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WPAFB Radiation Safety Office 1 Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept Used with permission from Wright-Patterson AFB.

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Presentation on theme: "WPAFB Radiation Safety Office 1 Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept Used with permission from Wright-Patterson AFB."— Presentation transcript:

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2 WPAFB Radiation Safety Office 1 Radiation Overview Presented by Capt. Colbrunn (Tank) Xenia Twp Fire Dept Used with permission from Wright-Patterson AFB Radiation Safety office -Unclassified -

3 WPAFB Radiation Safety Office 2 Ionizing radiation consists of electromagnetic or particulate radiations capable of interacting with the atom causing removal of one or more electrons such that the atom has a resulting net positive charge Ionizing Radiation

4 WPAFB Radiation Safety Office 3 Radioactivity - a property of some species of atoms to spontaneously emit radiation(s) usually by disintegration of the nuclei of the atoms Radiation - the energy or particles emitted when a radionuclide transforms or disintegrates (radiation is not the same as radioactivity) Radionuclide - a nuclide that emits radiation(s) DEFINITIONS

5 WPAFB Radiation Safety Office 4 Ionizing Non-ionizing Ionizing Vs Non-ionizing x-ray machine microwave radar AM/FM gamma ray (Matching Game)

6 WPAFB Radiation Safety Office 5

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8 7 curie (Ci) – The activity of 1 gram of 226 Ra – 3.7 x disintegrations per second (dps) becquerel – one disintegration per second (dps) one dps is NOT synonymous with the number of particles emitted by the isotope in one second Activity

9 WPAFB Radiation Safety Office 8 The interval at which a radionuclide decays to one-half the original activity Each radionuclide has its own characteristic half-life Half-lives range from microseconds to billions of years Half -life Radionuclide Half-life 57 Co 270 days 241 Am 433 years 63 Ni 100 years 226 Ra 1600 years 109 Cd 464 days

10 WPAFB Radiation Safety Office 9 Alpha (  ) Beta minus (   ) Beta positive (   ) (positron) and Electron Capture Gamma (associated with other types of decay) Decay Methods

11 WPAFB Radiation Safety Office 10 Line of Stability

12 WPAFB Radiation Safety Office 11 Roentgen (R) –the measure of the number of ion-pairs produced by gamma radiation in a certain volume of air Exposure ++ +

13 WPAFB Radiation Safety Office 12 RAD (Radiation Absorbed Dose) –an absorbed radiation dose of 100 ergs per gram –energy deposited by any ionizing radiation in a unit mass of any absorber Gray (Gy) –1 Gy = 100 rads DOSE

14 WPAFB Radiation Safety Office 13 DOSE REM (RAD Equivalent Man) –the absorbed dose (RAD) multiplied by a quality factor to equalize biological consequences Sievert (Sv) –1 Sv = 100 rems

15 WPAFB Radiation Safety Office 14 Radiation Quality Factor x-ray 1 gamma 1 beta 1 alpha 20 neutron (unknown energy) 10

16 WPAFB Radiation Safety Office 15 Exposure - the delivery of radiation to an individual that results in the receipt of a radiation dose Contamination - radioactive material distributed in an unwanted place or location Exposure Vs Contamination

17 WPAFB Radiation Safety Office 16  No biological sensors of ionizing radiation  Must depend on instruments  Interaction with matter principles used  Detection is dependent on type of radiation

18 WPAFB Radiation Safety Office 17 Dose Vs Dose Rate Dose - generic term that means absorbed dose, dose equivalent, effective dose equivalent or total effective dose equivalent (mrem) Dose Rate - the rate at which a dose is being delivered per a time interval (mrem per hour)

19 WPAFB Radiation Safety Office 18 Radiation TypeIn AirTypical Shielding Material Used Alphainchespaper or aluminum foil Betafeetaluminum or Lucite Gammahundredslead or concrete of feet Why does alpha have a higher quality factor?

20 WPAFB Radiation Safety Office 19 Dose Equivalent (H T ) - the product of the absorbed dose in tissue, quality factor, and all other necessary modifying factors at the location of interest. Effective Dose Equivalent (H E ) - the sum of the products of the dose equivalent to the organ or tissue (H T ) and the weighting factors (W T ) applicable to each of the body organs or tissues that are irradiated (H E =  W T H T ) Internal Dose

21 WPAFB Radiation Safety Office results from 0.06 for each of the “remainder” organs (excluding the skin and the lens of the eye) that receive the highest dose. ORGAN DOSE WEIGHTING FACTORS

22 WPAFB Radiation Safety Office 21 Committed Dose Equivalent (H T,50 ) - the dose equivalent to organs or tissues of reference (T) that will be received from an intake of radioactive material by an individual during the 50-year period following the intake Committed Effective Dose Equivalent (H E,50 ) - the sum of the products of the weighting factors applicable to each of the body organs or tissues that are irradiated and the committed dose equivalent to these organs or tissues (H E,50 =  W T H T,50 ) Internal Dose

23 WPAFB Radiation Safety Office 22 Total Effective Dose Equivalent (TEDE) - the sum of the deep-dose equivalent (for external exposures) and the committed effective dose equivalent (for internal exposures) TEDE = Deep Dose + CEDE

24 WPAFB Radiation Safety Office 23 Direct – ionization and excitation » radiation + H 2 O  H 2 O + + e -  H + + OH - »radiation + H 2 O  H o + OH o (free radical) – occurs anywhere in body Indirect – Radicals react with biological molecule and damage it – Radicals combine » OH o + OH o  H 2 O 2 (hydrogen peroxide)

25 WPAFB Radiation Safety Office 24 Cell Division Normal Parent Cell Division Daughter Cells Irradiated Cell Growth No Division Irradiated Cell Mutant cells (death, altered DNA)

26 WPAFB Radiation Safety Office 25 Linear/Threshold Confirmed Data

27 WPAFB Radiation Safety Office 26 Most to least radiosensitive Immature male sex cells White blood cells Bone marrow cells Epithelial cells of the intestine Cells such as the skin covering external surfaces Cells that line the closed cavities of the body (i.e., heart, blood vessels) Bone cells Nerve cells Brain cells Muscle cells

28 WPAFB Radiation Safety Office 27 Two types of exposure Acute - a single accidental exposure to a high dose during a short period of time Chronic - a long-term, low level exposure Radiation Effects

29 WPAFB Radiation Safety Office 28 Factors – Type of radiation – Absorbed dose – Dose distribution – Age Stages –Initial (nausea, vomiting) –Latent –Manifest illness –Recovery Acute Exposures

30 WPAFB Radiation Safety Office 29 DoseEffect 1 rad to bone marrow rad (whole body) > rad (whole body) 300 rad (skin) 450 rads (whole body) rad, (local to eye) > rads (whole body) 10,000 rads (whole body) (localized) risk of leukemia blood changes mild radiation sickness erythema LD 50/30 cataracts death in 1 to 2 weeks death in hours to days cancer treatments Acute Exposure

31 WPAFB Radiation Safety Office 30 Cancer –leukemia –bone –lung –skin – etc. Genetic Life shortening Chronic Exposure (Delayed Effects)

32 WPAFB Radiation Safety Office 31 Somatic - effects which occur to an individual being exposed during their lifetime Genetic - effects that are act on the offspring of the individual being exposed

33 WPAFB Radiation Safety Office 32 Stochastic – effects that occur by chance – occur among unexposed as well as among exposed – in radiation, main effects are cancer and genetic effects Non-Stochastic – certain minimum dose must be exceeded for effect – magnitude of effect increases with size of dose – clear causal relationship between exposure and effect Dose-Response Characteristics

34 WPAFB Radiation Safety Office 33 The human population has always received radiation exposure from natural sources such as cosmic, dietary, and soil. Additional sources of exposure are medical exposures, occupations exposures and some industrial and consumer products. RISKS

35 WPAFB Radiation Safety Office 34 Annual effective dose equivalent in the U.S. population Source Average Dose (mrem) Natural sources –Radon 200 –Other 100 Occupational 0.9 Nuclear fuel cycle 0.05 Consumer products –Tobacco –Other 5-13 Misc. Environ Sources Medical –Diagnostic x-ray 39 –Nuclear medicine 14

36 WPAFB Radiation Safety Office 35 Food 40 K pCi/kg 226 Ra pCi/kg Banana35201 Brazil nuts Carrot White potatoes Beer Red meat Lima bean raw Drinking water Natural Radioactivity in Food Ref:

37 WPAFB Radiation Safety Office 36 Cosmic 8% Terrestrial 8% Internal 11% Radon 55% Medical X-rays 11% Nuclear Medicine 4% Consumer Products 3% Other <1% Occupational Nuclear Fuel Cycle Fall out Misc Sources of Radiation Exposure Average Exposure 360 mrem/yr

38 WPAFB Radiation Safety Office 37 Source of Radiation (excludes indoor radon) 1. Cosmic Radiation: 40 mrem a sea level (Add 1 mrem for each 100 feet elevation) 2. House Construction: Wood: 35 mrem Concrete: 50 mrem Brick: 75 mrem 3. Water and Food a. U.S. average 25__ b. Heavy smoker (add 30 mrem) c. Drink beer (add 1 mrem for each 100 bottles) _____ 4. Air a. Natural - U.S. average 5 b. Weapons testing 2 5. Transcontinental Flights: Add 4 mrem for each 5000 miles in flight 6. Radium Dial Wrist Watch: (add 2 mrem) 7.Television: U.S. average 2__ 8. Radioactivity in Human Body a. Dose to yourself (K-40) 20__ b. Sleep with spouse (add 0.3 mrem) c. Dose to yourself (C-14) Medical and Dental Diagnosis a. U.S. average 55 mrem or b. For each chest, teeth, head neck and bone x-ray, add 20 mrem c. For each spinal column and kidney x-ray, add 200 mrem d. For each stomach, intestines and gall bladder x-ray, add 250 mrem 10. Live in the vicinity of large coal-fired power plant (add 0.1 mrem) 11. Live in the vicinity of large geothermal power plant (add 1 to 100 mrem) 12. Nuclear Power Plants: a. If you live (1) At boundary fence (fraction of year spent times 5 mrem) (2) One mile away (fraction of year spent times 0.5 mrem) (3) Five miles away (fraction of year spent times 0.05 mrem______ b. General U.S. population: Add 0.01 mrem Total mrem/year

39 WPAFB Radiation Safety Office 38 RISKS It is estimated that if 100,000 persons of all ages received a whole body dose of 10 rad of gamma radiation in a single brief exposure, about 800 extra cancer deaths would be expected to occur during their remaining lifetimes (BEIR V) It is estimated that if 100,000 persons of all ages received a continuous lifetime whole body dose of 100 mrad per year, about 550 extra deaths would be expected. (BEIR V)

40 WPAFB Radiation Safety Office 39 To prevent the occurrence of clinically significant radiation-induced deterministic effects by adhering to dose limits that are below the apparent threshold levels; and To limit the risk of stochastic effects, cancer and genetic effects, to a reasonable level in relation to societal needs, values, benefits gained and economic factors Objectives of Radiation Protection NCRP No. 116

41 WPAFB Radiation Safety Office 40 Time Distance Shielding External Radiation Protection Measures

42 WPAFB Radiation Safety Office 41 dose rate x exposure time = total dose 20 mRem/hr x 30 min = 10 mRem Reduce time reduces exposure TIME 1000 mR/hr for 2 minutes = ________________

43 WPAFB Radiation Safety Office 42 Radiation exposure decreases with increasing distance Decrease by inverse square law Double the distance decrease the exposure by 4 DISTANCE

44 WPAFB Radiation Safety Office 43 PaperPlastic Lead Concrete Alpha Beta Gamma and X-rays Neutron Shielding

45 WPAFB Radiation Safety Office 44 Fire, Explosion, Instrument Damage, etc. –Secure the area –Keep Unauthorized persons away –Alert people within the vicinity –Notify Department of Energy (DOE) »Initiate appropriate actions »Make appropriate written report Loss or Theft –Immediate notification of DOE and Nuclear Regulatory Commission »Immediate notification of Radioisotope Committee »Make written report –Immediately begin search Response Actions

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47 WPAFB Radiation Safety Office 46

48 WPAFB Radiation Safety Office 47 Susan, I see you have grown a foot since the last time I saw you !


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