Potential Communication Benefits by adoption of SI units in Radiation Safety Steven H. King CHP, DABMP Penn State Milton S. Hershey Medical Center
Radiation Protection in the 1970 s.
TMI & Chernobyl changed our lives in the late 1970 s & 80 s. Three Mile Island Chernobyl
Nuclear terminology suddenly became part of our lives.
Old form of the NRC regulations. Over 1000 pages!
New form of the NRC regulations. Look up anything!
. Needing 2 types of tools
Mars Climate Orbiter 12/11/1998 NASA lost 327.6 million dollars when the orbiter s trajectory was miscalculated. The error? NASA specified SI units and the contractor used English units.
Nebraska Emergency Management Agency Radiation Level (Dose Equivalent Rate) 1 Sv/h = 100 rem/h = 100,000 mrem/h 1 msv/h = 0.1 rem/h = 100 mrem/h 1uSv/h = 0.0001 rem/h = 0.1 mrem/h 1 rem/h = 0.01 Sv/h = 10 msv/h = 10,000 usv/h 1mrem/h = 0.00001 Sv/h = 0.01 msv/h = 10 usv/h
Nebraska Emergency Management Agency Equivalents For Conversion Quantity (Activity) SI to English Units 1 TBq = 27 Ci = 27,000 mci 1 GBq = 0.027 Ci = 27 mci = 27,000 uci 1 MBq = 0.000027 Ci = 0.027 mci = 27 uci English to SI Units 1 Ci = 0.037 TBq = 37 GBq = 37,000 MBq 1 mci = 0.000037 TBq = 37 MBq 1 uci = 0.037 MBq = 37,000 Bq 1 nci = 0.000037 MBq = 37 Bq 1 pci = 0.037 Bq = 37 mbq https://nema.nebraska.gov/tech-hazard/radiation-conversion-table
Nebraska Emergency Management Agency To convert a value from the "Customary System of Units" to SI units and vice versa, use the following directions: Step 1: On the left side, find the unit you want to convert FROM. Step 2: Find the factor in that line for the unit you want to convert TO. Step 3: Multiply the original value by the factor, and the result will be the measure in the desired units. Example: Say a package has 20 TBq of radioactive material. How many curies does this correspond to? Answer: Following Step 1, we immediately find 1 TBq = 27 Ci Following Step 2, we find that the "factor" is 27 Ci Following Step 3, we multiply 20 x 27 which = 540 Answer is: 540 Ci https://nema.nebraska.gov/tech-hazard/radiation-conversion-table
The Fukishima Disaster created. communication issues
. The Health Physics Society
Current Instruments have English Units.
Radioactive Materials Shipping In order to measure the packages you need the meter to read in proper, current regulatory units
10CFR 20 Standards for protection against radiation Appendix B to Part 20 Annual Limits on Intake (ALIs) and Derived Air Concentrations (DACs) of Radionuclides for Occupational Exposure; Effluent Concentrations; Concentrations for Release to Sewerage Table 1 "Occupational Values". The derived air concentration (DAC) values are derived limits intended to control chronic occupational exposures. The relationship between the DAC and the ALI is given by: DAC=ALI(in μci)/(2000 hours per working year x 60 minutes/hour x 2 x 10 4 ml per minute)=[ali/2.4x10 9 ] μci/ml, where 2x10 4 ml is the volume of air breathed per minute at work by "Reference Man" under working conditions of "light work.
Screenshot of a CT scanner screen
Information From the Nuclear Regulatory Commission Medical Procedure Doses Procedure Dose (mrem) X-Rays-single exposure Pelvis 70 Abdomen 60 Chest 10 Dental 1.5 Hand/Foot 0.5 Mammogram (2 views) 72 Nuclear Medicine 400 CT Full body 1,000 Chest 700 Head 200 http://www.nrc.gov/about-nrc/radiation/around-us/doses-daily-lives.html
A I recommend that you look as the x-ray risk calculator at xrayrisk.com. You can enter your x- ray examinations, age, and gender and it will provide an estimate of your radiation exposure and cancer risk. The calculator also allows you to enter DLP (if known) and it converts it to dose (again, this is an estimate). I did this for you with the following results: The Health Physics Society Answer to Question #10574 Submitted to "Ask the Experts" Category: Medical and Dental Patient Issues Diagnostic X Ray and CT The. following question was answered by an expert in the appropriate field: Q I am 19 years old and had a CT scan of the lumbar section (because the doctor suspected I have a herniated disc), then two months later I had an x ray of my pelvis and both hips. Earlier this year I had a chest x ray, and the year before I had two x rays of my abdomen. Now I'm very worried since I read a lot about radiation exposure and increased risk of cancer. In one article I saw that I have one in 600 chance of developing cancer in 10 years. I'm very depressed. I can't sleep, all I can think about is that huge risk. I want to have children and live my life, but now I'm so scared that I can't think of anything else. Please, tell me, have I been exposed to way too much radiation? I checked my CT scan dose report and it says 262.81 DLP, but I don't understand how much msv is this. Is it a lot?
Typical Doses from Diagnostic Radiology Exams As noted above, the tables below give dose estimates for typical diagnostic radiology exams. For comparison, we all receive about 3 msv of exposure annually to natural background radiation. Plain Film X Rays Single Radiographs Effective Dose, msv Skull (PA or AP) 1 0.03 Skull (lateral) 1 0.01 Chest (PA) 1 0.02 Chest (lateral) 1 0.04 Chest (PA and lateral) 5 0.06 Thoracic spine (AP) 1 0.4 Thoracic spine (lateral) 1 0.3 Lumbar spine (AP) 1 0.7 Lumbar spine (lateral) 1 0.3 Abdomen (AP) 1 0.7 Abdomen 6 0.53 Pelvis (AP) 1 0.7 Pelvis or hips 6 0.83 Bitewing dental film 6 0.004 Limbs and joints 6 0.06 http://hps.org/hpspublications/articles/dosesfrommedicalradiation.html
3 points to consider 1. In the United States, most work and workers dose is expressed in English Units while patient medical radiation dose is often expressed in SI units. 2. There can be confusion even with experts trying to convert units back and forth to explain radiation doses. 3. The public encounters 2 different types of units when trying to research and understand radiation dose. This confusion can spread to radiation workers as well. We as a radiation safety industry need to have world-wide common radiation units so we can all speak together and understand each other