1. Penn State University Radiation Safety Education for X-ray Users
Greg Herman
Environmental Health and Safety
Radiation Protection

2. Introduction
University policies and Pennsylvania Department of Environmental Protection rules and regulations require that anyone working with specific sources of ionizing radiation, including X-rays, must be instructed about the possible hazards of radiation exposure and the procedures to be used for the safe handling of those sources.

3. This course was developed to meet those requirements and is required for users and supervisors of ….
Medical X-ray systems
Veterinary X-ray systems
Industrial radiography systems
Analytical X-ray systems, including
Diffraction
Fluorescence
Laue

4. Course Structure
The course is divided into four parts. Part 1 is this online training module and will cover the following topics:
Fundamental principles of radiation and radioactivity,
X-ray production,
Biological effects from exposure to ionizing radiation,
Permissible exposure levels, and,
Radiation safety practices and controls.
This part of the training will take you approximately 1.5 hours to complete.

5. After completing this first part you will need to take the online X-ray safety training Quiz completing Part 2. Part 3 is the online sign-up for the practical class.
The practical class (Part 4) of this training is an opportunity to answer any questions you have and receive instructions in proper radiation survey instrument use, if applicable.
The Quiz is multiple choice and open note. A score of 70% is required for passing.

6. Course Outline 1. Introduction to Radiation and X-rays (slide 7)
2. How do X-ray tubes work? (slide 25)
3. Radiation Biology (slide 33)
4. Your Exposure (slide 48)
5. Personnel Dosimetry (slide 66)
6. Rules and Regulations (slide 77)
7. Working Safely with X-rays (slide 87)
8. Emergency Response (slide 121)

7. 1. Introduction to Radiation and X-rays

8. Wilhelm Conrad Roentgen
In 1895, while doing research on the recently discovered cathode ray, Roentgen identified an unknown invisible ray that he called an “X” ray. He published his findings in 1896.
Within one year of their discovery, documented injuries from exposure to X-rays were recorded.

9. Roentgen exposed his wife’s hand for 15 minutes to produce this image.
This is one of the earliest radiographs taken by Roentgen. It was taken on December 22, 1895, and is an image of his wife’s hand. The dark round object is a ring on her finger.
Roentgen exposed his wife’s hand for 15 minutes to produce this image.
Image copyrighted by Radiology Centennial, Inc.

10. What is Radiation?
RADIATION is ENERGY transmitted in the form of particles or electromagnetic waves.
When radiation has sufficient energy to dislodge the orbital electrons of an otherwise neutrally charged atom, creating an ion pair, it is called IONIZING radiation. Examples of ionizing radiation include alpha particles, beta particles, neutron particles, and X and gamma rays.
Unlike alpha, beta and neutron particles, X and gamma rays have no mass or electrical charge. They are electromagnetic waves and are part of the EM spectrum.

11. The electromagnetic spectrum also includes ultraviolet, visible light, Infrared, microwaves and radio waves. These five groups are forms of non-ionizing radiation: radiation that does not have sufficient energy to create ion pairs.

12. What is Radioactivity?
Radioactivity is the natural property of certain elements and individual nuclides to spontaneously emit ENERGY, in the form of IONIZING RADIATION.
Radioactive material can be a solid, liquid or gas.

13. Pick an Isotope, any Isotope!
X = Element
A = Total number of protons and neutrons in the nucleus
Z = Number of protons
N = Number of neutrons
( A – Z) A X Z

14. C 14 6 A Radioactive Isotope X = Carbon
A = 14 neutrons and protons in the nucleus
Z = 6 protons
N = 8 neutrons 14 C 6

15. Half-Life and Decay
Each radioactive nuclide has its own unique characteristic pattern of decay, such as alpha decay, beta decay, spontaneous fission, and a few others. The energies of the particles or waves emitted will have unique characteristics that can be associated with that specific radionuclide.
The decay rate of a radionuclide is called its half-life. A half-life is the amount of time it takes for one-half of the radioactive atoms present to disintegrate or decay away.

16. Radioactivity Units
The measure of the amount of radioactive material present is the rate at which radiation is being emitted. The unit for this is the Curie (Ci) , or in the SI system, the Becquerel (Bq).
1 Bq = 1 decay per second (dps)
1 Ci = 3.7 x 1010 Bq
1 Ci = = 37,000 Bq

17. Penetrability and Energy
All radiation, thermal, non-ionizing, and ionizing, has the ability to penetrate and transfer its energy to the material it is penetrating.
The term “Linear Energy Transfer”, or L E T, is used to describe the amount of energy imparted locally by ionizing radiation in a target.
The higher the value of a particle’s or wave’s L E T, the greater the amount of energy being transferred per interaction, and the lower its penetrating ability. This also means the greater the risk of potential injury and damage to the material absorbing the energy.

18. Alpha particles have a high L E T
Alpha particles have a high L E T. Their ability to penetrate anything is very low. Alpha particles can be shielded by a piece of paper.
Beta particles have a low L E T, and can only penetrate material of low density. They can be shielded with Plexiglas.
X and gamma rays also have a low L E T. Because they have no mass or electrical charge, they have the highest ability to penetrate material. High density materials are needed to shield against the EM waves.
The following slides show some more details.

19. Po  Pb + He Alpha Radiation () Helium nucleus
2 protons and 2 neutrons
Large, slow, +2e charge
High linear energy transfer (L E T)
Low penetrability
Decay:
Po  Pb + He
210
206 4 2 84 82

20. Beta Radiation () Electron emitted from nucleus
Small, fast, -1e charge
Medium L E T
Medium penetrability
Decay:
Neutron converted into a proton and an electron
P S +  MeV 32 32 15 16

21. Neutrons (n) Neutral particle Classified by energy
Fast neutrons - energy greater than 0.1 MeV
Thermal neutrons - same kinetic energy as gas molecules in the same environment
A concern at nuclear reactors and with soil moisture probes
Emission of neutrons accompanies the splitting of Uranium and Plutonium nuclei

22. Gamma () and X- Radiation
Electromagnetic waves called photons
No mass or electrical charge and can travel at the speed of light
Low L E T
High penetrability
Commonly accompany other radiation
Penetrability can vary; therefore, shielding and detection requirements vary

23. L E T and Penetrability
On the following diagram each dot represents a unit of deposited energy. As you will see from the diagram, alpha particles impart a large amount of energy in a short distance. Beta particles impart less energy than alphas, but are more penetrating. X and Gamma rays impart only a fraction of their total energy each time they interact with the atoms of the target material.

24. LET and Penetrability

25. 2. How do X-ray Tubes Work?
Very simply….
Physics and the law of conservation of energy.

26. An X-ray tube can emit radiation when energized
An X-ray tube can emit radiation when energized. The tube itself is not “radioactive”.
Inside a sealed vacuum tube a high voltage (HV) potential is applied between a cathode and an anode. This creates POTENTIAL ENERGY.

27. Electrons from a heated filament are “boiled” off, caught in the HV potential, and accelerated towards the anode. Electrons have mass. As they accelerate toward the anode they gain KINETIC ENERGY.
The potential energy of the electron at rest on the filament is converted to kinetic energy as the electron picks up speed.

28. The target anode is usually a heavy element whose individual atoms are made up of a highly positively charged nucleus surrounded by an equal number of orbital electrons. As the incoming negatively charged electrons enter the target anode, the electrons are attracted to the positively charged nuclei of the target, and repelled by the orbital electrons.

29. These interactions cause the incoming electrons to lose their kinetic energy. Most of that energy is converted into thermal energy and a tremendous amount of heat is generated in the target. But some of that energy is also converted into electromagnetic waves: X-rays!
There are two types of X-rays that can be produced; Bremsstrahlung and Characteristic X-rays.

30. BREMSSTRAHLUNG X-rays originate from the kinetic energy of the incoming electrons. As these electrons enter the electric field of the atoms in the target anode, they are repelled by the orbital electrons and attracted to the positively charged nucleus. This interaction causes the electron to change direction and lose its energy.
The kinetic energy of the incoming electron is converted into thermal energy and electromagnetic waves: X-rays. The X-rays produced can have an entire range of energies up to a maximum energy of the HV potential that was applied to the tube. For example, an X-ray tube operating at a potential of 80 kilovolts (kVp) can produce X-rays with energies up to 80 kilo-electron volts (keV)!

32. CHARACTERISTIC X-rays are produced by the target atoms themselves
CHARACTERISTIC X-rays are produced by the target atoms themselves. Orbital electrons surround a nucleus in discrete energy shells. If an incoming electron has sufficient energy to knock out an inner orbital electron, a void is created in that energy shell. The void will be filled with another electron from an outer orbital shell.
When the outer orbital electron drops into the inner orbital shell it changes energy levels and emits an X-ray. The energy of the X-ray emitted is equal to the difference in energy levels between the shell the electron comes from to the shell it fills.

33. 3. Radiation Biology
Even though Roentgen was the first to discover X-rays, ionizing radiation was nothing new. Radiation is a part of nature. All living things from the beginning of time have been and are still being exposed to radiation.
Scientists have been studying radiation and its effects for over 100 years. It is one of the most thoroughly researched and understood phenomena known to mankind.
It is NOT a mystery. Even YOU are radioactive!

34. To better understand the effects and risks of exposure to ionizing radiation we need to discuss several key items:
Biological effects from exposure,
Units for measuring radiation exposure, and
Different types of ionizing radiation exposure: Background, Occupational and Acute Exposures.

35. From the very beginning, many had noted the potential problems associated with repeated exposures to high doses of ionizing radiation.
Early X-ray devices were nothing more than glass vacuum tubes. Operators would be repeatedly exposed during the course of a days work.
Image copyrighted by
Radiology Centennial, Inc.

36. Don’t try it at work either!
Wives and female assistants often served as test subjects to determine if a tube was “ready” for the day’s work.
Reddening of the skin and burns to the hand were common.
Don’t try this at home!
Don’t try it at work either!
Image copyrighted by
Radiology Centennial, Inc.

37. It was not until the death of Clarence Dally ( ), that people agreed: X-rays could kill as well as cure. Dally was Thomas Edison’s assistant in X-ray manufacturing and testing.
X-rays were discovered in Radiation survey meters were not introduced until 1928!
Image copyrighted by
Radiology Centennial, Inc.

38. Clarence Dally, along with many other early X-ray users, died from cancer resulting from long and continuous exposure to high doses of ionizing radiation. At that time, medical physicians and technicians who were being repeatedly exposed to high doses of X-rays showed a definitive increase in cancer deaths compared to medical personnel who were not frequently exposed.

39. In addition to obvious injury such as a burn, ionizing radiation can produce biological effects at the cellular level. The primary cause of cell injury is due to the production of free radicals: OH- molecules generated by the ionization of water molecules. These free radicals can form other chemical molecules, such as hydrogen peroxide, sodium or potassium hydroxide, and others. These chemicals can directly damage or destroy a cell’s structure, or even the DNA in the nucleus of a cell.

40. Damage at the cellular level can result in a variety of possible effects, ranging from no ill effect at all to the possible development of a malignant cell that may lead to the development of a cancer.
Cellular injury can be induced by a number of factors, not just exposure to ionizing radiation. Physical injury, sickness, chemicals, heat, cold, and even stress can all cause damage to cells.

41. If the damage is minor, the cell may be able to repair itself
If the damage is minor, the cell may be able to repair itself. If the damage is severe, the cell may die outright. The effect, or more appropriately, the risk of injury from radiation exposure depends on several factors:
The type of radiation (alpha, beta, X, etc.),
The energy of that radiation,
The intensity and duration of exposure, and,
The part of the body being irradiated.

42. Since the discovery of X-rays, it has long been known that very high exposures to radiation over a short period of time will cause very specific effects, from nausea and reddening of the skin to death.
Thanks to a greater recognition of the possible hazards, education and training of users, written operating procedures, proper use of shielding, improvements in design, and the development of radiological safety standards, these types of injuries are uncommon today. However, they still do occur as a result of poor work practices and accidents.

43. The other known risk is the potential for cancer due to long term and repeated exposures to high doses of radiation.
To evaluate the potential risk we need to be able to measure and quantify radiation exposure. The units commonly used for this are:
1. The Exposure Unit
2. Radiation Absorbed Dose Unit, and
3. Dose Equivalence Unit.

44. The Exposure Unit
The exposure unit, known as the Roentgen or “R”, is defined as that quantity of either X or gamma radiation that will, through ionization, produce a total charge of 2.58E-04 coulombs in one kilogram of air at standard temperature and pressure.
The SI unit for exposure is the Coulomb per kilogram of air.
1 C/kg = R

45. Radiation Absorbed Dose
The unit of radiation absorbed dose, or “rad”, refers to the amount of energy from ionizing radiation being deposited in matter. The unit can be used for all types of ionizing radiation.
1 rad = 0.01 Joules of energy absorbed per kilogram of material. The SI unit for absorbed dose is the “Gray” or “Gy”.
1 Gy = 100 rad

46. Dose Equivalence
Research has shown that there are different levels of risk of injury, specifically cancer, from exposure to different forms of ionizing radiation: alpha, beta, neutron, X or gamma. Remember, the effect radiation exposure can have on a living cell depends on the type, energy, intensity, duration, and part of the body being exposed.
The concept of dose equivalence provides a common scale for equating the relative risk from exposure to different forms of ionizing radiation.

47. rem = rad x quality factor
Dose Equivalence
The unit for dose equivalence is the “rem”. It is the product of the absorbed dose in tissue multiplied by a modifying factor. This may also be referred to as a quality factor. For alpha radiation, this quality factor is 20. For beta, X and gamma radiation, this quality factor is 1. The SI unit for dose equivalence is the Sievert (Sv).
rem = rad x quality factor
1 Sv = 100 rem

48. 4. Your Exposure
Current radiation safety practices are focused on keeping your occupational exposure to radiation as low as reasonably achievable. However, the radiation exposure you might receive while working with X-ray equipment is only a fraction of your total radiation exposure!
Radiation is everywhere. You are constantly being exposed to ionizing radiation from many sources. Typically, your greatest source of radiation exposure comes from nature itself. This is called background radiation.

49. Sources of Background Radiation
Average person receives 620 mrem per year
Natural Sources mrem (82%)
Terrestrial mrem
Human Body mrem
Cosmic mrem
Man-made mrem (18%)
Medical mrem
(chest x-ray ~10 mrem)
Commercial Products mrem
(smoke detectors, self-luminous devices)
Other mrem
( fallout, nuclear power, etc.)

50. Terrestrial Radiation
Radioactive material is found throughout nature in soil, water and vegetation.
Some naturally occurring radioactive elements include uranium, thorium and radium. These elements and their decay products have been present since the earth was formed.
Radon, a naturally occurring radioactive gas, is a decay product of uranium and thorium. It can be found in all air everywhere. You are breathing it in right now.

51. Cosmic Radiation
The earth and all living things on it are constantly bombarded by radiation from outer space. Charged particles from the sun and stars interact with the earth’s atmosphere and magnetic field to produce a shower of radiation.
The amount of cosmic radiation varies in different parts of the world due to differences in elevation and the effects of the earth’s magnetic field.

52. The Human Body
People are exposed to radiation from radioactive material inside their own body. Naturally occurring radionuclides include hydrogen-3 (tritium), carbon-14, potassium-40, and many more. Anything that contains hydrogen or carbon is emitting radiation.
You and everyone you know are radioactive!

53. Medical
X-rays were being used for medical purposes as early as 1896! Who hasn’t been to the doctor or dentist and received at least one X-ray in their life?
Radioactive materials are commonly used to perform non-invasive diagnostic studies and therapeutic treatments. These types of studies have been around for decades. Chances are you know someone who has undergone one of these studies.

54. Consumer Products
There are literally hundreds of consumer products that contain radioactive material. Some of the most common are smoke detectors and self-luminous watches.
Cigarettes actually contain naturally occurring radioactive elements absorbed by the tobacco plant as it grow. Smoking 1 pack of cigarettes a day increases your background exposure by 8000 mrem per year!

55. Occupational Exposures
Occupational Exposure is the radiation exposure you receive working with and around radioactive materials or X-ray systems as part of your work.
Federal, State and University regulations limit the amount of radiation dose allowed for occupational adult and minor radiation workers, members of the public, and the fetus of a declared pregnant radiation worker.

56. Occupational Dose Limits
Member of the Public: 100 mrem/year
A member of the public is anyone who may be exposed to radiation as a result of the radioactive materials and radiation producing devices the University uses, but does not occupationally work with the material themselves.
Minor Whole Body 500 mrem / year
A minor is an occupational worker under 18 years of age.
Adult Whole Body 5,000 mrem / year
Adult Extremity 50,000 mrem / year

57. Occupational Dose Limits
A Declared Pregnant Radiation Worker
A “Declared Pregnant” radiation worker is a woman who has chosen to declare their pregnancy in writing to the Radiation Safety Officer. Once “Declared Pregnant”, the employer, Penn State, is required to ensure that the radiation dose to the fetus is kept below 500 mrem over the entire gestation period.
A woman can declare or un-declare her pregnancy at any time.

58. If a woman chooses not to declare her pregnancy, the employer, Penn State, is only responsible for ensuring that the occupational dose to the adult worker is kept below 5000 mrem per year.
For more information on this topic please contact the Radiation Safety Officer. Another excellent source is the Nuclear Regulatory Commission’s Guide 8.13: Instruction Concerning Prenatal Radiation Exposure. A link to this guide can be found at the end of this presentation.

59. REALITY CHECK
For regulatory and radiation protection purposes, it is ASSUMED that even small exposures to radiation carry some increased risk of causing cancer.
However, THERE IS NO SCIENTIFIC EVIDENCE THAT CONCLUSIVELY PROVES LOW DOSES OF RADIATION CAUSE CANCER!
The annual background exposure level for Pennsylvania residents is 620 millirem per year.
The average annual occupational dose for a Penn State radionuclide or X-ray user is less than 20 millirem per year!

60. Acute Exposures
Despite training, shielding, and multiple safety features, accidents still happen. A very high exposure to radiation over a short period of time will result in a direct and clearly related effect that occurs soon after the exposure.
This is called an ACUTE EXPOSURE and usually occurs following an accidental overexposure to the primary beam of the X-ray system.
Radiographic systems are a whole body exposure hazard.
Analytical systems are an extremity exposure hazard.

61. Biological Effects from an Acute Whole Body Radiation Exposure
25 – 200 rad (25,000 – 200,000 mrad)
Nausea and vomiting, malaise and fatigue, increase in body temperature and blood changes.
200 – 1000 rad
Hemopoietic Syndrome: Ablation of the bone marrow. Death results within months if untreated.
1000 – 2500 rad
Gastrointestinal Syndrome: Desquamation of the intestinal epithelium. Death results within weeks if untreated.
2500 rad and up
Central Nervous System Syndrome: Unconsciousness within minutes to hours. Death results within hours to a few days. There is no treatment.

62. Biological Effects from an Acute Extremity Radiation Exposure
Erythema, a reddening of the skin similar to a first degree burn. Pigmentation changes can also occur, resulting in a lightening or darkening of the exposed area. Full recovery usually occurs.
800 – 3000 rad
Effects similar to those of a second degree burn resulting in ulcerations of the injured area. Wound may become infected.
3000 rad and up
Effects similar to a third degree burn. Tissue damage may be permanent or worse. Necrosis of the tissue may require skin grafts or amputation of the injured area.

63. An Acute Exposure Example
While working late one night and performing a beam alignment procedure, you realize that you forgot to close the shutter before removing a beam stop. Your hand was accidentally exposed to the primary beam on an analytical system.
The dose rate was measured and determined to be 6000 rad per minute. Your hand was in the beam 15 seconds.
What dose did you receive and what would be the result?

64. If you answered 1500 rem your were correct!
Dose rate: 6000 rad per minute
Exposure time: 15 seconds (0.25 minutes)
Absorbed dose
= Dose rate x exposure time
= 6000 rad/min x min
= 1500 rad
Dose Equivalent
= rad x quality factor
= 1500 x 1
= 1500 rem

65. This type of acute exposure to the hand could cause second degree burns, blistering and ulcerations of the exposed area. However, these effects may not be seen till several days after the accidental exposure.
Later in this training we will discuss what to do if you suspect you may have been accidentally exposed to the primary beam of an X-ray system.

66. 5. Personnel Dosimetry
PSU requires personal dosimeters for X-ray equipment users in some cases. A personnel dosimeter can only monitor your radiation exposure. It cannot protect you from radiation.
Radiographic devices are typically a whole body radiation exposure hazard. Users of these systems are issued whole body dosimeters.
Analytical devices are an extremity exposure hazard. Users of analytical x-ray devices are not issued a badge unless they are performing open-beam calibration.
Users of medical and veterinarian x-ray units are issued dosimeters based on the machine they will be using.

67. Penn State uses the LUXEL dosimeter supplied by Landauer, Inc
Penn State uses the LUXEL dosimeter supplied by Landauer, Inc. This monitor is capable of measuring the radiation dose from exposure to gamma, X and higher energy beta radiation to the nearest 1 mrem above background per calendar quarter.

68. Environmental Health & Safety is responsible for maintaining dosimetry records. These records are considered confidential information.
Dosimeters are issued on a quarterly basis. Once you have been issued a dosimeter, you will receive a replacement badge every January, April, July and October.
The quarterly exchange is may be completed through a central department contact, such as at MRL, or your new badge may arrive by campus mail. Simply pop out the old badge from its holder and snap in the replacement. Place the old badge back in the envelope and return to EHS by campus mail as soon as possible.

69. How to Wear Your Dosimeter
Medical, Veterinary and Industrial X-ray users are issued whole-body dosimeters. These should be worn on the upper torso, between your waist and collar.
If you are using a lead apron wear the dosimeter on the outside of the apron.

70. Analytical X-ray users are issued extremity wrist dosimeters if they will be performing open-beam calibrations. Each system is set up differently and how you wear your dosimeter depends on you and the system set up
In short, if you are issued a badge for these calibrations, wear your dosimeter on the hand you would normally use to change the sample and with the badge facing towards the X-ray tube.

71. Analytical X-ray Users
For example, in this picture, the tube is on the right hand side and the user is right handed. The badge is on the right hand with the dosimeter facing the tube.

72. Analytical X-ray Users
In this picture the tube is on the right side but the user is left handed. The badge is on the left hand with the dosimeter on the inside of the wrist facing the source of X-rays.

73. Proper Dosimeter Use
Dosimeters will only be issued to personnel who have completed the PSU required radiation safety training.
The dosimeter you are issued is only to be used at Penn State facilities.
Dosimeters should be stored in your office when not in use. Please avoid taking them home.
All dosimeters, including those that were not used, must be returned to Environmental Health & Safety Office on a quarterly basis.
Never use or tamper with someone else's dosimeter.

74. Proper Dosimeter Use Report any lost or damaged dosimeter immediately.
Report any suspected overexposures immediately.
Promptly notify EHS when the dosimeter is no longer needed.
You will be notified of any dosimeter readings in excess of 10% of the regulatory dose limits. You may also make a written request for your dosimetry results from the EHS office at any time.
There will be a charge for dosimeters that are not returned promptly (10 days) after the new dosimeters are issued during the quarterly exchange.

75. How do I get a Dosimeter?
Now might be good time to download the dosimeter request form if you will need one based on the criteria highlighted in the previous slides. Simply go to:
Request Form.pdf
Download and print out the form. Read the instructions and then fill in all the information. You will need to have your supervisor’s signature as well.
Bring the application with you when you are scheduled to attend Part 4 of the X-ray Safety Training Course.

76. REALITY CHECK
It is important to remember that ALL forms of radiation are capable of causing injury.
Standing by a fire will keep you warm. Stand too close and you get burned.
Exposure to ultraviolet light can help you get a nice tan. It is also the leading cause of skin cancer

77. 6. Rules and Regulations

78. Radiation-Producing Instruments
Radiation-producing instruments are regulated by the Pennsylvania Department of Environmental Protection, Bureau of Radiation Protection (PA DEP BRP). Additional regulations of the U. S. Nuclear Regulatory Commission (NRC) and U. S. Food and Drug Administration (FDA) may also apply.
Simply put, if a device generates x-rays for the purpose of utilizing those x-rays, the instrument is regulated.

79. Regulated Equipment Includes
Medical X-ray systems
Veterinary X-ray systems
Industrial radiography systems
Analytical X-ray systems
Electron microscopes
X-ray vacuum spectroscopy systems
Electron beam welders
Some high voltage equipment

80. The University
Penn State has established a University safety policy (SY15) governing the acquisition, installation, operation, control, disposal and University compliance with State and Federal regulations. This policy applies to University owned radiation-producing instruments at all Penn State locations except the Hershey Medical Center.
The policy can be found at:
Time to review the responsibilities outlined in the policy.....

81. EHS’ Responsibilities
Environmental Health & Safety is responsible for the oversight, implementation, and enforcement of the radiation-producing instrument safety program at Penn State. EHS shall…….
Provide radiation safety training,
Issue personnel dosimeters,
Track the University’s inventory of instruments,
Perform required annual safety inspections and radiation survey checks, and,
Maintain all required records.

82. THE R S O The Radiation Safety Officer for Penn State is:
Certified Health Physicist
228 Academic Projects Building
University Park, PA
(phone)
(fax)

83. Supervisor’s Responsibilities
Supervisors are responsible for the safe operation and maintenance of the radiation-producing instruments under their control. Supervisors shall also…..
Adhere to the requirements of the University’s Safety Policy on radiation-producing instruments,
Notify EHS of the acquisition, modification, transfer or disposal of systems, and,
Develop written operating procedures for each instrument and provide training on those procedures to respective users.

84. Acquisitions & Transfers
Supervisors must notify EHS whenever a system is acquired. EHS will inspect the system for required labels, safety devices, radiation levels, and location to assure user and non-user safety. The system may not be put into routine service until approved.
Instruments transferred, donated, or sold to another supervisor, institution, or company require a written notification to the PA DEP-BRP. Supervisors are responsible for informing EHS prior to the transfer of the equipment. EHS is responsible for providing the written notification to the State.

85. Disposals
Disposal of radiation-producing instruments is typically done through University Salvage. However, before disposing of a system you must take into account the proper disposal of all hazardous substances. Lead, oils, and x-ray tubes containing beryllium must be removed from the device and disposed of as Hazardous Waste. Contact EHS for proper guidance and disposal.
Supervisors must inform EHS when a system is to be permanently removed from service, either to be disposed or to be used for spare parts. EHS must notify the State that these systems are no longer in service so that they can be removed from the University’s inventory.

86. User’s Responsibilities
Users of radiation-producing instruments are required to complete this safety orientation before beginning work with X-ray devices. Users must also……
Follow all written operating procedures,
Immediately report to the Supervisor any unusual or unsafe condition you discover, and,
Immediately notify EHS and their Supervisor if they have or even suspect they have accidentally been exposed to the primary beam of X-rays.

87. 7. Working Safely with X-rays:
Lights,
Labels, and the
Pursuit of Data!

88. just a note….
The majority of students who take this course will be using analytical X-ray systems. The information and presentation that follows is geared towards that need. However, most of the topics discussed are also relevant to medical, veterinary, and industrial systems as well.

89. The first place to start when it comes to working safely with X-ray equipment is with the written operating procedures. These procedures must be reviewed before using the instrument.
The scope of the procedures will vary depending on the type and intended use of the instrument. Procedures shall include as a minimum that which satisfies the state regulations governing the specific type of instrument. Links to those regulations can be found at the end of this presentation.

90. 1: Exposure to the primary beam;
The next step is to identify and address the possible sources of radiation exposure you may encounter with the X-ray system. There are three areas that pose a risk of radiation exposure to the user and bystanders;
1: Exposure to the primary beam;
2: Exposure to leakage from the tube housing; and,
3: Exposure to the scattered radiation field.

91. Primary Beam
Exposure to the primary beam usually only happens in accidental situations. The risk of exposures can be minimized by good engineering design, safety features such as fail-safe lights, and interlocks. A label with the words “Caution –High Intensity X-ray Beam” must be attached near the tube head or in the area of the primary beam path.

92. Leakage Radiation
Leakage radiation refers to the radiation field around a shielded tube, excluding the primary beam. Leakage can occur around shutter assemblies, collimators, joints, and seams of the tube head assembly.
Surveys for any changes in the leakage radiation levels must always be done following X-ray tube, collimator, or shutter replacements.

93. Scattered Radiation
Whatever the primary beam strikes, such as the sample, patient, detector, and beam stop, will produce a field of scattered radiation. The scattered radiation field will be much lower in intensity and energy than the primary beam. It can easily be shielded. Most analytical systems use an enclosure shield that serves two purposes: to shield the user from the scattered radiation and keep the user’s hands out of the primary beam.

94. A L A R A
The fundamental principle of radiation safety is to keep occupational radiation exposures As Low As is Reasonably Achievable.
The three primary ways to apply this principle is through proper application and use of time, distance, and shielding.

95. Minimize Your Exposure Time
Your radiation dose is a function of time. A medical X-ray unit may produce dose rates in the primary beam around 4000 R per hour, but is only activated for a fraction of a second.
Analytical systems can produce dose rates up to 400,000 R per minute, BUT THE PRIMARY BEAM IS USUALLY ALWAYS LEFT ON!

96. Maximize the Distance
As with all forms of radiation, increasing the distance between yourself and the source of radiation will decrease your dose.
Ionizing radiation follows the inverse square law. Doubling the distance decreases the dose by a factor of four. Tripling the distance decreases the dose nine-fold!

97. Use Appropriate Shielding
Increasing the distance is not always the most practical means of reducing one’s exposure. Shielding is the most common and usually cost effective means of keeping doses as low as reasonably achievable.
For example, if you work with radiography equipment, using a lead apron may be appropriate. If you work with analytical X-ray equipment, using leaded Plexiglas instead of unleaded is preferred.

98. Of course, it is always easier and much more comfortable to shield the X-ray tube and install an enclosure shield than it is to shield yourself.
Image copyrighted by
Radiology Centennial, Inc.

99. Safety Features
Most X-ray systems have a variety of safety devices designed to protect the user from an accidental exposure to the primary beam. These include warning lights, labels, interlocks and shield enclosures.
Some of these devices may be of Fail-Safe design, meaning that if the safety feature fails to work the X-ray system is placed in a safe configuration for the user.

100. Fail Safe Features
For example, if an “X-ray-On” light burns out, the tube will not energize. Or, if a shutter light fails the shutter may not open. Interlocks on the shield enclosure may be designed to automatically close the shutter when the enclosure door is opened.
BEWARE! Even Fail-Safe features can fail. The following two slides are a real example of how this can and does happen……

101. Shutter Problems
Oxidation build-up is a common problem in analytical x-ray systems. This is an exterior view of a shutter assembly. The oxidation build-up was not visible due to a collimator that was attached to the filter wheel.
This picture was taken at Penn State!

102. Shutter Problems
Interior view of shutter assembly showing oxidation build-up around the beam port. Large flakes of oxidized material blocked the channel that the shutter slides in, preventing the shutter from closing properly and resulting in a potential hand exposure.

103. REALITY CHECK
Fail-Safe systems are only mechanical devices. THEY CAN FAIL!!!
Also, not all X-ray systems are equipped with Fail-Safe features. Check with the supervisor and operating procedures to verify what safety features are in place and how they work.

104. X-ray On Light
An “X-ray” or “HV On” light must be near the tube head. This warns the user that the tube is energized and generating X-rays.

105. Shutter Indication Lights
Whenever you change a sample, always check the shutter indication lights on both the control panel and the shutter assembly, to verify the shutter is in a closed and safe configuration.

106. Enclosure Shields & Interlocks
Most analytical systems have an enclosure shield designed to protect the user from the radiation scattered off the sample, detector and beam stops.
NOT ALL ENCLOSURE SHIELDS ARE INTERLOCKED !!!!

107. Labels
A label bearing the words “Caution Radiation – This Equipment Produces Radiation When Energized” must be near any switch that energizes the X-ray tube.

108. REALITY CHECK
ANYTIME there is high voltage applied to the tube, X-rays are being generated.
Even if the filament current is set to zero, the HV potential alone is enough to generate X-rays!
The safest way to work with X-ray equipment is to turn the system completely off.
No electricity, no X-rays. Simple and safe.

109. Radiation Surveys and Safety Inspections
The only way to ensure all the safety devices in place are working properly is to perform radiation surveys and safety checks.
The Environmental Health and Safety Office will perform these checks on an annual basis, as required by state regulations. Supervisors and users should also perform these checks at frequent intervals.

110. When Else Should I Survey?
When the equipment is first installed.
During maintenance or alignment procedures that require the presence of a primary X-ray beam.
During and following maintenance that requires the disassembly or removal of key components such as a shutter, collimator, or x-ray tube replacement.
Following changes that could affect the scattered radiation field such as changes in shielding, beam stops, detector systems or the shield enclosure.

111. Bypassing a Safety Device
Only the University’s Radiation Safety Officer (RSO) can authorize the deliberate bypassing of an installed safety system or device, including shielding, interlocks, warning lights and alarms.
The RSO may only approve a temporary bypass for no more than 30 days.

112. Bypassing a Safety Device
The ONLY exceptions to this requirement are system maintenance or beam alignment procedures that require the presence of a primary beam. In these cases the procedures necessary to perform the task must be documented and included with the other operating procedures for the system.
All safety devices must be reinstated before returning the system to routine use.

113. Anything else? We’re tired!

114. Other X-ray System Hazards
Radiation is not the only safety concern you may encounter when working with X-rays. Electrical, chemical and temperature hazards may cause serious injury and even death. Take time to identify the other possible safety issues and use proper safety controls to minimize the chance for injury.

115. Electrical
All X-ray systems operate on high voltage. The generator and other electrical components are normally enclosed in a protective cabinet that provides a barrier between open electrical terminals and the user.
In this picture, the cabinet is located below the tube.

116. Electrical
X-ray tube changes, maintenance and repairs are only to be performed by someone trained and experienced in electrical safety.
Cover panels must be replaced for user safety. Open wiring and high voltage are a DEADLY combination.

117. Chemical
There are many chemical hazards associated with X-ray systems. Analytical X-ray tubes contain beryllium, a toxic metal. Unless they are being returned to the manufacturer, all X-ray tubes must be disposed of as hazardous waste.

118. Chemical
Other chemical hazards include lead, oils, and sometimes even the material being analyzed. Many samples contain heavy metals that may also be toxic. Some users are even analyzing biological materials.
Always contact EHS for guidance on chemical safety and proper waste disposal.

119. Temperature
Many analytical systems use detectors cooled with liquid nitrogen, a cryogenic liquid with a temperature of -195 C!
Splashes of liquid nitrogen on your hands will cause burns immediately. If it splashes in your eyes it can blind you!

120. Temperature
Filling dewars with liquid nitrogen usually results in the liquid boiling and splashing out of the spout and the dewar.
ALWAYS wear a shield to protect your face and eyes.
ALWAYS wear gloves to protect your hands.

121. 8. Emergency Response

122. Emergency Response
Exposure to the primary beam of an analytical or radiographic x-ray source may result in serious injury. These accidental exposures typically occur during sample changes, maintenance, and beam alignment procedures.
These exposures also happen when safety devices fail or are deliberately circumvented.

123. Emergency Response
Always check to see that beam stops or shutters for the primary beam are in place. Check the control panel AND the shutter indication light to verify the shutter is in a closed and safe condition.
If a situation arises where you have or even remotely suspect that you have been accidentally exposed, take the following action IMMEDIATELY….

124. Emergency Response
Shut off the X-ray equipment and secure it from use by other individuals.
DO NOT CHANGE THE EXPERIMENTAL OR EQUIPMENT CONFIGURATION.
Determining the exposed individual’s actual dose is most accurately done when the accident conditions can be reconstructed exactly as they happened.

125. Emergency Response
Contact EHS at Inform them that an individual working with an X-ray device may have received an accidental radiation overexposure and that you need to contact the Radiation Safety Officer immediately.
Inform the supervisor of the system about the accident.
If this is a life threatening emergency, such as electrical shock, fire, etc., dial 911 for emergency response.

126. Who Should I talk to if I have a Safety Concern?
First talk to the supervisor of the system. They should be able to answer any questions you have regarding proper operation and safety features in place with the system you are using.
For additional safety information always check with your Department or College Safety Officer. If you are not sure who that person may be, contact EHS for the information.

127. You can always contact EHS if you still have questions or concerns
You can always contact EHS if you still have questions or concerns. It is our job and responsibility to address all safety issues raised by any Penn State student or employee.
If after talking to EHS you still feel your safety concerns are not being addressed, you have the right to contact the Pennsylvania Department of Environmental Protection – Bureau of Radiation Protection (PA DEP BRP).

128. Notice to Employees
Posted near all labs that have radiation-producing instruments you will find a PA DEP BRP “NOTICE TO EMPLOYEES” form. This form lists the responsibilities of Pennsylvania licensees who possess and use radiation-producing instruments.
It also provides the address and phone numbers of PA DEP-BRP offices for employees to contact if they feel that their safety concerns are not being addressed by their employer. Their web address is listed at the end of this presentation.

129. Congratulations!
You have just completed Part 1 of the X-ray safety training course!
Part 2 is the online quiz.
Part 3 is online sign-up for the practical class.
Part 4 is the practical class in 229 Academic Projects Building
Also, don’t forget to bring your dosimeter request form when you come for the practical class if you will need one.

130. Web Resources A Century of Radiology
Environmental Health and Safety
EHS Dosimeter Request Form

131. Web Resources Health Physics Society - Expert’s Answers
NRC Regulatory Guide 8.13
PA DEP BRP

132. Links to the State Regulations
Start with:
And then type in the ending….
Link to all: articlesIDV_toc.html
Medical: chapter221/chap221toc.html
Veterinary: chapter223/chap223toc.html
Industrial: chapter225/chap225toc.html
Analytical: chapter227/chap227toc.html
Accelerators: chapter228/chap228toc.html