Radioactive Contamination in Consumer Products

Early this year the home retail chain Bed Bath & Beyond recalled over 200 shipments of a brushed steel tissue box holder.  The stir caused by the recall inspired great headlines like this one from Gizmodo¹:

Time to decorate! I'll take this potpourri urn, these palm frond bookends, a nice neutral-colored bathmat, and WHY IS THIS TISSUE BOX EMITTING DANGEROUS RADIATION?!!

The recalled tissue box from Bed Bath & Beyond. source

In reality, radiation contamination in consumer products is no laughing matter, and this is no isolated case.  Contaminated consumer products have been traded between many countries, and a wide range of products have been identified. 

In 2009, Wal-Mart was fined almost $400,000 by the Nuclear Regulatory Committee for exit signs containing radioactive material².  500 sets of radioactive elevator buttons were found in France in 2008³. A few cheese graters turned up in Michigan containing cobalt-60, the same isotope found in the Bed Bath & Beyond’s tissue box holders. Even a batch of 1000 La-Z-Boy recliners was found to have radioactive metal brackets in 1998⁴.  Due to the common occurrence of radiation in consumer products, the US government even set up a Nuclear Material Events Database in 1990.  Since then over 20,000 cases of radiation releases have been documented⁵.

The additional radiation exposure to consumers of these products is generally low level but still a cause for concern.  The tissue boxes were estimated to expose consumers using bathrooms with the boxes to the equivalent of a few extra chest x-rays per year.  Unexpected radiation sources add up: chronic exposure of even low doses of radiation can lead to cataracts, cancer and birth defects, according to the U.S. Environmental Protection Agency. A 2005 study of more than 6,000 Taiwanese who lived in apartments built with radioactive reinforcing steel from 1983 to 2005 showed a statistically significant increase in leukemia and breast cancer ⁶.

The question remains: if we don’t carry a radiation detector with us every time we go shopping, how will we know which products to avoid?  The solution has to involve better detection along increasingly complex supply chains.  Most of the tainted metal introduced into consumer products comes from contaminated batches of scrap metal, sometimes containing radiation acquired in nuclear power activities.  As this metal travels is formed, shaped, and implemented in products, too few check points are involved to catch radiation.  Radiation detectors need to become part of the manufacturing process, not just a safeguard against large foreign radiation sources.  And due to the wide range of consumer products tainted by radioactive materials, detectors need to screen more products. 

With new guideless and increased detection during manufacturing and distribution, we can finally be confident that our next hot buy won’t really be hot.

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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.      http://gizmodo.com/5875898/bed-bath--beyond-caught-selling-radioactive-tissue-boxes

2.      http://pbadupws.nrc.gov/docs/ML0930/ML093050018.pdf

3.      http://articles.latimes.com/2008/nov/12/business/fi-radioactive12

4.      http://nmed.inl.gov/AnnualReports/NMEDFY10%20Annual.pdf

5.      http://public.shns.com/node/43582

6.      http://www.businessweek.com/news/2012-03-19/nuclear-risks-at-bed-bath-and-beyond-show-hidden-danger-of-scrap

Fukushima: Long Term Impact

The gripping drama that unfolded during this month last year filled headlines and news hours all across the world.  On March 11th last year, a huge earthquake and tsunami left more than 20,000 people dead or missing in eastern Japan.  Amidst widespread destruction, the tsunami slammed into the Fukushima Daiichi Nuclear Power Station, disabling cooling systems and leading to fuel meltdowns in three of the six nuclear units.  As invariably occurs, after a few months the media coverage moved on, even though countless problems remain unresolved.  

So why hasn’t the radiation washed away or faded into neutrality?  This same query has plagued eastern Europeans for over 25 years as they continue to deal with heightened radiation levels stemming from the Chernobyl disaster. The answer is that radioactive materials released into the environment in both of these catastrophes are extremely finely dispersed and will last for decades.  In fact, just controlling the spread of radiation has become higher priority than cleaning up the mess in many cases.

In a nutshell, radioactive elements are unstable atoms. They seek stability by giving off particles and energy—ionizing radiation—until the radioisotope becomes stable. This process occurs within the nucleus of the radioisotope, and the shedding of these particles and energy is commonly referred to as ‘‘nuclear disintegration.’’  During their disintegration, most radioactive elements morph into yet other radioactive elements on their journey to becoming lighter, stable atoms. Some of the morphed-into elements are much more dangerous than the original radioisotope, and the decay chain can take a very long time¹. This is the reason that radioactive contamination has a variable lifespan, depending on the composition of the radioactive material. For more information on this topic, see this post on radioactive lifespans.

The most common contamination radionuclides in the Japanese crisis are cesium-134 (with a half-life of 2 years) and cesium-137 (with a half-life of 30 years).  Radiological risk assessment expert John Till, president of the U.S.-based Risk Assessment Corporation, says the fallout will probably be gone from the surface of plants within a few years, but attach strongly, through ion exchange, to soil — in particular to the clay soils common throughout Fukushima². From there, the rate and risk level at which cesium will move into plants is still unclear.  And the oceans are a different matter: sediment levels and changing currents make radioactive duration almost impossible to estimate.

Japanese soldiers collect contaminated leaves near the Fukushima nuclear power plant in December. source

 

All of this information adds up to the need for sustained radiation observation.  In particular, on-going dose rate measurements are essential to avoid overexposure to people, animals, and crops.  Since much of the radiation is mobile, weather changes can cause radiation levels to rapidly fluctuate.  This is a common occurrence in Japan, where after a rain storm brings down radioactive particles, the sun and wind can produce radioactive dust clouds that travel in unpredictable ways.  The mobility of these radioactive particles requires constant monitoring to warn people and keep them indoors on increased risk days.

Not only do these detectors need to consistently and accurately make measurements, they also need to efficiently relay information to analysis locations.  A self-healing mesh network is ideal for this kind of seamless measurement and communication.  This kind of network routes around disabled detectors and can incorporate new detectors at any location in the network.  The Rad-DX, D-tect’s newest addition, operates on the D-tect SensorNet – a mesh network with these capabilities.  To learn more about the SensorNet, visit this page. 

Although the cleanup in Japan may take decades, conditions are steadily improving.  With careful and constant radiation monitoring and improvements to safety standards, future risks may be mitigated.

1: http://www.oecd-nea.org/press/press-kits/fukushima-faq.html

2: http://www.energybulletin.net/stories/2012-01-09/fukushima-cleanup-begins-long-term-impacts-are-weighed

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

Radioactive Half-Life: How Long Will It Last?

Although it seems like this post should include some commentary on zombies or video games, we’re going to focus on the term ‘half-life’ as it’s used in physics, this time. The reason for this is that important research has been published last month on geothermal heat produced by radioactive decay. 

But before all that complicated stuff let’s start at the beginning. ‘Half-life’ is actually shortened from ‘half-life period’ which refers to the time in which exactly half of a radioactive substance decays. This measurement is especially useful because radioactive materials decay exponentially – meaning that they decay much more quickly at first than later on, where the decay process drags on more slowly.  This decay rate is directly connected to the rate at which radioactive materials emit radiation.  

Let’s take iodine as an example. I-131 has a radioactive half-life of just over 8 days and gives off both alpha and beta radiation (for a discussion of these radiation types see this post). As I-131 atoms give off radiation they transform into atoms of Xe-131, a stable (and non-radioactive) isotope¹. That means if you start with a pure sample of I-131, after 8 days about half of the sample will be I-131 and half will be Xe-131. If you wait another 8 days, 1/4 of the sample will be I-131 and 3/4 will be Xe-131, and so on. As you may expect, the sample of I-131 will emit much more radiation right at first versus many days later on, when the majority of the sample is Xe-131. 

 Not all materials have a half-life short enough to notice. In fact, the half-lives of radioactive materials can vary from fractions of a second to billions of years. These differences lend themselves to varied applications. Isotopes with short half-lives (such as I-131, Tl-201, In-111, and Tc-99) are commonly used in medical imaging and therapy because they show up clearly in the body and become non-effective quickly so that the patient is not exposed to too much radiation². Isotopes with long half-lives (such as U-238, C-14, and K-40) are often used in radiometric dating, where scientists can measure the abundance of these isotopes in various materials to determine their age³.

Newly published research⁴ from Japanese and Italian scientists also suggests that over half of the internal heat produced by the earth is caused by long-lasting radioactive materials such as thorium, uranium, and potassium – a quantity that adds up to nearly twice as much energy used annually by everyone on the planet⁵. The fact that radioactive materials are responsible for the heat is important because it helps to explain why our earth is hot enough to produce volcanoes, mountain ranges, and general plate tectonics while other planets in our solar system have long since gone cold. The geothermal heat of our planet isn’t going to cool soon either, thanks to the fact that the isotopes producing the heat have half-lives of billions of years.    

So although the adage “all good things must come to an end” (and all bad ones, too!) may be a great application to radioactive materials, there’ll be plenty of radiation and geothermal heat for years to come.

1)http://epa.gov/radiation/radionuclides/iodine.html

2)http://www.world-nuclear.org/info/inf55.html

3)http://www.world-nuclear.org/info/inf55.html

4)http://www.eurekalert.org/pub_releases/2011-07/dbnl-wkt071311.php

   5)http://www.scientificamerican.com/blog/post.cfm?id=nuclear-  fission-confirmed-as-source-2011-07-18   

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

Radon: Radiation on the Home Front

It seeps up through the ground, pooling in basements and cellars. It can infiltrate our homes and even our lungs, spreading radiation with every ripple of breeze. Present in nearly every country of the world, this substance is colorless, odorless, and tasteless. It kills thousands every year and requires special equipment to locate.

Although this sounds like something from a cheesy science fiction film, radon gas is a real threat to people all over the world. Radon-related diseases cause about 21,000 deaths per year in the US¹ (almost twice the number of drunk driving deaths), meaning in most countries only smoking causes more deaths from lung disease.

Deaths Per Year - Source: http://www.epa.gov/radon/pubs/citguide.html

The first reason radon is dangerous is because it’s all around us. The EPA estimates that 1 out of every 15 homes in the US has elevated radon levels² . In almost every country radon is the largest natural source of human exposure to ionizing radiation and makes up over half the radiation each person is exposed to in a year. Since radon is a decay product of uranium, it is more often found where there are large concentrations of granite, like those occurring in Ireland and the UK, Canada, and some US states such as Iowa and Pennsylvania.  

Radon Test Kit - Source: http://visualsonline.cancer.gov

The physical properties of radon also contribute to its effect on people.  Radon is one of the most dense gases on our planet – over 8 times denser than the atmosphere at sea level. This causes it to pool at the bottom of whatever container it is in. Because of this, elevated radiation levels from radon are found in the lower levels and basements of buildings. It also means that when breathed in, radon gets trapped in the bottom of the lungs and has more potential to do damage. Radon emits mostly alpha radiation which is made up of fast-moving particles with more mass than beta or gamma radiation. Alpha radiation doesn’t penetrate very well – it can be stopped by as little as a piece of paper or human skin. So the real risk to humans from alpha radiation is when it gets inside us and starts to affect our internal organs. Because it is a gas, almost all the damage done is in the lungs and can lead to lung cancer.   

The good news about radon is that it is easily detectable and many options are available to lessen radon risks in the home. Short- and long-term radon test kits are inexpensive and commercially available throughout the world. A short-term test (which takes several days) gives the homeowner an estimate of radon concentration in the home, and a subsequent long-term test (which takes a year or more) can give a more precise measurement. There are varying ‘action levels’ of radon throughout the world, but most countries recommend taking some action to reduce radon if average concentrations are above 4 pCi per liter of air³. Solutions to lower radon concentrations include venting air from lower stories of a house or pressurizing areas to keep external gases out.

An example of radon venting from the US EPA.

Although radon may sound scary and looks pretty bad on paper, many people can significantly lower their risk of radiation exposure from radon. Good information is widely available on this subject, including the World Health Organization’s Radon Handbook and A Citizen’s Guide to Radon by the US Environmental Protection Agency.  

1) http://www.epa.gov/radon/pubs/citguide.html

2) http://www.epa.gov/radon/pubs/citguide.html

3) http://www.who.int/mediacentre/factsheets/fs291/en/index.html

D-tect Systems is 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.

Am I at Risk of Radiation Exposure?

The ongoing uncertainty of the Japanese nuclear crisis has left people around the world questioning the danger of radiation contamination in their own communities. How much is the general public really at risk of radiation? Because D-tect Systems specializes in detecting threats from radioactive and chemical sources, we offer this article to provide some information on some of the current radiation risks in context and some general guidelines on radiation safety.

The first step in qualifying contamination risks is to separate fact from fiction. The way the public views radiation has mostly been shaped by a few incidents in modern history: Chernobyl and Hiroshima/Nagasaki. 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 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.

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 3 mSv (300 mrem) per year. According to the FAA, A coast-to-coast airplane trip will expose you to about 5 µSv per hour (which comes out to 43.8 mSv/yr for continuous flight), and a year of watching four hours of television of day adds up to about 20 µSv total (2 mrem). These quantities are pretty small compared to a federal occupational limit of radiation exposure set by OSHA at 50 mSv (5000 mrem) per year. Now let’s compare the situation in Japan to all this. Recent reports from the International Atomic Energy Agency stated that radiation levels at the perimeter of the Fukushima Daiichi nuclear complex have been measured at 1 – 3 mSv/hr. Although this is an elevated radiation level and prolonged exposure could be dangerous, the short-term radiation level set for Japanese workers working on the nuclear complex is 250 mSv, and would take considerable time to reach.

Although the risks of serious widespread radiation contamination in this case are low, the procedures outlined by government agencies should always 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 precaution against significant amounts of radiation, potassium iodide tablets are sometimes given to protect 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 crisis. 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.

Preparation is vital when it comes to any kind of disaster, and we recommend all public safety personnel keep an emergency kit close at hand so that they can be personally prepared to serve the public. This kit should include such things as food and water for a few days, emergency blanket, rain gear, batteries for radios and detectors, dust mask, extra clothing, 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 continues to make headlines and is a great source of fear for many, it is important to know the real risks involved and how to cope with them. With a little knowledge of radiation safety, and material preparation for a crisis, we can minimize future risks and know better what we’re up against.

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

Japan's Nuclear Crisis

Last week one of the largest earthquakes on record shook Northern Japan and triggered a devastating tsunami.  The damage is extensive: so few roads and runways are open that even humanitarian supplies have been seriously delayed.  But the greatest fear of the country isn’t the washed out roads or flattened villages.  It’s an invisible phenomenon with huge historical significance to the Japanese: the threat of nuclear radiation is rising like a ghost recalled from the past.

Nuclear power doesn’t make many headlines these days.  Until last Friday, nuclear plants have been considered in many parts of the world to be the best economical solution to growing power needs.  Japan has 55 nuclear reactors, providing approximately a quarter of the country’s power.  Advancing nuclear technologies have made power more efficient and seemed to invalidate radiation risks illustrated so horrifically by incidents at Chernobyl and Three-Mile Island.  But it is clear that innate nuclear power risks, however diminished, remain.

Japanese security personnel at the nuclear complex.  Photo credit cnn.com.

 The setting for the nuclear showdown in Japan is the Fukushima Dai-ichi nuclear complex.  Although this reactor, as well as two others, ceased operations as soon as the magnitude 9.0 earthquake hit, consequent damage to the structure has destabilized the normal cooling operation of the plant and lead to an atomic crisis.  Three hydrogen gas explosions have already rocked the plant, providing evidence that the fuel rods are at above normal temperatures.  Japanese authorities have already announced that steam from a nuclear cooling pond (used to cool the fuel rods) has been released into the atmosphere, meaning that some radiation has already leaked from the plant.  At this point, quantities of released radiation are unknown, but could rise dramatically if cooling of the reactor core is unsuccessful or a breach in the reactor wall occurs. 

But what is the real danger of nuclear radiation?  Unlike other forms of radioactive materials, such as those used commonly in hospitals and industry, nuclear materials are very heavily controlled throughout the world, and for good reason.  Nuclear materials, such as plutonium and uranium, give off neutrons at extremely high energy levels as their nuclei decay.  This kind of radiation easily passes through most matter, but can affect body tissues enough to cause serious medical problems. Short-term nuclear exposure can cause infections, hair loss, and fevers, and in extreme cases, organ failure and death.  Long-term exposure can cause cancer, tumors, and genetic damage.  Even shielded nuclear radiation sources can emit gamma radiation, which brings other health risks. 

The nature of this nuclear crisis, as well as many related scenarios, requires the use of a combination of radiation detectors all working together to minimize risks.  Our products are designed for just this.  In case of a radiation release, a perimeter could be set up using small, handheld MiniRad-D devices.  These pager-sized radiation detectors can sense radiation from tens of meters away.  The MiniRad-D could also be used to check personnel leaving the nuclear zone to determine if decontamination is needed.

The MiniRad-D is self-calibrating and uses a high-sensitivity scintillation detection system.

 The Rad-D unit is ideal for placement in unmanned locations to monitor ambient changes to radiation levels.  The system requires no maintenance and sophisticated neutron detectors can be configured into the system as well as gamma detectors. 

At the forefront of the crisis, specialized equipment designed for finding and identifying the type of radiation is needed.  The high-energy nature of nuclear radiation tends to saturate detectors and is hard to differentiate from gamma radiation.  Special neutron detector systems, such as the Helium-3 gas-filled tubes used by D-tect Systems in both the Rad-ID and Rad-D systems, sort out gamma rays and detect and identify neutron radiation.  The Rad-ID also contains a combination of detector types to find radiation over a wide range of energies, and from large amounts of radiation to sources emitting just above background radiation.

The Rad-ID can identify over 110 radioactive isotopes.

 We hope for the best in the Japan’s current nuclear crisis and that future wise decisions will mitigate the risks involved with nuclear power.

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