Category: ALARA

28 Apr 2022
Radiation Protection Survey of Package with Pancake Probe

A Beginner’s Guide to Radiation Protection Surveys

The purpose of a radiation protection survey is to identify higher-than-normal doses of radiation in medical environments, labs, and anywhere radiation-emitting machines or radioactive materials (RAM) are used. They are required by state and federal regulations to be performed regularly to ensure the safety of technicians, technologists, nurses, doctors, researchers, and patients.

In this brief guide weā€™ll talk about what a radiation protection survey is, why it is important, and the type of equipment required to perform a radiation protection survey.

What is a radiation protection survey?

Radiation protection surveys are a way to directly measure radiation levels and identify potential leakage through breaks or voids in shielding.

Surveys are performed on:

  • Diagnostic fluoroscopic and radiographic equipment
  • Non-medical industrial equipment such as those found in veterinary offices
  • CT and CBCT machines
  • Particle accelerators
  • Irradiators
  • Bone mineral densitometers
  • Cabinet x-ray machines
  • Areas that use sealed sources of RAM
  • Packages containing RAM

The Different Types of Radiation Surveys

Not all radiation surveys are created equal. Letā€™s talk about some of the different surveys you may encounter a need for in your radiation safety program.

Radiation Emitting Device Survey

X-ray machines and other radiation-emitting devices require regular surveys to be performed to confirm that the machine is operating as expected. Radiation producing machines are surveyed for:

  • Timer accuracy
  • Radiation output
  • Focal spot size
  • kVp and mA
  • Beam limitation accuracy
  • Filtration
  • Skin entrance exposure / rate of exposure
  • Scatter radiation measurements
  • Photo-timer operation
  • Proper signage, labels, and postings

If high or unexpected dose rates are measured during a survey, the machine should be turned off and undergo appropriate maintenance.

Area Survey

Area surveys are required anywhere a radiation device is in use and the potential for receiving a higher-than-normal radiation dose is present. These surveys are typically measured in milliRoentgen per hour (mR/hr). The Roentgen is a measure of the amount of ionization in the air from the radiation.

Anytime you have an area survey performed, you are required to keep the official records of the survey results for 3 years.

Contamination Wipe Test

A contamination wipe test, also known as an indirect or swipe survey, is used to identify radioactive material contamination on surfaces, equipment, and clothing such as those found in a lab. This type of survey can identify non-fixed radiation left behind from radioactive solids, liquids, or gasses.

Lab tech performing a wipe test

Wipe tests are recommended to be performed frequently, especially if you are a HAZMAT employee that receives or ships RAM packages. A wipe test involves wiping at least 300cm2 of the packageā€™s surfaces using an absorbent material. Afterward, the activity on the swipe is measured assuming a removal efficiency of 0.1 unless the actual efficiency is known.

Users in lab settings typically survey their work areas after an experiment or when a minor spill is suspected.

Radioactive Sealed Source

A radioactive sealed source is a source of special form RAM that has been contained or encapsulated to prevent contamination. These sources can only be opened by destruction. Semi-annual surveys of these sources are required to check for leakage.

Bioassay Survey

Internal exposure monitoring, or a bioassay survey, is performed on individuals that use unsealed radioactive materials. The survey estimates the internal organ dose to determine if any RAM has entered the body. It can also help determine if RAM is present in the air.

Bioassay surveys are performed by analyzing blood, tissue, or urine samples or by carefully monitoring the presence and/or quality of isotopes present in the organ of concern.

How often do I need to have a survey performed?

The frequency of a radiation protection survey depends on several factors, most of which depend on different state and federal regulations.

  • When a new or used x-ray equipment is installed
  • When existing x-ray equipment has been moved
  • If shielding has been modified
  • After the equipment has undergone significant repairs
  • If a potential problem is indicated

Who performs these surveys?

In general, surveys on radiation-producing equipment are conducted by health physicists and medical physicists.

Is special equipment required for a survey?

Special equipment is required to detect ionizing radiation. Most equipment is hand-held measurement instruments called survey meters. This equipment is required to be calibrated annually to maintain accuracy and to ensure that reliable measurements are recorded.

Survey meters consist of:

  • A probe which produces electrical signals when it is exposed to radiation
  • A control panel readout with an electronic meter that gauges the amount of radiation exposure
  • A speaker which provides an audible indication of the radiation exposure

There are several different kinds of survey meters physicists use to perform radiation surveys.

Geiger-Mueller Pancake Probe

One of the more commonly used survey meters is the Geiger-Mueller Pancake Detector. Although there is no ā€œuniversalā€ radiation detector, the G-M Pancake Probe comes pretty close. This is because the probe can detect alpha, beta, and gamma radiation, although they are generally used for detecting Beta Emitters. These probes come in a variety of models and configurations.

Surveying open package with pancake probe

The probe detects radiation by collecting counting gas within the tube. The counting gas is ionized when a photon or particle interacts with a released electron. When the voltage is high, radiation that interacts with the counting gas produces an electronic pulse that is measured with a separate counting instrument.

A pancake probe has a thin layer of mica on the active face of the detector, which allows most alpha and beta particles to interact with the counting gas inside the tube.

G-M Pancake Probes are frequently used to detect C-14, Ca-45, P-32, P-33, and S-35.

Scintillation Survey Meter

A scintillation survey meter is used to detect low-energy Gamma Emitters and x-rays. The scintillator, or sensor, is made of a transparent crystal or liquid which shines when it interacts with ionizing radiation. The scintillator is attached to a photosensor like a photomultiplier tube which detects the generated light.

This survey meter detects I-125 and Cr-51. They are an ideal equipment choice for surveying electron microscopes and x-ray diffractometers.

Diagnostic Physics Support and Radiation Surveys by Versant Physics

When it comes to hiring a consultant to perform radiation protection or QA surveys for your equipment, you want to make sure youā€™re working with the best. People who are experts in state and federal regulations regarding radiation machines and RAM, have access to top-of-the-line survey equipment and understand the importance of adhering to ALARA standards.

Versant Physicsā€™ proactive and transparent diagnostic physics support process minimizes safety concerns and reduces the likelihood of compliance violations. We support our clients by sharing our knowledge of best practices in advanced technologies, and by utilizing a team-based approach we feel enables our clients to focus on maximizing the quality of patient care.

Contact our team for a free 30-minute consultation to learn more about our diagnostic physics and radiation survey expertise.


06 Oct 2021
Odyssey Personnel Dosimetry module dashboard

Odyssey “How To” Series: Personnel Dosimetry Module

Join us for an interview with our Odyssey Implementation Analyst Katelyn Waters, where we discuss how to carry out certain functions of the Personnel Dosimetry module and answer some of your frequently asked questions.

Odyssey is a radiation safety software suite designed to help RSOs, EHS managers, and Radiation Safety Specialists manage affordable and efficient programs.

KB 00:10: Welcome to Part 1 of our Odyssey how-to series, where we highlight some frequently asked questions about the cloud-based radiation safety software suite and its application in real-world radiation safety programs. Over the next 12 weeks, weā€™ll be addressing each of Odysseyā€™s modules, and breaking them down to give a better idea of how they work. My name is KB, and today Iā€™m joined by Odyssey Implementation Analyst Katelyn Waters to discuss the Personnel Dosimetry Module. Thanks for joining me, Katelyn!

Katelyn 00:37: Thanks KB, Iā€™m happy to be here and hopefully we can help answer some of the frequently asked questions that we get for the Personnel Dosimetry module in Odyssey.

KB 00:46: So, the personnel dosimetry module is a key feature of the Odyssey platform. It features customizable widgets and reporting tools that help RSOs and EHS professionals managing a badge program do so in a very efficient way. But how exactly is dosimetry data made available in the module?

Katelyn 01:05: Thatā€™s an excellent question, and one of the first that we get whenever we are doing different demonstrations of the software. So, personnel dosimetry does support data from any vendor, but it is primarily designed for Mirion and Landauer. So what it actually does is the software uses a login to either AMP for Mirion or MyLDR for Landauer to view and import that dosimetry information into your account. And so this import happens automatically, we set it up to be daily for Mirion and monthly for Landauer, and so everythingā€™s going to be automatically pulled into the software for you.

KB 01:43: If I have multiple dosimetry accounts can I use this module to manage them?

Katelyn 01:48: Yeah, absolutely. So, it is designed to help aid in the management of multiple accounts. So, whether those accounts are all through one vendor, being Mirion or Landauer, or if theyā€™re from both vendors, this is very beneficial for managing those. You can change the dashboard, thatā€™s what weā€™re currently looking at here for the module, and this dashboard is a quick at a glance view of your dosimetry account. And you can change what account youā€™re looking at from this first dropdown menu here that Iā€™m hovering over currently, and you can also change it to look at specific locations or subaccounts, and thatā€™s from the second dropdown menu here.

Additionally, we also have something called a Common Wearer Profile, and what that does is it’s going to combine dosimetry information from more than one account. So if you have a wearer that has a badge from both vendors, or maybe they have two badges that are under different locations or subaccounts, you can combine that information into one profile to make viewing that dosimetry history a lot easier for that wearer.

KB 02:50: So, if I wanted to add or remove any of those multiple badges on my account, can I do so from within Odyssey?

Katelyn 02:57: Yeah, great question. So, the actual addition or editing of any of the badges for wearers for your program will still take place in your vendor portal, whether thatā€™s Mirion, Landauer, or another party. So this particular module is designed to give you some additional features that arenā€™t available in those vendor portals. Some of those features include ALARA reporting, easy form 5 access, different alerts and reminders, shipping, different management for some of those high-level activities that youā€™re going to need to do for your program.

KB 03:31: I see. What about this dashboard? Is it possible to change any of the information thatā€™s displayed here?

Katelyn 03:38: Yes. I definitely recommend that when you start utilizing this module in the software thatā€™s something you do right away because it makes it very beneficial for you, and you can do that by selecting this gear icon here, itā€™s going to take us to show us all of the settings. So each of these boxes we refer to as a widget, and each widget has its own settings for what you want to view on your dashboard. A good example here is the Recently Viewed widget in the top right-hand corner. I have what I want to see available for selection with these checkboxes, I have some drop-down menus for the number of things that I want to see here for the Read activity widget I can choose the time periodā€¦ so depending on what it is they each have their own settings for these particular widgets, and that way you can really make it for what you need to see for your program.

In addition to that, you can also click and drag things to more prominently display them. So, if I want to have this graph of Read Activity–these are doses that are coming in each day–I can put this at the very top so I can see that a more prominent position. You can also hide things if they arenā€™t useful to your program. So, say you donā€™t want this recently viewed widget, I can select the eye icon and hide that and if I were to save these settings it would remove that from my dashboard. So, itā€™s very customizable.

KB 04:59: You mentioned read activity. Is there a place that I can see who hasnā€™t read their badge?

Katelyn 05:06: Yeah, so we have a query data section which I can actually go to and show you here. And this section allows you to do some really in-depth searches on your dosimetry data. You can choose to select what you want to search for, so with your example, I would go and search for different personnel, and ones that donā€™t have a badge reading. And then I come down to this section where it says Include or Exclude and I can choose things that I want to either include in my search or exclude from my search. And for us today, Iā€™ll go ahead and add in an inclusion statement to include people for the current account that weā€™re looking at, just as an example, and then I can exclude people who have readings and we will only be left with those who do not, so Iā€™ll go ahead and exclude people who have a reading for this year by putting in the date of January 1st.

So we can hit this play button here and itā€™s going to then search through all of your dosimetry records and give you the corresponding data for your filters. Once it does so, you have a table result at the bottom. And so, the format of this data is a little odd due to the fact that weā€™re looking at primarily, or not primarily, exclusively demo data. So you can see the employee IDs are very long. But this is what the format of that table would look like for you, just have your own dosimetry data displayed in it.  

And these are linked to other areas of the software. So for these wearers, I can actually select them to go to their profiles, and in addition, we have a list of contact information here that if you were to select this mail icon for it would actually put all of these people into a mailing list for you so you can easily communicate with them. So if we do want to reach out to this group and say hey, you need to please read your badge for 2021, you can do so by this easy feature there.

KB 07:02: Well that seems pretty easy to do. Is there any way for me to receive notification of individuals with high doses?

Katelyn 07:10: Absolutely. So that is actually one of my favorite features that we have added into the Personnel Dosimetry module and it exists in this reporting section. So Iā€™ll go ahead and select that and weā€™ll take a look at that.

The reporting section has a tab called ALARA. The module has the ability to add in different custom ALARA thresholds. For this particular demo dosimetry account, we have two thresholds added in. Iā€™ve added in an ALARA 1 and an ALARA 2. These are both quarterly thresholds but you can also have them trigger on a single dose, they can be monthly, quarterly, or annually. So, you have a variety of options there. They can also be scoped to particular badge regions that a badge is assigned to. Since these are quarterly thresholds, this next filter of the period gives me the option to choose a quarterly time period but that will change depending on your threshold. And if I do put in last quarter as an example and select run report, what thatā€™s going to do is give me a table of results of individuals that have surpassed that threshold for the chosen time period. So we have these three demo people who have surpassed the ALARA 1 Threshold,  and then one person additionally also surpassed the ALARA 2, so this table is really nice because if they did surpass other thresholds it will let you know that. So if you only want to follow up on the higher of the two you absolutely can do that.

It will tell you the time period that weā€™re covering currently, and then the cumulative dose for that time period, and then the stage that youā€™re at in the process. So this will allow you to email each of these individual wearers either notification that they went over this dose threshold or a questionnaire ā€“ that form that they actually get sent is completely customizable ā€“ and the wearer will receive that via email. Once they do, they will open and view that, if they have any questions they can fill that out, it requires a signature and dates it for them automatically, and then that gets sent back to Odyssey. Once it does get sent back, this pie chart progresses and shows you where this process is. So it will change to being yellow for ā€œwaiting for RSO response.ā€ So if youā€™re an RSO, a radiation safety representative, you can come in here, review that questionnaire, and the responses, and sign off on that to complete the process.

And to get back to your initial question about alerts for these items, throughout this entire process youā€™re going to be receiving in-software alerts which can optionally be email alerts as well. So when a wearer initially goes over the threshold, any of these thresholds you have set up, youā€™re going to get an alert that looks like a post-it note like one of these. And then when they fill it out they also will trigger an alert and itā€™ll let you know they have it filled out so that way you can come in and review that as soon as possible. And so youā€™re always going to be notified of each stage of the process there as this progresses.

KB 10:07: Well that all sounds great! Thanks, Katelyn, for helping us address some frequently asked questions about Odysseyā€™s Personnel Dosimetry module. Join both of us next week for part 2 where weā€™re going to be talking about the inventory tracking module and its ability to assist with tracking radioactive materials in your radiation safety program.

Katelyn 10:26: Thanks, KB.


Schedule an in-depth demo with our Odyssey team to discuss how the software can assist you with your radiation safety management needs, or visit our website to learn more about Odyssey’s radiation safety modules.

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 ā€œas low as reasonably achievableā€ 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 ā€“ 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 workersā€”and patients undergoing medical procedures involving radiationā€”for several decades. Adhering to this principle as well as your stateā€™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/