Lead shielding for Radiation

Source:  Lead shielding for Radiation    Tag:  shielding radiation
Lead is used for shielding in x-ray machines, nuclear power plants, labs, military equipment, and other places radiation may be encountered. There is great variety in the types of shielding available both to protect people and to shield equipment and experiments. Personal shielding includes lead aprons (such as the familiar garment used during dental x-rays), thyroid shields, and lead gloves. There are also a variety of shielding devices available for laboratory equipment, including lead castles, structures composed of lead bricks, and lead pigs, thick containers for storing and transporting radioactive samples.



Criteria for the Selection of a Shield Material
Theoretically, almost any material can be used for radiation shielding if employed in a thickness sufficient to attenuate the radiation to safe limits. However, due to certain characteristics discussed below, lead and concrete are among the most commonly used materials. The choice of the shield material is dependent upon many varied factors, such as final desired attenuated radiation levels, ease of heat dissipation, resistance to radiation damage, required thickness and weight, multiple use considerations (e.g., shield and/or structural), uniformity of shielding capability, permanence of shielding, and availability.



Properties of "Lead for Radiation Shielding"
The properties of Lead which make it an excellent shielding material are its density, high atomic number, high level of stability, ease of fabrication, high degree of flexibility in application, and its availability.





For gamma rays and x rays, lead is a particularly effective shield because lead has a high atomic number (Z) of 82. The atomic number is the number of protons in an atom. Since the number of protons per atom of lead is large, the number of electrons is also large, and it is the electrons that stop gamma rays and x rays. So, density, thickness, and atomic number can all be important. 

Shielding reduces the intensity of gamma rays and x rays in an exponential manner (more or less). In other words, a shield reduces the intensity of the radiation getting through, but it might never stop all the gamma rays (at least theoretically). What I am saying is that the phrase "complete protection" in the question might be better changed to "almost complete protection" because some gammas have the potential to get through any shield (in theory). I recognize I am splitting hairs here. 





Forms of "Lead Used for Radiation Shielding"

  • Lead Brick - Convenient, easily handled; may be moved and re-used
  • Lead Sheet – Plate and Slab Permanent shield installations
  • Lead Shot - Where solid Lead is impractical to fill due to location, shape and accessibility. The Shots offers convenient solutions for shielding
  • Lead Wool - Lead Wool is used for filling deep cracks in a Radiation barrier
  • Lead Pipe - Shielding of radioactive liquids
  • Lead-lined / Lead-clad Pipe - Shielding of radioactive liquids
  • Lead Powder - Dispersed in rubber or plastic for flexible shielding; also mixed with concrete and asbestos cement
  • Leaded Glass
  • Lead Plate
  • Lead Pigs
  • Custom Lead Fabrication and Lead Casting




Diagram of standard shielded door options with lead glass and/or louver and door pair.


LEAD GLASS (X-RAY GLASS, RADIATION SHIELDING GLASS, LEADED GLASS) STANDARD SIZES


8" x 10"
10" x 12"
12" x 12"
12" x 16"
12" x 24"
12" x 36"
16" x 24"
18" x 24"
24" x 24"
24" x 48"
30" x 24"
30" x 30"
32" x 40"
36" x 24"
36" x 30"
36" x 36"
40" x 40"
40" x 42"
42" x 42"
48" x 36"
48" x 40"
48" x 42"
48" x 48"
60" x 36"
60" x 40"
60" x 42"
60" x 48"
72" x 36"
72" x 40"
72" x 42"
72" x 48"
84" x 36"
84" x 40"
84" x 42"
96" x 42"
96" x 48"
108" x 54"