Student Neil A. Armstrong Flight Research Center Maria Babakhanyan Stone San José State University

RADIATION SAFETY PROGRAM Mentor Dr. Miriam Rodón-Vachon Maria B. Stone Health Physics Manager

HEALTH PHYSICS HUMAN HEALTH RISK REDUCTION: EXAMPLE PROGRAM RESULTS

Armstrong Flight Research Center mission RF radiation can cause known biological damage by tissue heating. The effects might be: whole-body • Developed and updated radiation Identification heating, cataract formation, testicular damage. For example, cataracts (opacity in the lens) can be “to leverage atmosphere flight expertise produced with a single exposure at a threshold power density exceeding 100mW/cm2. equipment inventories, to include to advance technology and science for the the first RF inventory for the Center benefit of NASA and the Nation.” AFRC follows the IEEE Std C95.7-2014 to develop an RF safety program • Evaluated and analyzed health 1. to facilitate safe operation of the RF energy-producing equipment, systems, and devices Safety is a key requirement for mission success. 2. to make sure that both workers and the public are not exposed to hazardous levels of radiation hazards • Recommended and implemented The first phase in the Identification step is the Exposure Assessment Report for each branch. Health Physics controls, such as Safety Training and Inventory We collaborate with the users of RF equipment to create the first AFRC inventory of RF devices. Awareness campaigns is the application of scientific Table 1. AFRC Radiofrequency (RF) Inventory • Developed Training materials and principles to the protection of Average Power Gain RF instrument Frequency (Hertz) Exposure Category maintained Training records people from the hazards of (Watts) (dB) To be determined in • Developed Inspection Checklists, radiation. Antenna Example 3,400,000 2,000 2 the next step Inventory spreadsheets, Emergency Procedures Posters, Safety Signs Then we use the IEEE Standard maximum exposure limits (MEL) to categorize each RF instrument and to assess the Evaluation and Hazard Distance. Many factors must be considered, e.g. per IEEE Std C95.1 • Created Radiation Safety Newsletter RADIATION EXPOSURE HAZARD SOURCES Hazard Analysis • The Maximum Permissible Exposure levels are different for the general public and for the workers. • Exposure levels vary depending on the frequency of the instrument.

Table 2. RF Exposure Categories PROGRAM CHALLENGES 1 Public Exposure limit is not exceeded. 푷풐풘풆풓×푮풂풃풔 2 Public Exposure limit is exceeded. • Acquiring data for inventories of RF 푹푴푬푳 = The Occupational Exposure limit is not exceeded. 푴푬푳×ퟒ흅 equipment is challenging 3 Public Exposure limit is exceeded. R = Hazard Distance There is a potential to exceed the Occupational Exposure limit. • Diversity of RF equipment X-Ray Cabinets, X-Ray instruments, any 4 Exposure will exceed ten times the Occupational Exposure limit. equipment with active radioisotope • The regulation standards are not source Based on the RF Exposure Category, the recommended controls can be always user-friendly Recommendations Radar Equipment in the ER-2 chase car and Implementations • Follow up calculations with Surveys and Direct Measurements • Requires great collaboration of Controls • Posted Signs and site guidelines • RF equipment may affect medical • RF Awareness Training devices and implants • Advanced RF Training for workers in radio-frequency environments • Permits • Need to consider electro-explosive • Restricting access to the areas with RF equipment, e.g. fences devices if present • Developing safe work practices by Standard Operating Procedures • Lockout/ tag-out procedures Lasers aboard DC-8 Missions, e.g. ASCENDS II • Control of source power (e.g. turning off the power before access) • Personal and/or area monitors NEXT STEPS • Personal Protective Equipment • Ensure compliance with Safety Regulations • Program Self-Assessment • Equipment Self-Inspections • Program Audit • Safer Environment Scientific Research Instruments from Universities and Research Institutes on • Compliance with Safety Regulations platforms for Airborne Science Missions such Radio-frequency and Microwave as ATom, KORUS, and Ice-Bridge. radiation from transmitting antennae and Photo: DC-8 aircraft with different probes other telemetry and communication sticking out of windows. systems.

Industrial Hygiene branch, Dr. Gregg Bendrick (Chief Medical Officer), Charles Kreager, Greg Strombo, Darryl Burkes, Airborne OSHA, ANSI 136.1, IEEE 95.1, CA Title 17 Safety Standards, NPR ACKNOWLEDGEMENTS Science Program personnel, Mr. Eddie Zavala (SOFIA Program Manager), Mr. David McCallister (Deputy Program Manager), REFERENCES 1800.1D, DPL 1800.1, DPC. Images from NASA public archives and Chuck Irving (Associate Director, Science Mission Directorate), and personnel from NASA AFRC, AMES, and JPL personal photos by NASA AFRC personnel