1 / 51

Alpha Particles: 2 neutrons and 2 protons They travel short distances, have large mass Only a hazard when inhaled

lillian
Download Presentation

Alpha Particles: 2 neutrons and 2 protons They travel short distances, have large mass Only a hazard when inhaled

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

    1. Four Primary Types of Ionizing Radiation: Alpha Particles

    2. Four Primary Types of Ionizing Radiation: Beta Particles

    3. Four Primary Types of Ionizing Radiation: Gamma Rays A gamma particle is a photon. It is produced as a step in a radioactive decay chain when a massive nucleus produced by fission relaxes from the excited state in which it first formed towards its lowest energy or ground-state configuration. A gamma particle is a photon. It is produced as a step in a radioactive decay chain when a massive nucleus produced by fission relaxes from the excited state in which it first formed towards its lowest energy or ground-state configuration.

    4. Four Primary Types of Ionizing Radiation: X-Rays

    5. Four Primary Types of Ionizing Radiation: Neutrons

    6. Four Primary Types of Ionizing Radiation Alpha particles Beta particles Gamma rays (or photons) X-Rays (or photons) Neutrons

    7. RADIATION FUNDAMENTALS ATOMIC AND NUCLEAR STRUCTURE Bureau of Radiation Control

    8. Radioactivity: Elements & Atoms Atoms are composed of smaller particles referred to as: Protons Neutrons Electrons

    9. Ionization Ionizing radiation is produced by unstable atoms. Unstable atoms differ from stable atoms because they have an excess of energy or mass or both. Unstable atoms are said to be radioactive. In order to reach stability, these atoms give off, or emit, the excess energy or mass. These emissions are called radiation. How this can be dangerous How we can protect ourselves - Types will be discussed later How this can be dangerous How we can protect ourselves - Types will be discussed later

    10. Types or Products of Ionizing Radiation - Symbols- Symbols

    13. Direct Ionization Caused By: Protons Alpha Particles Beta Particles Positron Particles

    14. Indirect Ionization Caused By: Neutrons Gamma Rays X-Rays

    15. DNA and Radiation

    16. Ionizing Radiation at the Cellular Level Causes breaks in one or both DNA strands or; Causes Free Radical formation

    17. Commonly Transported Radioisotopes Americium-241= Diagnose thyroid disorders, smoke detectors. Cesium-137= Cancer treatment. Iodine-125,131= Diagnosis & treatment liver, kidney,heart, lung and brain. Technetium-99m=Bone and brain imaging; thyroid and liver studies; localization of brain tumors.

    18. Radiation Measurement Terminology: Exposure rate = amount radiation possible to receive per unit time. Dose = total amount of radiation received.

    19. Radiation and Radioactivity: Units and Quantities Department of Health Bureau of Radiation Control - Saved as UNITQ.PPT - Presentation time: 1 hr 45min - 28 Total slides covering Vol. I, Tab D- Saved as UNITQ.PPT - Presentation time: 1 hr 45min - 28 Total slides covering Vol. I, Tab D

    20. 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- 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

    21. Objectives Define 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- 4 bullets will transition 1 by 1 - Using a conversion table located on Pg. 10 - Using conversion table on Pgs. 9, 12

    22. 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- 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

    23. Roentgen - Unit of exposure- Unit of exposure

    24. Roentgen Pronounced rentgen 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- 4 bullets will transition 1 by 1 - Imphasize abbv. rules - Ionizations produced in air

    25. rad - Unit of absorbed dose- Unit of absorbed dose

    26. rad 1 rad = 1 Roentgen - 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) - 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)

    27. rem - Unit of dose equivalence- Unit of dose equivalence

    28. rem 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 - 5 bullets will transition 1 by 1 - For biological damage (tissue) purposes

    29. 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- Table Pg. 5 - Function of LET - Higher LET - Higher Q

    30. Curie (Ci) 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) - 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)

    31. 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 - 3 bullets will transition 1 by 1 - Pg. 8 - Abbreviations

    32. 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 - 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

    33. Unit Analysis (Cont.) 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) 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)

    34. 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?????????- 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?????????

    35. 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

    36. 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

    37. 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

    38. 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

    39. Half Life Calculation

    40. Annual Dose Limits

    41. Dose Response Relationships 0-150 remNo or minimal symptoms 150-400 remModerate to severe illness 400-800 remSevere illness deaths start above 500 rem Above 800 remFatal ***Acute whole body doses 0-150 Perhaps increased cancer with long latency\\\150-400 increased cancer risk---400-800 GI damage at higher rates0-150 Perhaps increased cancer with long latency\\\150-400 increased cancer risk---400-800 GI damage at higher rates

    42. Your Annual Exposure

    45. Estimated Exposure To The National Population Between 320 360 mr/yr

    46. 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. 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.

    47. 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

    48. 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.

    49. Spill Response On Skinflush completely On Clothingremove If Injuryadminister first aid Radioactive Gas Releasevacate area, shut off fans, post warning Monitor all persons and define the area of contamination

    50. ALARA

    51. Radiation Protection Decrease Time Increase Distance Increase Shielding

More Related