These are systems that enable protection against lightning using ionization generated by the radioactive isotopes inside. They started to be used in Turkey in 1974, but their sale was banned in 2000.
These systems were banned pursuant to the circular dated 30.07.2001 and numbered 10700-1485, and it was stipulated that the companies authorized by the same institution demount them and return them to Çekmece Nuclear Atom Energy Center. Only the production of americium-sourced conductor rods has been ceased. However, the TAEA (Turkish Atomic Energy Authority) recommends demounting radioactive conductor rods that were mounted more than 10 years ago because palladium covering the source (Am-241) in americium-sourced conductor rods will be subject to corrosion over time and the radioactive substance will come off leading to contamination. Conductor rods that are in use and contain Am-241, the use of which is still not banned, must be checked at least once a year.
Circular Letter of the Turkish Atomic Energy Authority
The use of conductor rods that are Ra-226 radioactive sourced has been banned all around the world, and it is known that conductor rods that are Am-241 radioactive sourced are not used by European Union states.
Pursuant to the circular letter of our institution dated 04.01.2000 and numbered 10700-0005, the import of radioactive sources (Am-241, Ra-226, etc.) used for conductor rod production is prohibited as from 31.03.2000. Such prohibition shall remain effective indefinitely.
Pursuant to another circular letter issued by our institution dated 30.07.2001 and numbered 10700-1485, Ra-226 radioactive sourced conductor rods that have been mounted and are still in use in our country shall be disassembled by the companies licensed by our Institution, and returned to the Directorate of Çekmece Nuclear Research and Training Center in Istanbul to be stored as nuclear waste, considering the potential hazards they may cause in terms of the environment and human health. The disassembly of Ra-226 radioactive sourced conductor rods and their return to our Institution by the companies licensed under our Institution is still in progress. Am-241 radioactive sources imported by the conductor rod manufacturing companies licensed by our Institution before 31.03.2000, which was the prohibition date of import, have been used up as of 06.02.2003, and radioactive sourced conductor rod production has ended. Radioactive sourced conductor rods shall not be manufactured or installed from now on.
There is no prohibition with regards to the use of Am-241 radioactive sourced conductor rods that are already installed in buildings and still being used. Such conductor rods must be checked by authorized people at specific intervals (at least once a year) to confirm that the original installation specifications of the radioactive elements on the conductor rod, as well as the conductivity of conductor rod are maintained, and returned to our Institution as radioactive waste by licensed companies as specified above if the Am-241 radioactive sourced conducting rods are decommissioned for any reason.
Even though the half life of radioactive sources used in conductor rod production is long, overseas manufacturer Amersham International – England states that the effective operating life of Americium-241 and Radium-226 radioactive sources mounted on conductor rods is 10 years in dry and clean air, and recommends that the source be replaced at the end of such period.
It is important for our country and human health to stop the import and production of radioactive substances considering the potential risks to the environment and human health. This can prevent unnecessary radioactive substance accumulation resulting from the widespread use of sources of radiation in radioactive sourced conductor rods that do not actually provide a clear benefit compared to alternative techniques, and the easy damage of said conductor rods due to earthquake, strong winds, rainfall, fire, fall, loss, theft, change of users over years, or them falling into the hands of untrained persons.
The head section that serves as the radioactive sourced conductor rod is mounted on an iron pole that is 6 to 6.5m above the top of buildings and which can be reached under normal conditions. There is the sharp attractor in the middle of the conductor rod head. The radioactive source consists of 1-4 metal pieces depending on the diameter of protection area, in the shape of a circle or rectangle with a diameter of about 1cm and thickness of a foil, mounted around the plate on the pole where the sharp attractor is connected. There is no radioactive source on other areas of the conductor rod. The area containing radioactive sources is covered due to the production specifications of some conductor rods. The plate part on the conductor rod specified above must not be approached closely, and under no circumstances must contact be made with metal foils that are radioactively sourced. Parasphere, Preventor and Helita conductor rods, which were produced and installed in Turkey in or before 1980, are most likely produced with Ra-226 radioactive sources, although the information on this is not definitive.
The energy of alpha particles radiated by radioactive substances is generally below 9 MeV, and can be stopped with very thin materials (such as a paper layer). Alpha particles lose their energy quickly by generating a dense ionization along their paths through the matter due to their relatively high electric load. The alpha radiated by the Am-241 radioactive substance used in conductor rods also generates a strong ionization in the air due to the high energy it possesses on the plate that is mounted somewhere near the sharp attractor of the conductor rod. The attraction of the lightning (negative loads) caused by friction between clouds to the positive loaded ground accelerates due to said ionization, and the electric current is grounded by means of the conductive wire that is connected to the attractor. Even if the alpha particles do not lead to an external radiation hazard due to their short access distances, the substances radiating alpha particles can be hazardous if they enter the body by means of digestion, respiration or wounds on the skin.
External factors such as dust layers, water drops, and mud that might be formed on the radioactive source found in conductor rods prevent the radiation of alpha particles, and neutralize the radioactive source. As the radioactive source of such conductor rods affected by environmental conditions will not be functional, and it will only be possible to conduct the lightning to ground through the sharp attractor, it is recommended to clean the undesired accumulations on the radioactive sources, such as dust and mud, at specific intervals, using pliers covered with cotton or a soft cloth, avoiding contact with bare hands. The use of alternative conductor rods without radioactive sources is considered to be more appropriate.