Specific and surface activity of nuclear waste

[wronski11]

Dear all,

I am looking for more information how specific activity $\frac{Bq}{g}$ and surface activity $\frac{Bq}{cm^2}$ is measured. This is done to determine whether the materials of interest can be treated as harmless and disposed as usual waste. I am interested how the experimental procedure looks like. I don't know how the name is in English, but in German this is called "Freimessung" Actually one measures the activity $A_i$ and compares it to given limits $FG_i$ using sums of the form
$$
\sum_i \frac {A_i}{FG_i} < 1
$$
Thank you for your answers

 

[Achy47]

.

Thank you for your inquiry about the measurement of specific activity and surface activity in order to determine the safety of materials for disposal. The process you are referring to is commonly known as "clearance" in English.

To measure specific activity, the amount of radioactivity present in a material is divided by the mass of the material, resulting in a value expressed in units of Becquerels per gram (Bq/g). This can be done using various techniques such as gamma-ray spectrometry, liquid scintillation counting, or alpha spectrometry.

Surface activity, on the other hand, is measured by dividing the amount of radioactivity present on the surface of a material by the surface area, giving a value in units of Becquerels per square centimeter (Bq/cm^2). This can also be determined using similar techniques as those used for specific activity.

The experimental procedure for measuring both specific and surface activity involves taking samples of the material and analyzing them for their radioactivity levels. This is typically done using specialized equipment and following strict protocols to ensure accurate results.

To determine if the material can be safely disposed of as regular waste, the measured values for specific and surface activity are compared to established limits, known as clearance levels or FG_i. These limits are set by regulatory bodies and are based on the potential risk posed by the material.

In summary, the measurement of specific and surface activity is a crucial step in determining the safety of materials for disposal. It involves taking samples and analyzing them using various techniques, and comparing the results to established clearance levels. I hope this answers your questions and provides some clarity on the experimental procedure.