skills application where attendees will be invited to make their own social media content to carry out public comminaction on technical issues under the direction and guidance of the presenter.

PEP 1-C: Experiences with Dental Cone Beam CTs, Thoughts after 10 years Since their Introduction

Carl Tarantino

While it’s been over ten years since the widespread use of Cone Beam Computer Tomography (CBCT) imaging systems was introduced in medical/dental officeComs, many questions remain on the pertinent oversight of these systems. This CEL focuses on some of the significant issues that should be addressed to ensure adequate radiation protection is provided to workers and the general public. The following points will be discussed: 1) Use of Dose Area Product (DAP) and how challenges with device shutters impact the DAP delivered to the patient and the quality of the image; 2) Cracking of plastic covers due to aggressive cleaning and radiative damage to plastic; 3) Inconsistent regulatory enforcement between states; 4) Shielding challenges, due to energies up to 120 kVp. This can cause the need to install at least 1/16th of an inch of lead, or interlocks on doors depending on the State regulations; and 5) Protective measures to staff because of the higher amounts of scatter radiation.

PEP 1-D: Evaluating Hazards When Using Or Processing Radionuclides

John Bliss

Identifying potential and explicit hazards is an important step in performing work safely and is vital for working with radionuclides. Several surrogates for rating radionuclide hazard are used in a variety of operational domains leading to a poor understanding of the actual hazard and, at times, poor selection of controls. In addition to the explicit hazards associated with radioactive material, radioactive decay and physical or chemical processing can introduce significant new hazards. As implementation of the “as low as reasonably achievable” (ALARA) process requires a full understanding of hazards and their magnitude, several measures of radionuclide hazard will be discussed and examples of processes that introduce new hazards will be discussed. Application to evaluating radionuclide hazards during an emergency will be introduced. (LA-UR-24-20321)

PEP 1-E: New Pixelated CZT 3D Detection Systems for Applications in Nuclear Power Plants & Medical Imaging Technology

David Miller

The health physics presentation discusses HP technology applications of pixelated, 3D CZT for nuclear plants isotopic mapping, medical 3D imaging, homeland security surveillance, and decommissioning site isotopic characterization. The pixelated, 3D, CZT detection system provides GPS location and digital camera color-coding of individual isotopic identification for the radiation protection manager to excel in characterizing the aging plant radiological environment.

The state-of-art advancement of CZT launched by the University of Michigan over the past 20 years under the US Department of Defense sponsored research is now in use at over eighty operating nuclear plants in US and Canada. NATC played a key role in helping to bring the USDOD technology to operating nuclear power RP Departments. The CZT detectors verify the adequacy of temporary shielding, contamination control, PWR Crud Burst isotopic mapping and radwaste shipment RP surveys.  The wide adoption of the CZT detectors have led to new applications in homeland security, safeguard on nuclear materials as part of the missions of the IAEA and nuclear emergency response.  IAEA organized a gamma-ray imaging workshop and conducted blind tests on gamma-ray systems developed by eight different organizations in the world. The pixelated, 3-D, CZT detectors were selected for deployment at IAEA for international nuclear safeguards inspectors.

The use of the new spectra, pixelated, CZT system at Palisades is discussed including the discovery of significant Ag-110m contamination in the charging pump room. Ag-110m has been found to create dose rates of over 35 mR/hr above the refueling pool at AP-1000 Westinghouse PWR units. The Palisades NATC studies show new methods of measurement and removal of Ag-110m contamination using US specialty resins developed at US National Laboratories. SRM applications for individual isotopic monitoring are currently being studied.

The Point Beach US PWR installed five pixelated CZT spectra detectors for PWR CRUD Burst measurements during a recent refueling outage. Upon restart of the unit, failed fuel was detected by the pixelated CZT detectors. This achievement is the first known use of CZT as a real-time failed fuel monitoring system.

Position-sensitive, 3-dimensional CZT room temperature semiconductor gamma-ray spectrometers and imagers have been designed and are now in medical research laboratories for applications for proton beam therapy dose measurements, PET, and radionuclide patient isotopic imaging. An elaborate pixelated CZT medical imaging system using over 150 CZT detectors has been built and delivered to Johns Hopkins Medical School to continue the new medical imaging technology development.

PEP 1-F: Cognitive Dissonance; Heuristics & Logical Fallacies in Risk Perception: Why It’s So Natural For So Many To Believe So Much That Is So Wrong

Jerrold Bushberg

Public resistance and fear of radiation is not a new phenomenon. Research on affective influences on public opinion suggests cognitive influences compete with various emotional variables in their influences on public perceptions of risk from technology employing ionizing and non-ionizing radiation. Specifically, people are often influenced by more affective aspects, such as concerns or fears, which are more a function of the potential severe outcomes or the vividness of potential risks rather than of objectively quantifiable probabilities or expectations. Even though cognitions, such as levels of scientific knowledge and education, are related to public support for radiation-related technology, they alone cannot fully explain the variations of public opinion on these issues. A significant body of literature has empirically examined the influences of cognitive dissonance, heuristics, and logical fallacies. This line of research has shown that (1) affective processes often precede cognitive evaluations and (2) people’s judgments about science and technology are often based on a general feeling about science and technology rather than analytical judgment. The seminal research of Paul Slovic, Daniel Kahneman, Amos Tversky, and others on intuitive toxicology can be used as a starting point to understand why it’s so natural for so many to believe so much that is so wrong. An overview of these topics will be presented along with specific recommendations to increase the effectiveness of communicating the risks of radiation exposure in a public forum.

Sunday, July 7, 10:30am – 12:30pm

PEP 2-A: So Now You Are the Radiation Safety Officer - Elements of an Effective Radiation Safety Program

Thomas Morgan

This presentation will outline and discuss best practices to develop and maintain an effective radiation safety program. It will include what is expected of the RSO, how the RSO can interact with managers, employees and others to be most effective, and discuss a number of problems and incidents that can provide a learning experience for the new RSO. Attendees will be encouraged to partcipate in these discussions.

PEP 2-B: Emergency Response and Information Communication – Considerations for the Health Physicist

Steve Sugarman

It is essential that health physicists are able to seamlessly integrate themselves into the response environment In the event of a radiation incident. The radiological situation needs to be properly, yet rapidly, assessed so that a safe and effective response can be planned. It is not always necessary to incorporate wholesale changes to the way things may usually be done in the absence of radioactive materials. Oftentimes health physicists get caught up in the minutiae and can lose sight of what needs to be done to provide the needed support in the early stages of an incident. When coupled with a good event history and other data, the proper tools and thought processes allow health physicists to have a large positive effect on the safe and effective response to a radiological event. In addition to performing the “normal” health physics duties, assisting with messaging and communication should be looked at as an area where health physicists can be of help. Radiation professionals may be called upon to provide information in a variety of ways during and after a radiation emergency. It is often necessary for someone with radiological expertise to assist those individuals/groups forming public messages create a clear and accurate message. The ability to successfully integrate radiation-related expertise into a response and communication scenario requires someone with an ability to break down complicated concepts into an understandable manner for a broad – if sometimes not overly large – audience. Effective communication is a skill set developed with years of experience and practice along with a willingness to change one’s approach based on feedback from target audiences. Successful communications can greatly affect the outcome of a variety of radiation emergency situations, so it is important that trained and capable subject matter experts are available to be integrated into emergency response plans and operations.

PEP 2-C: Fundamental Principles of Medical Internal Radiation Dosimetry

Darrell R. Fisher

This course reviews the core principles and scientific formalism for calculating internal doses from medically administered radiopharmaceuticals, including methods, models, assumptions, and computational tools available to radiation safety professionals. In practice, this formalism simplifies the problem of assessing dose for many different radionuclides—each with its unique radiological characteristics and chemical properties as labeled compounds—in the highly diverse biological environment represented by the human body, internal organs, tissues, fluid compartments, and cells. The major challenge in radiation dose assessment is to determine te time-dependent biokinetics of radionuclide uptake, retention, redistribution within, and excretion from the body. In clinical practice, direct patient measurements are obtained using calibrated imaging systems. Detected counts are translated to absolute activity resident in the major organs and tissues through disappearance or complete decay. Time-activity data may suggest mathematical functions that may be fitted to the acquired data points. Integration of the area under the time-activity curve through complete decay yields the time-integrated activity, that is, the total number of radioactive decays in the source organ. The time-integrated activity coefficient is the most important input to dosimetry software.

Internal dose calculations account for all radiation energy imparted to organs and tissues, including both self-organ dose and cross-organ dose contributions. These calculations are applied to human models representing male and female phantoms of many different ages and sizes. Given the many radionuclide choices available, and extensive differences in radiation emission properties, internal dosimetry becomes a computationally intensive effort that lends itself to computerization. Software solutions efficiently and conveniently implement the MIRD schema. Several new computer programs have been developed for use in medical internal dosimetry, both free to the user and commercially available. Some computer programs calculate time-integrated activities but have no dose-calculation functionality. The opposite is true for other software tools, while still others provide a complete suite of capabilities for tools for co-registering multiple clinical image formats at various timepoints to analyze biokinetic measurement data, compute time-integrated activity coefficients, and perform absorbed-dose calculations.

Dosimetry accounts for radionuclide nuclear emission properties, energy absorbed fractions, the geometry and density of body tissues, and cross-organ irradiations. Stylized, voxel, and mesh human anatomical models have been developed and incorporated within software tools to facilitate dose calculations. The virtue of the MIRD approach is that it systematically reduces complex dosimetric analyses to methods that are relatively simple to use, including software tools for experimental and clinical use.

PEP 2-D: Foundations of Radiation Shielding and External Dosimetry

Lily Ranjbar

This course provides an introduction to radiation shielding and external dosimetry for neutrons, photons, and charged particles and how they can be applied in real-world situations. The content of the course focuses on analytical and numerical solutions to address radiation protection and dosimetry challenges. Participants will learn theoretical concepts and engage in hands-on problem-solving exercises to better understand radiation shielding and dosimetry. By the end of the course, participants will have the knowledge and skills necessary for effective radiation protection in various professional settings.

PEP 2-E: Environmental Health Physics – Concepts and Applications for Environmental Radiological Assessment and Dose Calculation

Amber Harshman

This comprehensive course offers an in-depth overview of radiological assessment in the environment, focusing on the presence and impact of radionuclides. Participants will gain an understanding of various exposure routes and sources of radionuclide contamination, recognizing the crucial role of assessment and its implications for safeguarding human populations, biodiversity, and the overall environment. The course goes into both the theoretical knowledge and pragmatic aspects of evaluating internal and external doses caused by radionuclides in the environment. By incorporating real-world applications, including analyses of routine assessments and the aftermaths of significant incidents such as Fukushima and Chernobyl, the course aims to enhance practical knowledge of participants. This strategic integration of practical examples enables participants to obtain insights from historical cases, reinforcing their ability to address radiological challenges in varied scenarios and better understand exposure pathways for humans and wildlife. This course is designed to equip participants with the knowledge and practical skills needed to assess and calculate radiological doses in various environmental scenarios, ensuring compliance with safety standards and effective protection of both human and environmental health.

PEP 2-F: Ethical Decision Making Tools for Enhancing Organizational Radiological Safety Culture

Janet Gutierrez

The practice of radiation safety is actually the convergence of a variety of professional disciplines, thus changes and developments that affect the field can emerge from various sources. This presentation is designed to address a contemporary issue confronting radiation safety program operation. This topic covers ethical decision-making and the link to safety culture. Previous investigations of several tragic events have repeatedly identified the absence of a culture of safety as a common contributing factor. An organization’s safety culture is a collective reflection of individual decisions made by its workforce, each carrying with them ethical implications. Safety culture, good or bad, is the sum product of many individual ethical decisions, yet the notion of ethical safety decision-making is not often discussed. Safety professionals can encounter ethical dilemmas, and the decisions that are made can impact an organization’s overall safety culture. A set of ethical decision-making tools will be presented. Ethics codes from select professional organizations will also be summarized.

Sunday, July 7, 1:00pm – 3:00pm

PEP 3-A: Standard Test Methods for Remotely Operated Ground Robots, Aerial Drones, and Submersibles

Edward Walker

The public safety community must thoroughly understand the robot’s capabilities before deploying on a mission. Often the missions are in complex, obstructed and hazardous environments. These missions often require various combinations of elemental robot capabilities. A single capability can be represented as a test method with associated apparatus to provide tangible challenges for various mission requirements and performance metrics to communicate the results. These test methods can then be combined into a sequence to evaluate essential robot capabilities. The same test methods can also be used to evaluate remote operators to ensure they have the necessary skills to successfully complete the mission.

The ASTM committee for Homeland Security Applications supports the development of standards associated with security and emergency response, including testing of response robots. The Department of Homeland Security has funded NIST to develop multiple test methods suites for measuring the capabilities of the robot and operator proficiency. The NIST robotics team has developed and refined testing apparatuses for multiple capabilities that are simple to assemble, are scalable for various sizes and shapes of the various robots. To date, this approach has produced 20 standards for ground-based robots with an additional 11 in the ballot process and 8 additional test methods in development.

In addition, four draft standards are being developed for aerial robots (drones). One draft standard test method for testing the drones’ endurance (battery life) has been balloted. Three draft standard test methods to test maneuverability and payload capability in three different test bed configurations will be balloted in the upcoming months. Test methods for aquatics (ROV’s) are currently under development.

The presentation will describe the construction of standard testing apparatus that are scalable and simple to construct. It will then describe the various robot (ground and aerial) capabilities and operator proficiency that can be performed using these testing apparatus.

PEP 3-B: Incorporating science-based guidance into the nuclear power plant radiological emergency response and recovery planning paradigm.

William Irwin

Since the early commercial reactors started generating electricity in the 1960s, nuclear power plants (NPPs) and off-site response agencies have applied health physics practices for emergency response that are in many circumstances more appropriate to routine occupational radiological controls. Science has provided guidance that places some long-held elements of this paradigm in question. For example:

Can we run community reception centers for tens of thousands of people or more when the number of trained and available people to run them is small and perhaps needed elsewhere?
Should we evacuate or relocate hundreds of thousands of people for one to five rem radiation doses, when the biological effects may be immeasurable but the psychosocial, economic and health risks of evacuation and relocation as seen with Fukushima can be immense?
Are we going to wait until responders have an individual dosimeter and survey meter, as well as a respirator and anti-contamination clothing before they are allowed to enter the hot zone (>10 R/hour) to do work that saves lives or protects critical infrastructure?
Are the dozens of people who have the opportunity to occasionally practice radiological emergency response adequately prepared for the depth and breadth of complex problems a nuclear power plant accident may cause?
If a small modular reactor only releases radioactive materials sufficient to cause public doses that are one-half to three-quarters the EPA Protective Action Guideline of 100 millirem will that prevent calls for offsite environmental monitoring of food, water, farmland, and communities?

Over the last decade, a review of the application of health physics science in context of risk during a radiological incident has been critical to the development of updated NCRP and FEMA guidance that could result in more effective radiological emergency plans and procedures. Concurrently, technology is evolving to make training more efficient. Finally, there exists a critical need to de-exaggerate the risks of exposure to radiation and radioactive contamination, particularly at the lower dose levels. In this PEP, we will discuss the new guidance based on science, demonstrate new simulation capabilities to improve training and response planning, and discuss how health physicists can alleviate much of the inordinate fear of radiation so responders are as confident and effective in radiological incidents as they are in other complex and risky emergency scenarios.

We will also present the observations from two eight-hour workshops that reflect responder and response authority perspectives on how a new paradigm of emergency response guidance could assist them in effective response. These observations are a collection of ideas from a broad range of emergency response participants at the National Radiological Emergency Preparedness (NREP) and Conference of Radiation Control Program Directors (CRCPD) meetings in April and May this year. Incorporating this feedback with current health physics initiatives in emergency response guidance will contribute to important next steps that might be taken so NPP emergency response and recovery plans are more firmly grounded in updated science and balance the risk from all aspects of a radiological incident.

PEP 3-C: Design, Installation, And Commissioning Considerations Of A Self-Shielded Cyclotron For Healthcare: A Health Physicist’s Guide

Elizabeth Gillenwalters

The abundant global growth in molecular imaging and use of radiopharmaceuticals for diagnostic and theragnostic applications requires a steady supply of radionuclides. Given the short half lives of many medical use radionuclides and daily demands to meet patient needs, it is critical this supply is readily available. Onsite manufacturing and distribution of radiopharmaceuticals is desirable and typically accomplished by installation of a cyclotron. This PEP will discuss the radiation safety considerations for installation of a self-shielded cyclotron, including design of the cyclotron room and delivery lines, design and requirements for an effluent monitoring system, radioactive material licensing considerations, and eventual commissioning.

The calculations utilized in this presentation for determination of cyclotron room shielding and delivery line shielding will be based on guidance in National Council on Radiation Protection and Measurements (NCRP) report NCRP Report No. 144: Radiation Protection for Particle Accelerator Facilities, and AAPM Task Group 108: PET and PET/CT Shielding Requirements, respectively.

PEP 3-D: Essential Elements of Nuclear Security for Radiation Protection

Jason Harris

Radiation protection is an essential function in most facilities that use radioactive materials or radiation generating devices and the primary responsibility is a safety function. Over the last several years, nuclear security has become increasingly important, and the radiation protection professional may become tasked with understanding or even implementing security measures. Also, international organizations like the International Atomic Energy Agency (IAEA) have called for better integration of safety and security. Still, the role of radiation protection in nuclear security matters is not clearly defined even though a fundamental understanding of radiological hazards is required for understanding the total risk to the facility and/or material. Radiation protection professionals are multi-capable scientists, engineers and systems integrators that can contribute greatly at multiple levels for effective and efficient nuclear security. The purpose of this course is to introduce the basic elements of nuclear security, with specific emphasis on prevention, detection, delay, and response. The course will also cover two key components necessary for health physics integration with safety and security: culture and insider threat mitigation. The course format will include lecturing, case-study analysis with discussion, and a small simulation. Current events of importance will be highlighted. At the end of this course the participant should have a high-level overview of nuclear security and be able to formulate ways radiation protection can be integrated more effectively.

PEP 3-E: Advancements in Retrospective and Accident Physical Dosimetry: Techniques for Acute and Chronic Dose Assessment

Lekhnath Ghimire

In the field of radiological protection and public health, assessing radiation exposure retrospectively and in the aftermath of accidents is indispensable. This comprehensive course delves into crucial techniques for determining historical radiation exposure in various contexts, including workplaces, residences near nuclear facilities, nuclear or radiological incidents, and potential overexposure in diagnostic and therapeutic medical applications.

The course offers advanced methods for measuring doses, placing a particular emphasis on the application of physical biodosimetry techniques. Participants will gain expertise or knowledge in utilizing electron paramagnetic resonance dosimetry (EPRD) with biological samples such as mini biopsies of dental enamel, bones, nails (claws), horns, and shells. Additionally, the course covers thermoluminescence dosimetry (TLD) and optically stimulated luminescence dosimetry (OSLD), using environmental and other samples like quartz and feldspar, dust, brick, porcelain or ceramic, and touchscreen glasses from mobile phones.

The primary objective of this course is to provide participants with in-depth knowledge and practical skills essential for the comprehensive estimation of chronic and acute radiation doses using different types of samples. Participants will be familiar with these dose estimation techniques and be able to contribute significantly to advancements in radiation protection and public health practices.

PEP 3-F: Alpha Spectroscopy for the Health Physicist

Michael Clemmer

This course offers a fast-paced review of the basic principles of alpha spectroscopic analysis for the health physicist. The course includes a review of the nature and origins of alpha-particle emitting radioactivity, basic physics of alpha-particle interaction with matter, considerations and consequences of sample preparation for alpha spectroscopy, alpha spectroscopy system components and calibrations, and a primer on interpretation of alpha spectroscopy data.

Sunday, July 7, 3:30pm – 5:30pm

PEP 4-A: Dose and Effect: Lessons Learned from Birds, Bees, Dogs and Plants in Chornobyl, Fukushima & the International Space Station

Timothy Mousseau

The radioactive fallout from the Chernobyl accident, and to a lesser degree the accident at Fukushima, resulted in significant injuries to the flora and fauna in the surrounding regions. These injuries include effects on the genome, physiology, development, disease expression, and reproduction. For many species, long term consequences included reduced population abundances and subsequent impacts on biodiversity. However, not all species are affected to the same degree with tremendous variation in vulnerability related to specific endpoint, life history of the organism, sex and stage of development, and evolutionary history. Professor Mousseau will summarize key findings of the past three decades and will point to future directions that employ whole genome sequencing technologies for assessing genetic effects of chronic, multigenerational exposures to environmental contaminants. Special attention will be given to recent findings related to genomic effects on the dogs, nematodes, birds, and humans exposed to contaminants in the Chernobyl region. Additional topics to be covered will include key findings from naturally radioactive areas around the world (NORM), cosmic radiation in space environments, and atomic bomb test sites. A brief summary of the biological effects of tritium exposure will also be reviewed.

PEP 4-B: Studies on Dispersion of Am-241 and Associated Risk

Charles Potter

In 2000, the International Atomic Energy Agency released a document, IAEA-TECDOC-1191, Characterization of Radioactive Sources which, among other topics, addressed radioactivity of types of sources and dividing them into categories. This was the first attempt at addressing the possibility of dispersion of sources when they have been retired but not properly disposed. Sources addressed included both neutron/alpha/gamma-emitting 241Am/Be and alpha/gamma emitting 241Am, placing the former of activities 1–800 GBq into category 2 and the latter of activities 1–100 GBq into category 3. While groundshine tends to provide most of the dose to an individual exposed to dispersed beta/gamma emitting radionuclides, the majority of dose from alpha/gamma emitters is from internal dose from resuspended material. Prior to 2011, resuspension was estimated using a power function promulgated in NCRP Report No. 129. A new model created by Maxwell and Anspaugh in 2011 was adopted by the U.S. multi-agency Federal Radiological Monitoring Assessment Center as being more representative; however, this model greatly increased estimated effective dose from dispersed radioactivity. The ramifications of this change in resuspension model led to five studies of different aspects of 241Am and 241AmBe conducted by Sandia National Laboratories with university and national laboratory partners. This continuing education lecture will describe each study in detail and provide insights into the uncertain science of resuspension and its effect on prospective dose calculation.

PEP 4-C: Radiation Safety and Risk Mitigation in a Multi-disciplinary Y-90 Microsphere Program

William Gibbons

Transarterial Radioembolization with Yttrium-90 (Y-90) microspheres is widely performed for radioembolization of primary or metastatic tumors within the liver. Intravascular administration of glass or resin microspheres containing radioactive isotopes is performed in interventional radiology and typically involves a multidisciplinary team composed of authorized users, medical physicists, radiation safety officer, and nuclear medicine technologists. While two current products are commercially available, clinical trials are underway to bring additional products to market.

The frequency of Y-90 administrations performed may vary between institutions. Between institutions and between individuals in the same institution, the techniques employed may vary as well. Y-90 microsphere medical events continue to occur and while a medical event may not necessarily equate to harm to the patient, it is in our best interest to ensure the procedure goes in accordance with the written directive. In addition to discussing actual reported medical events, good catches and lessons learned will be shared. This discussion will engage the audience and provide a series of best practices, and techniques to minimize the risk of a misadministration.

Treatment planning systems and the application and workflow of implementing Y-90 dosimetry programs will be explored and discussed along with the difficulties one may encounter while acceptance testing the software.

This PEP will cover the fundaments of implementing a multidisciplinary Y-90 microsphere program and mitigating associated safety risks. This session will benefit not only those who are looking to support a new or upcoming Y-90 program but will also offer those more experienced an opportunity to review the fundamentals of such procedures and share personal insights related to the safe and effective use of Y-90 for radioembolization.

PEP 4-D: Application of Attila for Dose Rate Calculations in Large Rooms with Thick Shielding

Jenelle Mann

Two of the most difficult cases to solve for in radiation protection are thick shields and large geometries, especially coupled into one problem. Accurate solutions to these problems take computer power and time; often, the solutions or problems are simplified or limited to balance computing power and time. Attila (trademark of Silver Fir Software) is a commercially available, deterministic radiation transport solver that solves the Linear Boltzmann Transport Equation at nodal points on a tetrahedral mesh. Different mesh sizes can be used for different elements; allowing for larger elements in lower scattering regions, such as air and smaller elements through higher scattering regions, such as a shield. The resulting mesh has less elements than a traditional cartesian mesh, minimizing computing time while providing an accurate solution. Additional tallies may be used, such as point tallies and tallies over a surface. Attila also has the ability to interface with MCNP (Attila4MC), allowing the user to create complex geometries that would be difficult to make traditionally though MCNP. This session demonstrates the application of Attila to calculate dose rates during the change out of a filter containing Am-241 and Cs-137. The change out of the filter itself is performed hands-on by a worker in a large room where other radiation workers may be performing work; co-located workers are also located behind a thick shielded wall. Specifically, this session will go through how Attila is set up for the dose calculation, animation of a dose rate map through the room, display of key dose rate isosurfaces (i.e., high radiation area, radiation area), calculation of the dose rate at several key locations, and the dose rate on phantom surfaces. The session will also discuss how Attila can be used to improve the shielding design in place.

PEP 4-E: Radiochemical Measurements of Actinides in Biological Samples: Guide for Research Laboratories for a MARLAP-Based Approach to Uncertainty and Quality Management

Dan Strom

The United States Transuranium & Uranium Registries (USTUR) is a U.S. Department of Energy funded research program at the Washington State University that studies deposition, biokinetics, dosimetry, and possible biological effects of actinides such as plutonium, americium, and uranium. Other radionuclides of interest for analysis at the USTUR include thorium, radium, curium, and neptunium. USTUR registrants are former nuclear workers with measurable, documented exposures to TRU elements who voluntarily donated their organs and tissues to science for post-mortem study.

Systemic plutonium and americium concentrate in the liver and skeleton, while uranium primarily concentrates in the skeleton. Inhalation and wound intakes are most common routes of intake. Lungs, thoracic lymph nodes, liver, skeleton, and, for a wound intake, wound site and axillary lymph nodes are collected and analyzed. For “whole body donors,” many more tissues and organs are included.

Our measurands (the quantities intended to be measured) are activity and activity concentration in tissues and organs. To illustrate how we estimate these measurands from measurement results, we present the entire radiochemistry program, from sample collection at autopsy to the inference of activity and activity concentration in tissues and organs. Sample preparation by dry ashing, microwave digestion, chemical separation of elements, addition of tracers for estimation of radiochemical recovery, and electrodeposition are shown.

The program is presented in a MARLAP framework of measurement quality objectives (MQOs) and data quality objectives (DQOs) with a focus on uncertainty propagation and data management. To demonstrate compliance with MQOs, we calculate the predicted “activity-on-a-planchet” that would be expected 50 years after an intake of 74 Bq (2 nCi) for lung, liver, and skeleton to demonstrate that our radiochemical methods provide data of usable quality. Uncertainties in activity are calculated as a function of background counts and various other uncertain parameters. Methods used in calculations of counting efficiencies and radiochemical recovery are presented. Data and measurement system performance indicators, such as critical value (SC), p-value, minimum detectable activity (MDA), and minimum quantifiable activity (MQA), are calculated and recorded. Calculations are done with the “N+1” option presented in MARLAP. The overall Quality Assurance program is cast in numerical terms with control levels and tolerance limits.

PEP 4-F: Gamma Spectroscopy for the Health Physicist