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Presentation on theme: " If you are viewing this presentation in PowerPoint's edit mode (slides are listed on the left of this window), please change to the slide show view by."— Presentation transcript:

1  If you are viewing this presentation in PowerPoint's edit mode (slides are listed on the left of this window), please change to the slide show view by clicking on the “Slide Show” icon located at the lower right corner of this window.  Viewing as a slide show will change the presentation to a full screen mode, enable embedded links, and is necessary to complete the quiz. Viewing This Presentation

2 Radiological & Environmental Management Purdue University Sealed Source Safety Retraining Updated 09/2012

3  Basic Radiation Safety Principles  Familiarization with Regulations  Purdue’s Policies and Procedures Training Goals

4  Radioactivity is an energy  This energy is produced when an unstable nucleus spontaneously emits particles and/or electromagnetic radiation  Radioactive material sources  Sources are characterized as either sealed or unsealed (or “open”)  To qualify as a “sealed” source, the source must pass a battery of stress tests and be certified under NRC regulations What is radioactivity?

5 Sealed Source Means any byproduct material that is encased in a capsule designed to prevent leakage or escape of the byproduct material (USNRC Regulations 10CFR30.4) Definition

6 Pictures of common sealed sources

7  Alpha  Molecularly large particle (2 protons and 2 neutrons), give up their energy in a short distance (approximately 1 ½ inches in air)  Beta  Smaller particle (electron), distance traveled ranges from several inches to a few feet (depending on its energy)  Gamma  Non-particulate energy wave, can travel several feet and easily penetrates material with low atomic mass  Neutron  Neutral particle, can travel greater distances than gamma radiation and easily penetrate material with low hydrogen ion concentrations Ionizing Radiation Types

8  An average person in the United States receives annual radiation dose of ~620 mrem, which includes exposure received from cosmic and natural radiation, medical treatment, and consumer products.  Large doses of radiation have been known to increase risk of cancer, birth defects, and possibly genetic effects.  Low doses seem to show no statistical differences in biological risk; however, some people believe there is risk at all levels above background exposure.  At radiation levels around 1 rem, it has been estimated that the increased incidence of cancer is 0.03% - the normal incidence of cancer for the average person is 25%.  Risk of developing genetic effects is half the risk of cancer. Risks of Radiation Exposure

9  Contamination Control  gloves, lab coats, fume hoods, absorbent paper  Time  do dry run, practice procedure to minimize time  Distance  a little distance between you and a source can significantly decrease your exposure from it (follows the “Inverse-Square Law”)  Shielding  Use proper shielding between you and a source to decrease personal exposure  betas - wood, Plexiglas (do NOT use lead)  gammas - lead, leaded glass 4 Factors to Reduce Exposure

10 Click here for a sample calculation I1dI1d = I 2 d  Point Sources  The intensity of radiation decreases as the inverse square of the distance.  Doubling distance, exposure = ¼ of original; Tripling distance, exposure = 1/9 of original. Inverse Square Law

11  (I 1 )(d 1 ) 2 = (I 2 )( d 2 ) 2  (20 mR/hr)(1ft) 2 = (I 2 )(2ft) 2  (20 mR/hr)(1ft) 2 = I 2 (2ft) 2  (20 mR/hr)(1ft 2 ) = I 2 (4ft 2 ) I 2 = 5 mR/hr I 1 = 20 mR/hr I 2 = ?? d 1 = 1 ft d 2 = 2 ft Sample Calculation

12 Inverse Square Law - Diagram

13  Different shields are needed to minimize external exposure Ionizing Radiation Shielding

14  Radioactive material use must be licensed by the United States Nuclear Regulatory Commission (USNRC) or state agency. In Indiana, the USNRC is the regulating body.  Radiation Safety Officer (RSO) develops and maintains a Radiation Safety Manual, which must be followed by individuals working under the NRC license, and it is enforceable by law Radiation Safety Manual  Purdue University’s Radiation Safety Committee (RSC) also oversees and governs the radiation safety program. Rules Governing Use of Radionuclides

15  10CFR19 10CFR19  Rights and responsibilities of radioactive material licensees are outlined.  10CFR20 10CFR20  Standards for protection against radiation: this discusses issues such as procedures and regulatory limits  Declared pregnant worker  Security of radioactive materials Regulations

16  Rights  to be informed of storage, transfer, and use of radioactive materials  to further instruction on health protection problems associated with radiation exposure and procedures to minimize exposure  to receive radiation exposure history  to request an NRC inspection  to be instructed in and required to observe applicable provisions of NRC regulations and licenses  to be instructed in the appropriate response to warnings 10CFR Part 19 Instruction to workers

17  Retaliation against employees or students engaged in protected activities, whether they have raised safety concerns within the University or to the NRC, will not be tolerated  Problems should be addressed within the existing University hierarchy – contact the radiation safety office if you have any concerns regarding issues involving radioactive materials. NRC Policy Statement

18  Occupational dose limits  Surveys and monitoring  Precautionary procedures  Waste disposal  Records of surveys  Enforcement  Storage and control of licensed material 10CFR20

19 All dose limits include exposure from both internal and external sources. TargetDose Limit Whole Body5 rem/yr Organ or Tissue50 rem/yr Skin or Extremities50 rem/yr Lens of Eye15 rem/yr Minor (i.e. non-adult)10% of adult limits Declared Pregnant Worker0.5 rem per 9-month gestation period 10CFR20 Occupational Dose Limits

20  If a worker wishes to declare her pregnancy, she must declare it in writing to the Radiation Safety Officer.  A declaration of pregnancy is entirely voluntary, and can be withdrawn at any time – no reason needs to be given.  For a worker wishing to declare her pregnancy, she should contact REM for Declared Pregnant Worker Training, which covers important information, and provides her the declaration form she needs in order to declare her pregnancy. REM will also provide a fetal dosimeter at the time of declaration, assuming that it is warranted by the type of radiation that has the potential for exposure to the worker.  The dose limits will be reduced from 5 rem per year to the worker, to 0.5 rem to the fetus for the 9-month gestation period (this is for both external and internal exposure) Regulatory Guide 8.13 Regulatory Guide 8.13 Prenatal Exposure

21  Exposure= ability of photons to ionize air  Roentgen (milliroentgen, mR)  Geiger-Mueller readings  Absorbed Dose= energy deposited in matter  Rad (millirad, mrad)  Dose Equivalent= biological weighted absorbed dose (tissue)  rem (millirem, mrem)  these units are what film badge (dosimetry) results are reported Radiation Units

22  Non-stochastic:  Until a minimum exposure level is reached, there is no biological effect.  Once that minimum exposure level is exceeded, the biological effect grows proportionally with the exposure.  The Lethal Dose to 50% of the population (LD50) is about 600 rad  Examples of biological response (effects) from radiation  erythema (skin reddening)  blood changes (marrow depression is seen at approximately 200 rad)  Gastrointestinal Syndrome (severe vomiting, diarrhea) – happens at approximately 1000 rad, and death is a likely outcome. Acute Effects of Radiation Exposure

23  Stochastic (occur by chance, statistical basis)  No threshold, but as the dose increases, the probability of the effect also increases  Examples of stochastic effects: may be seen 5 to 20 years after the exposure  Cancer  Leukemia  Cataracts  Life Shortening  Data extrapolated from high dose data (early radiology, Hiroshima/Nagasaki bombing, Chernobyl nuclear plant fire) Delayed Effects of Radiation Exposure

24  High doses - there is a correlation between dose and effect  Low doses (<10 rem) - it is unclear what the risk is at this level  difficulty performing long-term studies on effected people, while eliminating other factors (e.g. did the radiation worker get cancer from her work, or that she smoked cigarettes, or that she was genetically programmed that way)  Hormesis – this is a theory that low doses of radiation may actually be beneficial Risk Analysis

25  You can use Geiger-Mueller Survey instrument for detection of higher-energy beta and gamma sources.  REM will be conducting “leak tests” on sealed sources to evaluate whether the source containment is intact  this will be done at timely intervals.  Survey work areas, floors around work areas and any doors, lab coat, hands, shoes, if it is felt that the source integrity has been compromised (e.g. dropped, smashed, had acid spilled on it)  Record survey results, maintain records for 3 years Surveys

26  Secure laboratories when unoccupied (if this is not feasible, secure the radioactive material)  Challenge visitors or unauthorized individuals  REM accounts for RAM through inventory records  Assume only you are approved for the type of materials you are using. If another group wants to borrow them, you must ALWAYS check with the radiation safety office before relinquishing control of the material. Security NRC Area of Emphasis

27  Call 911  Assist personnel if injured  Monitor personnel if contamination is suspected  Control area - inform other personnel of the situation and advise them not to enter  Notify radiation safety office, once emergency personnel are en route Emergency Procedures

28  Medical needs come first! Postpone monitoring, call 911, notify of radioactive material use  Wait for medical personnel - calmly advise radioactive materials may be involved  Trained radiation worker may need to accompany patient to treatment center.  Notify REM Severe Personal Injury

29  Always use ALARA  No eating, drinking, or smoking in labs  Always secure materials, lock doors  Never allow unauthorized users access to radioactive materials  Call REM for any related questions ( )  All Emergencies – call 911 Review

30  James F. Schweitzer, Ph.D Radiation Safety  Zachariah C. Tribbett Health  Sharon K. Rudolph Isotope Ordering &  Jerry J. Gibbs Waste Handling & Meter  Mike Nicholson Waste Handling & Animal Hospital  REM Main Office Civil Engineering Building, Room B173www.purdue.edu/remwww.purdue.edu/rem REM’s Radiation Safety Group

31  Complete the test indicated below. You must have a minimum score of 75% to pass.  Your results will be sent to you through , and, if you have passed, will be the documentation you would use to prove certification for renewal.  If the quiz does not automatically pop up after clicking the link below, it may be necessary to exit the slide show by hitting the ‘Esc’ key. Once out of the slide show, the quiz should be open in the internet browser. Test


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