RBC Shield, LLC

"The Complete WMD Protection Solution"


Introduction to Shelter-in-Place (S.I.P) Shielding Calculation

On the following page you will be able to determine how long you can stay in an RBC Shield® enhanced shelter before you reach the limit of annual radiological exposure deemed acceptable by OSHA. Beyond that time, the shelter should be evacuated and the occupants re-located to a point outside the danger zone.

Using a scientifically and mathematically based calculating tool, you can adjust the three most important variables that impact your S.I.P. time: amount of radiation, amount of lead shielding, distance from the radioactive source.

Using the RBC Shield® S.I.P. Calculator you can:

  • Select from two different types of radiation (Cobalt-60 or Cesium-137) that are commonly found in such commercially available items as density/moisture gauges, fruit fly sterilization tools, radiographic imaging machines, X-Ray machines, and blood/tissue sterilization devices. The radioactive materials in these devices could easily be used to fabricate a "dirty bomb."
  • Select the amount of radiation at the source of detonation, ranging from 1 gram to 3 lbs.
  • Select the thickness of the lead on an RBC Shield® tile. Thickness selections range from 1/16th-inch to 1/2-inch.
  • Select your distance from the detonation site. Distances range from 1/10th-mile to 50 miles.

Once you have made your choices, and press "CALCULATE S.I.P" you will get an immediate display of the number of days it is safe to stay in your RBC Shield® enhanced shelter under the conditions you have selected.

IMPORTANT: The calculated result assumes you have an adequate air supply!


A note to mathematicians: When distances are doubled, the amount of time one can remain in a shelter is quadrupled. The calculator formulas apply the "law of inverse squares" because of the nature of radioactivity and the impact on exposure caused by distance.