1 presentation is adapted from carnegie mellon university radiation producing device requirements...

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Presentation is adapted from

Carnegie Mellon UniversityRadiation Producing

Device Requirements and Safety

Training12-2004 Rev.2

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Radiation FundamentalsRadiation Fundamentals

Definition of RadiationDefinition of Radiation: The transfer of : The transfer of energy, in the form of particles or energy, in the form of particles or waves as it passes through a medium.waves as it passes through a medium.

Radioactive MaterialRadioactive Material: A material-solid, : A material-solid, liquid or gas-which emits radiation liquid or gas-which emits radiation spontaneously.spontaneously.

Radiation Producing DeviceRadiation Producing Device: A device : A device capable of producing ionizing radiation, capable of producing ionizing radiation, except those devices with radioactive except those devices with radioactive material as the only source of radiationmaterial as the only source of radiation..

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Radiation Fundamentals (cont.)Radiation Fundamentals (cont.)

Dose or Radiation DoseDose or Radiation Dose:: a generic term a generic term that means absorbed dose or dose that means absorbed dose or dose equivalent. The units for does equivalent equivalent. The units for does equivalent are the REM and the Sievert.are the REM and the Sievert.

Absorbed doseAbsorbed dose:: the energy imparted by the energy imparted by ionizing material. The units of absorbed ionizing material. The units of absorbed dose are the RAD and the gray dose are the RAD and the gray

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Radiation Fundamentals (cont.)Radiation Fundamentals (cont.) RADRAD: is a unit used to measure a quantity : is a unit used to measure a quantity

called absorbed dose. This relates to the called absorbed dose. This relates to the amount of energy actually absorbed in some amount of energy actually absorbed in some material. It does not describe the biological material. It does not describe the biological effects of the different radiations.effects of the different radiations.

REMREM: the special unit of any of the : the special unit of any of the quantities expressed as dose equivalent. quantities expressed as dose equivalent.

The dose equivalent in rems is equal to the The dose equivalent in rems is equal to the absorbed dose in rads multiplied by the absorbed dose in rads multiplied by the quality factor (1 rem = 0.01 sievert).quality factor (1 rem = 0.01 sievert).

The quality factor for x rays is 1. The quality factor for x rays is 1. 1 RAD of X ray exp. = 1 REM 1 RAD of X ray exp. = 1 REM

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Radiation Fundamentals (cont.)Radiation Fundamentals (cont.) Gray (GyGray (Gy): the Systems International unit of ): the Systems International unit of

absorbed dose, 1 gray is equal to an absorbed dose, 1 gray is equal to an absorbed dose of 1 joule / kilogram (1 Gy absorbed dose of 1 joule / kilogram (1 Gy =100 rads).=100 rads).

SievertSievert: the SI unit of any of the quantities : the SI unit of any of the quantities expressed as dose equivalent(1 Sv = 100 expressed as dose equivalent(1 Sv = 100 rems).rems).

Declared pregnant womanDeclared pregnant woman: a woman who : a woman who has voluntarily informed her employer, in has voluntarily informed her employer, in writing, of her pregnancy and the estimated writing, of her pregnancy and the estimated date of conception. date of conception.

77An individual in CO receives an average of 360 (Denver) or 450 (Mountains) mRem annual exposure from background.

What is Background Radiation?Radioactive materials surround us constantly; radioactive materials are located in the air we breath, the ground we walk on, even inside of our bodies. It consists of radiation from cosmic sources; naturally occurring radioactive materials, including radon and global fallout as it exists in the environment from the testing of nuclear explosive devices.

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Two types of radiation

RF wave infrared visible uv x ray -ray cosmic

Ionizing Radiation - can deposit energy in neighboring atoms resulting in the removal of electrons.

Non Ionizing - does not have enough energy to remove electrons from surrounding atoms.

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X rays are photons (electromagnetic radiation) which originate in the energy shells of an atom

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 absorbed

What are X rays?

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• Medical

• Industrial

• Research

• Environmental

• Construction

• Teaching

• Imaging: Isotopic & Non Isotopic - Non Destructive Testing

• Gauges for precision: thickness, density, moisture, elemental makeup, sterility, airport security & bomb squads

Modern uses of the X ray

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Open Beam Van de Graff Accelerator

Examples of X - Ray Generating Devices

XRD Tin/Polycarbonate/Leaded enclosure

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Regulatory RequirementsRegulatory Requirements X-ray generating devices are regulated by X-ray generating devices are regulated by

the State of Colorado the State of Colorado

Registered with the Department of Public Registered with the Department of Public Health and EnvironmentHealth and Environment

Regulations: Colorado 6CCR 1007-1 Parts 1, Regulations: Colorado 6CCR 1007-1 Parts 1, 2, 4, 82, 4, 8

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Personnel Requirements

MUST receive instruction in and demonstrate competence as to:

• Identify hazards of operating X-Ray generating devices• Significance of warning and safety devices (Bypassing interlocks)• Written operating procedures-must be trained on each device• Symptoms of acute exposure & procedures for reporting actual or suspected exposure • Survey & personnel monitoring equipment

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Sources of Radiation ExposureSources of Radiation Exposure

The next step is to identify and address the The next step is to identify and address the possible sources of radiation exposure you possible sources of radiation exposure you may encounter with the X-ray system. may encounter with the X-ray system. There are three areas that pose a risk of There are three areas that pose a risk of radiation exposure to the user and radiation exposure to the user and bystanders;bystanders;

1: Exposure to the primary beam;1: Exposure to the primary beam;2: Exposure to leakage from the tube 2: Exposure to leakage from the tube housing;housing; and, and,3: Exposure to the scattered radiation field.3: Exposure to the scattered radiation field.

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Primary BeamPrimary Beam

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

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Leakage RadiationLeakage RadiationLeakage radiation refers to the radiation field Leakage radiation refers to the radiation field around a shielded tube, excluding the primary around a shielded tube, excluding the primary beam. Leakage can occur around shutter beam. Leakage can occur around shutter assemblies, collimators, joints, and seams of the assemblies, collimators, joints, and seams of the tube head assembly.tube head assembly.

Surveys for any changes in the leakage Surveys for any changes in the leakage radiation levels must always be done following radiation levels must always be done following X-ray tube, collimator, or shutter replacements. X-ray tube, collimator, or shutter replacements. However, you are not permitted to perform such However, you are not permitted to perform such replacements at any time without approval from replacements at any time without approval from the Radiation Safety Office.the Radiation Safety Office.

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Scattered RadiationScattered Radiation

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

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Radiation Exposure LimitsRadiation Exposure Limits

Most likely your employer is using Most likely your employer is using General Public guidelines, no more than General Public guidelines, no more than 100mrem/yr100mrem/yr

For “Occupational radiation workers, For “Occupational radiation workers, there are exposure limits for parts of the there are exposure limits for parts of the bodybody• The whole body (consisting of the head, torso The whole body (consisting of the head, torso

to knees, to elbows) has an annual exposure to knees, to elbows) has an annual exposure limit of 5 REMlimit of 5 REM

• The extremities (consisting of the elbows and The extremities (consisting of the elbows and below and the knees and below) has an below and the knees and below) has an annual exposure limit of 50 REMannual exposure limit of 50 REM

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Why the Difference in Exposure Why the Difference in Exposure Limits?Limits?

Answer-Answer-RadiosensitivityRadiosensitivity: Cells of the : Cells of the human body respond to radiation human body respond to radiation differently, some are more sensitive differently, some are more sensitive than others i.e. Lymphatic and bone than others i.e. Lymphatic and bone marrow.marrow.

In other words, the cells in the region In other words, the cells in the region defined as your whole body are more defined as your whole body are more sensitive to radiation than the cells in sensitive to radiation than the cells in your extremities. Therefore, the your extremities. Therefore, the annual exposure limit for your whole annual exposure limit for your whole body is lower.body is lower.

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Main Causes of AccidentsMain Causes of Accidents Main causes of accidents when using Main causes of accidents when using

X-Ray producing devices: Poor X-Ray producing devices: Poor equipment configuration, equipment configuration, manipulation of equipment when manipulation of equipment when energized, equipment failure, energized, equipment failure, inadequate training and inadequate training and failure to use failure to use the survey instrument.the survey instrument.

Accidents can often lead to what is Accidents can often lead to what is know as an know as an acute exposureacute exposure or a large or a large exposure occurring in a short period exposure occurring in a short period of time.of time.

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Biological Effects of an Acute Biological Effects of an Acute ExposureExposure

25-100 REM: Minor blood 25-100 REM: Minor blood changes changes

100-200 REM: Nausea, 100-200 REM: Nausea, vomiting, diarrhea, hair vomiting, diarrhea, hair loss, skin reddening loss, skin reddening

200-300 REM: Same as 200-300 REM: Same as above plus internal above plus internal bleedingbleeding

Above 300 REM: Severe Above 300 REM: Severe blood disorders & deathblood disorders & death

>450 REM: LD 50 = 50% >450 REM: LD 50 = 50% of test animals will die of test animals will die within 30 days without within 30 days without medical attention; blood medical attention; blood transfusions & bone transfusions & bone marrow transplants.marrow transplants.

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Procedure for reporting an overexposure or accident:

Emergency Procedures should be posted:

In the event of an emergency or possible radiation exposure:

Call the Radiation Safety Office ____________ or after hours call “RSO” on his cell phone ________________

If unavailable, call “Alternate RSO or SO” at __________ or after hours on his cell phone ______________

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Controlling Exposures-ALARAControlling Exposures-ALARA ALARA is probably the most important ALARA is probably the most important

acronym in radiation safety and it stands acronym in radiation safety and it stands for- for- As Low As Reasonably Achievable.As Low As Reasonably Achievable.

ALARA is a mandated legal requirement and ALARA is a mandated legal requirement and can be maintained using three important can be maintained using three important methods:methods:• TimeTime-Decrease time in area (Practice, Dry -Decrease time in area (Practice, Dry

runs) follow procedure!runs) follow procedure!• DistanceDistance-Increase distance between you -Increase distance between you

and the source-Avoid beam.and the source-Avoid beam.• ShieldingShielding-Utilize shielding - add sheets of -Utilize shielding - add sheets of

lead and use collimators. lead and use collimators.

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Minimize Your Exposure TimeMinimize Your Exposure Time

Your radiation dose is a function of time. A Your radiation dose is a function of time. A medical X-ray unit may produce dose rates medical X-ray unit may produce dose rates in the primary beam around 4000 REM per in the primary beam around 4000 REM per hour, but is only activated for a fraction of a hour, but is only activated for a fraction of a second.second.

Analytical systems however can produce Analytical systems however can produce dose rates up to 400,000 REM per minute dose rates up to 400,000 REM per minute (6000 REM+ per second), BUT THE PRIMARY (6000 REM+ per second), BUT THE PRIMARY BEAM IS USUALLY ALWAYS LEFT ON!BEAM IS USUALLY ALWAYS LEFT ON!

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Maximize the DistanceMaximize the Distance

As with all forms of radiation, increasing As with all forms of radiation, increasing the distance between yourself and the the distance between yourself and the source of radiation will decrease your source of radiation will decrease your dose.dose.

Ionizing radiation follows the inverse Ionizing radiation follows the inverse square law. Doubling the distance square law. Doubling the distance decreases the dose by a factor of four. decreases the dose by a factor of four. Tripling the distance decreases the dose Tripling the distance decreases the dose nine-fold!nine-fold!

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Use Appropriate ShieldingUse Appropriate Shielding

Increasing the distance is not always the Increasing the distance is not always the most practical means of reducing one’s most practical means of reducing one’s exposure. Shielding is the most common exposure. Shielding is the most common and usually cost effective means of and usually cost effective means of keeping doses as low as reasonably keeping doses as low as reasonably achievable.achievable.

For example, if you work with radiography For example, if you work with radiography equipment, using a lead apron may be equipment, using a lead apron may be appropriate. If you work with analytical X-appropriate. If you work with analytical X-ray equipment, using leaded Plexiglas ray equipment, using leaded Plexiglas instead of unleaded is preferred.instead of unleaded is preferred.

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Required Signs/Documents for Locations Required Signs/Documents for Locations Housing X-Ray Producing DevicesHousing X-Ray Producing Devices

Rooms must contain signage on the Rooms must contain signage on the outside of the room indicating an X-Ray outside of the room indicating an X-Ray producing device is located within.producing device is located within.

Rooms must be locked while devices with Rooms must be locked while devices with operational interlocks are in operation and operational interlocks are in operation and unattended.unattended.

A PA DEP “Notice to Employees” as well as A PA DEP “Notice to Employees” as well as an Emergency Procedures form must be an Emergency Procedures form must be present inside the room and must be present inside the room and must be visible and accessible at all times.visible and accessible at all times.

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Required Documents for X-Ray Required Documents for X-Ray Producing DevicesProducing Devices

Source housings and operational switches must Source housings and operational switches must be labeled, especially any switch that turns x-ray be labeled, especially any switch that turns x-ray onon

Written operating procedures must be present for Written operating procedures must be present for each device and must be read and understood by each device and must be read and understood by each person who will be using the deviceeach person who will be using the device

Inventory, safety circuits and surveys results Inventory, safety circuits and surveys results must be recorded every 6 monthsmust be recorded every 6 months

Optional: Log books must be present and must be Optional: Log books must be present and must be used each time the X-ray producing device is used each time the X-ray producing device is energizedenergized

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Warning and Safety DevicesWarning and Safety Devices

• Operators must be made aware of the Operators must be made aware of the significance of the various radiation significance of the various radiation warning and safety devices and warning and safety devices and interlocks incorporated into the interlocks incorporated into the equipment and the extra precautions equipment and the extra precautions necessary if the devices are absent or necessary if the devices are absent or bypassed. bypassed.

• Area postings to indicate x-rays are Area postings to indicate x-rays are being usedbeing used

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X-ray On LightX-ray On Light

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

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Shutter Indication LightsShutter Indication Lights

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

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Enclosure Shields & InterlocksEnclosure Shields & Interlocks

Most analytical Most analytical systems have an systems have an enclosure shield enclosure shield designed to protect designed to protect the user from the the user from the radiation scattered off radiation scattered off the sample, detector the sample, detector and beam stops.and beam stops.

NOT ALL ENCLOSURE NOT ALL ENCLOSURE SHIELDS ARE SHIELDS ARE INTERLOCKED !!!!INTERLOCKED !!!!

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LabelsLabels

A label bearing the words “Caution –A label bearing the words “Caution –High Intensity X-ray Beam” must be High Intensity X-ray Beam” must be attached near the tube head or in the attached near the tube head or in the area of the primary beam path.area of the primary beam path.

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LabelsLabels

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

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Radiation Surveys and Radiation Surveys and Safety InspectionsSafety Inspections

The only way to ensure all the safety The only way to ensure all the safety devices in place are working properly is to devices in place are working properly is to perform radiation surveys and safety perform radiation surveys and safety checks.checks.

The Radiation Safety Officer will perform The Radiation Safety Officer will perform these checks on an semi-annual basis, as these checks on an semi-annual basis, as required by state regulations. Supervisors required by state regulations. Supervisors and users should also perform these and users should also perform these checks at frequent intervals.checks at frequent intervals.

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Radiation Monitoring Equipment With the use of a survey instrument we can determine

the exposure rate in the area.

A Pre-Operational Check must be completed prior to using an instrument. This check consists of a physical assessment, calibration check, battery check and response to radiation.

Readout is in milliRoentgen (mR) /hour.

Typical background is ~0.02 mR/h

Contact the RS Office should the device fail any of the checks.

A survey is to be performed at the beginning, during and upon completion of using a x-ray generating device

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When Else Should a Survey Be When Else Should a Survey Be Performed?Performed?

The Radiation Safety Officer will perform a The Radiation Safety Officer will perform a survey:survey:• When the equipment is first installed.When the equipment is first installed.• During maintenance or alignment procedures that During maintenance or alignment procedures that

require the presence of a primary X-ray beam.require the presence of a primary X-ray beam.• During and following maintenance that requires During and following maintenance that requires

the disassembly or removal of key components the disassembly or removal of key components such as a shutter, collimator, or x-ray tube such as a shutter, collimator, or x-ray tube replacement.replacement.

• Following changes that could affect the scattered Following changes that could affect the scattered radiation field such as changes in shielding, beam radiation field such as changes in shielding, beam stops, detector systems or the shield enclosurestops, detector systems or the shield enclosure. .

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Analytical X-Ray Training Outline Analytical X-Ray Training Outline and Certificationand Certification

This certification is good for only one device.This certification is good for only one device.

You must be specifically trained on each You must be specifically trained on each device prior to operating it.device prior to operating it.

At the time of device training the instructor At the time of device training the instructor will cover all the topics listed and sign the will cover all the topics listed and sign the certification logcertification log

After having all questions and concerns After having all questions and concerns addressed by the radiation safety office addressed by the radiation safety office and/or the device instructor, sign the and/or the device instructor, sign the certification logcertification log

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Personnel Monitoring Personnel Monitoring EquipmentEquipment

Required for each operatorRequired for each operator If after 6 months of monitoring the results If after 6 months of monitoring the results

show that operators will receive less than show that operators will receive less than 10 mr/yr, you can apply to the Department 10 mr/yr, you can apply to the Department of Health to discontinue program. Only of Health to discontinue program. Only upon their approval can the monitoring be upon their approval can the monitoring be discontinued.discontinued.

If you think you may need personnel If you think you may need personnel dosimetry, contact your Radiation Safety dosimetry, contact your Radiation Safety Officer for more information.Officer for more information.

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Other X-ray System HazardsOther X-ray System Hazards

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

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ElectricalElectricalAll X-ray systems operate All X-ray systems operate at high at high voltage/amperage, voltage/amperage, typically 60-90 amps. typically 60-90 amps. The generator and other The generator and other electrical components electrical components are normally enclosed in are normally enclosed in a protective cabinet that a protective cabinet that provides a barrier provides a barrier between open electrical between open electrical terminals and the user.terminals and the user.

In this picture, the In this picture, the cabinet is located below cabinet is located below the tube.the tube.

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ElectricalElectrical

X-ray tube changes, X-ray tube changes, maintenance and maintenance and repairs are only to be repairs are only to be performed by performed by someone trained and someone trained and experienced in experienced in electrical safety and electrical safety and must never be done must never be done by X-ray users. by X-ray users.

Cover panels (as seen Cover panels (as seen here) must be replaced here) must be replaced for user safety. Open for user safety. Open wiring and high voltage wiring and high voltage are a DEADLY are a DEADLY combinationcombination..

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

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ChemicalChemical

Other chemical Other chemical hazards include lead, hazards include lead, oils, and sometimes oils, and sometimes even the material even the material being analyzed. Many being analyzed. Many samples contain heavy samples contain heavy metals that may also metals that may also be toxic. Some users be toxic. Some users are even analyzing are even analyzing biological materials.biological materials.

Always contact EHS for Always contact EHS for guidance on chemical guidance on chemical safety and proper safety and proper waste disposal.waste disposal.

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TemperatureTemperature

Many analytical Many analytical systems use detectors systems use detectors cooled with liquid cooled with liquid nitrogen, a cryogenic nitrogen, a cryogenic liquid with a liquid with a temperature of -195 C!temperature of -195 C!

Splashes of liquid Splashes of liquid nitrogen on your nitrogen on your hands will cause burns hands will cause burns immediately. If it immediately. If it splashes in your eyes splashes in your eyes it can blind you!it can blind you!

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TemperatureTemperature

Filling dewars with liquid Filling dewars with liquid nitrogen usually results nitrogen usually results in the liquid boiling and in the liquid boiling and splashing out of the splashing out of the spout and the dewar.spout and the dewar.

ALWAYS wear a shield to ALWAYS wear a shield to protect your face and protect your face and eyes.eyes.

ALWAYS wear gloves to ALWAYS wear gloves to protect your hands. protect your hands.

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Any Questions?Any Questions?

Please contact your Radiation Please contact your Radiation Safety Office with any concerns. Safety Office with any concerns.

It’s time for the quiz. Be sure to It’s time for the quiz. Be sure to discuss and return the quiz to your discuss and return the quiz to your Radiation Safety Officer.Radiation Safety Officer.