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IMPACT ON PEOPLE AND THE ENVIRONMENT
Release

BASIS OF DEFINITIONS FOR RELEASES FROM TRANSPORT AND SOURCE EVENTS

 

stands for dangerous

There is a D value for each isotope, defined as

that quantity of radioactive material, which, if uncontrolled, could result in the death of an exposed individual or a permanent injury that decreases that person’s quality of life.

In order to assess the D value for each isotope, different scenarios are considered. Two D values are calculated (D1 and D2), and the limiting one is taken as the D value.

The Dvalue is the activity of a radionuclide in a source that if uncontrolled, but not dispersed (i.e. it remains encapsulated) might result in an emergency that could reasonably be expected to cause severe deterministic health effects.

The Dvalue is the activity of a radionuclide in a source that if uncontrolled and dispersed might result in an emergency that could reasonably be expected to cause severe deterministic health effects.

The D value is the lowest value of the D1 and Dvalues for a radionuclide.

The definition for atmospheric release is based on the D2 value.

We will learn more about D values later, but if you want more information look at Categorization of Radioactive Sources, No. RS-G-1.9 Safety Guide or Dangerous quantities of radioactive material (D values), EPR-D VALUES 2006.