Radiation and Radioactivity: Units and Quantities - Saved as UNITQ.PPT - Presentation time: 1 hr 45min - 28 Total slides covering Vol. I, Tab D www.assignmentpoint.com

Introduction Quantities (mass, volume, time, etc.) vs. Units (grams, gallons, hours) Units of exposure, radioactivity, and energy associated with ionizing radioactivity As hours and minutes are to time ... - Explain difference and relate to next bullet - Introduce some of the units students will learn - Compare importance of rad protection units with units of time www.assignmentpoint.com

Objectives Define Discuss the use and conversion of unit prefixes ROENTGEN, RAD, REM, CURIE, GRAY, SIEVERT, BECQUEREL. SI units vs. Standard English units Discuss the use and conversion of unit prefixes Transform units using “unit analysis” - 4 bullets will transition 1 by 1 - Using a conversion table located on Pg. 10 - Using conversion table on Pgs. 9, 12 www.assignmentpoint.com

Background Early risk associated with use of ionizing radiation skin erythema dose - 25yrs 1928 - ROENTGEN introduced by ICRP - Radiation studies began in 1895 with the discovery of x-rays - Early physicist and therapist eventually knew that ionizing radiation was hazardous, however, there was no definite way to quantify the dose or damage. No suitable unit. Many injuries and deaths. - For therapy-dose making skin red - International Committee of Radiation Protection www.assignmentpoint.com

Roentgen - Unit of exposure www.assignmentpoint.com

Roentgen Named after Wilhelm C. Roentgen (thus the abbr... is capital “R”) Pronounced rent’gen with a hard “g” Limitations only applies to photons only applies in air only applies to energies less than 3 MeV - 4 bullets will transition 1 by 1 - Imphasize abbv. rules - Ionizations produced in air www.assignmentpoint.com

rad - Unit of absorbed dose www.assignmentpoint.com

rad 1 rad = 1 Roentgen www.assignmentpoint.com - 3 bullets will transition 1 by 1 - 1953 - dose relates to an irradiated medium - 1 Roentgen equivalent to 95 ergs/g of tissue - gamma vs. neutron (LET) www.assignmentpoint.com

rem - Unit of dose equivalence www.assignmentpoint.com

rem Roentgen Equivalent Man The unit of dose equivalent for any type of ionizing radiation absorbed by body tissue in terms of estimated biological effect - Unit of dose equivalent Dose in health record is in units of rem 1 rem = 1 Roentgen - 5 bullets will transition 1 by 1 - For biological damage (tissue) purposes www.assignmentpoint.com

Quality Factor (Q) The specific value that accounts for the ability of different types of ionizing radiation to cause varying degrees of biological damage X-rays, gamma rays, & beta particles 1 Neutrons & High energy protons 10 Alpha Particles 20 - Table Pg. 5 - Function of LET - Higher LET - Higher Q www.assignmentpoint.com

Curie (Ci) Named in honor of Pierre Curie Radiation hazard does not solely depend on the activity. It also depends on the type of decay (alpha, beta, photon, etc.) - 2 bullets will transition 1 by 1 - Transformation of the nucleus- DECAY - Decay per unit time - Activity - Beta(H3) vs. Photon(Co-60) - A transformation may produce more than one photon/particle emmision (dependent on radionuclide-Table Vol. II, Tab M) www.assignmentpoint.com

SI Radiation Protection Units Becquerel (Bq) for Curie 1 Ci = 3.7 x 1010 Bq Gray (Gy) for rad 1 Gy = 100 rad Sievert (Sv) for rem 1 Sv = 100 rem - 3 bullets will transition 1 by 1 - Pg. 8 - Abbreviations www.assignmentpoint.com

BASE UNIT CONVERSION TABLE Unit Analysis BASE UNIT CONVERSION TABLE Unit Unit Conversion 1 Bq 2.7 x 10-11 Ci 1 Ci 3.7 x 1010 Bq 1 Bq 1 dis/sec 1 dis/sec 2.7 x 10-11 Ci 1 Ci 3.7 x 1010 dis/sec - 2nd Method for prefix conversion - Only method to go from one unit to another - Relations Pg. 12. Imagine an (=) between columns. WRITE ON BOARD - Reference Ex. 6- .25 in/week to _ mi/hr - Imphasize units must be diagonal to cancel www.assignmentpoint.com

BASE UNIT CONVERSION TABLE Unit Analysis (Con’t.) BASE UNIT CONVERSION TABLE Unit Unit Conversion 1 rem 0.01 Sv 1 Sv 100 rem 1 rad 0.01 Gy 1 Gy 100 rad 1 R 2.58 x 10-4 C/kg 1 meter 3.28 ft (39.37in) Continuation - In some cases will need both conversion table and unit analysis - Lights on work examples (1) 12 ft to _ m (2) 25 mi/hr to _ ft/sec (3) 22 Ci to _ Bq (4) Ex. 7 (5) 35 GBq to _ Ci ( w/out table) www.assignmentpoint.com

Summary Radiation Protection unit definitions (including SI units) Unit Prefixes Unit conversions - 3 bullets will transition 1 by 1 - Terms very important - Methods: Table, Unit analysis, your own BE CAREFUL! Check quantity in relation to prefix (quarters, dimes, nickels) - Units must be diagonal to cancel -QUESTIONS????????? www.assignmentpoint.com

Old Terms Roentgen-Based on the quantity of electrical charges produced in air by X or Gamma photons 1R=2 billion pr RAD-Radiation Absorbed Dose is the work energy resulting from the absorption of one ROENTGEN or 6.24 E5 Mev            www.assignmentpoint.com

More Old Terms REM- Roentgen Equivalent Mammal is equal to the absorbed does in RADS multiplied by a quality factor Quality Factors Beta = 1 Gamma & X ray photons = 1 Alpha = 10 Neutrons = 20            www.assignmentpoint.com

New Terms sort of International Units have replaced the RAD and REM GRAY (Gy) = 100 RAD SIEVERT (Sv) = 100 REM Same Quality Factors apply to the Sv www.assignmentpoint.com

Units of Radioactivity Curie (Ci) = 2.22 E12 dpm or 3.7E10 dps Becquerel (Bq) = 1 dps Maximum Dose/year = 5 REM or 50 mSv Maximum Dose/year for Declared Pregnant Woman & Minors= 0.5 REM or 5 mSv            www.assignmentpoint.com

Half Life Calculation www.assignmentpoint.com

*Effective dose equivalent Annual Dose Limits External/Internal Exposure Limits for Occupationally Exposed Individuals   Adult ($18 yrs) Minor (< 18 yrs) Whole body* 5000 mrem/yr 500 mrem/yr Lens of eye 15000 mrem/yr 1500 mrem/yr Extremities 50000 mrem/yr Skin Organ www.assignmentpoint.com *Effective dose equivalent

Dose Response Relationships 0-150 rem—No or minimal symptoms 150-400 rem—Moderate to severe illness 400-800 rem—Severe illness deaths start above 500 rem Above 800 rem—Fatal ***Acute whole body doses 0-150 Perhaps increased cancer with long latency\\\150-400 increased cancer risk---400-800 GI damage at higher rates www.assignmentpoint.com

Your Annual Exposure Activity Typical Dose Smoking 280 millirem/year Radioactive materials use  in a UM lab <10 millirem/year Dental x-ray 10 millirem per x-ray Chest x-ray  8 millirem per x-ray Drinking water  5 millirem/year Cross country round trip by air  5 millirem per trip  Coal Burning power plant 0.165 millirem/year  www.assignmentpoint.com

www.assignmentpoint.com

www.assignmentpoint.com

Estimated Exposure To The National Population Between 320 – 360 mr/yr www.assignmentpoint.com

Another Look at Sources The cosmic radiation which strikes the earth induces radioactivity in the atmosphere in the same way that the TRIUMF accelerators induce radioactivity in their shielding. Most of this radioactivity is very short-lived. Some radionuclides however survive to eventually reach the surface of the earth. Among these are H (tritium), Be (beryllium-7) and C (carbon-14) which has the longest half-life (5730 years). The concentration of these radionuclides in the air is quite low and they are all radioactive species with low radio-toxicity. As a result the average dose equivalent from this source is small: only approximately 0.01 mSv per year. www.assignmentpoint.com

Some Exposure Limits 2 mr/hr Dose rate to public / Federal 500 mr Emergency responder limit / State/BRC 5 r/yr Occupational /Federal 5 r/hr Turn back value / State/BRC 10 r Property / Federal 25 r Life saving / Federal >25r Volunteers only / Federal Ref - 10CFR PART 20, EPA 400, FL-SOP www.assignmentpoint.com

Security All Radioactive Materials must be secured or under direct supervision at all times There MUST be someone in the room at all times OR the door must be locked. www.assignmentpoint.com

Spill Response On Skin—flush completely On Clothing—remove If Injury—administer first aid Radioactive Gas Release—vacate area, shut off fans, post warning Monitor all persons and define the area of contamination www.assignmentpoint.com

ALARA As Low As Reasonably Achievable—means making every reasonable effort to maintain exposures to radiation as far below the dose limits as is practicable consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to the state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest. www.assignmentpoint.com

Radiation Protection Decrease Time Increase Distance Increase Shielding www.assignmentpoint.com