Dirty Bombs: What are they and how they could affect you?

It is human nature to fear things that we don’t understand. One of these things is how radiation exposure actually works. There is an incredible amount of misinformation about radiation and its effects on human beings. Truthfully small quantities of radiation are negligible, and in fact we are exposed to small amounts of various kinds of radiation all the time.

One concern that has been raised by the public is that terrorists will escalate from explosive or shrapnel bombs to bombs with hidden dangers as well as physical ones. In fact, one of the major worries in the aftermath of the recent Boston Marathon bombings was whether or not the shrapnel bombs were also radiological dispersion devices (RDDs) also known as dirty bombs.

Explosives Plus an Easily Dispersed Radioactive Source

First, an overview of dirty bombs and how they work.

Dirty bombs go a step beyond traditional explosives and add a radioactive component in the form of pellets or powder to the mix. One thing to note is that devices containing materials classified as radioactive does not equate them to a nuclear or atomic bomb. The violent fission reactions found in atomic bombs are not present in RDDs. Dirty bombs are meant to foment chaos and disruption instead of mass destruction. Terrorists count on public misinformation to help create further panic in a crisis situation.

When an RDD explodes, it coats everything nearby including people and objects with radioactive particles which can travel beyond the initial blast radius. Because of this, in addition to immediate contamination, secondary contamination can occur well beyond the radius of the blast.

What should I do if I find myself within the blast radius of one of these bombs?

First of all, don’t panic. While exposure to the types of radioactive material that would be found in these bombs could be an issue eventually if not properly cleaned up, the strength of the material used is not going to cause immediate radiation sickness, cell damage, or instant cell mutation¹.

Because radiation cannot be felt or seen, the cautious thing to do is assume that there was a radioactive component to the bomb and respond accordingly. The Nuclear Energy Institute (NEI) has listed some general guidelines to follow if you find yourself in this situation and you are not seriously injured by the initial explosion.

• Leave the immediate area on foot—do not take public transportation.
• Go inside the nearest building. Seeking immediate shelter will reduce exposure to any radioactive material at the scene of the explosion.
• Remove clothing as soon as possible and seal it inside a plastic bag. Save the clothing so that emergency response personnel can test it. Removing clothing will eliminate 90 percent of the radioactive contamination, according to the Centers for Disease Control and Prevention.
• Take a shower or wash yourself as completely as possible. This will reduce the amount of radioactive contamination.
• Seek more information from emergency response personnel who respond to the explosion. 

What if I live nearby? Should I evacuate or stay where I am?

If emergency responders have not made their way to your area, unless your building is damaged, it is recommended that you stay put. Many of the radioactive materials that are likely to be used in dirty bombs have a short half-life and decay quickly. They are also unlikely to penetrate building walls. If you are instructed to or choose to shelter where you are in the absence of instruction, it is recommended that you turn off your heating/air conditioning and any other device that draws air from the outside temporarily. As the situation becomes more organized, you should be able to get feedback from emergency personal by radio or in person for instructions on how to proceed.

In a particular event, who determines whether or not a bomb contains radioactive material?

The National Guard has a Civil Support Team (CST) whose members are deployed to most major events. Included in the gear that they have on hand is a portable radiation detector. As these individuals scan the area for various threats, they will determine whether or not radioactive material was mixed with the explosives. The CSTs will then alert the nearby population with the results of their testing.

Portable Radiation Detector with a Belt Clip

The best defense against these kinds of terrorist actions is to be informed. Knowing what to do if you find yourself in this situation robs them of their goal to spread chaos and fear. Better yet, spread the knowledge you’ve gained and together we can stand against those that want to harm us and take away our freedoms.

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D-tect Systems is a supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com

¹    Information provided by NEI

References:

Steps for Public Safety Against a ‘Dirty Bomb’, Nuclear Energy Institute
http://www.nei.org/resourcesandstats/Documentlibrary/Safety-and-Security/factsheet/publicsafetystepsagainstadirtybomb  
Boston Marathon Bombings Raises New Concerns of “Dirty Bombs,” Emergency Film Group 
http://www.efilmgroup.com/emergency-film-blog/boston-marathon-bombings-raises-new-concerns-of-dirty-bombs/  
Dirty Bomb, National Terror Alert Response Center
http://www.nationalterroralert.com/dirtybomb/

Healthy Radiation? The Benefits and Danger of Medical Isotopes

Out of all the man-made radiation we are exposed to every year, more than half comes from diagnostic x-rays.  Medical tests and treatments that make use of radiation have a huge range: from simple dental procedures to aggressive radiation therapy for cancer patients.  Physicians use x-rays in more than half of all medical diagnoses to determine the extent of disease or physical injury¹.  The kind of radiation that medical professionals use is generally strong at first, but has a short half-life (weakens quickly) and isn’t readily absorbed into the body.  This way the radiation is out of the patient before it has time to do much damage. 

Most medical isotopes are used for imaging, whether they are ingested, inhaled, or injected into the body.  These materials are easily picked up by x-ray machines and other types of detectors, allowing specialists to track the flow of fluids in the body. The most common isotope used for imaging is technetium-99m, which is used for nearly 80% of diagnostic imaging procedures².  Common isotopes for radiation therapy include yttrium-90 and iodine-131.

The vast majority of all concentrated radiation that a normal person runs across comes from medical sources.  In fact, we here at D-tect Systems recently ran across a mysterious source.  Even though medical isotopes are generally carefully controlled and disposed of, many landfills get quite a steady influx of medical radiation.  We recently received permission to take a few samples of a mysterious radiation source in the Trans-Jordan Landfill located at the south end of the Salt Lake Valley.  Like many landfills in the United States, the Trans-Jordan Landfill has a set of huge portal monitors for scanning all incoming loads for radiation.  We were told that loads of scrap metal almost invariably set off the detectors, as well as other materials.

The object of our inquiry was a strong radiation source in a black plastic bag that that landfill workers had located and were observing.  We brought in the D-tect Systems Rad-ID system (a handheld isotope identifier) to see if we could figure out what the mystery isotope was.  It was definitely a strong source – it set off the highest level on our MiniRad-D detector from several meters away.  After a few tests, we found it the source contained at least two medical isotopes: Barium-133 and Radium-226.  These isotopes are commonly used in conjunction in medical treatments.

So how can you make sure medical isotopes are worth the risk?  Talk to a doctor.  Health care personnel take radiation very seriously and use it on a case-by-case basis.  Before receiving x-rays or other types of medical treatments involving radiation, discuss the risks and benefits of the procedure and make sure it’s worth it to you. 

If you’d like more information on radiation in medicine, we invite you to visit World Nuclear Association’s page.  It contains lots of good basic information on radiation usage in medicine as well as technical details on different isotopes.

1) http://www.epa.gov/radiation/docs/402-k-07-006.pdf

2) http://ie.lbl.gov/toi/

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D-tect Systems is a supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com.

Relative Doses of Radiation

As we've discussed earlier on this blog, to truly understand the health threat that radiation poses we have to put radiation in perspective. To help with this, we've just released a page that lists a number of relative doses of radiation and how they compare to the alarm levels of the MiniRad-D radiation detector. When it detects radiation, the MiniRad-D displays a number from 1 to 9 to indicate the strength of the radiation. The ranges of these numbers are listed on the graph and compared with varying radiation doses.

Because the MiniRad-D is a very sensitive device, lower levels of radiation that it picks up pose almost no health threat at all.

D-tect Systems is supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com.

Immersed in a Sea of Radiation

You don’t have to look far to find radiation in the world around us. In fact, the vast majority of radiation that we are exposed to throughout our lives comes from natural sources. Naturally Occurring Radioactive Materials (NORM) are very common in the environment and can be found in many products in our homes and cars. These materials generally pose very little, if any threat to our health, and it may surprise you how many everyday items have radioactive properties.

This rock from southern Utah contains Thorium-232.

The most common NORM contain radioactive isotopes of uranium, thorium, and potassium, as well as the isotopes these decay into (such as radium and radon). Although  much of the earth’s surface contains very low concentrations of radioactive materials, NORM is concentrated in many raw industrial products and activities such as the following:

Coal: although other rocks in the earth’s crust have approximately the same concentration of NORM, the large quantities of coal needed to fuel much of the world’s energy demands are responsible for a sizable amount of radiation and a wide variety of isotopes including potassium, lead, and radium. An interesting fact about NORM in coal is that the naturally occurring uranium contained in coal could be a fuel source more powerful than the coal itself if used in a certain type of nuclear reactor¹. 

Phosphate Rock: mainly used for fertilizers, phosphates can have much more concentrated amounts of NORM than other mining products. The radioactive content of phosphates has attracted media attention after European fertilizer manufacturing had been found responsible for radioactive material in the Atlantic.

Granite: this type of stone has traces of uranium in it, which means that many federal buildings such as the United States Capitol are faintly radioactive. We’ve found that the MiniRad-D (a small radiation detector) reads a constant radiation level of 2 around the perimeter of the Utah State Capitol, which has a granite facing on its exterior. Radiation measurements on granite surfaces can even show comparable levels to those from low-grade uranium mine tailings.

Oil and gas production: most of the radioactive material brought out of the ground in oil and gas production is deposited in pipes and other equipment. The concentration of NORM has made the resale of used equipment more difficult in recent years.

Although industrial activities are responsible for large amounts of NORM, many common household items also have significant amounts of radiation. Here are a few examples:

Smoke detectors: one of the most radioactive items in a home is the smoke detector, which uses an isotope of americium to sense the presence of airborne particles carried by smoke.

A small Americium-241 pellet from a smoke detector is contained in the plastic holder on top of the MiniRad-D device.

Ceramics: some of the most famous antique radioactive items are Fiesta Ware ceramics, which were produced from 1936-1943². The red glaze on these dishes contains Potassium-40, as do  the glazes of other ceramics with red, yellow, green, and black colors. The clay itself used in some ceramics can also contain NORM. Ceramic products such as bathroom tiles and porcelain can also show up on a radiation detector.

Cat litter: the main ingredient of cat litter is clay, which like that used in ceramics, often contains low levels of NORM.

Colored glass: uranium was commonly used as a coloring agent in yellow and green glass produced in the first half of the 20^th century. You can find antique dinnerware, home décor, and even children’s marbles that emit a measurable amount of radiation.

These antique marbles contain trace amounts of uranium.

Glossy paper: Kaolin, a substance known as “white gold” for its versatility and value, was commonly used to create glossy paper on magazines in the early 1900s. Kaolin contains clay with low concentrations of uranium and thorium.

Instrument dials: due to its ability to fluoresce, radium was used in paint for marking instruments and watch dials. This paint exhibits a bright green color when fluorescing.

Spark plugs: dating back to 1940, some old spark plugs contain an isotope of polonium that was used to make a more brittle alloy that readily creates sparks.

Lantern Mantles: old Coleman lantern mantles contain low levels of Thorium-232, an isotope with a 14 billion year half-life. Special care should be used when dealing with used mantles to ensure the radioactive dust isn’t breathed in.

A Coleman lantern mantle with a MiniRad-D detector.

Food: many foods contain trace amounts of radiation, including potatoes, bananas, kidney beans, and Brazil nuts. Salt substitute, which contains potassium chloride instead of sodium chloride, may also have a low level of radiation due to the presence of Potassium-40.

1) http://www.world-nuclear.org/info/inf30.html

2) http://www.orau.org/ptp/collection/consumer%20products/consumer.htm

D-tect Systems is supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com.

D-tect Systems Video

To give a better idea of what we do here at D-tect Systems, we shot this short film on site here at our Draper, Utah facility. It gives a short introduction to the radiation and chemical detection field and then gives a short description of each of our products. We hope it can give you a sense of what D-tect is all about!

D-tect Systems is supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com.

My Trip to Japan

While in Japan, I was paired with a group that was sent to check on the structural integrity of several church buildings in several cities. My role was to show them how to use the equipment and gauge the levels of radiation at each site. To check on these levels I went armed with two different radiation detectors: the MiniRad-D (a small, pager-sized detector) and the Rad-ID (a portable radiation identifier).

In my visits to cities from Tokyo to Iwaki I checked radiation levels and talked with the local church officials about what those levels meant. Radiation levels in downtown Tokyo were near natural background levels but the closer I got to Fukushima, the higher the radiation levels rose. The cities I visited showed readings of anywhere from 0.35 µSv/hr to 2 µSv/hr above background radiation, which are elevated levels, but definitely not dangerous. Using the Rad-ID, I found out that most of the radiation came from the radioactive isotopes Co-60, I-131, I-132, and Cs-137, which are commonly given off in nuclear processes.


An interesting observation that I made was that storm drains in the areas I visited showed higher levels of radiation than the surrounding areas. I surmised that rainfall had carried down and collected some of the radioactive dust in the air and deposited the contamination as it flowed down these drains.


Although the Japanese have shown amazing resilience and are working as hard as they can to solve these enormous problems, there is still much uncertainty about health risks and what the future will bring. We’ll be back soon to check on the radiation levels again. If you’d like to brush up on your radiation basics, you can check out this sheet we’ve complied. It has basic conversions, safety levels, and doses to put radiation exposure in perspective. An interesting chart on radiation dose rates can be found here.

Radiation Contamination in Food and Water: What's the Risk?

As Japanese emergency workers continue to pump out thousands of gallons of contaminated water from the damaged reactors of the Fukushima Power Plant, radiation contamination in food and water has emerged as a new focus of the international media.  

Before explaining the risks of food and water contamination, it’s important to understand the difference between radiation exposure and radiation contamination.  The United States Center for Disease Control (CDC) defines exposure and contamination with the following:

A person exposed to radiation is not necessarily contaminated with radioactive material. A person who has been exposed to radiation has had radioactive waves or particles penetrate the body, like having an x-ray. For a person to be contaminated, radioactive material must be on or inside of his or her body. A contaminated person is exposed to radiation released by the radioactive material on or inside the body. An uncontaminated person can be exposed by being too close to radioactive material or a contaminated person, place, or thing.”

Source: U.S. Department of Health

As the CDC implies, there are many ways that radiation can enter the body for contamination to occur.  Radioactive materials that enter into digestive tract can do damage while they reside in the body, but most of these materials pass through quickly. Radiation that gets trapped in other areas of the body, such as radioactive dust being breathed in and lodged in the lungs, can cause serious threats because the longer the radiation resides in the body, the more harm it can do.

So what are levels of radiation we actually need to worry about in food or water? The unit of measurement used for quantifying radiation in food and water is the Becquerel (Bq) and defined as the activity of a radioactive material in which one nucleus decays per second. More dangerous sources of radiation give off higher readings, and amounts decrease as radioactive isotopes decay. The Becquerel is a very small quantity of radiation; the human body itself produces over 4000 Bq per second. The standards set by the United States Food and Drug Administration (FDA) for food and water is about 375 Bq/lb (170 Bq/kg).

Recently Japan reported a reading of 463 Bq/lb (210 Bq/kg) in Tokyo’s tap water, leading to widespread fear and a government advisory against giving tap water to children (who are more susceptible to radiation and have lower exposure limits). Since this incident, the radiation in Tokyo’s tap water has returned to safe limits. Radiation in food has also been a problem, especially since much of the Fukushima Prefecture near the crippled nuclear plant is dedicated farmland.  Widespread bans have gone into place on the sale and consumption of crops from affected areas, as well as seafood caught in the ocean near the plant. Much of the radiation present in the contaminated food and water is Iodine-131, which has a half-life (meaning that half of a quantity of the material has broken down and is not longer radioactive) of only 8 days. This means that this type of radiation won’t be around for long, but the fear of radiation is more likely to hurt the Japanese economy as buyers shy away from food that they think might still have some contamination.

Source: Associated Press

Although the fear that Japanese radiation in dangerous amounts will end up in other countries is often unfounded, we can’t let down our guard just yet. Japan provides 4% of US food imports, including many seafood products that can have concentrated levels of radiation, such as shellfish and seaweed.

So how can we assure that our food and water is contamination free? Finding trace amounts of radiation in food and water is often difficult because products are usually shipped in large containers that shield radiation. Common radiation detectors such as Geiger Counters just aren’t sensitive enough to detect radiation at these levels. The FDA works to safeguard our food supply by using the MiniRad-D, a hand-held radiation detector, to search for radiation. The MiniRad-D uses a scintillation detector, which is over 100 times more sensitive than a Geiger counter, and because it can pick up radiation from tens of meters away, it can be used to scan whole containers of food at once. 

The MiniRad-D radiation detector

The procedure of scanning food is becoming increasing popular as Japan increases its exports. According to a recent New York Times article, even some fish markets and high-end restaurants have begun radiation detection procedures to ensure the safety of their customers. Knowing for sure that food and water is clean is a big draw for these businesses as Japan’s nuclear clean-up continues to make headlines.

So, although the direct danger of radiation contamination in food and water is very low, the effects of the nuclear crisis are sure to be felt for years to come. And as many companies involved with food imports are discovering, peace of mind is not only attainable, but extremely valuable. With the right equipment, good information, and correct procedures, this peace of mind is truly available to everyone.

D-tect Systems is supplier of advanced radiation and chemical detection equipment sold around the world. www.dtectsystems.com.

 

Protecting the Public from a Nuclear Power Plant Radiation Leak

How can you feel safe? How much warning will you have?

The ongoing battle to control the reactors at the Fukushima Nuclear Plant is terrifying to follow, but also leads millions that live near nuclear power plants to look over their shoulder and wonder “what if”? How many of us live within 50 miles of a nuclear power plant? In the U.S. alone, there are 104 nuclear power plants, most with multiple reactors.

When a leak is detected, there are two primary tools to measure the radiation: dosimeters and radiation detectors. Both provide different critical functions.

Dosimeters are the important instruments at the radiation leak. When worn on the body, often clipped to a pocket or belt, they measure how much radiation your body has absorbed. This is critical because the human body can absorb an amazing amount of radiation without damage, but there is a limit. A dosimeter shows when it is time to get away from the radiation before health consequences can occur. Everyone working in an area of high radiation needs to have a dosimeter. Especially the workers trying to stop a radiation leak.

Radiation detectors are faster and more sensitive than dosimeters, react instantly when radiation is detected, and indicate the amount of radiation.  If dosimeters are like a doctor looking over your shoulder to continually measure your health, radiation detectors are more like guard dogs. Radiation detectors are used just like guard dogs – they can monitor a perimeter and provide instant warning if that perimeter is violated. They can also be used to inspect people and vehicles for radiation. When people leave a contaminated area they are scanned with radiation detectors to quickly determine who needs to go through decontamination and who can be waved on.  Often contamination is in the form of dust present on skin, clothes and shoes. This contamination can be washed off once detected. The people who need radiation detectors are those who establish and guard the perimeter around ground zero, control the road blocks, evacuate the local population, control hospital admittance, and check people and vehicles for contamination as they leave the danger area.

How much warning will you have if a radiation leak occurs at the local nuclear power plant? Radiation detectors inform the authorities that a leak has happened within seconds.  Then it’s up to the authorities and the local emergency management team to determine how to respond and what the public needs to know.  And if a perimeter needs to be established and  an evacuation ordered.

After the leak is stopped, how can you feel safe living next to a Nuclear Plant? How do you know radioactive dust isn’t blowing around during windy days? Those same radiation detectors keep monitoring radiation levels 24/7.  They are sensitive enough to detect very small levels of radiation and can be set to alarm at far below hazardous levels. No radiation contamination can move without detection within a network of these devices.

Radiation is invisible to us, but we have the tools to track its every move.

Mark Kaspersen is the Director of Engineering of D-tect Systems, producers of radiation detection equipment sold around the world. www.dtectsystems.com.

Radiation Exposure: What Can I Do?

Experiencing the front line of a crisis is a terrifying experience, especially in the face of uncertainty and fear of the unknown.  This point is especially well illustrated in Japan’s ongoing nuclear crisis.  For over a week now, rescue workers in Japan have dealt with floods, fires, power outages, and infrastructure damage, all compounded with the threat of an escalating nuclear crisis.  Radiation levels are at elevated levels for miles around the Fukushima Dai-ichi nuclear complex and scientists are scrambling to determine how much radiation has already been released into the environment.  In the interest of providing a little peace of mind to security personnel across the globe whose line of work brings them into contact with critical situations, we have a few basic suggestions on how to avoid radiation risks.

The way the public views radiation has been shaped by some of the most horrific incidents in modern history: Chernobyl and Hiroshima.  These extreme cases have influenced many to assume that radiation is an exotic and deadly phenomenon.  In reality, our environment is steeped in radiation that our bodies absorb without any proven ill effect.  The most important factor in understanding the impact of radiation is quantity – how high radiation levels are and how these levels translate to risk. 

Security personnel are key and assist as the first line of defense against these varying dangers of radiation.  Organization is extremely important in crisis situations, and even just a few informed individuals can drastically change the outcome of a hazardous situation.  Security personnel have to act quickly to mitigate and ascertain the amount of radiation in the environment.  Two tools that are absolutely essential to security personnel in a radiation crisis are the dosimeter and radiation detector. 

A dosimeter is a small badge worn on the body or a small handheld device used to measure how much radiation the person has been subjected to.  Security personnel are often exposed to more radiation in their line of work, and must carefully monitor their dosimeters to tell them when they are approaching risk levels and must leave the danger area.  To give some idea of safe radiation levels, natural background radiation – the radiation that we are exposed to every day from cosmic rays and naturally-occurring radioactive materials – is about 370 millirems per year in the United States.  A coast-to-coast airplane trip will expose you to about 12 millirems, and a year of watching four hours of television per day adds up to about 2 millirems.  These quantities are miniscule compared to a federal occupational limit of exposure at 5000 millirems per year. Children and pregnant women have much lower exposure levels, and very high levels of radiation can cause serious health risks in a short time. 

Radiation detectors are indispensable to security efforts because they allow personnel to find contaminated areas and people quickly.  A common detector that has been used in the past is a Geiger-Mueller detector, or a Geiger counter. A Geiger counter is a very low cost detector, typically less than $500 USD, and provides very basic detection of large levels of radiation. However, they have significant limitations in a radiation crisis including limited to no detection of lower levels of radiation that can still be dangerous, as well as slower response time. One of the best detection technologies on the market is called a scintillation detector.  These detectors, on average, are 100 times more sensitive than Geiger counter and respond more rapidly to radiation, usually within one second, and typically cost around $1,200 USD.  The much greater sensitivity of scintillation detectors is important in situations like the Japanese nuclear crisis because the heightened environmental levels of radiation in the ocean near the complex (which are 127 times normal background levels) would not even show up on a typical Geiger counter.  The information scintillation detectors gather from radiation can even be used to identify different radioactive isotopes.  Devices such as the D-tect Systems MiniRad-D (a personal handheld detector) and Rad-ID (a handheld radiation detector and identifier) and regularly used by security personnel and individuals in such situations to detect and, where necessary, identify the types of radioactive materials a person has been exposed to.

The procedures outlined by government agencies are carefully adapted to each dangerous situation and should be strictly adhered to.  These procedures aim to limit the spread of radiation and minimize risk to exposed areas.  Although the specific instructions given out for each incident vary, here are a few general guidelines that should always be followed. 

First, in case of radiation contamination, get people (including yourself) out of harm’s way as quickly as possible and notify authorities. Radiation spreads easily though blowing dust and smoke, so radiation-free secure zones must be established by sealing off areas from the outside environment by closing and weather-proofing doors and windows and placing food and water in well-insulated areas such as basements.

Second, since human skin generally acts a good barrier against low-level radiation, the biggest threat is breathing in radioactive materials or somehow ingesting them.  Make sure to wear a face mask in areas that may be contaminated and wash hands regularly.  If you suspect someone has been exposed to radioactive dust, the best solution is usually as simple as discarding contaminated clothing and washing with soap and water, as this will rid the body of radiation before it can cause damage.  As an additional guard against significant amounts of radiation, potassium iodide tablets are sometimes given to protect to the thyroid gland.

Third, preparation is vital when it comes to any kind of disaster, and we recommend everyone keep an emergency kit close at hand so that they can be personally prepared in case of any crises.  This kit should include such things as food and water for a few days, water filtration kit, emergency blanket, rain gear, batteries for radios and detectors, dust mask, extra clothing, flashlight, candles, waterproof matches, cooking utensils, necessary medications, and a first aid kit.  Although we generally take these supplies for granted, shortages can occur quickly in crisis situations.   

Although the current nuclear crisis is fraught with unanswered questions, appropriate preparation will enable you to minimize potential risks and provide you the ability to safely navigate through any crises, including potential radiation exposure.

Radiation Detector Overview

“The only thing constant in life is change.” -  François de la Rochefoucauld

Although they report on thousands of different stories each day, the covers of newspapers in recent weeks have all carried a similar theme – instability.  On-going political changes in many parts of the world, as well as the rapid power transfers and challenges in the Egypt, Yemen, Libya, and many bordering countries have made it clear that political unrest is on the rise.  Recent upheavals have also made it clear that finding security in an increasingly unstable world is a difficult task. 

Adding to political turmoil, terrorist organizations have become increasingly aggressive in both their tactics and technology.   The release of diplomatic cables lays bare new plans by terrorist organizations, such as the Taliban, to construct ‘dirty bombs’ – weapons designed to spread radioactive material over large areas.  We here at D-tect Systems focus on this increasingly relevant area of that security effort: radiation detection. 

With dozens of detector types utilized of literally thousands of radiation detection products, matching the right technology to a threat is a daunting task.  To make this search a little easier, we’ve compiled a general overview of some of the main radiation detectors currently in use.

Geiger-Mueller Tubes, with low sensitivity and a wide range, are the most commonly used detectors on the market.  Available in sizes from ring-worn dosimeters to giant cargo scanners, Geiger-Mueller detectors can pick up certain types of alpha, beta, and gamma radiation.  The downside to these kind of detectors is that they are much less sensitive to radiation than other detector types and cannot differentiate between radiation types.  They are also too slow to detect moving radiation, but are cheap and durable.

Sodium Iodide (NaI(Tl)) and Cesium Iodide (CsI(Tl)) are among the most common gamma radiation detectors.  These two types of materials are commonly referred to as inorganic scintillators because of their composition and method for detecting radiation.  Unlike Geiger-Mueller Tubes, they are fast, sensitive, and can measure the actual energy of gamma rays.  D-tect Systems’ MiniRad-D and MiniRad-V devices uses CsI(Tl) detectors equipped with photo-multiplier tubes that allow the operator to detect radiation from tens of meters away.  

CsI(Tl) detectors, like those used in the MiniRad-D, can detect gamma radiation from even some shielded sources.

Plastic Scintillators (PVT) use the same detection method as NaI(Tl) and CsI(Tl) detectors but usually require much larger detector sizes the achieve the same sensitivity.  They are commonly used in high-volume portal monitors and come in a variety of shapes and sizes.

Lanthanum Bromide (LaBr3) detectors are capable of finding energy peaks more quickly (known as detector efficiency) than a corresponding NaI(Tl) detector, but LaBr3 detectors exhibit internal radioactivity that reduces its spectral resolution at energies below 100 keV.  The current cost of LaBr3 detectors is generally much higher than that of comparable NaI(Tl) detectors. 

 

High Purity Geranium (HPGe) detectors figure into the top end of radiation detection and identification.  Devices using HPGe detectors are able to identify isotopes 2-3 more quickly than NaI(Tl) partly because they need sense far less radiation to come up with an identification.  The downside to this type of detectors is that HPGe detectors must be cooled with liquid nitrogen to operate, which makes HPGe devices bulky and much more expensive than scintillator units.

Cadmium Zinc Telluride (CZT) detectors have higher resolution and stability (for gamma rays and x-rays) than NaI(Tl), but are expensive in large crystal volumes.  Many CZT systems contain arrays of multiple small CZT detectors because the detection sensitivity increases with volume and some directionality can be established this way.  The Rad-ID device by D-tect Systems is available in configurations that contain four or eight CZT crystals, as well as a large NaI(Tl) detector. The combination of multiple detector types allows the Rad-ID to quickly and accurately identify over 110 radioactive isotopes.

Detection systems for neutron radiation (extremely high-energy radiation produced by elements such as Uranium and Plutonium) are also critical for security.  This type of radiation only comes from a few highly-controlled materials. The most commonly used neutron radiation technology involves the use of He3 tubes and requires relatively large volumes.  D-tect Systems’ Rad-ID device has neutron radiation detection capabilities with an optional He3 tube.

So whatever kind of radiation detection you need, we hope this short overview allows you to make informed decisions to help ensure security in an unstable world.

D-tect Systems Counters Newly Discovered ‘Dirty Bomb’ Threats

Draper, Utah, February 3, 2011 – D-tect Systems, a leader provider of radiological and chemical security products, is a long time participant in the war against terrorism.  The silent technology battles of security vs. terrorists have remained, for the most part, out of sight and out of mind for most Americans.  A shift, however, is underway that may bring this battle much closer. 

An article entitled “WikiLeaks: al-Qaeda ‘is planning a dirty bomb’”¹ was released yesterday by The Telegraph news organization.  According to the article, leaked diplomatic documents published by WikiLeaks portray much greater advances in terrorist technologies than previously thought, especially in the field of radiological warfare, such as ‘dirty bombs.’  These bombs, though lacking the raw power of nuclear weapons, have the potential to produce devastating effects because they disperse radiation-emitting substances over a large area.  Exposure to various types of radiation has serious medical implications: burns, loss of sight, long-term diseases such as cancer, and even death.  The materials for making these bombs are much easier to gather than nuclear weapons-grade material: the article cites examples of increased radioactive material trafficking in various parts of the world. 

Although the new information published by WikiLeaks is shocking, the US government has known about the threat of ‘dirty bombs’ for years.  In fact, the US Department of Health included this in a 2007 handbook for response for radiation emergencies: “government authorities and other experts believe a real probability exists that a radiological or nuclear device could be used in a terrorism attack in the future.”  The fact is that response to these concerns has been slow.  Precious few gamma or neutron radiation systems are in place in the United States.  Less than 25% of American hospitals, a logical target of terrorist organizations, have the equipment and training capabilities to deal with the event of a dirty bomb. 

Morgan Taylor, president of D-tect Systems, discusses the magnitude of newly-discovered threats.  “Preparation is key.  To effectively combat threats such as these, the technology to find and contain radiation has to already be in place.  It’s too late once it happens.”

D-tect Systems has long known of the threats facing the American people and provides a line of radiation and chemical detectors, used globally as well as by the Department of Homeland Security, to counter this danger.  D-tect Systems products include the MiniRad-D, a small, pager sized radiation detector containing a sensitive radiation detection system, has been used by police and military forces for years, and the handheld Rad-ID device which can not only detect radiation, but can also identify 110 different radioactive istopes, giving emergency response personnel the lifesaving edge to control and contain dangerous materials. 

¹http://www.telegraph.co.uk/news/worldnews/wikileaks/8296956/WikiLeaks-al-Qaeda-is-planning-a-dirty-bomb.html