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

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.

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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.

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.

Putting Radiation in Perspective

Due to the recent nuclear crisis in Japan, we've seen much more technical jargon than usual on major news stories. A reason for this is that radiation physics is a highly technical field and even quantifying radiation can be very complicated: a shift of a few decimal places can mean the difference between no risk and a major radiological hazard. Even the units are new - how many people have ever used 'becquerel' or 'half-life' in a casual conversation?

In conjunction of the new language hitting newspapers and TV screens, we've seen a great push to put radiation in perspective. This basic education goes a long way to help people make choices on how much they should worry about what is going on in Japan and what they can do to protect themselves. Visual examples are popular such as this one on xkcd.com, as well as thorough explanations discussed here by Harvard Medical School.

In supporting this movement, we recently released a Radiation Basics Sheet that we put together with data from the World Nuclear Association and US Environmental Protection Agency. We included some relative doses such as how much radiation you'll get from watching a year of TV, how much from a chest x-ray, and how much you'll get from flying across the US. We hope that this information can be used to turn dispel fears and boost confidence. 

Our sheet was recently featured on the blog of STORMWATER (a journal for surface water quality professionals). The post What do the Numbers Actually Mean? is very informative and talks about radiation contamination in Tokyo's tap water. We're excited that someone is putting this information to good use, and we're grateful to STORMWATER for the coverage.

If you would like more information to help you put radiation risks in perspective, we here at D-tect Systems have experts in the radiation detection field who can provide more information by email (info@dtectsystems.com) or even on the phone (801.495.2310). 

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.

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.

Radiation Basics Sheet

A pdf version of this document can be found on the D-tect Systems website, here.

Background radiation: ~ 3 mSv/yr (300 mrem/yr) in North America and slightly higher in Asia. 88% of background radiation comes from natural sources (half of this from radon gas), almost all the remaining radiation comes from medical sources.

World Nuclear Organization

Safety Levels: American regulatory limit for occupational exposure: 50 mSv/yr (5 rem/yr). This limit was chosen because it is the lowest rate at which there is evidence of cancer being caused in adults. Pregnant women and children should have no more than a 10^th of this (5 mSv/yr or 500 mrem/yr). A lethal full-body dose for a man is around 4-5 Sv (400-500 rem) in a short time period.

Radiation Sickness Threshold: 1000 mSv (1 Sv or 100 rem) in a short time period. Symptoms: nausea, hair loss, weakness, skin burns

Long-term Radiation Exposure: cancer, cell mutation, birth defects.  The danger of continued overexposure to radiation is that symptoms can appear after 20 years after exposure.

Radiation Exposure vs. Distance: if you double the distance, you reduce the exposure by a factor of 4.

Ionizing Radiation Types

Alpha

Penetration: stopped by skin or paper, dangerous when ingested or breathed in.

Beta

Penetration: stopped by aluminum plate or 1 cm of human flesh, heavy clothing may be needed.

Gamma & X-rays

Penetration: easily passes through most matter, shielding requires concrete, lead or water.

Neutron

Penetration:  Just like gamma rays, shielding requires concrete or water.  Neutron radiation only comes from cosmic rays and nuclear reactions, and although it isn’t ionizing, it can cause other materials to become radioactive and is often accompanied by other radioactive materials.

Protection from Radiation

Limiting Time: For people who are exposed to radiation in addition to natural background radiation through their work, the dose is reduced by limiting exposure time.

Distance: In the same way that heat from a fire is less the further away you are, the intensity of radiation decreases with distance from its source.

Shielding: Barriers of lead, concrete or water give good protection from penetrating radiation such as gamma rays. Radioactive materials are therefore often stored or handled under water, or by remote control in rooms constructed of thick concrete or even lined with lead.

Containment: Radioactive materials are confined and kept out of the environment. Radioactive isotopes for medical use, for example, are dispensed in closed handling facilities, while nuclear reactors operate within closed systems with multiple barriers which keep the radioactive materials contained. Rooms have a reduced air pressure so that any leaks occur into the room and not out from the room.

Radiation Exposure Units of Measurement

Exposure: measure of the strength of a radiation field at some point in air.  Basic unit: “roentgen” (R).

Dose: absorbed dose is the amount of energy that ionizing radiation imparts to a given mass of matter.  Basic units: “gray” (Gy) and “radiation absorbed dose” (rad). 1 Gy = 100 rads.  In human tissue, 1 R of gamma radiation = 1 rad of absorbed dose.

Dose Equivalent: relates to the absorbed dose to the biological effects of that dose. Basic units: “sievert” (Sv) and “roentgen equivalent in man” (rem). 1 Sv = 100 rem.

Dose Rate: a measure of how fast radiation a radiation dose is being received.  Basic units: mSv/yr, mrem/yr, etc.

Half-life: The time it takes for half the nuclei in a specific isotope to undergo decay.

Radiation Examples

Air travel: measured dose during air travel is 5 µSv/hr (43.8 mSv/yr or 4380 mrem/yr) according to the FAA.  This is about 15 times background radiation.

Watching TV: 4 hours a day adds up to 2 mSv/yr (200 mrem/yr)

Allowable short-term dose for workers on the Fukushima accident: 250 mSv (25 rem)

Radiation Measurement on the perimeter of the Fukushima Nuclear Plant: 1-3 mR/h (about 10-30 µSv/h)

U.S. Environmental Protection Agency

Atomic Shorthand

Example: “Iodine-131” = ₅₃I¹³¹

Radioactive Iodine

Iodine concentrates in the thyroid. Because of this, radioactive iodine (a byproduct of nuclear reactions) contributes to thyroid cancer more than other types of cancer. For this reason, potassium iodide tablets are given to increase the amount of safe iodine in the body, as this limits the amount of radioactive iodine the body will absorb.

The most common kind of radioactive iodine (Iodine-131) has a half-life of only 8 days.

Nuclear Plants

There are over 440 commercial nuclear power plants operating in 30 countries which accounts for about 14% of the world’s power.  The US has 104 operating reactors, the most of any nation.  Japan previously had 56.

International Atomic Energy Agency

Alarm Levels for the MiniRad-D Radiation Detector

Alarm Level	µrem/hr	mrem/hr	µSv/hr	mSv/hr
1	35	0.035	0.35	0.00035
2	40	0.04	0.4	0.0004
3	55	0.055	0.55	0.00055
4	65	0.065	0.65	0.00065
5	100	0.1	1	0.001
6	200	0.2	2	0.002
7	350	0.35	3.5	0.0035
8	600	0.6	6	0.006
9	1100	1.1	11	0.011

D-tect Systems

 The radiation facts and protection information in this post were published by the World Nuclear Association and health information was published by the US Environmental Protection Agency.