Are nuclear density gauges a security risk?
There has arisen a safety and security problem involving these nuclear density gauges, however. They are getting stolen. One FBI representative reported that there have been over 100 reports of theft or loss of density gauges over the last 2 years.
Are density gauges dangerous to touch?
(Density gauges can contain small amounts of radioactive cesium-137 and americium-241.) Any handling of unshielded sources outside the container could carry a risk of potentially dangerous radiation exposure.” Luckily, in this instance the thief was found and arrested, and nuclear inspectors are reviewing the case.
What is a nuclear densometer and how dangerous is it?
As you may have guessed from their name, a nuclear densometer uses nuclear energy to measure the density of the soil being tested. Of course it follows that operators of the nuclear gauge, and anyone who spends time around them, are inevitably exposed to radiation. How does this translate to the gauge’s effects on worker’s health?
Do nuclear gauges give off radiation?
Workers usually receive little or no radiation from nuclear gauges due to the safety measures in place. When properly used, nuclear gauges will not expose the public to radiation. When no longer in use, nuclear gauges must be stored safely. Safe storage locations should be fireproof and weatherproof.
Are nuclear gauges radioactive?
Nuclear gauges are devices that use radioactive sources to measure parameters such as thickness, density, moisture or fill level. Nuclear gauges normally incorporate a nuclear source, a detec- tor and a shutter. Although radiation is being emitted all the time, the shutter can be closed to shield the radiation beam.
How much radiation does a nuclear gauge emit?
It is typically a source of about 40 to 50 milli-Curies. Devices can be built to measure either soil density or soil moisture content, or both.
What are some of the advantages of nuclear gauges?
Portability. One person can easily transport a typical nuclear density gauge.Quick results. Most nuclear gauges allow both one and four minute readings. ... Virtually non-destructive. Used in the backscatter mode, the nuclear density gauge is entirely non-destructive.
How much does a nuclear density gauge weigh?
Dimensions/WeightGauge:Dimensions (base):15.75" x 8.66" x 5.5" (400 x 220 x 140mm)Handle Height:18" or 21.5" (450 or 550mm)Weight:30 lbs (13.6kg)Reference Standard:9 more rows
What is a safe distance to live from a nuclear power plant?
If something happens to go wrong at a nuclear reactor, anyone living in a 10-mile radius of the plant may have to evacuate. This map also shows a 50-mile evacuation zone, the safe distance that the U.S. government recommended to Americans who were near Fukushima.
What's the safest level of radiation?
Adult: 5,000 Millirems. The current federal occupational limit of exposure per year for an adult (the limit for a worker using radiation) is "as low as reasonably achievable; however, not to exceed 5,000 millirems" above the 300+ millirems of natural sources of radiation and any medical radiation.
Can you use a nuclear density gauge in the rain?
Do not use the gauge in the rain. If it gets wet dry it immediately.
How does nuclear density gauge work?
The gauge works by counting the radiation that is received over a given period of time, usually one minute. When you push the button to take a test the gauge counts the radiation for one minute and calculates the density based on the depth of measurement.
What property of nuclear radiation is most harmful?
Gamma rays are the most harmful external hazard. Beta particles can partially penetrate skin, causing “beta burns”. Alpha particles cannot penetrate intact skin. Gamma and x-rays can pass through a person damaging cells in their path.
Does turning the gauge off Turn off the radiation?
Turning the gauge off turns off the radiation. You should always remove the batteries when not in use. This will prevent the release of radiation.
How much does a Troxler 3440 cost?
New Troxler 3440 T-3440 $18,000 approx.
How much does a Troxler 3430 cost?
Various Troxler 3430 & 3401-B Nuclear Density GaugesAuction ClosedSold Amount:$2,500.00Buyer's Premium (5.00%):$125.00Total Price:$2,625.003 more rows
What is a nuclear gauge?
A nuclear gauge (also called a nuclear density gauge, a soil moisture gauge, or a moisture density gauge) is a tool used for civil engineering projects and construction that measures soil density or soil water content . Nuclear gauges are also used for industrial, mining, and scientific purposes. In USDA, nuclear gauges are used for building roads and dams, and for collecting scientific data on soil water content in agricultural and forestry settings.
How to purchase a nuclear gauge?
Before a purchasing agent can place an order to buy a nuclear gauge on behalf of a Permit Holder, the Radiation Safety Division must review and approve the information on the purchase order. A nuclear gauge may also be transferred from another USDA employee, who has a nuclear gauge Permit. The Radiation Safety Division must review and approve such gauge transfers between Permit Holders, in order to review and update Permit and inventory data for both people. If a Permit Holder at a location leaves permanently, and the gauge is to be maintained at that location, it must be transferred to another Permit Holder at that location. A nuclear gauge may also be transferred from a person or organization outside of USDA that is authorized to have the gauge under a state or NRC license. Before a nuclear gauge can be transferred from outside of USDA, the Radiation Safety Division must review the authorizing license and must approve the gauge transfer.
How does a soil density gauge work?
For measuring soil density, a radioactive source emits gamma radiation into soil, and a sensor measures the radiation that is reflected by the soil. By calculating the percentage of radiation that returns to the sensor, the gauge can be calibrated to measure the soil density.
How often do you need to refresh your nuclear gauge?
DOT HazMat Refresher Training for Nuclear Gauges is also required every three years.
Where to post a warning sign for nuclear waste?
Post a "Caution Radioactive Materials" sign in rooms or areas where nuclear gauges are stored. Post an NRC Form-3 "Notice to Employees,” in areas where employees will see it, for example, on a safety bulletin board.
What is the radioactive source used to measure water density?
For measuring water density, the radioactive source emits neutrons and then measures the returning scattered neutrons. Hydrogen, a major constituent of water, characteristically slows down neutrons; the sensor’s measurements can therefore be used to calculate the water content of the sample.
Can a nuclear gauge be given away?
A nuclear gauge cannot be given away, placed on excess property lists, thrown away, or abandoned. Any of these actions is a serious violation of NRC Federal Regulations. If a Permit Holder leaves USDA without arranging for proper transfer of a gauge, local management or the LRPO (Location Radiation Safety Officer) must maintain control of the nuclear gauge until the name of a new Permit Holder candidate can be submitted to the Radiation Safety Division.
Why are nuclear gauges used?
Nuclear gauges use radioactive sources to identify the thickness, density or make up of a wide variety of material or surfaces. These gauges, which are safe to use when the proper safety measures are followed, help people build safe buildings, roads, and make reliable products.
What to do if your nuclear gauge is broken?
What You Can Do. Do not handle broken equipment. If you believe that a nuclear gauge is broken, do not attempt to handle it yourself. Never handle an unshielded radiation source. Call local authorities immediately and report it. People who work with nuclear gauges know the appropriate steps to ensure proper management.
How do portable gauges work?
Portable gauges work in a similar way to fixed gauges, but because they are not permanent, both the radioactive source and the detector need to be able to move. Sometimes, parts of the gauges are inserted into the ground in order to get an accurate measurement.
What is the purpose of radiography?
Radiography is the use of radiation to produce an image on photographic film. This is similar to the way a medical x-ray uses radiation to produce images of bones. Nuclear gauges measure three main things: thickness, density, and fill level. Thickness gauges are used in manufacturing to make sure an entire product or material is ...
What happens when a radioactive source is opened?
When the radioactive source is opened, radiation is emitted from the gauge and some of the radiation will pass through the object. The rest of the radiation is absorbed by the object. Any radiation that is able to pass completely through the object will be measured at the detector.
What is a level gauge?
Level gauges measure how much liquid is in a container, to make sure that each container has the same amount of product. Nuclear densometer. Nuclear gauges have a radioactive source that is covered by a radiation blocking shield. Gauges can contain a gamma, beta or neutron radiation source.
What is a thickness gauge used for?
Thickness gauges are used in manufacturing to make sure an entire product or material is the same thickness throughout, or to make sure the coating on a material is even. Density gauges are used in cement, petroleum, and road production to make sure that the density of a material is the same.
What happens when density gauges are lost?
When these instruments are lost or stolen, officials must be able to monitor, detect, and respond.
Why are density gauges stolen?
There has arisen a safety and security problem involving these nuclear density gauges, however. They are getting stolen. One FBI representative reported that there have been over 100 reports of theft or loss of density gauges over the last 2 years. Some of the gauges are getting stolen because thieves think they are expensive pieces ...
What equipment is often overlooked in radiation preparedness plans?
One type of equipment that is often omitted from radiation preparedness plans are nuclear density gauges .
What gauges can accurately measure the density of a liquid?
There are high-performance non-intrusive, non-contact nuclear density gauges that can accurately measure the density or percent solids of a liquid or slurry in a pipe for any application that may involve a high temperature, highly toxic or highly corrosive process.
What is density gauge?
Density gauges are used to measure variations in the density of materials and are often found in the concrete, construction, oil and gas, petrochemical, chemical, food and beverage, and general process industries. There are high-performance non-intrusive, non-contact nuclear density gauges that can accurately measure the density or percent solids ...
What to do if a nuclear gauge is stolen?
As soon as it becomes known that a nuclear gauge has been stolen, lost or, misplaced, the Permit Holder, or the individual in possession of the nuclear gauge, must immediately call the Radiation Safety Division for assistance. Finding the gauge must be an urgent priority, which may involve law enforcement and the resources of the NRC.
Why are some of the gauges being stolen?
Some of the gauges are getting stolen because thieves think they are expensive pieces of equipment they can pawn, but others are stealing them to sell the nuclear source on the open market.
How many readings did a solid waste engineer show?
I was at a seminar where a well respected solid waste engineer told everyone how much successive readings of the gauge could be. He showed 4 readings and explained how his grad student pressed the button, rotated the gauge 90 degrees, pressed the button . . . , until he had tested 360 degrees around the same hole in the ground (4 tests).
Is the gauge a tool?
Let us not forget that the gauge and any other testing method is a tool to support observations. Terzaghi and Peck stressed the observational method - these tools we have are straying us from the basics.
Is NCGeo a valid method?
NCGeo..the one-point proctor is certainly a valid method of checking the field material against the lab material. My biggest disagreement with the one point proctor, if run in the field, is the proper determination of the moisture content. Further, I would want to check the actual technician's capability to replicate, with a manual proctor hammer, the automatic proctor hammer results most likely used in the lab.
Is a gauge accurate?
In summary, in my opinion a gauge can be accurate enough (when calibrated and in conjunction with other tests) for many projects, but each case is different and each should be assessed on a risk basis.
Is nuclear density gauge accurate?
Just to go back to the original post, which was basically Nuclear density gauges are not accurate. Well, from reading through all the posts (many times, including my own comments), I was struck by one fundamental comment which was missing, what level of accuracy (degree of certainty) is appropriate. The answer will be different for different projects and uses, which in turn should be reflected by the person/organisation writing the specification.
Do testing agencies produce paper reports?
It seems that a lot of testing agencies are only in business to produce paper reports to "pass" instead of actually providing a service to the project.
Is moisture density a stochastic relationship?
The concept of moisture- density relationships is not a stochastic concept but a physical one. Statistical inference is not necessary for the technician to apply the laboratory result as a comparison for the field testing.
What is a nuclear densometer?
As a first step to understanding how a nuclear densometer works, you should know the basic components of the gauge. A nuclear geotechnical gauge consists of 3 main elements:
Where are the sensors on a gauge?
Sensors – located at the back of the gau ge, the sensors detect the amount of radiation coming from the source rod. Display/controls – where you input the proctor value, set the testing depth and time, etc. Although how each component works on its own would be very complicated, how they work together is quite simple.
Why is it important to select the correct depth of penetration of the source rod?
This is why it is important to select the correct depth of penetration of the source rod, as a more shallow depth will allow for more radiation to reach the sensor than if it were deeper in the same material. In backscatter mode, the source is in the same plane as the sensor.
What type of radiation is used to measure moisture content?
The source rod uses two different types of radiation to provide complete measurements. Gamma radiation is used to measure density and neutron radiation is used to measure moisture content.
