Man-Made Sources of Radiation

May 2nd, 2015 | By Mirion Technologies

Outside of naturally occurring sources of radiation, there are man-made processes that produce radioactive material that the average person may come into contact with on a regular basis. The levels are still fairly low, with annual exposure to the public due to artificial sources being roughly equal to the dose received from natural sources.

GRANITE COUNTERTOPS, FIESTAWARE

One of the more commonly found, if relatively weak and low-impact, sources of artificially generated radiation exposure is simply from the use of naturally occurring elements in man-made items. Granite contains trace amounts of uranium, and some samples can end up with a high enough concentration of uranium to be measureable with detection equipment.

*Granite countertops can sometimes contain trace amounts of radioactive elements*

Other places that radioactive material may be found in a household setting are in some varieties of vintage Fiestaware (or any red glazed pottery from the 40s-60s) that used uranium in order to achieve the bright colors in the glaze. Modern products use artificial dyes to achieve the same colors, of course.

NUCLEAR POWER

Nuclear power is perhaps the first thing that springs to mind when you ask someone about man-made sources of radiation. Using fission reactions in uranium to turn water into steam to power giant turbine generators, nuclear power plants generate tremendous amounts of electricity. Much of Europe gets electricity from nuclear power plants, as do many sections of the US.

*Advanced Test Reactor core, Idaho National Laboratory by Argonne National Laboratory used under CC BY-SA 2.0*

Nuclear power plants are tightly regulated, with tight limits on both radiation exposure to workers and the public. The annual average dose to a member of the public from nuclear power plants is roughly equal to the amount generated internally by the decay of radioactive materials naturally found in the body. In fact, due to the presence of radioactive Uranium and Thorium in the fly ash from coal burning, coal-burning power plants give off more radiation into the environment, typically, than a nuclear power plant.

TERRORISM, DISASTER, WAR

The detonation of the atomic bombs at Hiroshima and Nagasaki, along with the nuclear weapons tests of the 50s and 60s, deposited a certain amount of radioactive fallout into the atmosphere. The Limited Test Ban treaty of 1963 mostly put an end to this, though both France and China continued testing into 1974 and 1980, respectively, as neither country is a signatory of the treaty. The 1986 explosion at the Chernobyl nuclear power plant in Ukraine also contributed to global levels of atmospheric radioactive material, with a much greater impact in the immediate areas due to elements such as Strontium-90 and Iodine-131, leading to an increase in the incidence of thyroid cancer.

*A Russian Topol-M Ballistic Missile launcher as part of a military parade*

Despite all the possible health issues arising from the increase in atmospheric radiation due to fallout from nuclear testing and accidents, there has been one area where it has presented a surprising benefit. Authorities in charge of preventing the poaching of elephants for their ivory have discovered that it’s possible to tell if the ivory is recently poached, or “antique” based on the presence of these elements, since they are absorbed by the bones of living animals. So ivory that is purported to be hundreds of years old, which contains elevated levels of strontium-90, for example, will be able to be seized as illegal.

System Selection Guide

Mirion offers guidance with selections to meet your needs, based on application, software and hardware.

Spectrum Analysis

Radioactive decay occurs randomly in time, so the measurement of the number of events detected in a given time period is never exact, but represents an average value with some uncertainty. Better average values can be obtained by acquiring data over longer time periods.

Neutron Detection and Counting

Neutrons have mass but no electrical charge. Because of this they cannot directly produce ionization in a detector, and therefore cannot be directly detected. This means that neutron detectors must rely upon a conversion process where an incident neutron interacts with a nucleus to produce a secondary charged particle. These charged particles are then directly detected and from them the presence of neutrons is deduced.

Gamma and X-Ray Detection

The choice of a particular detector type for an application depends upon the X-ray or gamma energy range of interest and the application’s resolution and efficiency requirements.