Radioactive Material Safety

Mashael Almowallad
Health Physicist III
- Phone: 314-747-2679
- Fax: 314-362-1995
- Email: mashael.almowallad@wustl.edu
Services: Clinical Radioactive Material Use, X-Ray Producing Machines
Mashael Almowallad is an experienced Medical Health Physicist with over 12 years of expertise in radiation safety, regulatory compliance, and quality assurance in healthcare. Her work spans diagnostic and nuclear medical physics, radiation protection, and MRI safety, ensuring the highest safety and performance standards in medical imaging and radiation use.
Mashael’s journey in medical physics began in Jeddah, Saudi Arabia, where she completed her early education before earning her Bachelor of Science in Nuclear Medicine Technology from Saint Louis University and a Master of Science in Health Physics from the Illinois Institute of Technology. She holds multiple board certifications in nuclear medicine, radiation safety, MRI safety, and laser safety, reflecting her dedication to advancing medical physics and radiation protection. Throughout her career, Mashael has played a crucial role in radiation risk assessment, regulatory compliance, and training healthcare professionals in radiation safety and imaging techniques. She has worked extensively with radiopharmaceuticals, PET/CT, and x-ray quality assurance programs, ensuring compliance with industry regulations and optimizing imaging procedures for patient safety and diagnostic accuracy.
Mashael is an active member of several professional organizations, including the Health Physics Society, the Society of Nuclear Medicine and Molecular Imaging, the American Association of Physicists in Medicine (AAPM), and Women in Nuclear (WiN) Global. Her leadership and expertise contribute to ongoing advancements in medical physics and radiation protection. Currently, Mashael continues to drive excellence in radiation safety programs, regulatory compliance, and medical imaging quality assurance. Her passion for safety and education fosters a collaborative approach to enhancing patient care and medical technology standards.

Mairio Bradley
Radiation Safety Specialist III
- Phone: (314) 362-0599
- Fax: (314) 362-1995
- Email: bradleyma@wusm.wustl.edu
Services: Laser Safety; Radioactive Waste Pickup and Disposal; Radioactive Material Orders; Survey Meter Calibration

Briana Davis
Interim Radiation Safety Officer
- Phone: (314) 362-4966
- Fax: (314) 362-1995
- Email: davisbr@wusm.wustl.edu
Services: Radioactive Material Authorizations and Amendments; Drain Disposal of Radioactive Material; Radioactive Material Research Lab Inspections; Radiation Safety Training Information, Requirements, and Scheduling; Generally Licensed Radioactive Materials
Briana Davis, Assistant Radiation Safety Officer and current Interim Radiation Safety Officer, has been with Radiation Safety for over 27 years. She holds a Bachelor of Science degree from The University of Missouri- Rolla. Originally starting with the department as a Radiation Safety Specialist I, she has since grown into a leadership role, managing the Authorizations, Inspections, Training, Decommissioning/Closeout, and Part 37 Security Programs for many years. She is currently the Executive Secretary of the Radiation Safety Committee, and the Authorizations Subcommittee of the Radiation Safety Committee, and serves as a Reviewing Official for the Part 37 Security Program.

Daniel Doenges
Radiation Safety Officer & Director, Division of Radiation Safety
- Phone: 314-362-2988
- Fax: (314) 362-1995
- Email: daniel.doenges@wustl.edu
St. Louis area native (southern Jefferson County) who has a B.S. and M.S. in Nuclear Engineering from Missouri University of Science and Technology in Rolla Missouri. After college, 4 years working for Knolls Atomic Power Laboratory as a Nuclear Physicist designing and building submarine and aircraft carrier reactors. In 2014 moved back to St. Louis and began a career in health physics working as a Health Physicist here at Wash U. During that time, specialized in several areas including launching/growing the Increased Controls, Magnet, General Licensed Materials, and Laser Programs. During time at Wash U began the accreditation program through the American Board of Health Physics (2 years of examinations) and became a Certified Health Physicist (CHP) in 2017. In January 2019 accepted a position at the University of Missouri Research Reactor as the Health Physics and Safety Manager/Radiation Safety Officer. MURR is the leading producer of Lu-177, I-131, Mo-99/Tc-99m, Y-90, and several other isotopes in the United States. In the position, led a team of ~40 safety professionals shipping upwards of 1.6 million patient doses per year (based on activity shipped). In January 2025 rejoined Washington University as the Director of Radiation Safety/Radiation Safety Officer.

Joshua Eickhoff
Radiation Safety Assistant
Joshua Eickhoff is a Nuclear Engineering student at Missouri University of Science and Technology, with a minor in Mathematics and Engineering Management. He currently works as a Radiation Safety Assistant at Washington University School of Medicine, where he conducts laboratory inspections, x-ray surveys, and assists the team with managing radiation safety programs. Joshua is certified as a Radiation Worker and is in the process of becoming a Qualified Expert on X-ray devices in the state of Missouri.

Bhea Jaime
Health Physicist I
- Phone: 314-362-3476
- Fax: 314-362-1995
- Email: jmaria@wustl.edu
Services: Clinical Radioactive Material Use
Bhea Jaime is a highly skilled Health Physicist with over 6 years of experience in radiation safety and compliance within clinical and medical settings. Currently, Bhea works as a health physicist for the radiation safety program at Washington University. Bhea has expertise in performing audits, leading the Y90 program, and conducting shielding calculations, among other key responsibilities.
Previously, Bhea worked as a Senior Nuclear Medicine Technologist, creating, and reviewing SOPs, conducting training, and ensuring radiation safety in the nuclear medicine/PET departments. Bhea also has hands-on experience with QA, administering radiopharmaceuticals, and adhering to safety protocols at institutions like Missouri Baptist Medical Center, Memorial Belleville Hospital, and SSM Health Cardinal Glennon Children’s Hospital.
Bhea holds a Bachelor of Science in Nuclear Medicine Technology from Saint Louis University and is a certified nuclear medicine technologist.

Sonny Johnson
Radiation Safety Specialist II
- Phone: (314) 362-2994
- Fax: (314) 362-1995
- Email: johnsonlo@wusm.wustl.edu
Services: Radioactive Material Package Receipt; Radioactive Waste Pickup and Disposal

Brian Kim
Assistant Radiation Safety Officer
- Phone: (314) 362-2997
- Fax: (314) 362-1995
- Email: suhankim@wustl.edu
Services: Radioactive Material Orders/Shipping/Transfers; Radioactive Waste Pickup and Disposal; Survey Meter Calibration and Repair; Bioassays
Works for the Radiation Safety Department as a lead in several programs. Lead in Cyclotron and Radiopharmacy radiation safety, Waste management, receiving and shipping of radioactive materials, technical measurements, calibration of radiation detectors, Bioassay and assists in other areas as needed. Assisting our customers and affiliate to stay in compliance with federal regulations involving the use of radioactive materials.

Joseph Lake
Health Physicist Assistant
- Phone: (314) 362-3400
- Fax: (314) 362-1995
- Email: lakejoseph@wustl.edu
Services: Clinical Radioactive Material Use; ALARA Investigations

David Luechtefeld
Assistant Radiation Safety Officer
- Phone: (314) 362-3478
- Fax: (314) 362-1995
- Email: luechted@wusm.wustl.edu
Services: Clinical Radioactive Material Lab Inspections; Clinical Radioactive Material Use; Radioactive Sealed Sources; MRI Support
David L. Luechtefeld is an experienced radiation safety professional with over 25 years of expertise in regulatory compliance, radiation protection, and medical health physics. Currently serving as the Assistant Radiation Safety Officer (RSO) at Washington University School of Medicine, he provides leadership and oversight for human-use radioactive material (RAM) programs, sealed source management, MRI safety, and medical radiation audits.
With a strong background in radiation safety inspections, dosimetry investigations, and regulatory compliance, David plays a critical role in ensuring the safe and responsible use of radioactive materials within the Washington Medical Center. His extensive experience includes emergency spill response, shielding evaluations, and personnel training in radiation safety protocols.
David holds a Bachelor of Science in Engineering Physics from Missouri State University and an Associate of Science in Pre-Engineering from East Central College. He is a certified Qualified Expert in Radiation Safety (QE350) and has been instrumental in developing safety protocols, reviewing authorization permits, and maintaining compliance with federal, state, and local regulations. His commitment to excellence and expertise in radiation safety make him a key asset to the institution’s health and safety programs.

Matt Schildz
Assistant Radiation Safety Officer
- Phone: 314-362-2996
- Fax: 314-362-1995
- Email: mschildz@wustl.edu
Services: Clinical Radioactive Material Use; Radioactive Material Authorization Review

Karla Spafford
Health Physicist I
- Phone: (314) 362-4968
- Fax: (314) 362-1995
- Email: spaffork@wusm.wustl.edu
Services: Decommissioning & Closeouts; Radioactive Materials Authorization Inspection & Review.

Tracey Whitfield
Business Manager
- Phone: (314) 362-3333
- Fax: (314) 362-4776
- Email: whitfiet@wusm.wustl.edu
Services: Radioactive Material Ordering; Radioactive Material Waste Billing