Category: Regulatory

20 Apr 2022
Nurse standing behind radiation shielding

The Basics of Radiation Shielding in Medicine

Basic radiation protection guidelines can be summed up in three simple concepts: time, distance, and shielding. While both limiting the time spent and increasing the proximity to an ionizing radiation source is something that lies within the power of the individual, shielding and X-ray room design require careful planning and execution by the facility or Radiation Safety Officer.

What is radiation shielding?

Radiation shielding is simply a barrier placed between a source of radiation and the area or person that needs to be protected. The purpose of radiation shielding is to limit, control, or modify the radiation exposure rate at a set point.

Shielding is based on attenuation or the gradual reduction in the intensity of energy through a specific medium. X-ray radiation that passes through certain materials decrease and are absorbed, thereby reducing the exposure to the other side of the barrier.

Without shielding, the public, radiation workers (including dentists and veterinarians), and even nearby office workers could be exposed to levels of radiation outside regulated exposure limits, which can potentially lead to negative health effects. Although it is impossible to completely avoid exposure to radiation, shielding is a critical consideration in any medical facility that greatly reduces unnecessary exposure.

Shielding Materials

There are several different materials that provide protection from penetrating radiation. Concrete, water, special plastic shields, air stops, and lead are all barriers that stop different types of rays and particles, reducing the overall dose a person receives.

In medical environments, the most common shielding materials used include lead, lead-free shielding, and lead composites.

Lead

Lead is one of the most used and most effective shielding materials. It is a highly dense material with a high atomic number and a high number of electrons which make it ideal for shielding in most medical radiation environments. This is because the type and energy of radiation in a medical environment that passes through lead are absorbed or scattered by the electrons present in the material.

Vet team wearing shielding garments during exam

Lead is also cheap and easy to process. It can be mixed with other materials like glass, or binders like vinyl, which allows it to be used as construction materials in X-ray rooms or worn as shielding garments.

Lead-Free Shielding

Technological advances have allowed for the creation of non-toxic, lead-free shielding materials as well. Other attenuating materials such as antimony (Sb), tungsten (W), and tin (Sn) are used in place of lead and combined with additives and binders to create wearable protective garments or materials. They offer equal protection from scatter radiation.

Lead-free shielding has several benefits, including being both recyclable and non-toxic. Lead-free shielding materials can also be lighter which makes them easier for personnel to wear during longer procedures.  

Lead Composite

Lead composite shielding is a long-lasting mixture of lead and lighter materials that attenuate radiation just as successfully as traditional lead shielding barriers.

Because of lead’s weight, it can be cumbersome to use and wear for long periods of time, limiting the efficacy of a radiation worker. Lead composites solve this problem. They are made with blends of tin, vinyl, and rubber and create a shielding barrier that can be up to 25% lighter than traditional shielding without sacrificing their ability to block penetrating radiation.

Shielding and Scatter Radiation

In some diagnostic X-ray procedures, medical personnel such as operators, radiologists, and technologists are required to remain in the room with the patient. This proximity frequently exposes them to something called scatter radiation or radiation that bounces off a patient’s body during a procedure.

To limit this exposure, some medical personnel are required to wear frontal or full wrap-around style lead aprons, thyroid shields, and lead glasses/gloves. These protective garments can attenuate roughly 93% of photons at typically scattered energies.

Lead apron and thyroid collar on hangar

Shielding Products and Design

There are several different ways radiation shielding can be applied or designed to protect healthcare workers.

Room Shielding

Shielding may be required in the floor, ceiling, doors, or any wall of any X-ray or radioactive material use room.  Shielding is used to protect workers, patients, or the public that may be in the adjacent areas/rooms.

During a room’s construction, special shielding materials are installed where their need has been determined. These materials can include lead-lined windows and doors, lead-lined drywall or plywood, lead sheets for floors and ceilings, pipe shielding, and more.

X-ray room shielding requirements vary from state to state. It is important to consult with a qualified expert familiar with these regulations as well as work with an architect experienced in constructing X-ray suites before building a new room.

Leaded Glass and Curtains

In some cases, it isn’t possible for a facility to build shielding into the physical structure of a building.

Leaded glass barriers are a barrier used by techs and doctors which allow them to safely view a patient during an imaging procedure. This type of glass is ideal for radiation-producing equipment in the 80-300 kV range thanks to its high lead content.

Lead curtains are also used to shield radiation workers, particularly in large animal hospitals or operating rooms. These curtains are leaded rubber or vinyl sheets that are ideal for protection against low-level or secondary radiation. They make for room-saving partitions that can be open or closed as needed and typically offer protection from 0.5mm to 2.00mm lead equivalency.

Mobile Shielding Barriers

In some cases, additional barriers are needed to protect doctors and techs during radiology, nuclear medicine, cath lab, or diagnostic imaging procedure. These barriers are lead-lined partitions on wheels, often with a protected window to allow for patient observation.

Mobile radiation barriers come in a variety of shapes, sizes, and lead equivalencies. They are ideal for maintaining flexibility and ease of movement in a procedure room while successfully minimizing the scattered radiation dose to workers in the room.

Versant Physics Shielding Services

Understanding the detailed shielding requirements for your state or facility can be a time-consuming challenge. If executed incorrectly, there can be serious consequences to the health and safety of radiation workers, patients, and building staff as well as potential regulatory compliance fines.

That’s why it is important to have a radiation safety consultant like Versant Physics on your side. Whether you’re constructing a new X-ray room, remodeling or repairing an existing shielding setup, or looking to upgrade your current shielding equipment, our team of expert health and medical physicists can assist.

We provide radiation shielding calculations, evaluation, and design for facilities of all kinds, including hospitals, clinics, dentist offices, chiropractor offices, and veterinary clinics. Our range of expertise includes:

  • Radiography
  • Fluoroscopy
  • Computed Tomography (CT)
  • Nuclear Medicine/PET
  • Mammography
  • Dental/Veterinary X-ray

Not sure what materials or type of shielding is right for your facility? Contact our regulatory experts for a free 30-minute consultation.

25 Feb 2022
CT radiation medical event

What are Radiation Medical Events and How to Prevent Them

The use of radiation in medicine via radiology, nuclear medicine, and radiotherapy helps detect and treat a variety of medical conditions in humans. It is a commonly used practice, with over 10 million procedures performed in the United States each year and thousands of lives saved as a result.

When radiation is administered improperly it is classified as a radiation medical event. A radiation medical event can occur when certain forms of radioactive sources are applied differently from what was intended or prescribed.

Although a radiation medical event does not necessarily result in harm to the patient, it does indicate that there is a potential problem in the medical facility’s use of radioactive sources (materials or equipment). An investigation into the event is required as soon as a medical event is suspected, typically by a clinical health physicist, as well as a written report documenting their findings.

What is a Radiation Medical Event?

The NRC defines an incident as a radiation medical event when (10 CFR 35.3045) the administration of byproduct material or radiation from byproduct material for, except permanent implant brachytherapy, results in—

  1. A dose that differs from the prescribed dose or dose that would have resulted from the prescribed dosage by more than 0.05 Sv (5 rem) effective dose equivalent, 0.5 Sv (50 rem) to an organ or tissue, or 0.5 Sv (50 rem) shallow dose equivalent to the skin; and
    1. The total dose delivered differs from the prescribed dose by 20 percent or more; or
    1. The total dosage delivered differs from the prescribed dosage by 20 percent or more or falls outside the prescribed dosage range; or
    1. The fractionated dose delivered differs from the prescribed dose for a single fraction, by 50 percent or more.
  2. A dose that exceeds 0.05 Sv (5 rem) effective dose equivalent, 0.5 Sv (50 rem) to an organ or tissue, or 0.5 Sv (50 rem) shallow dose equivalent to the skin from any of the following—
    1. An administration of a wrong radioactive drug containing byproduct material or the wrong radionuclide for a brachytherapy procedure;
    1. An administration of a radioactive drug containing byproduct material by the wrong route of administration;
    1.  An administration of a dose or dosage to the wrong individual or human research subject;
    1. An administration of a dose or dosage delivered by the wrong mode of treatment; or
    1. A leaking sealed source.
  3. A dose to the skin or an organ or tissue other than the treatment site that exceeds by:
    1. 0.5 Sv (50 rem) or more the expected dose to that site from the procedure if the administration had been given in accordance with the written directive prepared or revised before administration; and
    1. 50 percent or more the expected dose to that site from the procedure if the administration had been given in accordance with the written directive prepared or revised before administration.
  4. For permanent implant brachytherapy, the administration of byproduct material or radiation from byproduct material (excluding sources that were implanted in the correct site but migrated outside the treatment site) that results in—
    1. The total source strength administered differing by 20 percent or more from the total source strength documented in the post-implantation portion of the written directive;
    1. The total source strength administered outside of the treatment site exceeding 20 percent of the total source strength documented in the post-implantation portion of the written directive; or
    1. An administration that includes any of the following:
      1. The wrong radionuclide;
      1. The wrong individual or human research subject;
      1. Sealed source(s) implanted directly into a location discontiguous from the treatment site, as documented in the post-implantation portion of the written directive; or
      1. A leaking sealed source resulting in a dose that exceeds 0.5 Sv (50 rem) to an organ or tissue.
  5. Intervention of a patient or human research subject in which the administration of byproduct material or radiation from byproduct material results or will result in unintended permanent functional damage to an organ or a physiological system, as determined by a physician.

Radiation Medical Event Reports

Any of these medical events must be reported by telephone to the appropriate regulatory agency (i.e., Nuclear Regulatory Commission or Agreement State agency) no later than the next calendar day after discovery. A detailed written report, as described in 10 CFR 35.3045, must be submitted within 15 days after the discovery of the event. Such reports do not include information that could identify the affected patient as these reports are made available to the public.

medical event report

While medical events are accidental, it should be noted that a radiation medical event and a radiation accident are not the same things. Radiation accidents are defined as an event that “has led to significant consequences to people, the environment, or the facility,” such as a nuclear reactor core melt.

The purpose of medical event reporting is to initiate a process that will: (i) determine the root cause(s) and contributing cause(s); (ii) implement immediate corrective actions as may be necessary; (iii) identify preventative actions necessary to prevent a reoccurrence, and (iv) ensure appropriate notification of the patient and referring physician has occurred.  Additionally, the event may trigger the regulatory agency to alert other licensees to a potential problem that should be addressed.   

A medical event may indicate that there are problems within a facility that needs to be addressed. Communication problems, improper labeling, lack of training, and basic human error are all possible explanations.

An investigation into the technical aspects of the procedure, overall quality assurance practices (i.e., audits), and treatment delivery are required. A physician may also need to provide a separate analysis of potential injury or inadequate treatment to determine if any harm came to the patient because of the medical event.

Other medical event reports include:

  1. Report and notification of a dose to an embryo/fetus or a nursing child (10 CFR 35.3047) This includes an unintended dose to an embryo/fetus or a nursing child greater than 5 rem resulting from administration of a byproduct material to the mother/breast feeding individual. No report is required if the dose to the embryo/fetus was approved by the authorized user; or
  2. Report of a leaking sealed source (10 CFR 35.3067). The written report should include the model number, serial number, the radionuclide and its estimated activity, the date and results of the leak test, and the action taken.

How Are Patients Notified of a Medical Event?

NRC regulations state that it is the licensee’s responsibility to notify the exposed individual and their referring physician of the medical event within 24 hours of its discovery. If the notice is made verbally, the patient can request a written notification as well as access to the full report.

Severe events are rare, and harm is unlikely to befall a patient involved with a radiation medical event. However, it is important that the individual receive the appropriate medical care as soon as possible if needed.

Radiation Medical Events Can Be Prevented

With proper continuing education training, regular machine and technology upkeep, a working standard operating procedure, and efficient reporting systems, radiation medical events can be prevented.

It also helps to have a third-party consultant who can identify potential problems in your radiation safety program.

The team at Versant Physics is trained and equipped to help radiology departments and medical facilities prevent radiation medical events. Our board-certified medical and health physicists can help by performing acceptance testing of radiation-producing machines, conducting regulatory compliance audits, performing shielding evaluation and design calculations, and leading training opportunities.

Contact our regulatory team to discuss your radiation safety program needs.

Further Reading:

07 Feb 2022
Dosimetry management

How to Increase Dosimetry Compliance Rates with Versant Physics Proven Management Process 

One of the many responsibilities of a Radiation Safety Officer is to manage their facility’s personnel dosimetry program and monitor the exposures of the radiation workers employed there. This may seem like a simple task; however, it can be a challenge to get workers to wear and exchange/read their dosimeters in accordance with state and federal regulations. This leads many RSOs to wonder if it is possible to improve dosimetry compliance rates, particularly in large programs that have hundreds of occupationally exposed individuals to monitor. 

With the right dosimeter and the right management process, improving dosimetry compliance rates is very possible, regardless of the size of your dosimetry program.

Below we explain the common problems associated with traditional methods of personnel dosimetry program management, as well as offer a solution for improving your dosimetry compliance rates without increasing costs or workload for your staff.

The Problem with Traditional Methods of Dosimetry Management

Dosimetry is one of the key elements of a radiation safety program, but it can also be one of the biggest headaches for Radiation Safety Officers and Environmental, Health, and Safety managers. There are several problems with traditional methods of dosimetry management that managers often encounter, including:

  • A time-consuming badge collection and redistribution process
  • High costs of running a badge monitoring program
  • Time between when an exposure or anomaly is received and when an individual is made aware of the exposure
  • Keeping track of historical dose reads and measurements
  • Efficient communication with wearers regarding read reminders, exceeding dose limits, and more

These problems can make an RSO feel as though they’re herding cats at worst and like they’re constantly one step behind at best. Juggling these many tasks within just one aspect of a radiation safety program, along with a variety of other responsibilities, it’s not hard to see why dosimetry compliance rates can be rather low.  

Versant Physics Personnel Dosimetry Management

Versant Physics manages personnel dosimetry programs a bit differently. In addition to using top-of-the-line electronic dosimeters that utilize the latest monitoring technology, our team of badge specialists and physicists combines customer service, technical support, and quality administration tactics to manage everything your program needs to run successfully. From ordering new badges to ensuring wearers read their badges promptly, our team’s management process is proven and effective.

Versant Physics also utilizes their proprietary radiation safety software Odyssey to manage the personnel dosimetry programs of their clients.

Personnel Dosimetry Management Module

Odyssey is a cloud-based software that features an entire module devoted to personnel dosimetry management. The module includes useful tools like a query builder for compiling data records and a Form Generator for easy management of Form-5s. The module also features a series of customizable widgets that allow users to visualize pre-set metrics in their program, including a User Watch List for wearers likely to exceed internal or annual dose limits, Read Activity, and Badges Communicated.

Instadose+ by Mirion Technologies

Personnel dosimetry programs managed by Versant Physics also utilize the Instadose+ dosimeter. These small, lightweight badges combine Bluetooth technology, Direct Ion Storage (DIS), and SmartMonitoring to wirelessly and remotely transmit radiation dose data. Mobile devices, such as a smartphone or tablet, as well as PCs or hotspot stations, assist with this process.

Instadose+ Dosimeter

Each dosimeter has a built-in memory chip with a unique serial code that is assigned to the specific wearer. The badges are assigned long-term, meaning they do not need to be sent in for processing at the end of a monitoring period. Instead, wearers are responsible for reading their badges per the monitoring period set up by their radiation safety program.

Reading the badge is easy and takes less than a minute to complete from start to finish. Wearers typically read their badge by opening the Instadose+ app on their mobile device and holding down the button on the back of the dosimeter for 5 seconds, or until the light on the top of the badge turns green. Readings are then stored within their secure account.

The Instadose+ allows for unlimited, on-demand dose reads, so wearers can complete this process as often as they desire. Not only is this useful from a dose history standpoint, but it also gives wearers the power to view their current and historical dose reads from their online account anytime they want. If they have a question or a concern, the answers are already at their fingertips.

Overall, the Instadose+ simplifies dose reads and makes them more accessible to the individual worker and radiation safety officer. This allows for improved dosimetry compliance across the board.

Its user-friendly read process, historical dose transparency, and accurate, reliable readings are some of the reasons why it is a key player in Versant Physics’ badge management process.  

Badge Administration

Our experienced technical support specialists are equipped to handle the entire badge management process. This includes ordering badges from the manufacturer to removing wearers from the program. They also handle:

  • Remote and/or in-person badge training
  • Initialization of badges
  • Vendor credentialing and attestation
  • On-site event support

Compliance Administration

Versant Physics assigns a physicist to each client to help drive program compliance. The physicist works with the program RSO to develop an effective plan for making sure wearers read their badges. In the event there is no program RSO, Versant Physics’ physicists can serve as in-house RSOs as well.

Together with the badge team, they are also responsible for: 

  • Regular communication with wearers (weekly, monthly, or quarterly)
  • Read-day reminders
  • Non-communicated follow-up reminders
  • Comprehensive monthly compliance reports
  • Dose monitoring
  • High dose alerts
  • Dose discussions with RSOs/workers

Consistent communication with wearers is a necessary part of improving overall dosimetry compliance rates. Depending on the monitoring period set by the program RSO, Versant Physics sends out scheduled read-day reminder emails. They also send follow-up emails to those that have not read their badge.

Furthermore, RSOs and program leadership are always kept in the loop as to where their program currently stands. This is done through the use of a comprehensive monthly report.

Versant Physics monthly report displays badges that have not submitted a reading during the monitoring period. It also lists duplicate badges, lost and defective badges, as well as any new badges that were assigned in that month. The report provides status updates on mid-month follow-up with wearers, an active wearer list organized by location, and high dose reports as well.

This report paints a clear picture of program compliance month over month and helps pinpoint areas of concern. It also addresses program elements that could be improved upon in the following months.

Customer Service and Technical Support

When issues arise or wearers experience problems with their badges, Versant Physics’ team of technical support specialists are trained and ready to handle them promptly. They will help with:

  • Badge troubleshooting
  • Issuing replacement badges
  • Phone and email support

Additionally, wearers have access to the Versant Physics support desk, where they can submit questions or concerns with their badges 24/7. All requests submitted by wearers and program personnel receive a response within 24-hours.

A Note on Radiation Dose Limits

Versant Physics clients can set their own dose limits for their employees (within the regulatory limits) depending on what works best for their program.

For example, some clients prefer to set specific limits for single doses. Others have more lenient thresholds that are measured quarterly. Whatever your program’s monitoring preferences are, Versant Physics is prepared to help you implement and manage them.

The Takeaway

Versant Physics badge specialists, physicists, and technical support teams provide efficient badge management catered to the needs of your program. With the help of the Instadose+ dosimeter, Odyssey radiation safety software, and years of experience managing dosimetry programs of all sizes, we can work with you to help improve dosimetry compliance rates in your program.

Contact our team to learn more about our badge management process and pricing.

24 Jun 2021
Packaged tomatos

What is Food Irradiation?

Food irradiation is a common practice that is frequently misunderstood. Not only has the process of exposing food products to ionizing radiation, including X-Rays or electron beams, been heavily researched and utilized safely for over a century, it is a process that has proven benefits for the health of human beings.

The history of food irradiation.


The process of irradiating food began as early as 1905 when patents were issued in the U.S. and Great Britain to use ionizing radiation to kill bacteria found in foods. After World War II, research was conducted by the U.S. Army to verify the safety and efficacy of the irradiation process for meat, dairy products, fruits, and vegetables. Food irradiation has been controlled by the Food and Drug Administration since 1958 and recognized by the United Nations since 1964, when the first meeting of the Joint Expert Committee on Food Irradiation took place. It was determined by this committee in 1980 that “irradiation of foods up to the dose of 10 kiloGrays introduces no special nutritional or microbiological problems,” and the use of irradiation in the U.S. food supply was expanded by the FDA in 1986. In addition to the FDA and the UN, irradiation has been endorsed by the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the U.S. Department of Agriculture (USDA).

Why irradiate food?


There are several important reasons to irradiate food which ultimately benefit humans.

  • Prevention of Food borne Illness – Nobody likes having food poisoning. Food irradiation eliminates bacteria and molds like Salmonella and Escherichia coli (E. coli) which can spoil food and cause serious foodborne illnesses.

  • Sterilization – Irradiated foods can be used to sterilize foods which do not require refrigeration. These can be used in hospital settings for individuals with compromised immune systems or those undergoing chemotherapy. A variety of household and consumable products are also irradiated for sterilization purposes, including Band-Aids, cotton balls, medical products like surgical gloves, and even cosmetics.

  • Preservation – Have you ever wondered why spices have such a long shelf life, or why that bag of potatoes you bought last week is still sprout free? The answer is food irradiation. Food irradiation can extend the shelf life of certain foods by destroying organisms that cause spoilage and early sprouting.

  • Pest-Control – Irradiation helps control invasive insects that live in or on imported fruits and vegetables by killing or sterilizing them to prevent new bugs from infecting U.S. crops. This method is also safer than certain pest-control practices which have the potential to harm the produce through the use of toxic chemicals.

Of course, the benefits to irradiating food do not diminish the need for safe food handling practices by growers, processors, and consumers. All food should be stored, handled, and cooked appropriately. If safe handling practices are not followed, disease-causing organisms can still contaminate food and illness can occur.

It also does not completely remove all food dangers. For example, food irradiation can slow fruits and vegetables from aging, but it does not stop them. It also does not eliminate dangerous toxins that are already in food, such as Clostridium botulinum, a common bacterium which produces a toxin that causes botulism.

What kind of foods are irradiated?


In the United States, the FDA has approved a variety of foods to undergo irradiation, including:

  • Beef and Pork
  • Poultry
  • Lobster, Shrimp, and Crab
  • Fruits and Vegetables
  • Lettuce and Spinach
  • Shell eggs
  • Shellfish
  • Spices and Seasonings
green radura symbol

The international symbol for irradiation is called the Radura. This green symbol is required to be present on food packaging of irradiated food alongside the statements “Treated with radiation” or “Treated by irradiation.” According to the FDA, bulk foods like fruits and vegetables must be individually labelled with this symbol, however it is not required for individual ingredients in multi-ingredient foods, such as spices, to be labelled. If this symbol is present, this also indicates that the food is not classified as organic no matter how it was grown or produced.

How is food irradiated?


The overall process is simple. Three different kinds of radiation are approved for use: Gamma rays, electron beams, or x-rays. Packaged or bulk food pass through a radiation beam in a radiation chamber on a conveyor belt. The ionizing radiation breaks the chemical bonds into the bacteria or mold cells, which kills or damages the pathogens enough that they cannot multiply. This process does not affect the taste or smell of the food being irradiated.

This process also does not bring food into contact with radioactive materials, nor does it make food radioactive. Irradiated food does not expose those who eat it to radiation.

Are there risks to eating irradiated food?


Eating irradiated food is not harmful and there are no radiation-related risks. In fact, irradiating foods increases the availability of healthy and nutritious food supplies on a global scale. The chemical changes to food caused by irradiation are comparable to the changes food undergoes when cooked or canned.

Safe and beneficial.


Exposing food products to ionizing radiation is a safe, heavily researched process endorsed by governing agencies around the world. It is responsible for controlling invasive insects, destroying harmful bacteria that can cause food borne illnesses, and increases the shelf-life of certain foods which allows for more widespread access to healthy, nutritious food. This process also poses no radiation-risks to the public.

Further reading:

http://hps.org/publicinformation/ate/faqs/foodirradiationqa.html

https://www.epa.gov/radtown/food-irradiation

https://ccr.ucdavis.edu/food-irradiation/history-food-irradiation

https://www.fda.gov/food/buy-store-serve-safe-food/food-irradiation-what-you-need-know

08 Apr 2021
Radiation Worker Behind Shielding

ALARA: The Gold Standard of Radiation Protection

The ALARA principle is a relatively simple safety protocol designed to limit ionizing radiation exposure to workers from external sources.

This principle was established by the National Council on Radiation Protection and Measurements (NCRP) in 1954 in response to the atomic bombings of Hiroshima and Nagasaki and the increased interest in nuclear energy and weaponry post-WWII. The philosophy has been refined over the years by different regulatory agencies such as the Atomic Energy Commission (AEC) and Nuclear Regulatory Commission (NRC) as more knowledge about radiation and its effects on living tissue has come to light. In its current form, ALARA stands for “as low as reasonably achievable” and is considered the gold standard for radiation protection.

ALARA is based on the idea that any amount of radiation exposure, big or small, can increase negative health effects, such as cancer, for an individual. It is also based on the principle that the probability of occurrence of negative effects of exposure increases with cumulative lifetime dose. As such, the ALARA principle is considered a regulatory requirement for all radiation programs licensed with the NRC and any activity that involves the use of radiation or radioactive materials.

Check out VersantCast Episode 3: Linear No Threshold with Dr. Alan Fellman

To successfully implement ALARA principles in your radiation safety program, “it is important that every reasonable effort be made to maintain exposures to radiation as far below the dose limits in this part as is practical consistent with the purpose for which the licensed activity is undertaken, taking into account the state of technology, the economics of improvements in relation to state of technology, the economics of improvements in relation to benefits to the public health and safety, and other societal and socioeconomic considerations, and in relation to utilization of nuclear energy and licensed materials in the public interest.” (10 CFR 20.1003)

Time, Distance, and Shielding


There are three factors to the ALARA philosophy which, when executed correctly, can reduce and even prevent unnecessary exposure: time, distance, and shielding.

Time

Limit the amount of time spent near a radiation source. If you must work near a radioactive source, you should work as quickly as possible and then leave the area to avoid spending more time around the source than necessary.

Distance

Increase the distance between yourself and a radiation dose. The farther away you are, the lower the dose you will receive. In many cases, the dose rate decreases as the inverse square of the distance – when the distance is doubled, the dose rate goes down by a factor of four.

Shielding

Put a barrier between you and the radiation source. The type of barrier will depend on what kind of radiation source is being emitted but should be made of a material that absorbs radiation such as lead, concrete, or water. This can also include PPE such as thyroid shields and lead vests.

medical professionals implementing time, distance, and shielding principles

Conclusion


The ALARA principle has successfully limited exposures to workers—and patients undergoing medical procedures involving radiation—for several decades. Adhering to this principle as well as your state’s radiation safety regulations will result in keeping workers healthy and protected.

Visit our website for more information on how Versant Physics’ board-certified health physicists, medical physicists, and radiation safety officers can help you implement safe practices in your radiation safety program.

Sources

  1. https://nucleus.iaea.org/sites/orpnet/resources/frquentlyaskedquestions/Shared%20Documents/faq-list-en.pdf
  2. https://hps.org/publicinformation/ate/q8375.html
  3. https://www.cdc.gov/nceh/radiation/alara.html#shielding
  4. https://www.nrc.gov/reading-rm/basic-ref/glossary/alara.html
  5. http://large.stanford.edu/courses/2015/ph241/baumer2/
10 Mar 2021
Reviewing the License Regulations

A Guide to Limited vs. Broad Scope Radioactive Materials Licenses

We are often asked questions about applying for or changing licenses to possess and use radioactive materials. There are many different types of licenses; choosing amongst them can be confusing. In this post, we will discuss four common types.

US NRC logo

With some exceptions, approval by a regulatory agency (U.S. Nuclear Regulatory Commission or equivalent state agency), in the form of a license, is required to use and/or dispose of radioactive materials.

The type of license authorizing the purchase, possession, use, and disposal of radioactive materials is based on several factors:

  • Type, form and quantity of radioactive materials requested
  • Proposed use(s)
  • Experience of the proposed licensee with managing the use of radioactive materials

Types of licenses include, but are not limited to:

  • Limited scope specific academic and research and development
  • Limited scope specific medical use
  • Broad scope specific
  • Broad scope specific medical use

In this post, we will discuss the regulations under which the U.S. Nuclear Regulatory Commission (NRC) issues two common types of licenses: (i) limited scope specific and (ii) broad scope specific.  Some states, called Agreement States, have the authority under NRC regulations to issue licenses.  Their regulations are equivalent to NRC regulations.

1. Limited Scope Licenses


These licenses are issued to applicants subject the following limitations:

  • Radionuclides
  • Specified chemical and physical form(s)
  • Possession limits
  • Proposed use(s)
  • Radiation Safety Officer (RSO)
  • Authorized User(s)
  • Location(s) of use

The RSO’s training and experience should be applicable to and generally consistent with the types and quantities of licensed materials listed on the license.  Authorized users (AUs) must have adequate training and experience with the types and quantities they intend to use (NUREG 1556, Vol. 7, Rev. 1).  The applicant must submit to the regulatory agency for review and approval the specific training and experience of each proposed user and the facilities and equipment available to support each proposed use.

If the licensee wishes to change any of these limitations or add or remove an Authorized User (AU), permission must be sought from the issuing regulatory agency to amend the license. 

Medical Licenses – general comments

Licensing for the use of radioactive materials to diagnose and treat human disease is subject to more complex regulations than the academic and research and development licenses described above.  A wide variety of radionuclides and physical and chemical forms are used for a multitude of purposes in human medicine.  Consequently, AUs and the RSO must meet specific and extensive training and experience criteria focusing on the type, form, and quantity to be used as well as the intent of the use (diagnosis vs. treatment).

An AU is charged with the responsibility for (NUREG 1556 Vol. 9, Rev. 3)

  • radiation safety commensurate with use of radioactive materials;
  • administration of a radiation dose or dosage and how it is prescribed;
  • direction of individuals under the AU’s supervision in the preparation of radioactive materials for medical use and in the medical use of radioactive materials; and
  • preparation of a written directive, if required.

To be named as an AU on a medical license, the individual must satisfy one or more of the requirements outlined in Subparts D, E, F, G or H of 10 CFR 35.  In general, this requirement can be met by:

  • being board certified in a specialty medical discipline appropriate to the intended use that is recognized by the Commission or Agreement State; or
  • being named as an AU on another license issued by the Commission or Agreement State for the same or similar type, form, and quantity of radioactive materials in question; or
  • having completed training and experience as specified in the regulations.

The RSO on a medical license must satisfy the training and experience requirements outlined in 10 CFR 35.50:

  • be certified by a specialty board whose certification process has been recognized by the Commission or an Agreement State; or
  • have completed a structured educational program as outline in 10 CFR 35.50(b); or
  • be a medical physicist who is certified by a specialty board recognized by the Commission or an Agreement State, has experience with the radiation safety aspects of similar types of radioactive materials for which the licensee seeks approval and has training in the radiation safety, regulatory issues, and emergency procedures for the types of use for which a licensee seeks approval; or
  • be a medical AU, authorized medical physicist, or authorized nuclear pharmacist identified on a Commission or an Agreement State license, a permit issued by a Commission master material licensee, a permit issued by a Commission or an Agreement State licensee of broad scope, or a permit issued by a Commission master material license broad scope permittee, has experience with the radiation safety aspects of similar types of use of byproduct material for which the licensee seeks the approval and Is an authorized user, authorized medical physicist, or authorized nuclear pharmacist identified on a Commission or an Agreement State license, a permit issued by a Commission master material licensee, a permit issued by a Commission or an Agreement State licensee of broad scope, or a permit issued by a Commission master material license broad scope permittee, has experience with the radiation safety aspects of similar types of use of byproduct material for which the licensee seeks the approval.

2. Limited Scope Specific Medical Licenses


A specific license of limited scope may be issued to private or group medical practices and to medical institutions.   Each type, form, quantity and use and condition of use of radioactive materials as well as the RSO and AU(s) are named on the license (NUREG 1556 Vol. 9, Rev. 3).  These licenses may also be issued to an entity requesting authorization to perform mobile medical services and certain non-medical activities such as self-shielded blood irradiators.  Changes to any of these specifications or conditions must be requested and approved by amendment.

Research Involving Human Subjects

“Medical use” of radioactive materials includes administration to human research subjects.  A license condition authorizing such research is not required if the research is conducted, funded, supported or regulated by a Federal Agency that has implemented the Federal Policy for the Protection of Human Subjects.  Otherwise, the licensee must apply for and receive an amendment before conducting such research.  In all cases, licensees must obtain informed consent from the human subjects and prior review and approval by an Institutional Review Board.  All research involving human subjects must be conducted only with the radioactive materials listed in the license and for the uses authorized in the license (NUREG 1556, Vol. 9, Rev. 3).

Research involving human subjects may be conducted under either limited scope or broad scope specific licenses.

3. Broad Scope Specific Licenses


Broad scope specific licenses generally authorize possession and use of a wide range of radioactive materials.  Because regulatory agencies grant significant decision-making authority to broad scope licensees through the license, a broad scope license is not normally issued to a new licensee. An applicant for a broad scope license typically has several years of experience operating under a limited scope license and a good regulatory performance history (NUREG 1556 Vol. 11, Rev. 1).  Changes to the radiation safety program approved via in-house review and approval by the RSO and/or RSC (see below) do not appear on the license but are subject to review by regulatory agencies during routine inspections.

Title 10 of the Code of Federal Regulations (10 CFR) Part 33, “Specific Domestic Licenses of Broad Scope for Byproduct Material,” provides for three distinct categories of broad scope licenses (i.e., Type A, Type B, and Type C), which are defined in 10 CFR 33.11, “Types of Specific Licenses of Broad Scope.”

Type A

Type A licenses of broad scope are typically the largest licensed programs and encompass a broad range of uses.  Licensees use a Radiation Safety Committee (RSC), radiation safety officer (RSO), and criteria developed and submitted by the licensee and approved by the NRC during the licensing process to review and approve all uses and users under the license.

An applicant for a Type A broad scope license must establish administrative controls and provisions related to organization and management, procedures, record keeping, material control, and accounting and management review necessary to ensure safe operations, including:

  • establishment of an RSC
  • appointment of a qualified RSO
  • establishment of appropriate administrative procedures to ensure the following:

— control of procurement and use of byproduct material

— completion of safety evaluations of proposed uses that take into consideration adequacy of facilities and equipment, training and experience of the user, and operating and handling procedures

— review, approval, and recording by the RSC of safety evaluations of proposed uses

  • use of byproduct material only by, or under the direct supervision of, individuals approved by the licensee’s RSC

Because these controls and provisions have been established, the applicant may approve in-house, without requesting amendment:

  • Authorized Users
  • location of use within the confines of the physical location(s) listed on the license
  • changes in use of radioactive materials so long as the use is consistent with the license conditions and appropriate safety evaluations have been performed, documented, and approved by the RSC

The requirements for issuance of a Type A broad scope license are described in 10 CFR 33.13, “Requirements for the Issuance of a Type A Specific License of Broad Scope.”

Type B

Type B broad scope licensed programs are normally smaller and less diverse than Type A broad scope programs. Type B broad scope licensees use an RSO and criteria developed and submitted by the licensee and approved by the NRC during the licensing process to review and approve all uses and users under the license. Because the RSO reviews and approves all uses and users under the license, rather than a full RSC, as established for Type A broad scope programs, the types and quantities of byproduct material authorized by the Type B broad scope license are limited to those described in 10 CFR 33.11(b) and 10 CFR 33.100, “Schedule A,” Column I.  Generally, the scope of authorization for Type B licenses is limited to the experience and knowledge of the RSO.

Changes to the type, form and quantity of radioactive materials may have to be approved by the regulatory agency by amendment, depending on the specific provisions of the license.

The requirements for issuance of a Type B broad scope license are described in 10 CFR 33.14, “Requirements for the Issuance of a Type B Specific License of Broad Scope.”

Type C

Type C broad scope licensed programs typically are issued to institutions that do not require significant quantities of radioactive material but need the flexibility to possess a variety of different radioactive materials. Users of licensed material under these programs are approved by the licensee based on training and experience criteria described in 10 CFR 33.15(b). The types and quantities of byproduct material authorized by the Type C broad scope license are limited to those described in 10 CFR 33.11(c) and 10 CFR 33.100, Schedule A, Column II, again, considering the unity rule.

While 10 CFR 33.15 does not require Type C broad scope licensees to appoint an RSO, the licensee must establish administrative controls and provisions related to procurement of byproduct material, procedures, record keeping, material control and accounting, and management review to ensure safe operations. This should include the appointment of someone responsible for the day-to-day operation of the radiation safety program, such as an RSO.

Changes to the type, form and quantity of radioactive materials may have to be approved by the regulatory agency by amendment, depending on the specific provisions of the license.

The requirements for issuance of a Type C broad scope license are described in 10 CFR 33.15, “Requirements for the Issuance of a Type C Specific License of Broad Scope.”

4. Broad Scope Medical Licenses


The NRC issues specific licenses of broad scope for medical use (i.e., licenses authorizing multiple quantities and types of byproduct material for medical use under 10 CFR Part 35, as well as other uses) to institutions that (i) have experience successfully operating under a specific license of limited scope and (ii) are engaged in medical research and routine diagnostic and therapeutic uses of byproduct material (NUREG 1556, Vol. 9, Rev. 3).  Typically, these are large medical centers/teaching hospitals that have a need to administer or use a wide variety of radionuclides and/or radiopharmaceuticals for diagnosis and therapy.  Because these institutions have complex programs, the authority to approve changes in-house makes the program flexible and nimble. 

AUs and the RSO on a broad scope medical license must meet the same criteria for training and experience as for a limited scope medical license discussed above. 

Regulatory Services by Versant Physics


Our team of experienced Radiation Safety Officers can help you navigate the NRC regulations and determine which license type is appropriate for your facility. Contact sales@versantphysics.com to speak to a team member or learn more about our Regulatory services.

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Forum Article "Radiopharmaceutical Extravasation: Pragmatic Radiation Protection" published ahead of print

An article written by Versant team members Dr. Darrell R. Fisher, Ph.D. and Misty Liverett, M.S., CNMT was recently published ahead of print in Health Physics. The article provides an unbiased, scientific assessment of pragmatic and reasonable health physics actions that should be taken in response to inadvertent extravasation events. Click the link below to view the article.

Permits

THE PERMISSION SYSTEM FOR INVENTORY TRACKING, MACHINE MANAGEMENT & EQUIPMENT CATALOG MODULES

Permit Profile

Each permit has a dedicated profile of information that includes authorized personnel, radioactive material, machines, and devices. Permit conditions, completed audits, and forms are also found on this profile.

Authorized Condition Database

Create and view authorized conditions included on permits. Previously created authorized conditions are listed with their code, category, and description.

Permit Enforcement

Information specified on a permit not only serves as a record of that permit, but also controls what can be added to other modules. The location, owner and type of radioactive materials, machines, and equipment can be enforced by permits.

Permit Audits

Perform permit audits, mail the results to relevant personnel, and track responses to non-compliances.