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2011 Radiation Machine (xrd) User Refresher Radiation Safety Refresher for Radiation Producing Machine (xrd) Safety Conrad Sherman x9-3911 RSO/Health Physicist.

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Presentation on theme: "2011 Radiation Machine (xrd) User Refresher Radiation Safety Refresher for Radiation Producing Machine (xrd) Safety Conrad Sherman x9-3911 RSO/Health Physicist."— Presentation transcript:

1 2011 Radiation Machine (xrd) User Refresher Radiation Safety Refresher for Radiation Producing Machine (xrd) Safety Conrad Sherman x RSO/Health Physicist Marcus Balanky x ARSO/ Health Physicist Vern Ares x Assistant Health Physicist Environmental Health & Safety Radiation Safety

2 2011 Radiation Machine (xrd) User Refresher Annual Refresher Training is Required Option 1 –Challenge the test Option 2 – review this presentation, radiation safety manual, rpm fundamentals workbook (ucsc radiation)ucsc radiation Option 3 –request a class then Pass the Test Test is on e-commons Please complete within 30 days of your last test date (if you don’t know it, then look on e-commons, in your PI’s radiation safety folder/training is a report showing training for all users within your lab group. Location of EHS/Radiation published materials

3 2011 Radiation Machine (xrd) User Refresher Radiation Safety

4 2011 Radiation Machine (xrd) User Refresher Purpose of This Class Annual x-ray XRD RPM users at UCSC Fulfill regulatory requirements Campus and UC Policy

5 2011 Radiation Machine (xrd) User Refresher You are here

6 2011 Radiation Machine (xrd) User Refresher Pregnancy Policy

7 2011 Radiation Machine (xrd) User Refresher X-ray Diffraction Safety Training Slides modified from a class offered by John Pickering SJSU Radiation safety Officer

8 2011 Radiation Machine (xrd) User Refresher What are x-rays? X-rays are photons (electromagnetic radiation) which originate in the energy shells of an atom, as opposed to gamma rays, which are produced in the nucleus of an atom.

9 2011 Radiation Machine (xrd) User Refresher Visible Light

10 2011 Radiation Machine (xrd) User Refresher X-rays on EM spectrum

11 2011 Radiation Machine (xrd) User Refresher What are x-rays? X-rays are produced when accelerated electrons interact with a target, usually a metal absorber, or with a crystalline structure. This method of x-ray production is known as bremsstrahlung. The bremsstrahlung produced is proportional to the square of the energy of the accelerated electrons used to produce it, and is also proportional to the atomic number (Z) of the target (absorber).

12 2011 Radiation Machine (xrd) User Refresher

13 Photon Energy and Total Power The total power P = V x I As the voltage increases the penetration increases As the Current increases the dose rate increases

14 2011 Radiation Machine (xrd) User Refresher What are x-rays? Many different types of machines produce x-rays, either intentionally or inadvertently. Some devices that can produce x-rays are x-ray diffractometers, electron microscopes, and x-ray photoelectron spectrometers. X-rays can also be produced by the attenuation of beta particles emitted from radionuclides.

15 2011 Radiation Machine (xrd) User Refresher How X-rays are Produced X-ray Tube When fast-moving electrons slam into a metal object, x-rays are produced. The kinetic energy of the electron is transformed into electromagnetic energy.

16 2011 Radiation Machine (xrd) User Refresher Radiation Sources X-ray diffraction is a source of very intense radiation. The primary beam can deliver as much as 400,000 R/minute Collimated and filtered beams can produce about 5,000 to 50,000 R/minute Diffracted beams can be as high as 1 R/minute

17 2011 Radiation Machine (xrd) User Refresher At HIGH Doses, We KNOW Radiation Causes Harm High Dose effects seen in: – Radium dial painters – Early radiologists – Atomic bomb survivors – Populations near Chernobyl – Medical treatments –Criticality Accidents In addition to radiation sickness, increased cancer rates were also evident from high level exposures.

18 2011 Radiation Machine (xrd) User Refresher Ionizing Radiation Produces damage through ionization and excitation

19 2011 Radiation Machine (xrd) User Refresher Bioeffects Somatic (body) effects of whole body irradiation can be divided into "prompt" effects and "delayed" effects. Prompt – effects that appear quickly Delayed – effects that may take years to appear Prompt Delayed Diagnostic X-ray Exposure

20 2011 Radiation Machine (xrd) User Refresher Genetic Effects Somatic –Damage to genetic material in the cell –May cause cell to become a cancer cell –Probability is very low at occupational doses Heritable –Passed on to offspring –Observed in some animal studies but not human

21 2011 Radiation Machine (xrd) User Refresher Biological Effects of Radiation are dependent upon: –Total energy deposited –Distribution of deposited energy Low dose, low-dose rate radiation exposure. The effects are in great dispute. It is thought that the effects of a protracted dose of radiation are not as great as with an acute dose because of biological repair mechanisms.

22 2011 Radiation Machine (xrd) User Refresher Prenatal Radiation Exposure Sensitivity of the unborn –Rapidly dividing cells are radiosensitive Potential effects –Low birth weight - (most common) –Mental retardation –Chance of childhood cancer

23 2011 Radiation Machine (xrd) User Refresher Bioeffects- X-rays and Skin Most radiation overexposures from analytical x-ray equipment are to the extremities. For x-rays of about 5-30 keV, irradiation of the fingers or hands does not result in significant damage to blood- forming tissue. At high exposures some general somatic effects to the skin can occur. Very high exposures may necessitate skin grafting or amputation of the affected extremity. Biological effects can be observed at 10 rem in special blood studies. Typically effects are visually observed at 50 to 100 rem.

24 2011 Radiation Machine (xrd) User Refresher X-Ray Burns vs. Thermal Burns Most nerve endings are near the surface of the skin High energy x-rays penetrate the outer layer of the skin that contains most of the nerve endings so one does not feel an X-Ray burn until the damage has been done X-rays penetrate to the deeper, basal skin layer, damaging or killing the rapidly dividing germinal cells, that are destined to replace the outer layers

25 2011 Radiation Machine (xrd) User Refresher Accident Case Study Case Study - A radiation accident at an industrial accelerator facility 3MV accelerator. 40 rad/s inside victim’s shoes, 1300 rad/s to hands. 3 days after exposure Note erythema and swelling 1 month after Note blistering and erythema 2 months after

26 2011 Radiation Machine (xrd) User Refresher ALARA As Low As Reasonably Achievable

27 2011 Radiation Machine (xrd) User Refresher XRD (tin/polycarbonate enclosure) Properly enclosed and interlocked x-ray diffractometer. The enclosure is made of tin-impregnated polycarbonate. –Leaded glass enclosures are also used. If a panel is opened while the XRD is being used, the interlock should either shut off the x-ray or close the shutter, preventing accidental exposure to personnel.

28 2011 Radiation Machine (xrd) User Refresher Dose Examples

29 2011 Radiation Machine (xrd) User Refresher

30 Documenting Surveys surveys must be documented Record the following: –date performed –area(s) surveyed (a map helps!) –results –identity of surveyor –instrument used –action taken if problem is found

31 2011 Radiation Machine (xrd) User Refresher Engineering Controls Interlocks – never bypass interlocks or other safety devices Warning Lights – know the beam status whenever working with XRD Shielding Locked doors

32 2011 Radiation Machine (xrd) User Refresher Failsafe Equipment Getting better High reliability Still see reports of failures Always use survey meter

33 2011 Radiation Machine (xrd) User Refresher Precautions If you rely on an interlock to turn off the beam for the purposes of accessing the sample area, you must confirm the beam is off using a calibrated survey meter before your put your hand in the cabinet enclosure.

34 2011 Radiation Machine (xrd) User Refresher Interlock as on-off switch Never

35 2011 Radiation Machine (xrd) User Refresher Key Control Who has keys Special alignment bypass keys Never Left Out, always locked in case/cabinet Only PI and Lab Manager hold access to bypass keys

36 2011 Radiation Machine (xrd) User Refresher Access You are required to secure access to your RPMs. Rooms where RPMs are present must be kept locked if the machine is left unattended. If your RPM is equipped with a key interlock then the key must be removed when the machine is not being used.

37 2011 Radiation Machine (xrd) User Refresher New Machine Moving Machine? Decommissioning? Call RSO

38 2011 Radiation Machine (xrd) User Refresher Problems with equipment If there are any questions or concerns about the functioning of an XRD unit, it must be taken out of service immediately and reported to the unit supervisor. [Be aware that shutter mechanisms can fail. Warning lights can fail.]

39 2011 Radiation Machine (xrd) User Refresher General Methods of Protection Time Distance Shielding

40 2011 Radiation Machine (xrd) User Refresher Verify you have viewed this powerpoint Logon to ecommons RAD SAF Exams and take 2011 RPM XRD Refresher

41 2011 Radiation Machine (xrd) User Refresher Test To receive credit for this online training course, you must complete the exam and receive a score of 80% or greater. You may take test up to 3 times Some questions have multiple correct answers You can review answers at end of each test Each test is a new set of questions randomized from test bank If you do not pass, we will go over failed questions with you

42 2011 Radiation Machine (xrd) User Refresher Test Completion Online e-commons RADSAFE EXAMS PAPER PRINT A COPY OF TEST, Send to ehs trailer

43 2011 Radiation Machine (xrd) User Refresher Verify you have viewed this powerpoint Logon to ecommons RAD SAF Exams and take 2011 rpm machine user Refresher quiz e-commons portale-commons portal (https://ecommons.ucsc.edu/xsl-portal)

44 2011 Radiation Machine (xrd) User Refresher We’re there for you. Environmental Health & Safety x –Conrad Sherman x –RSO/Health Physicist –Marcus Balanky x –ARSO/ Health Physicist –Vern Ares x –Assistant Health Physicist Environmental Health & Safety Radiation Safety (831) Web site


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