Friday, March 30, 2012

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.

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

Monday, March 26, 2012

Rad-DX Mesh Network

Everyone knows that a single camera doesn’t make a very effective security system.  Even if placed in an optimal location, a single camera can miss important details – a fact that becomes very apparent on countless action movies.  The same is true with radiation detection.  Many detectors working together can identify threats that might slip by a single detector.  This is the core idea behind the mesh network capabilities of the Rad-DX
The D-tect Sensor Net, a wireless mesh network built on the 802.15.4 hardware layer, is responsible of the novel network capabilities of the Rad-DX..  All Rad-DXs used in a system (for example multiple devices used at various entrances of building complex) communicate to each other via the D-tect SensorNet.  Each Rad-DX in range of the system automatically connects to the network, the devices automatically form the most efficient network possible, and all units can be monitored at once.  Because each Rad-DX has integrated WiFi and Ethernet, network data is available to smartphones, iPads, and PCs from anywhere in the world.
The D-tect SensorNet is a self-healing network, meaning that even if a Rad-DX loses its connection to the rest of the network (power outage, communication failure, etc.), the rest of the Rad-DXs will route communications around the inoperative unit and continue to communicate effectively.  Have a large area to cover?  The node-to-node range of the Rad-DX is up to 1 km (line of sight), and systems with multiple nodes can cover great distances.  Integrated GPS in every Rad-DX unit allows you to quickly identify the exact location of incidents.
Each detector is able to communicate with the entire mesh network.  Information is relayed anywhere in the world by units in WiFi range.
The communication abilities of the network are supplemented by the following unique features to ensure security.  First, the both the network and WiFi connections are 128-bit encryption protected.  Monitoring can be conducted in real-time, or past even logs can be reviews.  And floor plans can be integrated into the Rad-DX display to provide an intuitive understanding of where radiation is detected. 
So, remember the lessons of James Bond and don’t try to protect your facility with a single detector.  With a mesh network of Rad-DXs you’ll be able to identify and track threats in ways that were never possible before.  Visit the Rad-DX page for more mesh network explanations and examples.

Monday, March 12, 2012

New Rad-DX App

If there is one thing we’ve learned from designing and implementing radiation detection systems, it’s that security takes work.  Monitoring large areas for moving threats can be tedious and time consuming.  That’s why we’ve designed the new Rad-DX to simplify the protection process and work for countless security application.
One of the most convenient features of the Rad-DX is the app we’ve designed for tablets and PCs.  The app allows you to monitor all the Rad-DXs in your network in real-time, as well as allowing you easily playback events and access alarm logs. With the following steps, you can monitor any Rad-DX in the network from a remote location. 
All you’ve got to do is enter the URL of your Rad-DX and login with your username and password.  Your network of Rad-DXs will automatically connect with your tablet.  To create an intuitive display of your network, you can upload the layout of your building or complex to the Rad-DX app. An icon for each Rad-DX detector can be added to its location, giving the operator a simple view of entire detector system, and allowing a user to track the arrival or motion of radiation through the system. 
Rad-DX Screenshot
 Once you’re logged in, you’ll be able to see each Rad-DX in your network.  Touch the icon for any one of the units and you can access the its name, current alarm level, temperature, dose rate, and alarm level.  You can also adjust the settings on your tablet for audio levels and several graph views.  To see a Rad-DX in action, visit 
At the bottom of the screen you’ll find buttons to help you play see what’s going on right now, or play back past events. You can speed through an entire day to see trends in radiation detection, or slow down to focus on a specific event.  For any specific recorded time you can access all the information for each Rad-DX, a feature critical for reviewing alarm records.
With these new features, you’ll be able to keep an eye on your Rad-DX network wherever you go.  For more information on how the Rad-DX can simplify your security network, visit
D-tect Systems is a supplier of advanced radiation and chemical detection equipment sold around the world.

Tuesday, March 6, 2012

New Radiation Detector: Rad-DX

The Rad-DX is the newest addition to the D-tect family of rugged radiation detectors, and has capabilities unlike anything else on the market.  The Rad-DX is a lightweight fixed-mount radiation detector and dose rate monitor, perfect for mounting on a wall, ceiling, or gate. 

The Rad-DX operates on the new D-tect SensorNet - an automatic communication network that allows users to monitor a full network of Rad-DXs as long as they are in range of a single Rad-DX system. The Rad-DX units will automatically form an intelligent, self-healing mesh network, allowing them to be constantly connected to each other as well as to the user network.
Rad-DX software
The Rad-DX is designed to easily integrate into existing networks via WiFi or Ethernet.  Each unit can be controlled and monitored by a PC on the network or across the internet on any PC, Smartphone, or Tablet.  The network is 128-bit encryption protected and monitoring can be conducted in real-time or past event logs can be reviewed.  You can also monitor Rad-DXs on a integrated floor plan or map display providing an intuitive understanding of the location of a radioactive source. Dose rates can be viewed in multiple graph formats. 
The Rad-DX can be controlled by remote PC or tablet
Like the rest of the D-tect radiation products, a sensitive scintillation detector allows the Rad-DX to detect even faint sources of radiation within 1 second. Directionality is also available so you can track the motion of radiation threats.  The Rad-DX is also IP65 rated for both indoor and outdoor operation.  The Rad-DX will be available in March 2012.  For more information, visit the Rad-DX page on the D-tect Systems website.
Multiple versions of the Rad-DX are available

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

D-tect Systems Featured on KSL News!

Check out this great article that KSL News published over the weekend! It talks about local homeland security companies and reports on our recent trips to Japan and has some great information and photos of D-tect products in the field.

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

Relative Biological Effectiveness - What Kind of Radiation is the Most Risky?

As you read this right now, you are being bombarded by radiation – cosmic rays flying in from the dark reaches of space, photons streaming out of the hot core of the earth, and miniscule particles issuing from your computer and other objects around you. But not all radiation is created equal. A new field of study has unearthed the fact that different kinds of radiation affect us differently.  

Although quite a mouthful, this study is called Relative Biological Effectiveness (abbreviated RBE). It seeks to put all radiation on an equal plane and find out what kind poses the highest risk to our organism. Higher values of RBE mean that certain types of radiation are more harmful. Ionizing radiation, which is made up of alpha, beta, and gamma rays, constitute electrically charged particles that interact with matter. These interactions can cause ionization, which refers to changes within the structure of an atom that can cause it to destabilize or behave differently.
Alpha particles are the largest kind of ionizing radiation, each consisting of two protons and two neutrons. Because they are highly charged and quite large, they are quickly stopped by as little as 4 cm (1.4 inches) of open air or a sheet of paper1. Beta particles are much smaller, meaning they can penetrate further: through 9 meters (19 ft) of open air or 11 mm (.4 inches) of body tissue. Gamma rays are high-energy photons, meaning that they penetrate much further and interact differently with matter than alpha or beta particles. Thick, dense materials such as lead are necessary to block gamma rays. Another related form of radiation is neutron radiation, which is commonly referred to as indirectly ionizing radiation. Free neutrons, which are emitted from nuclear materials such as uranium and plutonium, have about a quarter of the mass of an alpha particle2. Neutrons are not charged but readily cause ionization by knocking away electrons or slamming into atomic nuclei. The neutral charge of these fast-traveling neutrons also allows them to penetrate much further into most materials than other types of ionizing radiation, even through many feet of concrete.
Source: American Nuclear Society
 To test how damaging different types of radiation is on the human body, scientists expose living tissue to equal amounts of energy from each type. Surprisingly enough, scientists have found that beta and gamma radiation are nearly equally damaging, so the RBE value of beta and gamma radiation is 1. It gets more complicated from here, though. Alpha and neutron radiation have different RBE values depending on what kind of cells are exposed to them. The RBE for bacteria is 2-3, but can be 6-8 for more complex cells like those found in the human body. This means that a certain amount of alpha radiation is 6-8 times more damaging then the same amount of beta radiation. Neutrons are even more damaging with a RBE of 4-6 for bacteria and 12-16 for complex cells3.  
The high RBE values of alpha and neutron radiation should make us think twice about how we deal with these types. Because incoming alpha particles are stopped by a single layer of skin, they can’t do much damage unless they get in our bodies. That’s why breathing in alpha radiation (from radon or radioactive dust) or ingesting it (in contaminated food or water) is so dangerous. When alpha particles get to really important cells in our organs, the RBE can shoot up: scientists have measured RBE values of 1,000 for alpha radiation inside hamsters4. Neutron RBE values are more constant because neutrons penetrate just about everything, but they are also much harder to contain. That’s why materials that emit neutrons are highly controlled, very hard to transport, and large neutron sources are only found in research facilities and power plants.
The Rad-ID device by D-tect Systems has a special way of finding neutron radiation. A container filled with Helium-3, a rare and stable gas, is included with other radiation detectors inside the Rad-ID. As neutrons shoot through the detector, they collide with some of the He-3 atoms, causing them to change into charged particles. These particles are quickly identified and counted by a detector and a measurement of this radiation is sent to the user. Since neutron sources give off varying levels of gamma radiation, the Rad-ID can also identify these materials and let the user know what they are dealing with.
The Rad-ID can detect neutron radiation sources.
D-tect Systems is a supplier of advanced radiation and chemical detection equipment sold around the world.

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

Meth - the Dark Crystal

Although this blog has mostly focused on radiation detection, we also have quite a bit of expertise in the chemical detection field, and we support law enforcement in their mission to mitigate threats to the public from drug production and chemical accidents.
From its street cost to the health effects it causes, the drug methamphetamine (meth) is expensive – an ounce of pure meth is worth up to 10 times than of an ounce of pure gold. The real problem with meth usage is that the meth’s cost to users in consumption and health problems is dwarfed by meth’s cost to society. This cost comes in the form of increased funding to health care, law enforcement, and cleanup procedures, and was estimated at $23.4 billion dollars in 20101.

 The most common source of meth is small home labs – the DEA reported 11,239 meth lab seizures last year alone2 – which are often set up in motels, trailers, and rental properties. The production of meth involves a number of extremely hazardous chemicals, including:
·  Acetone
·  Ammonium Sulfate
·  Sulfuric Acid
·  Methanol
·  Mineral Spirits
·  Muriatic Acid
·  Organic Ether
·  Toluene

These chemicals are often absorbed into the walls, floor, and ceiling of a meth lab home and cause serious health problems for its residents for years to come. Take this example of a family from Tennessee that was featured in a New York Times article:
The spacious home where the newly wed Rhonda and Jason Holt began their family in 2005 was plagued by mysterious illnesses. The Holts’ three babies were ghostlike and listless, with breathing problems that called for respirators, repeated trips to the emergency room and, for the middle child, Anna, the heaviest dose of steroids a toddler can take. Ms. Holt, a nurse, developed migraines. She and her husband, a factory worker, had kidney ailments. It was not until February, more than five years after they moved in, that the couple discovered the root of their troubles: their house, across the road from a cornfield in this town some 70 miles south of Nashville, was contaminated with high levels of methamphetamine left by the previous occupant, who had been dragged from the attic by the police. The Holts’ next realization was almost as devastating: it was up to them to spend the $30,000 or more that cleanup would require.

Stories like this are in nowise uncommon; there are an estimated 1 to 1.5 million homes that are previously or currently being used to produce meth3. Although most of these homes appear no differently than other residences, many working meth labs do exhibit telltale signs, including:
·   Storage of large amounts of household items such as the chemicals listed above, matches, salt, Coleman fuel, plastic containers, coolers, and aluminum foil
·  Accumulation of garbage including red- or yellow-stained rags and coffee filters, latex gloves, empty cans, bottles, and plastic tubing
·  Chemical staining on walls and floors
·  Covering or blacking-out of windows
·  Security measures such as cameras or baby monitors outside of buildings or guard dogs
·  Unusual traffic patterns, such as excessive night traffic or large numbers of visitors with short stays
·  Burn pits, stained soil or dead vegetation indicating dumped chemicals or waste from a meth lab
·  Abnormal chemical odors not normally associated with apartments, houses or buildings. These odors may be similar to sweet, bitter, ammonia or solvent smells

More sophisticated equipment is often used by law enforcement to monitor meth lab activities and find areas that may be contaminated by previous meth lab use. D-tect Systems’ Chem-ID is a valuable asset in this search. The Chem-ID is a portable chemical detector that can identify over 100 different chemicals including many of those used in the production of meth. This device can identify multiple chemicals at once, and can even identify chemicals at a concentration as low as several parts-per-billion. The Chem-ID can gather samples near a suspected meth lab and analyze them on the spot, giving law enforcement valuable information about the status of the site.
The Chem-ID being operated remotely via Bluetooth
To find more information on meth, check out the Drug Enforcement Agency’s website at or, an excellent nonprofit website with up-to-date statistics and news reports.

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

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:

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