Radiation on the Move

Radioactive materials have a nasty habit – they like to travel.  This phenomenon has caused panic at various times in history after nuclear events and accidents, and continues to do so these days. The nuclear disaster at Chernobyl created clouds of radioactive dust that swept across great swaths of Eastern Europe. Because most of the radiation was leaked into the environment when explosions and resulting fires destroyed the plant, the particles carrying radioactive material were very small and were carried easily by weather patterns. With little warning and even less monitoring, thousands were exposed to unknown amounts of radiation.

As the cleanup of the Fukushima Daiichi Nuclear Complex proceeds, we see a continuation of the same trend. Minute radioactive particles in steam and smoke rose into the atmosphere and were dispersed by wind and rain.  In addition, the proximity of the Fukushima plant to the ocean exacerbated contamination as an immense amount of contaminated ground water leaked into the sea. Although some of the more short-lived radioactive isotopes (such as I-131) soon faded, longer-lasting isotopes continue to cause problems as they travel and coalesce in unexpected areas. The contamination has posed such a problem in ecosystems near the plant that TEPCO began pouring concrete over 786,000 sq. ft. of seafloor near the accident site to encase radioactive materials¹.

A recent study published in the journal Proceedings of the National Academy of Science shows another example of traveling radiation. Pacific bluefin tuna were discovered to have carried radiation from the Japanese coast to the shores of Monterrey, California in their annual migrations². This news is surprising because scientists expected radioactive material to be metabolized and shed by the fish much earlier in their vast migratory movements. The isotopes found were not at dangerous levels for consumption, but definitely identifiable as cesium-134 does not occur naturally in the Pacific Ocean and cesium-137 only occurs at minimal levels. 

Tuna caught off the coast of California are found to have traces of radiation originating in Japan. source

This discovery illustrates how easily radiation can spread even great distances, and is a signal that constant widespread monitoring needs to be part of the Fukushima contamination solution. As radiation continues to travel and settle, we need detectors capable of notifying the public of these trends. Only with increased detection capabilities and constant monitoring can we truly understand the travel patterns of radiation. 

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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 Scrap Metal – a Global Issue

The world is becoming a smaller place. The accelerating pace of technology is pulling people together through communication, travel, business, and industry. Globalization makes it easier to for us to share – a phenomenon with both positive and negative implications. In the great melting pot of world industry, radiation contamination is proving to be an increasingly harmful side-effect. 

As discussed in the previous post, much of the radiation contamination of consumer goods has been linked to contaminated scrap metal. Metal used in the production of goods comes from a variety of sources and almost invariable contains a large amount of recycled materials – a fact that efficiency and environmental controls demand. The problem is that long-lasting radioactive scrap from sources such as medical equipment, food processing, mining equipment, and even decommissioned power plants, is making its way into smelters. The metal turned out from these contaminated batches spreads to other consumer goods – most of which are never checked for radiation.

A scrap metal foundry.  source

Another aspect that further complicates the scrap contamination problems is size – the scrap metal market is worth over $140 billion¹. With so much material in flux, an unreported contamination event can send radioactive material to unknowing manufacturers across the globe.  Although the US has stopped over 120 major radioactive shipments since 2003², there is ample evidence that radioactive scrap is still slipping through the cracks.  For example, a Texas recycling facility accidentally created 500,000 pounds of radioactive steel byproducts after melting metal contaminated with cesium-137 according to U.S. Nuclear Regulatory Commission records for 2006.

Scrap yards and recycling operations truly are the primary line of defense against rogue radiation but most of these facilities are under no specific federal government or state regulations and reporting is often voluntary if problems are found.

We’ve seen the results of contamination close at hand – at a recent visit to the nearby landfill, we were told that almost every load of scrap metal that comes in sets off radiation detectors and has to be scanned a second time.

To aid in this crucial detection stage of industry and commercial operations, D-tect Systems has designed several radiation detectors that are sensitive and easy to mount.  The Rad-D is currently being used in hospitals, factories, embassies, and waste disposal locations.  It can easily be mounted to scan conveyor belts and integrate with existing security systems.  The Rad-DX, D-tect’s newest product, is smaller and more visually innocuous.  The Rad-DX also has novel mesh-networking abilities that allow an operator to monitor multiple radiation detectors in real time or look at past event logs.   

The Rad-D is easily mounted to a wall or pole and monitors for radiation in real time.

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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://atrisk.net/radioactive-scrap-metal-is-new-threat-to-global-supply-chains/

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

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

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.

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.